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                                         C3
                    HABITAT EVALUATION:

              GUIDANCE FOR THE REVIEW OF
ENVIRONMENTAL IMPACT ASSESSMENT DOCUMENTS
                             January 1993
                                                             ^
                                               Northern Lakes
                                                and Forests
 Western
 Deserts
   and
Grasslands
                                                         Southeastern Forests
                                                           and Cropland
                                                              r-ralD «. — a vixootf u.
                         Office of Federal Activities
                    U.S. Environmental Protection Agency
                             401  M Street, SW
                          Washington, DC 20460

                                                                   :ed on Recycled Paper

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                 HABITAT EVALUATION:
            GUIDANCE FOR THE REVIEW OF
ENVIRONMENTAL IMPACT ASSESSMENT DOCUMENTS
                   EPA Contract No. 6S-CO-0070
                   Work Assignments B-21, 1-12
                          January 1993
                          Submitted to:

                           Jim Serfis
                 U.S. Environmental Protection Agency
                     Office of Federal Activities
                         401 M Street, SW
                      Washington, DC 20460
                          Submitted by:

                        Mark Southerland
                       Dynamac Corporation
                       The Dynamac Building
                      2275 Research Boulevard
                       Rockville.MD  20850

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                                        CONTENTS



                                                                                        Page

INTRODUCTION	     1

       Habitat Conservation	     2
       Habitat Evaluation Methodology	     2
       Habitats of Concern	     3
              Definition of Habitat	     4
              General Habitat Types	     5
       Values and Services of Habitats  	     5
              Species Values	     5
              Biological diversity	     6
              Ecosystem Services	     7
       Activities Impacting Habitats	     8
              Land Conversion  	     9
                     Land Conversion to Industrial and Residential Uses	     9
                     Land Conversion to Agricultural Uses	 .    10
                     Land Conversion to Transportation Uses	    10
              Timber Harvesting  	    11
              Grazing	;	    12
              Mining	••	    12
              Water Management	    13
              Recreational, Military, and Other Activities	    13
       Types of Impact to Habitats	    14
              Destruction	    15
              Fragmentation  	    16
              Simplification   	    17
              Degradation	    17
              Vulnerability to Impacts	    17
       General Mitigation Procedures	 . •	    18
              Habitat Integrity	    18
              Mitigation Guidance	    19
              Mitigation Principles	    21
                     Habitat Buffers	    21
                     Habitat Corridors  	    22
              Mitigation Measures   	    22
                     Timber Harvesting Mitigation Methods	    23
                     Grazing Mitigation Methods	    23
              Monitoring for Mitigation Compliance	    24
Habitat Evaluation                            iii                                  Introduction

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NORTH HABITAT REGION - NORTHERN LAKES AND FORESTS  	   25

Geographical Description of the Region *	   25
Habitats of Concern	   26
Habitat Values and Trends  	   26
       Northeastern Forests  	   27
       Northern Lakes Forests	   27
       Forest Values   	   28
       Old-Growth and Mature Forest	   28
       Great Lakes Coastal Ecosystems	   29
       Wetlands and Aquatic Systems	   29
Activities and Impacts  Affecting Habitats   	   29
       Land Conversion  	   30
       Timber Harvesting  	   31
       Recreational'Activities	   31
Mitigations of Impacts	   31
       Land Conversion  	   31
       Timber Harvesting  	   32
Guidelines for Reviewers  	   34
Contacts and Information Sources	   35

MIDWEST HABITAT REGION - MIDWEST CROPLAND	   37

Geographical Description of the Region  	   37
Habitats of Concern	   38
Habitat Values and Trends	   38
       Savanna	   39
       Grasslands  	   39
       Forests	   39
       Wetlands   	   40
Activities and Impacts  Affecting Habitats   	   40
       Land Conversion  	   41
       Agricultural Impacts  	   42
       Impacts on Aquatic Systems  	   42
Mitigations of Impacts	   42
       Land Conversion  	   43
       Agricultural Impacts  	   43
       Wetlands   	   43
Guidelines for Reviewers  	   44
Contacts and Information Sources	   45

SOUTHEAST HABITAT REGION - SOUTHEASTERN FORESTS AND CROPLAND	   47

Geographical Description of the Region  	   47
Habitats of Concern	   48
Habitat Values and Trends  	   49
       Forests	   49
Habitat Evaluation                           iv                                Introduction

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       Grasslands, Barrens, and Scrub Habitats	    51
       Wetlands  	    52
       Aquatic Systems	,	    53
Activities and Impacts Affecting Habitats  	    53
       Land Conversion  	    54
       Agricultural and Grazing Impacts  	    55
       Timber Harvesting  	    55
       Mining	    56
       Water Management	    56
       Military Activities	    57
Mitigations of Impacts	    57
       Timber Harvesting  	    57
       Land Conversion  	    59
       Mining	    59
       Military Activities	    60
Guidelines for Reviewers  	    61
Contacts and Information Sources	    62

GREAT PLAINS HABITAT REGION - GREAT PLAINS AND PRAIRIES	    63

Geographical Description of the Region  	    63
Habitats of Concern	    64
Habitat Values and Trends  	    64
       Grasslands  	    64
       Texas Habitats	    65
       Riparian Areas	    66
       Wetlands  	    67
Activities and Impacts Affecting Habitats  	    67
       Land Conversion  	    68
       Agricultural Impacts  	    68
       Grazing  	    69
       Riparian Areas	    69
       Water Management	    70
Mitigations of Impacts	    70
       Land Conversion  	    71
       Grazing  	    71
       Wetlands  	    73
Guidelines for Reviewers  	    73
Contacts and Information Sources	    74

WESTERN RANGELANDS HABITAT REGION - WESTERN  	    75
  GRASSLANDS AND DESERTS

Geographical Description of the Region  	    75
Habitats of Concern	    76
Habitat Values and Trends  	    76
       Woodland and Shrubland  	    78
Habitat Evaluation                           v                                 Introduction

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       Grasslands  	    78
       Deserts  	    79
       Riparian Areas	    79
       Wetlands  	    80
       Aquatic Systems	    81
Activities and Impacts Affecting Habhats  	    81
       Land Conversion	    82
       Agricultural Impacts  	    83
       Grazing	    83
       Riparian Areas	    84
       Mining	    85
       Water Management	    85
       Recreational Activities	    85
       Military Activities	    86
Mitigations of Impacts	    86
       Grazing	    86
       Land Conversion  	    88
       Mining	    89
       Wetlands  	    90
       Military Activities	    90
Guidelines for Reviewers  	    91
Contacts and Information Sources	    92

WESTERN FORESTS HABITAT REGION - WESTERN FORESTS	    93

Geographical Description of the Region  	-.	    93
Habitats of Concern . .	    94
Habitat Values and  Trends   	    94
       Rocky  Mountain Forests	    94
       California Forests	    95
       Pacific Northwest Forests	    96
       Riparian and Wetland Areas   	    97
       Aquatic Systems	    98
Activities and Impacts Affecting Habitats  	    98
       Timber Harvesting   	    99
       Land Conversion  	   100
       Impacts on  Riparian and Wetland Areas  	   100
       Impacts on  Aquatic Systems  	   101
Mitigations of Impacts	 .   101
       Timber Harvesting   	   101
       Land Conversion  	   103
       Mining	   104
       Wetlands  	   105
       Guidelines for Reviewers  	   105
       Contacts and Informationd Sources  	   106
Habitat Evaluation                            vi                                  Introduction

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 ALASKA HABITAT REGION - ALASKA  	   107

 Geographical Description of the Region  	   107
 Habitats of Concern	   108
 Habitat Values and Trends  	   108
       Tundra	   108
       Forests	   109
       Alaska Coastal Plain  	   109
       Aquatic Systems	   109
 Activities and Impacts Affecting Habitats  	   110
       Land Conversion  	   110
       Timber Harvesting  	   110
       Mining	   Ill
       Military Activities	   Ill
 Mitigations of Impacts	   ill
       Timber Harvesting  	   Ill
       Mining	   114
       Land Conversion  	   115
       Wetlands  	   115
 Guidelines for Reviewers  	   115
 Contacts and Information Sources	   116

 HAWAII AND ISLAND TERRITORIES   	   117

 Geographical Description	   117
 Habitats of Concern	   117
 Habitat Values and Trends  	   117
 Activities and Impacts Affecting Habitats  	   118
Guidelines for Reviewers  	   119
•Contacts and Information Sources	   120

 REFERENCES	   121
Habitat Evaluation                           vii                                Introduction

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                                    INTRODUCTION

       Based on the recent Science Advisory Board (SAB) teponRedudng Risk, the U.S. Environmental
Protection Agency (EPA) has concluded that habitat alteration and destruction are among the greatest risks
to ecological and human  welfare.  The SAB specifically recommends that EPA consider reducing
ecological risk to be as important as reducing human health risk. The recommendation states mat EPA
should protect ecosystems because they are essential to human health and  a sustainable economy, and
because they have intrinsic value.

       This document is designed to assist NEPA reviewers in evaluating the ecological risks associated
with the impacts of federal activities.  The information provided will assist NEPA reviewers in developing
informed comments for project scoping, EIS review, and section 309 analyses related to the issues of
habitat loss and degradation.  In particular, mis document is designed to  help reviewers recommend
mitigations to prevent the loss of habitats.  This document also should be useful to other EPA program
offices and other federal agencies.

       The first part of this document is a general discussion of habitat issues relevant to environmental
analysis review; it  should be  read  before the regional  discussions.  This  section provides a basic
description of habitat and its values, and of the degrading activities, impacts, and mitigations relevant to
habitats in general. Eight Regional Habitat Evaluation sections, representing the six major habitat regions
of the conterminous United States plus Alaska and Hawaii (see figure below), provide more specific
                           Habitat Regions of the United States
Habitat Evaluation
Introduction

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information on habitats of concern, values and treads, degrading activities and impacts, and potential
mitigations.  Specifically, each regional discussion includes a list of habitats of concern,  a table of
activities impacting habitats,  and recommended mitigations for habitat conservation.  Because each
regional section considers only the major impacts affecting habitats in that region, reviewers should refer
to different regions for discussions of other impacts mat may be relevant to their specific project reviews.
At the end of each section, basic guidelines are provided to aid in the environmental project  reviewer's
consideration of the full range of habitat impacts.

        This document is not intended to serve as complete guidance  or as a simplified checklist for
environmental  project review.   In particular,  mis document focuses on  activities occurring in the
terrestrial environment, although impacts of these activities on wetlands and aquatic  systems are also
considered.   Additional information on activities directly degrading aquatic systems should be reviewed
where appropriate. It is expected that specific habitat issues relevant to the project site will be  addressed,
and that appropriate information on the ecology of the project site will be obtained.  A list of useful
institutional contacts is included with each regional discussion.

Habitat Conservation

        Habitats are those environments  or ecosystems  that provide substantial ecological values and
services such as fish and wildlife populations, nutrient cycling, water purification, and climate control.
All natural  areas  contain definable units mat  can be called either ecosystems  or habitats.  In this
document, the  term habitat is equivalent to ecosystem  and includes both the physical  and biological
components of the environment.  All habitats are important for the conservation of ecological values at
their specific location. However, certain habitats, and types of habitat,  can be designated as  "of special
concern."   For the purpose of mis document, habitats of concern  are  defined as those sensitive
environments whose degradation or loss results in  significant diminution of ecosystem integrity or
ecological values.   The habitats of concern listed in this document represent the most obvious cases of
loss of ecological values and services on a regional scale.

        The following general discussion of habitat conservation begins with a summary of the important
issues and steps involved in assessing habitats, follows with a working definition of habitats of concern,
and continues with discussions of the values and services provided by habitats, the activities affecting
habitats, the types of impacts caused by these activities, and potential mitigation measures to address these
impacts on habitats.

Habitat Evaluation Methodology

        The definition of habitat in this document is based on ecosystem values and functions.  Therefore,
it is necessary to present habitats as classes of similar ecosystems that contain a known set of ecological
values and functions.  The habitats discussed in this report are broad  vegetation-based  categories that
include a range of more specific ecosystem types.  While this document will  categorize habitats and
identify individual impacts, h must be remembered that each habitat is unique. An individual habitat must
be evaluated in the context of its specific geographic location to determine its true value.  At the same
tune, the effect of alterations to a habitat by degrading  activities must be considered in terms of the
impact on the entire  landscape.   Therefore, an ecological  perspective is  essential for the adequate
consideration of habitat issues. This approach requires that the interactions of ecological components be
Habitat Evaluation                              2                                     Introduction

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considered, and  that  the unique characteristics  of each  ecosystem be evaluated.   The following
considerations should be central to any process of habitat evaluation:

        •      Apply an ecosystem-level perspective that considers the full range of interactions
               among habitat components.

        •      Assess the cumulative effects that arise from the additive and synergistic impacts
               of several degrading activities occurring over time or space.

        •      Analyze the true  effectiveness  of mitigation  measures  in conserving natural
               habitats and their ecological values.

        It is common for habitat considerations to be neglected within environmental analysis because of
the difficulties of individual site-specific  assessments.  To better address the consideration of impacts to
habitat in environmental analyses, regional information on the impacts to habitats of concern and their
mitigation can be used. Therefore, the sections  that follow describe general habitats that are threatened
with loss or degradation from human activities.  The condition of these habitats, the activities that affect
them, and potential mitigations for the impacts that degrade them are discussed.

        The application of this regional information should improve the quality of environmental analyses
of all kinds.  Along with an ecosystem perspective, attention to cumulative effects,  and measures of
mitigation effectiveness, the following steps can be used to incorporate landscape-scale considerations into
both regional-level and site-level environmental  analyses:

        Step 1.    Review the status and trends  of habitats in the regions  under consideration.

        Step 2.    Identify habitats of concern for  the region that may occur at the site.

        Step 3.    Analyze the impacts of all activities on the functions and values of these
                  habitats.

        Step 4.    Derive mitigation  measures  to eliminate or ameliorate the  impacts on
                  habitats of concern.

Habitats  of Concern

        Virtually all of the natural environments in the United States have been degraded to some extent
by  the  impacts of human activities.   Even  relatively pristine ecosystems  are affected by the  loss of
contiguous habitats  and other changes to the landscape.  Therefore, the most important criterion for
designation of a natural area as a priority concern is the importance of a habitat to the ecological integrity
(i.e., the health and natural functioning) of the larger landscape or  eco-complex (sensu Polunin  and
tyorthington 1990).  In this way, a habitat may be thought of as analogous to a "keystone species" within
a biotic community.  For practical reasons, rarity is often the criterion by which a  habitat's value is
determined.   However, in assessing  the value of a habitat, rarity, ecological functioning, regional
diversity, and other important attributes  also should be considered.
Habitat Evaluation                              3                                     Introduction

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          of Habit
        The standard definition ofhabiuu is based in the environment of individual species; for example,

        "Habitat is the environmental setting in which an animal or plant normally lives, grows,
        and reproduces" (NRC 1982);

        and

        "Habitat is the area which provides direct support for a given species, population, or
        community.   It includes all environmental features that comprise an area such as air
        quality, water quality, vegetation and soil characteristics and water supply (including both
        surface and ground water)" (Fish and Wildlife Service, FR 46(15):7662-7663).

Although this definition has been important to the management and preservation of many individual
species, it is inadequate for regional or global biodiversity protection efforts. Indeed, national inventories
of species-specific habitat are not practical for most species, and in fact have been accomplished only for
the critical habitats of  endangered  species  (Flather and Hoekstra  1989).   The need  to address  the
conditions of a wide range of species, and biological diversity in general, requires an ecosystem approach
to habitat inventory.  For the purpose of this document, the following definition is used:
      Habitat  •  a natural  environment  composed of bom  living organisms and  physical
      components that function together as an ecological unit.
       In many contexts, this definition is synonymous with ecosystem or sensitive environment.  It
assumes that the natural condition of an environment is preferred because h represents a system that
through evolution  is most likely to provide the desired values of biological diversity and ecosystem
functioning. Although the difficulties in classifying habitats or ecosystems have prevented the completion
of adequate national inventories, different  classifications have been used for specific purposes or for
restricted locations.  The National Wetlands Inventory of the U.S. Fish and Wildlife Service uses the
widely accepted Cowardin classification  system for wetlands and deepwater habitats (Cowardin el al.
1979).  The U.S.  Forest Service has  used  a variety of classification systems including the Forest and
Range Environmental  System  (FRES) (Garrison et  al. 1977)  based on  KuchJer Potential  Natural
Vegetation units (1964) and Bailey Ecoregions  (1976).  The U.S. EPA has recently defined  general
classes of  ecological resources for all  habitat types  as part of hs Environmental Monitoring and
Assessment Program (EMAP) (Hunsaker and Carpenter 1990). Greater resolution in habitat classification
has been obtained by state natural heritage programs in coordination with The Nature Conservancy.
Extensive natural heritage databases that once consisted of only species element occurrences now include
"community" elements. At present, each state has a community classification, and many are working
toward regional classifications.  If this is  accomplished, mere will someday be national coverage of
community types from which to base a quantitative assessment  of habitats  (Larry Master, personal
communication).
Habitat Evaluation                              A                                    Introduction

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        Given the mixture of classification systems, systematic status and trends information is not
 available for most habitats (Southerland and Hirsch 1989). However,  considerable information on the
 status and trends of individual species iff available and can be useful in  characterizing habitat status and
 trends.  In fact, the Fish and Wildlife Service (FR 46(15):7662-7663) has developed the concept of
 evaluation species upon which they base analyses  of environmental impact.  The evaluation species
 include species of high public interest and economic value, and species that provide broad  ecological
 representation.  Environmental analyses can use identification of such "species of concern" as a useful
 starting point for identifying habitats of concern.  Throughout this document, species status  and trends
 will be included  to the extent they reflect habitat conditions, but h  must be remembered that they
 represent only a few of the many species in each habitat, all of which are required to maintain a healthy
 ecosystem and a full range of values and services.

 General  Habitat Types

        Before colonization by Europeans, North America was covered  from the Atlantic Ocean to west
 of the Mississippi River with diverse eastern deciduous forests of large oak, chestnut, beech, and maple;
 farther west spread a lush  tallgrass prairie; beyond that was a semi-arid shortgrass prairie with regional
 deserts, grasslands, and coniferous forests (Norse 19905).  A nearly unlimited number of unique habitats
 existed within these regions, varying with soil conditions and topographic differences. The exploitation
 and manipulation of land by human activities has since eliminated  or modified many of these habitats.
 This document uses  the  major  land types of forests,  rangelands,  and  wetlands to  facilitate the
 identification  of more specific habitats of concern.  It focuses on habitat types that are repeated across
 the region and does not consider individual plant communities that vary with exact geographic location.
 The scale of these habitat types varies,  and although a medium scale is applied in this document,  it is
 important to remember that the following additional classes of habitats of concern should be  considered
 in individual environmental analyses:

        •       Individual  plant  communities (e.g., those compiled by  state natural heritage
                programs).

        •       Transitional habitats and functional mosaics of habitat,  e.g.,  the sandhill-scrub-
                lake complex of the natural upland hardwood forest of Florida (Moss 1987).

        •       Landscape-scale  ecosystems, or  eco-complexes  (e.g.,  the Chesapeake  Bay
                watershed).

 Values and Services of Habitats

        Habitats provide the full complement of ecological values and services contained in a naturally
f volved ecosystem. These include many services that have economic benefits, as well as aesthetic and
 BJoral values.  All individual  species values, overall biodiversity  values, and ecosystem  services are
 encompassed  in ecological integrity. Therefore, it should be the objective of habitat conservation efforts
 to preserve the ecological  integrity of habitats.

 gpecies Values

        Individual species  are the values most often associated with habitats. Historically, commercial
Habitat Evaluation                              5                                    Introduction

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timber species and crop plants, and game animals aod sport fish have been the most prized species;
subsequently, noncommercial plants, nongame birds, endangered species, and other popular species have
received attention.  Those interested in. species preservation are now viewing habitat conservation as a
means of protecting species "wholesale* (Waller 1991). This is in contrast to the single-species approach
required by the Endangered Species Act, often referred to as  "emergency rescue operations" (as in the
cases of the California condor and black-footed ferret). The best example of the habitat-based approach
is the effort of The Nature Conservancy which  has  adopted a "coarse filter" approach to protecting
species based on protecting the natural communities in which they  reside.  This approach provides
protection for the majority of species, including unknown and undescribed ones.

        The most visible values of any habitat are the many plant species mat make h up.  Plants are
prized for their intrinsic value and for their roles in ecosystem functioning.  Recently, previously ignored
species are receiving attention for their contributions to genetic diversity. There is also ample evidence
of the importance of habitat to animal populations. Among state wildlife and fish management agencies,
habitat loss ranked first in  national priority for all  species,  for big game,  for small game, and for
waterfowl (Flatber and Hoekstra 1989). Habitat also ranked second to barriers to migration in importance
for sustaining anadromous fish populations. Wildlife management efforts have bad their greatest success
with species (big game and some endangered species) for which habitat is abundant.  Species whose
habitat is declining in  amount and quality are currently,  and will continue to be,  most threatened with
extirpation (Thomas 1990).

Biological Diversity

       The interest in preserving particular species has broadened in recent years to encompass a concern
for all biotic resources  under the general term  "biological  diversity."   The Office of Technology
Assessment (1987) defines biological diversity as

        "The variety and variability among living organisms  and the ecological complexes in
       which they occur";

while the Keystone Dialogue on Biodiversity on Federal Lands (1990) defines biological diversity as

        "The variety of life and its processes."

Both  of these definitions emphasize that  biological  diversity, or  biodiversity, entails all ecosystem
components and includes the  myriad functions and values  provided  by the living organisms in each
habitat. The number and relative frequency of hems that make up biological diversity may be organized
along the continuum from genes to species to ecosystems.  The overall amount of genetic diversity  is
decreased when species diversity is lowered, as is species diversity when ecosystem diversity is lowered.
For this reason, habitat loss and ecosystem degradation are the principal causes of reductions in biological
diversity.  Essentially, the conservation of habitat is the  conservation of the ecological complexes that
constitute biological diversity.  In addition, the preservation of biological diversity may be the best means
of protecting overall biological integrity and ecological  health.  Preserving biodiversity means maintaining
the integrity of the genetic structure within populations, the richness of species within ecosystems, and
the mosaic of ecosystems within the landscape  (Norse 1990b).
Habitat Evaluation                               6                                    Introduction

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Ecosystem Services
        Although the conservation  of individual species and overall biodiversity  are essential to
maintaining die  ecological integrity of a habitat, a wide range of ecosystem functions must also be
protected. Using a broad definition, habitat, like the ecosystem, is characterized by a particular energy
flow, nutrient cycling, and capacity  for self-perpetuation (given radiant energy from the sun).   The
services that ecosystems perform include serving as a store or sink for energy or materials, providing a
pathway for nutrient transport, acting as a buffer against chemical changes,  and  producing the natural
resources people use such as minerals, wood, food, water, and air (Hollis et al. 1988).  A comprehensive
list of ecosystem values is shown in the accompanying box.
                                         Ecosystem Values1
              Climate control:
                      COj sequestration
                      wapotravpintion
              Geomorphological control:
                      wave and wind buffering
                      erosion control
                      noni input trapping
                      •oil building
              Water supply:
                      groundwater recharge
                      fioodflow alteration
                      water supply
              Energy and nutrient exchange:
                      energy fixation
                      carbon •uptake
                      nutrient uptake
              Purification of resources:
                      sediment/toxicant retention
                      nutrient removal/transformation
                      pollutant detoxification
              Biotic resources:
                      biotic productivity and food chain support
                      genetic conservation of biodiversity
                      fisheries
                      wildlife diversity/abundance
                      aquatic diversity/abundance
                      aesthetics/cultural heritage

              'Ad*ptod from Rao* tad Chru6« (19S2), Adumu « «1. <19S7). Hiackty (1990), and Nub (\99\).
Habitat Evaluation
Introduction

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Activities imparting Habitats

        After identifying the habitats of'concern, the next important step is the linking of tbese habitats
to the activities that cause their degradation or loss.  The following major  activities  may cause the
degradation or loss of habitats:

               Land conversion to industrial and residential land use.
               Land conversion to agriculture.
               Land conversion to transportation.
               Timber harvesting practices.
               Grazing practices.
               Mining practices.
               Water management practices.
               Military, recreational, and other activities.

Environmental analyses of these activities arise during both broad programmatic reviews and specific
project environmental impact statements.  The following common projects entail significant impacts to
habitats and may require federal review:

        •       Community and public land use development, including planning, regulation, and
               federal funding for building construction and highway development.

        •       Renewable resource use and  development (logging and grazing) on public lands
               or  requiring permits.

        •       Energy production, including petroleum, natural  gas, and coal development,
               extraction, generation, transmission, and use.

        •       Non-energy mineral resource development, processing, management, transport,
               and use.

        •       Water projects and permits for wetland modification.

        •       Natural resources conservation, including protection of environmentally critical
               areas.

        This document focuses on  the direct physical effects of the aforementioned activities on habitat
extent and  quality. However, another important source of impacts on habitat is the contamination of
ecosystems from the pollution of the air, water,  and land. Habitat pollution is addressed, in pan, by the
air quality, water quality, and hazardous substances programs of federal and state regulatory agencies.
Therefore, habitat impacts from the generation of toxic and waste materials from manufacturing processes
and fossil fuel combustion are not specifically addressed in this document.  The following are examples
of activities contributing to the contamination of habitats that should be added to the considerations in this
document when  a complete environmental analysis is prepared:

        •       Industrial and  municipal  discharges into  water  (e.g., toxic chemicals and
               conventional pollutants) and emissions into the air (e.g., acid deposition, gaseous
Habitat Evaluation                              R                                    Introduction

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                phytotoxicants such as ozone, and global ozone depleting and greenhouse gases).

        •       Industrial and municipal*waste dumps and landfills (e.g., asbestos and plastics in
                the marine environment).

        •       Agricultural contamination (e.g., pesticide spraying and nutrient discharges from
                cultivated fields and livestock feedlots).

        •       Mining waste  discharges (e.g., mercury, arsenic, cyanide, crude oil, drilling
                muds, and saline-produced waters).

        •       Military accidental releases (e.g., nerve gas and plutonium).

        The following sections briefly discuss the history and impacts of the major activities on habitats.

 Land Conversion

        The conversion from one land use to another is the activity most severely affecting terrestrial
 environments.  The type of land conversion depends on the  end use^of the land.  In each case, the
 original natural  characteristics of the  land are eliminated, and  the associated ecological values are
.modified to varying degrees.   Urban  conversions,  as well as other large industrial and commercial
 development projects, severely alter natural conditions, seriously disrupting ecosystem functions and
 eliminating most ecological values.   Residential development in suburban and rural areas usually
 maintains some plant and wildlife values while disrupting the natural ecosystem processes of the area.
 Similarly, conversion to traditional agriculture alters the natural vegetation and ecological processes while
 still providing some hedgerow areas for wildlife populations.  Large-patch  industrialized agriculture,
 however, usually removes aH wildlife habitat. Conversions to industrial, residential, and agricultural uses
 occur on many scales, but often cover very large areas.  In contrast, conversions to highways, railways,
 and power  lines affect terrestrial environments more by fragmentation  than by  total area converted.
 Landfills and the development of recreational areas are other kinds of land use conversions, .but ones that
 «over relatively small areas.

        Land Conversion to Industrial and Residential Land Uses

        Conversion of natural environments to industrial, commercial, and residential land use continues
 to increase with population and with the general suburbanization of many previously natural areas.  The
 large urban areas of the east and west coasts continue to grow, reducing the natural areas in the corridors
 between them.  Land conversion due to infrastructure construction and landfills also contributes to the
 development pressure on natural areas near urban centers.  Urban growth is most rapid  in the Sun Belt
 states.

        Urban and suburban conversion of terrestrial  environments  is also occurring  throughout the
 Country as "spinoff development" following new road construction. Even in areas of relatively little or
 no overall population growth (such as  the Northeast),  spinoff development is a major cause of forest
 fragmentation and the decline of wildlife and bird populations. This effect is augmented by the increasing
 frequency of second home development in previously undeveloped regions.
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        Arid environments in the Southwest are rapidly being converted to urban and residential uses as
a result of population growth. The Southern California region is a classic example of suburban sprawl
where roadways, residential communities, and commercial development have expanded into previously
pristine environments. Many underappreciated desert habitats are at risk because of this continued land
conversion. Riparian areas are another environment at risk in the West from land conversion to industrial
and residential development.  Because of their proximity to water and their desirability for industrial and
residential use, riparian areas are being disproportionately destroyed. Also because of their proximity
to water, riparian areas are critical for many  migratory bird and  wildlife species.

        Land Conversion to Agricultural Uses

        The United States uses a large pan of its available land area for livestock and  crop production,
an area totaling more than 900 million ac (U.S.  EPA  1989).  Over 400 million of these ac. are classified
as cropland. More than 50% of this area is in the corn and wheat growing regions of the Midwest
Cropland and Great Plains and Prairies Habitat Regions.  Land conversion to agriculture has stabilized
in recent years,  and much of the conversion  to urban uses is now occurring on old agricultural lands.
Conversion to agriculture continues to be a  regional problem depending on  the pricing variability of
specific crops.  For example, bottomland hardwoods in the South have recently suffered from extensive
conversion to soybeans.

        Although total agricultural acreages are not changing, many important wildlife habitats are being
lost as a  result of large-patch agriculture, which causes the elimination  of fence rows and  ditch banks.
Current agricultural practices, and certain "conservation" programs, provide incentives for cultivating
previously uneconomical areas.  For example, the construction of grass waterways in riparian areas is
destroying wildlife habitat rather man conserving h.

        The loss of rip&rian and  bottomland hardwoods to agriculture in  the Southeast represents one of
the most significant losses of ecological values of terrestrial environments. Similarly, the conversion of
wetlands and adjacent grasslands in the central and western United States is another impact that has had
serious consequences for  ecological values, in particular waterfowl populations in the Prairie Pothole
Region and along the Pacific and Mississippi Flyways.

        Land Copvergipn to Transportation Uses

        Construction of highways, railways, and power line right-of-ways contributes to the degradation
of terrestrial habitats, especially  in less developed areas.  Although the actual  areas converted are small
(27 million ac) the fragmentation of habitats  is often severe (Frey and Hexem  1985).  Powerlines and
other transportation routes can be described  as "disturbance corridors" that disrupt the natural, more
homogeneous landscape (Barrett and Bohlen 1991). In forested environments, these disturbances cause
(1) dramatic physical disruption  to the continuous vegetative community; (2) disruption to the structure
and function of wildlife habitat;  and (3) impacts to resident wildlife, which must negotiate, tolerate, and
cope with the habitat barriers. In addition, disturbance corridors created by forest fragmentation provide
habitat for early successional plant and animal species. They replace forest trees with grasses and shrubs
so that forest-interior species cannot nest.  While they provide dispersal  routes for small mammals such
chipmunk and white-footed mice, they present barriers to many species.

        The impacts of highway construction also represent an important problem in cumulative impact
Habitat Evaluation                               10                                    Introduction

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 assessment.  Although individual road segments are usually evaluated for potential environmental impact,
 it is actually the combined effect of the entire highway system that most seriously degrades terrestrial and
 wetland environments.  In  addition, the cumulative impact of several highway systems can seriously
 disrupt migratory pathways.  As mentioned above, the building of roads is invariably accompanied by
 additional land conversions to industrial or residential use.

        Both forested and nonforested environments can be disrupted  by fragmentation due to highway
 construction. However, the dense canopy structure of certain shrublands may be most severely impacted
 by fragmentation.  An example is the fragmenting of pocosin wetlands and uplands  in the Southeast.
 Because of the scale at which many pocosin inhabitants move, highway development can effectively
 isolate much of the pocosin fauna.

•Timber Harvesting

        Since the early 1600s, 20 to 40% of the nation's original forest cover has been converted to other
 land  uses,  and much  of what remains has  been  substantially  altered as a result  of past logging.
 Regeneration of timbered areas is increasing forest acreages in the East, but these numbers are more than
 offset by timber harvests in the West. Many of the remaining forests of the United States are being
 altered by  timber harvesting practices  that fragment, simplify, and degrade  natural forests.   The
 combination of clear cut logging and road building increases forest fragmentation and soil erosion.  The
 clear-cut natural stands are  often replaced with fewer and different tree species resulting in the loss of
old-growth  trees and natural forest habitats essential to a wide variety of wildlife.

        Forest habitats are the forum for the most acute biodiversity issues facing the nation, including
 (1) decreases in contiguous old-growth forest that support the spotted owl in the Northwest, (2) the loss
 of old pines needed   by  the red-cockaded  woodpeckers in  the Southeast,  (3) increased habitat
 fragmentation and forest edge causing declines in forest-interior songbirds, and (4) increasing ungulate
 populations in the East and Midwest (Waller 1991).  These problems are primarily the result of clear-cut
 Ipgging and the institution of short-rotation single-species plantations. All timber harvesting activities
affect forests in two ways (Cutter et al. 1991):

        •      Like natural fires, timber harvesting allows sunlight to reach the  ground and
               stimulate new growth, while the slash (limbs too small to use) contributes to
               increased nutrient release.  Thus,  like fire,  harvesting is a  catastrophic but
               temporary disruption that removes large amounts of soil, nutrients, and biomass
               from the ecosystem, changes water  yields, and increases stream temperatures.

        •      Unlike natural disturbances, timber harvesting involves road building and die use
               of heavy equipment on the land; this causes damage and compaction to the soil
               surface and accelerates soil erosion beyond the rates following fires. Especially
                along steep slopes, surface erosion and landsliding produce heavy sediment loads
               to streams,  degrading aquatic habitats  and  damaging fish and  invertebrate
               populations; the loss of biomass in the form of logs slows reestablishment of new
               growth, and the lack of fire may  retard regrowth from fire-adapted  seeds.

 The major impacts of timber harvesting on forest  degradation and loss include four major problem areas
 that can be  addressed on a national or regional basis:
 Habitat Evaluation                              11                                    Introduction

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        • Loss of old-growth forests.
        • Effect on critical ecosystems (such as Greater Yellowstone).
        • Decrease in roadless areas or.wildlands.
        • Impacts of silviculture! practices (such as clear cutting).

Grazing

        Widespread devastation of rangelands resulted from uncontrolled overgrazing between 1880 and
1935, and me damage was amplified by the drought years of the 1930s (Branson 1985).  The enactment
of the Taylor Grazing Act of 1934 reduced grazing pressure at that time. With the advancement of range
management science and the moist years  following I960, range vegetation improved considerably.
However, the U.S. Forest Service (1989) reports that 21 % of its rangelands were still in "unsatisfactory"
condition. The Bureau of Land Management (1989) reports that BLM rangeland condition is 33% good
or better, 38% fair, and  13% poor.

        Although the total area of rangeland has remained relatively constant, the condition of the range
ecosystems has varied considerably with competition by livestock for forage and other factors. Cattle,
sheep, and wild horses and burros have contributed to reduced forage and to changes in vegetation
composition on the majority of U.S. rangelands. Grazing and fire suppression have allowed brush species
to replace many  of the grass forage species on 200 million ac of the Southwest (National Association of
Conservation Districts 1979).  As with forest habitats, the fragmentation of rangeland vegetation can
negatively affect native fauna and ecosystem health.

        Unfortunately, traditional rangeland  improvement measures  often run  counter to wildlife
conservation.  Herbicides reduce vegetation diversity, as do practices mat till  under sites and convert
vegetation to normative species, usually replacing pinyon jumper with exotic grasses.  Management of
brush invasion in the southwestern deserts, savannas, and  southern Great Plains is perhaps the greatest
problem affecting rangeland wildlife.  While deer and turkey populations have increased, native range
forage is reduced by the invasion of  mesquite, juniper, cacti, acacia, sand sagebrush, creosote bush,
tarbush, wbitebrush, yucca, and others.  Mechanical or chemical reduction of these scrubs, as well as
sagebrush in the Northern Plains, decreases forage  for many species  including prairie chicken, sage
grouse, quail, and  pronghorn.

        Grazing is also detrimental to hardwood forests,  riparian habitats, and areas where  livestock
compact root systems or increase erosion.  In general, grazing reduces structural diversity  of forest
understory (by eliminating plants, altering species composition, modifying growth form, and shifting serai
stages)  and  can  negatively impact forest bird  communities. Of particular concern are the impacts  of
grazing on forested riparian zones, which support the majority of species in the rangeland environment.

Mining

        Millions of hectares of marginal and barren land can be found in the United States, much of it
due to mining activity.   These areas are a source of acid  mine drainage, surface runoff, erosion, and
sedimentation, which create water pollution and land degradation problems. Mining activities leave a
harsh environment for vegetation because of the lack of nutrients and organic matter,  low pH, low  water-
retaining capacity,  toxic levels of trace metals, compaction, and poor physical conditions of spoil material
(Sopper 1988).
Habitat Evaluation                              12                                   Introduction

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        It is important to note that mining often occurs on the mountain-plain ecotone, an area of special
importance  to wildlife.  Nonetheless, mining disturbs relatively less land area than other  activities
affecting terrestrial environments. Only.5.7 million ac were disturbed between 1930 and 1980 by surface
mine excavation, subsidence from underground workings, and disposal of mining wastes.  Additional
areas have been impacted by haulroads, reservoirs, and railroads and highways to  mining properties.
Stream habitats have been  affected  by acid drainage  and sedimentation.  The greatest potential for
increased mining impacts exists in the area of exploration and extraction of fossil fuels.

        Nearly half of  all  U.S. land used for mining  is concentrated in  the states of Pennsylvania,
Kentucky, West Virginia (2% of each state) or in Ohio, Illinois, and Indiana (1% of each state).
California and Florida have also mined more man 250,000 ac (Johnson and Paone 1982). Intense mining
also occurs in the Arizona  copper region and the northern Minnesota's Mesabi Iron Range.  Among
federal lands, 732 million ac are available for leasing to surface and subsurface mineral development, the
majority in the west and Alaska; currently,  95 million ac  are leased to oil and  gas, 2 million to
geothermal, and 1.3 million to coal (USDA Forest Service 1989).

        Mining impacts are substantial but variable depending on the mining method, the mineral, the
processing technology, and the ecological nature of the site.  Impacts include destruction or impairment
of fragile ecosystems  and wildlife habitats, contamination of surface and subsurface water supplies and
soils from toxic chemicals and radioactivity, and adverse effects on scenic values.

Water Management

        Damming activities, impoundments, and  water diversions  for municipalities, industry, and
agriculture severely affect the natural water supply, resulting in  the destruction of terrestrial, wed and,
and aquatic environments.  In particular, the reduction of streamflow from  diversions of water for other
uses adversely affects riparian habitats in the Southwest.  The Corps of Engineers stream channelization
projects affect large areas of both terrestrial and aquatic environments. In fact, few streams or waterways
still run free to the ocean without diversion or management that affects their natural flow. The inundation
of large areas for flood control and  water supply has decreased in recent years, but still constitutes a
major impact on local environments. In the Mississippi Basin (mid-south Alabama,  Tennessee, eastern
Texas, and Oklahoma), considerable acreage of bottomland hardwoods was  lost to reservoir development
between 1962 and 1985 (Gosselink and Lee  1987).

        Changes in water  quality,  flow, and dam passage  affect  the success of anadromous  fish
populations, including recreationally important game species.  In addition to the intrinsic value of these
species, the degradation of important aquatic resources has a detrimental effect on many terrestrial
systems,  including migratory birds  and riparian forests.  The importance of wildlife impacts  from
hydropower activities is evidenced by the provisions for wildlife habitat mitigation in the Columbia Basin
under the Northwest Power Act (Brown 1988).

Recreational. Military, and  Other Activities

        Several other human activities can seriously affect terrestrial environments. The introduction of
normative species into wild  areas also has the potential for devastating alterations of terrestrial habitats.
Even nonconsumptive human activity (e.g., recreational  hiking and camping) can seriously affect natural
ecosystems.
Habitat Evaluation                              13                                    Introduction

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        Recreational activities are the principal reason for human intrusion into natural environments.
Hiking and camping have a minor but significant impact on natural forests, range!ands, and desert
ecosystems.  The amount of disturbance* is proportional to the volume of activity and the proximity to
population centers; access by roads is the determining factor.  Cole (1989) has estimated vegetation loss
as a result of camping, concluding that his sample campsites had absolute vegetation losses of 37 to 85 %.
Off-road vehicles (ORVs) can have even more severe impacts on local terrestrial habitats. In particular,
ORV races can devastate fragile desert ecosystems. These environments are very slow to  recover and
often include rare endemic species. In addition to many rare plant species, the endangered desert tortoise
is at  risk.  Skiing  and other  winter sports are examples of activities mat impact relatively  isolated
mountain areas.  These activities are often accompanied  by the more deleterious effects  of land  use
conversion into resort development.

        Military maneuvers and other training or testing activities can also have significant impacts on
terrestrial  environments.  Bird communities and certain  small mammal populations were negatively
affected by Army training maneuvers in the Mojave desert (Krzysik 1984). The management of military
installations in the Southeast has serious implications on the survival of the endangered red-cockaded
woodpecker.  Both physical disturbance (especially from tracked vehicle activity) and noise contribute
to habitat degradation from military activities.

        Exotic species have been introduced  into natural areas for game  bunting, and as biological
controls for other pest species. Accidental releases have  also had  major negative impacts on natural
habitats and native species.  Indeed, the entire eastern deciduous forest ecosystem has been  permanently
altered by the chestnut blight; the loss  of tree mast likely precipitated  the extinction of the common
passenger pigeon.  Similarly, the outbreak of dutch elm disease also contributed to the degradation of
riparian habitats in the Midwest.  Today, severe habitat impacts from exotic species are most prevalent
in Hawaii.

        The Hawaiian archipelago has lost more than 75% of its original endemic land bird fauna through
prehistoric and historic extinctions; the comparable Galapagos archipelago as a whole is not known to
have lost a single land bird species (Loope et al. 1988).  The aboriginal Hawaiians converted most of the
land below the 600-meter elevation to agriculture on the eight main islands.  Subsequently introduced
species and factors contributing to habitat destruction include herbivorous mammals (goats and pigs),
predation by ants, frequent and intense fires, dogs, cats and mongoose, alien arthropods, mollusks,  and
alien plants.  More than 80 vascular plant species in Hawaii currently pose threats to the native biota.

Types of Impact to Habitats

        The degrees of impact caused by each of the aforementioned activities varies both within and
among different kinds of activity. The level of impact is determined both by the intensity and extent of
the activity, and by the specific type of impact on die habitat of concern. The impacts to habitats, and
to their values and functions, from the activities discussed in the previous section fall into  four general
categories:

        •      Destruction of habitat.
        •      Fragmentation of habitat.
        •      Simplification of habitat.
        •      Degradation of habitat.
Habitat Evaluation                              14                                   Introduction

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 The nature of these-impacts depends on the specific stress created by each activity. In most cases, a
 single activity will include several stressor processes that impact habitat.  For example, the activity of
 logging a forest  includes removal of. the trees,  associated drying  of the  forest floor,  erosion  and
 sedimentation of nearby streams, and disturbance  from noise and human activity.  The major stressor
 processes affecting habitats include the following:

                Vegetation removal.
                Dehydration and inundation.
                Erosion, sedimentation, and soil compaction.
                Eutrophicalion.
                Acidification.
                Salinization.
                Thermal wanning.
                UV-B exposure.
                Contaminant toxicity.
                Noise and visual disturbance.
                Introduced species.

 These stressor processes can result in the following effects on habitat:

                Direct mortality of resident species.
                Physiological stress and decreased  reproduction.
                Disruption of normal behavior and activities.
                Segmentation of interbreeding populations.
                Modified species interactions and alien species invasion.

        Although  all of the stressors affecting habitat can  have serious impacts, physical  alteration of
 habitat has eclipsed intentional  and incidental taking as the major cause of population reduction among
 species. At greatest risk are the following groups of species: large terrestrial mammals, bats,  hole- and
 ground-nesting birds, amphibians, snails, conifers, herbs, grasslands, freshwater stream organisms, river
Wishes and mollusks, and estuarine vegetation (Norse 1990b).

        Traditional impact analyses have concentrated on degradation of habitats from contamination.
 The focus of this analysis is on  the loss and  degradation  of  habitat through direct  conversion  and
 exploitation of the ecological resources.  Although these stressors usually have a much greater impact,
 additional impacts from contamination should also be considered. In addition, it is important to consider
 the cumulative  impact of multiple effects and the  indirect effects of activities. The following sections
 discuss the different kinds of impacts on habitat.

 Destruction

        The ultimate form of habitat degradation is the destruction of a natural ecosystem through its
 "conversion" to another land use.  In each conversion, the original natural characteristics of the land are
 eliminated, while the associated habitat values are modified to varying degrees.  Occasionally, wildlands
 (providing ecosystem services and  wildlife values) that have been converted to managed lands (providing
 harvestable timber or agricultural crops) can be restored to a similar, although not identical, natural state.
 In contrast, lands converted to urban or industrial uses virtually  never recover their ecosystem integrity
 or habitat values.


 Habitat Evaluation                               15                                     Introduction

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        Physical alterations of many kinds cause habitat destruction.  In terrestrial environments, the
clearing of vegetation (trees, shrubs, grasses) is the principal stressor.  The greatest impacts occur when
vegetation removal is accompanied by leveling operations (mat destroy the original topography and soil
profile) and building or road construction (covering the area with permanent structures).  The burning
of vegetation and  the creation of landfills for waste disposal are other means of destroying terrestrial
habitats.  Gear-cut logging and severe overgrazing can also clear habitats of native vegetation.

        In wetland environments, filling and draining operations destroy wetland habitats and create
modified terrestrial habitat, while impoundments flood wetlands to create deepwater aquatic systems. As
with terrestrial environments, the  construction of buildings  or roads can eliminate  wetlands.  The
extraction of peat  can also destroy  wetlands.  In aquatic environments, the inundation or diversion of
water through flow alteration (via  damming or channelization) is the principal means of eliminating
habitat. Dredging, filling, and draining also destroy aquatic habitat.

Fragmentation

        While all the activities mentioned in the previous section can  result in the destruction of entire
habitat types, they  often only destroy part of a habitat, leaving other areas intact. Depending on the scale
of concern,  many  instances of local habitat destruction are better thought of as habitat fragmentation.
The interruption of a river with a reservoir, the clearcut logging of mature forest, and the building of a
road through a salt marsh are all examples of habitat fragmentation (Norse 1990b).

        Such fragmentation is the principal cause of loss of "area-sensitive" species (Harris 1985) and the
most serious threat to biological diversity (Wilcox and Murphy 1985; Harris 1988).  The consequences
of habitat fragmentation (Harris and Atkins 1990) include the following:

        •       Amplification  of mortality and inbreeding (i.e.,  risk to sedentary species  from
               random variation in demographic and genetic variables when isolated).

        •       Extinction of wide-ranging species  (e.g.,  wolves,  black bears,  panthers,
               manatees).

        •       Loss of interior or  area-sensitive species (e.g.,  sharp-shinned hawk, Cooper's
               hawk, Swainson's warbler, red-cockaded woodpecker).

        •       Erosion of genetic diversity from within rare species.

        •       Increased abundance of weedy species (regionally distinct communities give way
               to  globally homogeneous ones).

As an example, only  2 of 11  native large mammals in Florida (the raccoon and white-tailed deer) are
doing well in the face of increasing fragmentation of natural habitats. Other examples of negative impacts
from  fragmentation include the spotted owl;  the Spotted  Owl Committee proposed  that  habitat
conservation areas (HCAs) be linked by forests with a minimum canopy closure.  Studies in Maryland,
Michigan, and Oregon show that the occurrence of most forest-dependent species is correlated with forest
Habitat Evaluation                              16                                   Introduction

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 size; contiguous forests of 100 to 300 ac are needed by  area-sensitive birds, primarily long-distance,
 insectivorous, neotropical migrants, such as flycatchers, vireos, and wood warblers (Jahn 1991).
        Habitat simplification includes the removal of ecosystem components such as standing dead trees,
 cover logs, or stream debris; the death  of sensitive submerged plants from siltatipn;  and the loss of
 microhabitats (such as nests and dens) mat are rendered unusable by human intrusion.  Universally, the
 removal of vertical habitat structure reduces the diversity of species.  Structural diversity provides more
.microhabitats (e.g., nest sites) and allows for more complex species interactions (e.g., avoidance of
predation and partitioning of foraging space).

        While forest clearcutting is both a form of destruction (for the forest stand) and of fragmentation
 (for the forest watershed), selective logging of preferred tree species is a form of habitat simplification.
This is in contrast to timber harvesting practices that are nonselective and often closely mimic natural
stand conditions.  During selective cutting, not only does the composition of tree species change, but
logging creates more extreme microclimates that are usually hotter, colder, drier, and  windier than in
.natural forests. The immediate impact on resident species is the desiccation of forest plants, fungi, slugs,
and salamanders mat require moist conditions  (Norse 1990b).

        Within rangeland systems, ecosystem integrity is maintained through the balance of native grass
and shrub species.  Grazing by  domestic livestock can  selectively remove species and facilitate the
invasion of exotics. In most cases, the proliferation of normative species results in habitat simplification
that is detrimental to native birds  and other wildlife.

Degradation

        Degradation of habitats can include the fragmentation or simplification of habitat structure, but
more specifically refers  to a decrease in the health  or ecological  integrity  of the "intact" habitat.
Chemical contamination resulting from air or water pollution is a significant cause of habitat degradation.
Although toxic effects may be the most  severe, conventional pollutants and  other effects may exist in
greater frequency and extent.  For example,  soils are degraded through erosion or soil compaction.
Lakes are particularly sensitive to eutrophication and acidification. Rivers and streams can be degraded
by nutrient enrichment, as well as siltation and turbidity.  Salinization and salt water intrusion also
degrade habitats,  as do temperature modification and  noise.  Underground water sources  and their
contributions to ecosystem integrity can be degraded by activities, such as irrigation and mineral mining,
that result in the draw down of aquifers. The invasion of exotic plants and animals can seriously degrade
natural systems through  modified species interactions.  Global climate change,  including  increased
temperatures and UV-B exposure, has the potential  to degrade habitats of all  kinds.

Vulnerability  to
        The impacts of degrading activities on habitat depend on the vulnerability of the habitat and the
relative contributions of other cumulative and interactive impacts.  A habitat's sensitivity is determined
by its resistance to change (i.e.,  its ability to resist degradation)  and its resilience (i.e., its ability to
recover its original condition) (Westman 1978).  Resistant habitats often have  intrinsically stable and
fertile soils, moderate rates of water movement, mild climate regimes, and food webs that are functionally
Habitat Evaluation                              17                                     Introduction

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diverse and contain individuals or species preadapted to the particular stress. Resilient habitats are often
topographically low and proximate to unstressed habitats containing highly mobile colonizers (Sedell et
al. 1990).

        Species are  usually more vulnerable to anthropogenic impacts if they possess small effective
population size, narrow geographic distributions, large area requirements, specialization, intolerance of
disturbance, large size,  slow reproductive rate, evolutionary naivete, or "amphibious" habits (Norse
1990b).   Vulnerability characteristics of habitats  or ecosystems (and the stressor to which they are
vulnerable) are listed below:

               Impermanence (suppression of fire frequency).
               Oligotropby (alteration of nutrient cycling).
               Undersaturation (biological invasion).
               Isolation (elimination of recolonization).
               Small size (impacts on edges).
               Proximity to human populations (disturbance).

The undersaturated naive biotas of the Hawaiian Islands and southern Florida are especially susceptible
to many stressors, including invasion by exotic species. All habitat areas are vulnerable to unprecedented
permanent major changes in environmental conditions. Unlike periodic natural disturbance (such as fires,
windthrow, and flooding), global atmospheric change (e.g., warming and increased UV-B or CO,) and
the introduction of alien species pose challenges beyond the capabilities of most natural systems. Perhaps
the greatest threat to biodiversity is the impending interaction between  climate change and habitat
fragmentation.

General Mitigation Procedures

        Appropriate measures for the mitigation of habitat loss or degradation depend on both the habitat
type and the specific degrading activities, stressor processes, and habitat impacts.  Specific mitigation
information is provided in the regional sections  of mis document. In this section, general considerations
for habitat mitigation are discussed.   For a mitigation to be  successful,  the ecological integrity of the
habitat must be maintained.  This can be accomplished directly by preservation measures that  avoid
impacts.  In other cases, careful mitigation plans can reduce or eliminate impacts on the integrity of the
habitat.

Habitat Integrity

        Traditionally, mitigations have concentrated on species-specific habitat components such as the
availability and appropriate interspersion of cover, food, and water.  Other species requirements include
protein-rich foods,  den or nest sites, and  territorial spacing or colonial  clustering, and may  vary
seasonally, especially among migratory waterfowl and anadromous fish. Greatest attention has been paid
to the diversity of habitat structure, both vertical layering and horizontal edge or transition zones, that
provide for greater  species and ecological diversity.  While these considerations are appropriate for
mitigations focusing on certain species or individual site diversity, they do not incorporate landscape-level
concerns  for regional diversity.  For me purposes of this document, mitigations of habitat degradation
will focus on  the ecological  integrity of the habitat of concern and  not on the species or diversity
components that may be desirable from a wildlife management point of view.
Habitat Evaluation                              lg                                    Introduction

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        Recent research has indicated that floristic (plant species) diversity is superior to  structural
 (number  of vegetation layers  and patches) diversity as  an indicator of wildlife  distribution.  This
 emphasizes the need to avoid oversimplification in habitat analyses and to look at the detailed ecology
 of each habitat and define it in precise ecological terms. Natural habitats are dynamic ecological systems
 that require natural patterns of disturbances.  Proper mitigation plans must provide for natural habitat
 heterogeneity in time  and space.  An important tool for providing natural disturbance patterns is fire
 management.  Proper use of controlled fires  can be an effective mitigation of  the  impact of fire
suppression in managed areas.

        Mitigation for habitat conservation must ensure that the cumulative impacts of all activities within
 the landscape (perhaps over areas of  10,000 to several 100,000 ac) are addressed to  maintain ecosystem
 integrity and health.  The preservation of individual habitat areas  is often not sufficient to maintain the
 ecological integrity of the greater ecosystem.  In addition, the size, diversity,  and distribution of key
 habitat tracts must be conserved to  provide for the natural diversity characteristic of the larger eco-
 complex or region.  Finally, unique ecosystems (such as islands) may require unique  mitigation solutions
 (Samson etal. 1991).

 Mitigation Guidance

        Mitigations to  address the habitat  impacts of destruction, fragmentation,  simplification, and
 degradation include the following four measures (modified from Flather and Hoekstra 1989):

        1.     Preservation
               •       Outright purchase or set aside of land
               •       Partial   purchase  through  conservation  easements,  long-term  leases,   or
                       management  agreements.

        2.     Management practices
               •       Rotation and  method of timber harvesting
               •       Timing and extent of grazing
               •       Control of pollution
               •       Elimination of structures.

        3.     Restoration
               •       Direct manipulation through seedings, plantings, physical  or chemical treatment
               •       Creation  of wetlands
               •       Control of pollution
               •       Removal of barriers to fish migration
               •       Control of livestock access to riparian areas.

        4.     Compensation
               •       Purchase of lands of comparable habitat size and quality
               •       Provision of  financial restitution.
Habitat Evaluation                              19                                    Introduction

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A more detailed set of Mitigation Means and Measures (in general priority order) has been devised by
tiie  Fish and Wildlife Service for mitigation development related to fish and wildlife and their habitats
(FR 46(15):7660, 1981).  This list is provided in the accompanying box.
                                            U£. Vfch mnd Wildlife Service
                                          Mitigation Means and Measures
A. Avoid impact
    1. oaaigB projact to avoid damage or laaa feehtdi&f aaaajamaot pncaeaa aucfa at
      • iB^iog 01 aottvitMa or
      • amictural faaterat ance a» multiple os*JaU, pea*a^ or avoidaac* ammura^ and watar pothitkw ocarol fecilftie*
    2. uat aoojtntceoa) altarnatrv*
    3.«aaoalpTqjact

B. Mioimixa impao
    t.iDctodacoaaar
               2. locate a laaita
               3. nduca the aiza of the pttjact
                                  »of fiah «ad wildlife aa autboniw) pnpow

                  and Atoetioo
               5. uw Ml*ctiv» IT«C elMiiiv or oth*r habit*! Bunpukttoo
               «. eootrol wiur pollution tfaroujt BMPi
               '7. time ud tattroi flow dmnioot «nd nbnM
               E. fMrntiin public ICOMI
               9. cootpol pubiie MOMt for Ncnttioa*) or cooMaareta] puipeaai
              10. control doooMticirnatocl: BM.

            C. ftaetify the ioapact
               1 . nfrade di«urt>«3 ana* to wotoun for optimal babhat or orifinal eoodition
               2. *aed. fntiHxc, and traat araa« to /more fiab aad wildlife
               3. piant abrubi and traM and other vagatation to apaad raoovcry
               4. control potlutioo apoil arcei
               5. faatock fiah aad wttdlift taMpaaadaraai
D. Raducc or aJimintU taa impact overtime
    I. oanodieally monitor to aoaura coonau
                                                    '• opacatioo
               2. train panooae! piopaily to pnnarva fiab and wildlife
               3. maintain or vaplaoa aquipmaot« atructura* to pravaot low doa to •fa^taaBt/tmicturafulure
                    tnaaaf aoMotactivttaa to ineraaat habitat raloaa; fiva friority to projaet landi and naarby
            E. Coa^xnaata for iBftaeu
                1. conduct wildfifa
                  iaadt
               2. eoBftruct habitat to folly laatora aad rababilitata aharad habitat, or to modify anftiqf habkat auitad *«valuatioo
               tpaoa' to cooaplataly ofltat habitat vaiua Joaaai
               3. 4nigiun» fitfa pTOpafanonliariBtiaa
               4. «aaifoat« lafialatrva aat-aaid* or protaetjya tfactfoation for public land*
                5. llaaignatc buffer
                6. laaae habitat
                7. acquire wildlife aaiama
                8. acquire watar rifhu
                9. aoqub* land m faa tiUt
Habitat Evaluation
                                                         20
                                                                                          Introduction

-------
Mitigation Principles

        The development of specific mitigation plans must be based on a thorough understanding of the
site conditions and the activities impacting habitats.  Nonetheless, certain basic principles of ecological
management should be followed when specific mitigation measures are developed. The following seven
general mitigation principles apply to all habitat conservation efforts:

        1.      Base mitigation goals and objectives on a landscape-scale analysis that considers the needs
               of the region.

        2.      Mimic natural processes and promote native species.

        3.      Protect rare and ecologically important species and communities.

        4.      Minimize fragmentation of habitat and promote connectivity of natural areas.

        5.      Maintain structural diversity of habitats  and,  where appropriate,  species diversity to
               promote the natural variety of the area.

        6.      Tailor management to site-specific environmental  conditions and to the unique impacts
               of the specific degrading activity.

        7.      Monitor for habitat impacts from activities and revise mitigation plans as necessary.

        A landscape  or  ecosystem-level perspective is central to these  principles.  R. Max Peterson
(Emeritus Chief of the Forest Service and Executive Vice President of the International Association of
Fish and Wildlife Agencies) stated that  "when land  is cleared,  care must be  taken to maintain the
minimum size areas of sensitive habitats, with buffers and corridors as needed to ensure the integrity of
the landscape ecosystem" (Giltmier 1991). The concept of providing for landscape integrity when habitats
are fragmented is central to habitat mitigation in forest, rangeland, wetland, and aquatic systems.  The
two most important methods for maintaining the integrity of fragmented habitats are (1) the provision of
buffer areas, and (2) the creation of habitat corridors. Buffers represent the principal method of avoiding
impacts to  sensitive areas,  and habitat corridors provide the best means  of mitigating habitat isolation.
The most common means of creating both buffer areas and corridors is the preservation of natural habitat
along streams, steep slopes, and other sensitive areas.

        Habitat Buffers

        The preservation of a habitat of concern includes both the  avoidance of direct conversion of the
area and the maintenance of adequate buffer areas so that edge effects and other negative impacts do not
affect the sites. For example, powerline corridors through forests can be "feathered" to avoid some edge
effects (Gates '1991).  Additional areas  adjacent to die corridor can be cut to create successional bands
of vegetation parallel to the corridor opening; this reduces predation rates at the edge and minimizes the
barrier effects. However,  a wider edge results in  less forest interior.

        Mitigation procedures for many projects can be designed to  reduce the effective width of a cleared
area and thus decrease the barrier effect. These include creation  of small lobes or peninsulas of dense
Habitat Evaluation                              21                                    Introduction

-------
vegetation reaching into the open area, or the creation of entire breaches across the area, either by leaving
the habitat intact or by staggered defoliation regimes.  The establishment of a stable shrub community
in a forest corridor can provide movement by less mobile animals with small home ranges (Niering and
Goodwin 1974).

        Research into the impacts on beuthic invertebrate communities of streams indicates that buffer
strips of at least 30 m are required to prevent alteration in invertebrate diversity and ecological structure
(principally the increase in abundance of pollution-tolerant taxa such as ehironomids).  These buffer strips
serve to maintain riparian canopy and stream channel stabilization. Failed road crossings also negatively
impact stream ecosystems (Ennan et al. 1977).

        Habitat Corridors

        Mitigation of habitat fragmentation involves the  restoration of habitat "connectivity" (Norse
1990b).   To address the effects of fragmentation, conservation biologists are calling for increased
provision of habitat corridors. Unlike untested management plans based on island biogeography theory,
corridors have been used successfully in wildlife management for 50 years  (Harris and Atkins 1990).
Corridors provide for the movement of  animals, serve as  a population  source, contain whole
communities,  and  withstand  natural disturbance events, but they also provide  for  contamination
transmission  (Csuti 1991).  Because edge effects reach 200 to 600 m into  the forest,  Pace  (1990)
recommends  a minimum  corridor width of 6.4 km to mitigate edge effects.

        In a landmark court decision concerning the USDA Forest Service timber sales in the Klamath
National Forest, federal agencies were required to consider an area's importance as  a "biological
corridor" linking wilderness areas before permitting logging. The resultant Klamath Corridors Proposal
can serve as  a model  of  habitat fragmentation mitigation (Pace 1990).  It recommends connectivity as
superior to isolation, continuity over fragmentation, and creation of larger rather man smaller corridors.

Mitigation Measure;

        The  first  priority in  developing mitigation plans for habitat loss  or degradation should  be
avoidance of the impact. This is usually a siting issue, where construction operations and degrading
activities are  located at a distance from the habitats of concern.  The habitat is adequately preserved if
all possible impact scenarios are accounted for.  Barring this solution, effective management measures
must be implemented to ensure the protection of the habitats of concern.  Failing effective management,
mitigation falls to the  restoration of habitat,  which is often problematic, or finally to compensation.

        Restoration activities will not be discussed in mis document, although they are receiving increased
attention as mitigation measures, especially in wetland and aquatic systems.  The recent volume produced
by the National Research  Council (1992) provides a comprehensive discussion of the science, technology,
and public policy involved.  Many of the  principles espoused  in  mis book  also apply to terrestrial
systems.
        This document focuses on the general  management practices that can be undertaken to mitigate
habitat degradation and loss resulting from activities in forest and rangeland environments.  A central
tenet of the management approach to habitat mitigation is the control of pollution.  This is especially true
for wetland and aquatic systems where, after physical alteration, off-site impacts to hydrology and water
quality pose the greatest threat. There is also a growing body of literature on best management practices
Habitat Evaluation                              22                                   Introduction

-------
 (BMPs)  as mitigation measures for aquatic systems.  Notably the nonpoint source,  clean lakes,  and
 national  estuary programs of EPA are promoting BMPs to protect sensitive habitats.  Many of these
 measures apply to wetlands and are being implemented under section 404 of the Clean Water Act  and
 provisions of the Coastal Zone  Management Act.   The reader should refer to  these programs for
 additional information on mitigating impacts to wetland and aquatic systems.

       In contrast to  aquatic systems, forests  and  rangelands are primarily threatened  by direct
 exploitation of their resources (trees and forage grasses).  Specific guidance on mitigation measures is
 provided in  each regional  habitat evaluation section.  The following  discussion addresses general
 mitigation issues for timber harvesting and grazing methods.

       Timber Harvestine Mitigation Methods

       At a minimum, the production of commercial wood products from an area  must not exceed the
 sustainable level if the ecological integrity of a forested area is to be maintained. Where sensitive forest
 types exist, logging may be completely prohibited or constrained to specific methods to prevent habitat
 loss or degradation.  In other areas, more extreme harvesting methods may be allowed or prescribed to
 establish or maintain desired forest conditions.  Acceptable methods will  vary according to local forest
 ecology and the desired future  condition of the site.  Analysis of harvesting techniques must be based
 upon  an analysis of the structure and diversity of the forest canopy, midstory, and understory.

       A recent directive of the Chief of the U.S. Forest Service acknowledges this fact and points out
 that clear cutting is acceptable  only when needed to  replicate natural ecological processes.   Selective
 cutting can preserve forest structural diversity, the primary determinant of wildlife habitat (Harris et al.
 1979). However, it can reduce horizontal diversity (NRC 1982).  The harvesting  technique employed
must  be based upon sound silvicultural prescriptions and demonstrate its capability to  maintain vertical
 diversity (foliage height diversity), horizontal diversity (interspersion, edge, juxtaposition, patcbiness),
 and a mixture  of live and dead wood.   Specific timber harvesting  operations should be designed to
preserve the structure and diversity of the natural  forest habitat.

       Grazing Mitigation Methods

       The current degraded state of rangelands requires restoration as well as management plans. In
both cases, the timing  and extent of continued grazing will determine whether range conditions worsen
 or improve.  Increased irrigation for agriculture may  delay improvements by adversely affecting water
tables and stream flow on rangelands.  Rest-rotation grazing can  improve  range conditions,  while
 intensified chemical use and mechanical brush removal will likely further degrade range habitats.   The
 future management of riparian areas will have the greatest impact on rangeland wildlife and ecosystem
 health (NRC  1982).

       In the past, range condition has been estimated by forage production or production of livestock.
 More recently, condition  has been based on the deviation from an ideal  range condition or ecological
 climax.  More  effective use of  ecological analyses of range condition will improve the management of
 rangelands.  In particular, range managers need the following tools (Wald and Alberswerth 1989):

       •      More data (range condition is unknown on many rangelands).
Habitat Evaluation                              23                                    Introduction

-------
               Management plans for each she (these should be ecologically based and site specific).

               More management resources.
        •      Commitment from management to implement grazing  reductions or riparian habitat
               improvement.

Monitorpg for Mitigation Compliance

        Successful mitigation of habitat impacts requires mat the proposed mitigation measures are
effectively implemented and maintained. However, the consideration of habitat effects is often hampered
by information gaps and limits to predictive capability. Therefore, it is essential that all mitigation plans
include adequate provisions for baseline and post-project monitoring of habitat conditions.

        The fact that many restoration projects designated as mitigation have not achieved their desired
objectives is  well documented.   It is also believed that  mitigation measures for many projects are not
adequately implemented or enforced.  Therefore, determination of the true effectiveness of mitigation
should be the goal of monitoring programs. The following ten-step process for monitoring mitigations
for habitat impacts has been modified  from Noss (1990):

               Establish objectives of the mitigation.
               Gather and integrate data.
               Establish baseline conditions.
               Identify elements at risk.
               Formulate specific questions to be addressed by monitoring.
               Select indicators.
               Identify control areas and treatments.
               Design and implement the sampling scheme.
               Validate relationships between indicators and endpoints.
               Analyze trends and recommended management actions.
Habitat Evaluation                              24                                   Introduction

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                 North Habitat Region: Northern Lakes and Forests
 Geographical Description of the Region

        The North Habitat Region, Northern Lakes and Forests, contains all of eight states and parts of
 eight additional states.  The region includes all of Maine, New Hampshire, Vermont, Massachusetts,
 Connecticut, Rhode Island, New York, Michigan, and parts of New Jersey, Pennsylvania, Ohio, Iowa,
 Indiana, Illinois,  Wisconsin, and Minnesota.  EPA Region 1  is included in its entirety;  parts of EPA
 Regions 2, 3, 5, and 7 are also included.  The accompanying map indicates the boundaries  of this habitat
 region and the states it comprises.

        The Northern Lakes and Forests comprises eight ecoregions (Omernik 1987). The vegetation of
 this region includes northern hardwoods (maple, birch, beech, hemlock), elm, ash,  Great Lakes spruce
iand fir,  Great Lakes pine, conifer bogs (spruce, larch, arborvitae), maple, bass wood, and oak savanna
 (oak and bluestem).  The land use patterns include swamps, marshlands, forests and woodlands (mostly
 -ungrazed), croplands, croplands with pastures, and urban.
 Habitat Evaluation
25
                                          North

-------
 Habitats of Concern
        The Northern Lakes and Forest* contains many habitats of concern, of which the most obvious
fall into the three general categories of old-growth forest, barrens, and Great Lakes ecosystems. The
principal habitats of concern most at risk in the Northern Lakes and Forests are listed below.
                          PRINCIPAL HABITATS OF CONCERN
                        IN THE NORTHERN LAKES AND FORESTS

                     I,     Old-growth and mature forests
                           • northeast conifer and hardwoods forests
                           • central hardwoods forests
                           • boreal forests of northern lake states

                     2.     Barrens
                           • pitch pine-scrub oak barrens
                           * Appalachian shale barrens
                           • other cliff and ridge talus, tundra, meadow, and heath
                              communities

                     3.     Great Lakes coastal habitats
                           • barrier islands
                           * dune systems
                           • coastal wetlands
                           • pannes or intradunal ponds
                           • rocky shores along Lake Superior with arctic species
                           * bluffs with oak savannas, jack pine woodlands, and
                              beech-maple forests
Habitat Values and Trends

       The Northern Lakes and Forests originally consisted of a vast forested area covering both New
England and the northern Lake States.  Once virgin forest, New England was cultivated on 75% of arable
land by 1840, but is now primarily forested again (DeGraaf 1991).  The White Mountains of New
Hampshire and  western  Maine contain many  forest cover types;  northern hardwoods constitute
approximately half of the area.  Because of the glacial origin of soils in New England, many of the most
fertile sites are on midslope and produce hardwood forests.  The impervious layer (fragipan) underlying
much of these till soils produces vernal pools, seeps, and wet ground during the spring even on upper
slopes. Therefore, the forest landscape of New England is a mosaic of forest types and nonforest habitats
mat occur in  relatively small patches, especially  in the mountains.  Among these isolated habitats are
various forms of barrens that support numerous rare species. The vegetation of the northern lakes region
Habitat Evaluation
26
North

-------
has a more recent history of timber harvesting and forest regrowth, but consists of a greater variety of
habitats including many northern forest types, coastal habitats, and wetland types.

Northeastern Forests

        Forests of seven northeastern states comprise 49.5 million ac or about 70% of the total regional
land area (Barrett 1980). Major forest type groups are maple-birch-beech, white-red jack pine, spruce-fir,
Joblolly-sbortleaf pine, and oak-hickory.  By  1890, most of the northern spruce bad been cut; the
hardwood forests soon followed. Large fires swept over northern New England shortly after the turn of
the century.  Other forest losses have been due to the chestnut blight, diseases of birch and beech, and
gypsy moth attacks on oak.  Overcutting of commercially desirable species has resulted in the expansion
of elm-ash-red maple at the expense of  beech-birch-sugar maple.  In  the Northeast, substantial  area!
declines have occurred in oak-gum-cypress (53%), loblolly-shortleaf pine (49%), elm-asb-cottonwood
(38%),  aspen-birch (25%), oak-hickory (20%), and spruce-fir (14%) (Flather and Hoekstra 1989).

        In the last 100 years, one-fifth of the region's total acreage has reverted from pasture and tillage
to brush and forest (Hagenstein 1990). Since the 1950s, most of the increase in forest area is directly
linked to the decrease in farm area, especially dairy farming.  By the 1960s, the area! extent of suburban
developed  land surpassed that  of agricultural land.  Since that  time, the development of recreational
homes in  the mountains and along coasts and lakeshores has resulted in large areas of fragmented,
sensitive lands.  This process has fragmented ownership in a region with the lowest ratio of publicly
owned land of any forested region in the United States.  The result of this long history of exploitation
is that less than 1 % of New England's total acreage is in pristine ecosystems (Giltmier 1991).

        Extended wildfire protection and insect and disease control programs have greatly reduced the
loss of forest trees to these factors.  However, both mortality and towered growth rates have resulted
from air pollution in the Appalachians and eastern Canada. Projections indicate a decline throughout the
North over the next 50 years.   Urban area has doubled, and small forest parcels and low-value timber
lands will  likely be  converted  to other uses.   However, several states in the North have adopted
regulations to ensure the regeneration of  logged areas and to protect water quality (Hagenstein 1990).

Northern Lakes Forests

        Approximately 43% (52 million ac) of the total area of Michigan,  Minnesota, and  Wisconsin is
forested (Barrett 1980). Replacement of forest with agriculture increases from the East to the  West and
from the North to the South. The Lake States forests are 75% hardwoods (principally aspen-birch) and
25 % conifer (mostly spruce-fir). They include 15 northern forest cover types, 4 central hardwood cover
types in the "big woods" area of Minnesota and the southern portions of Wisconsin and Michigan, and
8 boreal forest cover types.

        In  1902, the region led  the country in timber production; by 1910, the majority of commercially
valuable white and red pine was gone.  In later years, overexpansion of farming cleared vast areas of
forest.  Fires and swamp drainage also contributed to devastation of the forest area in the  region.
Substantial losses are still occurring in  the  forested areas in the northern Lake States.   Logging is
proceeding at a rapid rate in Michigan. In Wisconsin, oak forests are being intensively harvested for oak
veneer, and aspens are declining as a result of forestry management practices. White pine  and hemlock
in southern Michigan, once dominant in the area,  are today  nearly absent. The elm-ash forest  type in
Habitat Evaluation                              27                                         North

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 Ohio, Indiana, and Michigan has been reduced by 90%  as a result of conversion to  agriculture
 urbanization.

 Forest Values

        Forest ecosystems support 90% of the total bird, amphibian, and fish species and 80% of ynjunmai
 and reptile species in the United States.  In addition, the Northern Lakes and Forests contains an average
 2.6 endangered and threatened species per county as of 1984 (Flather and Hoekstra 1989).  Some of the
 ecological values of each of the regional forest types are listed below:

        •      Oak-hickory - supports southern bald eagle,  red wolf, red-cockaded woodpecker and
               contains many diverse mesic environments.

        •      Maple-beech-birch - includes a wide variety of tree, shrub, and forb species that provide
               aesthetic, wildlife (e.g., moose), and recreational resources.

        •      Spruce-fir - contains many remote  and pristine environments that support moose, great
               homed owl.

        •      Aspen-birch - represents a pioneer community that follows disturbance and supports
               ruffed grouse and moose.

        •      White-red-jack pine - supports threatened species such as eastern timber wolf, peregrine
               falcon, and Kirtland's warbler.

        •      Elm-ash-cottonwood - represents important riparian habitat  along moist river and stream
               bottoms, and in and around swamps and depressions.

Old-Growth and Mature forests

        Old-growth forests are unique, vanishing  environments that merit preservation for aesthetic,
ecological, and scientific values (Society of American Foresters 1984). Although the Northern Lakes and
Forests do not contain the acreages of virgin forest still found in other parts of the country, many mature
forests greater than 100 years old do exist.  These mature forests possess a variety of important ecosystem
values and should be the focus of habitat conservation efforts.

        As an example, the majority  of remaining old-growth stands in Pennsylvania are on steep
mountain slopes and deep, narrow, boulder-strewn ravines. This is a result of a long history of natural
disturbance and anthropogenic degradation that has dramatically changed the composition of the present
day oak forests  of Pennsylvania.  They differ dramatically from the  original  types that were present
before settlement in early 1600s.  Even with extensive clearing for agriculture and coal mining, the state
was 75% forested in early 1800s. By 1850, however, Pennsylvania was the logging center of nation.
Subsequent attacks by  the  American  chestnut blight and beech  bark  fungus and severe vegetation
destruction from growing white-tailed  deer populations  killed many trees.  Most important, extensive
clearcutting caused a shift in species composition with declines in  white pine and eastern hemlock and
increases in yellow birch, black cherry, and red  maple.  Remaining old growth in Pennsylvania can be
classified into four types after Kuchler (1964): beech-maple; hemlock-northern hardwood forest (hemlock-
Habitat Evaluation                              28                                         North

-------
 white pine-beech-black birch); Appalachian oak forest (chestnut oak-white oak-red  oak-hickory); and
 mixed mesophytic forest (white oak-red oak-yellow poplar-basswood) (Smith 1989).

        Hie  old-growth forests  of the northern  Lake  States are  another important habitat  type.
 Historically, pine and hemlock-northern hardwood forests were most extensive.  Nontraditional old-
 growth ecosystems include northern white-cedar, speckled alder, northern pin oak, black ash, bigtootb
 aspen, and trembling aspen.  The old-growth forest ecosystems of this region contain a greater regional
 and local diversity than has been generally appreciated (Barnes 1989).  Northern Lakes and Forests
 habitats vary with the pattern of structurally (physiography, soil, vegetation) and functionally different
 landscape ecosystems.

 Great Lakes  Coastal Ecosystems

        The many wetland and sand dune ecosystems of the Great Lakes coastal region are important in
 the Northern Lakes and Forests and vary according to physiography,  associated soils, and other abiotic
 factors (Barnes  1989).  Many of the ecosystems that have not been  destroyed or highly modified are
 imminently threatened.  Impacts include the lumbering of most Great Lakes forests in the late 1800s,
 destruction of over half of the wetlands, pollution from heavy industry, and the proliferation of lakefront
 residences and structural modifications to protect shoreline property.  Degradation from recreational use
 and the accidental or purposeful introduction of alien species are also important (Hiebert 1990).

 Wetlands and Auatic
        Because the Great Lakes contains 54% of the nation's water area (a total of 58 million ac),
wetlands and aquatic systems are especially important habitats in the Northern Lakes and Forests.  Along
the Great Lakes, large inland coastal marshes lie behind beach ridges and are often influenced by lake
water levels and wind tides.  Other wetlands are eu trophic or boglike and, although still common, are
much reduced in size (e.g., 71 % of Michigan marshes have decreased in area). In addition, many glacial
wetlands occur within the northern forests.  They are often surrounded and invaded by trees producing
boglike edges with sedges and mosses and alder willow.

        Many smaller lakes  exist throughout  the  Northern Lakes and Forests.   Acidification from
atmospheric deposition has had a severe impact on lakes of the Northeast. Diverse marine environments
.exist along the northern Atlantic coast, including many glaciated estuaries and the modified Hudson River
Valley.

Activities and Impacts Affecting Habitats

        The major sources impacting habitats in the  Northern Lakes and Forests include residential
developments, industrial and  commercial developments,  dam construction, interstate highway or
expressway construction, logging and silvicultural practices, solid waste disposal, and peat mining.
These activities have had  adverse impacts on species populations and their behavior, as well as on
ecosystem processes such  as energy flow  and nutrient cycling.  They have also contributed  to the
proliferation of nuisance plants and animals. In its  comparative risk analysis, EPA Region 1 concluded
mat the highest risk to upland and aquatic habitats  in New England is concentrated in rapidly growing
areas (e.g., central Connecticut, southern Maine, and New Hampshire).  Historical losses of terrestrial
environments  are greater toward the coast and the southern part of the region.
 Habitat Evaluation                             29                                          Nortn

-------
        Agricultural conversion and grazing are relatively minor activities in the region, while timber
harvesting practices and peat mining continue to degrade terrestrial environments throughout the region,
especially in Maine and the northern Lake States.  However, the  conversion  of land  to industrial.
residential (including second homes), and transportation uses is the most severe cause of terrestrial habitat
loss in the Northern Lakes and Forests.  The major metropolitan areas in mis region are under enormous
pressure from human populations, and the effects are degrading the remaining natural habitats in the area.

        The following activities result in the major impacts on habitats of concern in the Northern Lakes
and Forests.
IMPACTS ON HABITATS OF CONCERN IN THE NORTHERN LAKES AND FORESTS

Mature
forest
Barrens
Great lakes
ty stems
|*n<*
Conversion
Destruction from
residential
development
Destruction from
residential
development
Destruction from
residential
development
Timber
Harvwtiag
Simplification
by replacement
with plantation
species
Degradation
Moderate
Grazing
Minor
Degradation
Minor
Water
Management
Minor
Minor
Destruction of
wetlands
Other
Degradation
with
increased
recreation
pressure
Degradation
with
increased
recreation
pressure
Degradation
with
increased
recreation
pressure
Land Conversion

       Historically, land conversion of both uplands and wetlands has profoundly affected the natural
communities in the Northeast. The early clearing of eastern forest for small farms  benefitted robins,
woodchucks, and bobwhite quail, but negatively impacted wild turkeys, black bears, and moose.  Since
that time, the large population centers are primarily responsible for the conversion of natural areas, i.e.,
through industrial and residential development.  Because cities concentrate on coastal areas, the unique
environments of the Atlantic and Great Lakes shores have been most affected. Recent increases in second
home and resort development are now contributing to construction in previously pristine areas.  In many
cases, rare  barrens, dunes, and wetlands areas are being converted  with  the loss of many rare plant
species.  More generally, "spin-off development" associated with highway construction has facilitated the
expansion of land use conversions into  rural areas.  This increased road construction is causing severe
fragmentation of terrestrial habitats.
Habitat Evaluation
30
North

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Timber Harvesting

        Timber harvesting activities can fragment, simplify, and degrade forest habitats.  The faunal
communities  inhabiting forests  vary with  the succession*!,  or serai,  stage such  as grass/fbrb,
shrub/seedling/sapling, medium tree, and large tree. Because the principal impact of timber harvesting
practices is to convert  forest stands from later to earlier serai stages, logging has a major impact on
resident animal  as well as plant species.   Timber harvesting telescopes plant succession,  shortens
rotations, compresses serai stages; and decreases the proportion of old growth. For example, old-growth
spruce, fir, and white cedar disappear with short rotations in Maine (i.e., reducing wintering grounds for
deer).  The conversion of hardwoods to conifers creates structurally simplified  plantations that reduce
structural diversity and wildlife. This has produced a trend away from declining habitat types and toward
common habitat types.  Management for monotypic even-aged stands  causes increases in  forest pest
damage which often result in large-scale spraying and the accompanying impacts.  Timber harvesting
activities also impact nearby aquatic systems  through erosion and sediment transport.

        Second in concern to the decrease in old-growth forests is the general decline in neotropical
migrants that breed  in  eastern  hardwood forests.  Although the situation is complicated by losses  of
wintering habitats for long-distance migrants  in Latin America, results indicate that species still present
in large blocks of forest are absent from small patches (Robbins et al. 4989). Fragmentation of forest
habitat from timber harvesting and from land conversions, especially for transportation, appears to be the
major cause of these declines (Terborgb 1989).

Recreational  Activities

        Forest habitats, and especially the many unique  barrens, dunes, and wetland habitats in the
Northern Lakes and Forests, can be negatively impacted by  recreational activities.   These impacts are
usually  localized, but can severely affect  the hydrology and  nutrient  cycling  regimes of vulnerable
habitats. As  an example, the annual Canaan Valley motorcross contributes to the degradation of sensitive
wetland habitats through soil erosion.
Mitigations of Impacts

        The conservation of habitats  requires consideration of mitigations  for  the  major activities
impacting habitats of concern.  In the Northern Lakes and Forests, the primary habitat impacts are caused
by the following:

        •      Land conversion and timber harvesting of old growth and mature forests.
        •      Land conversion of barrens and other rare habitat types.
        •      Land conversion and pollution of Great Lakes ecosystems.

Land Conversion

        Effective mitigation of land use conversion activities can sometimes be obtained only by avoiding
impacts on rare or unusual  habitat types.  Rarely, if ever, is restoration or compensation an adequate
mitigation for the loss of these habitats.  In these cases, mitigation is a siting issue, where construction
and degrading activities are located a distance from the habitats of concern.  The  habitat  is adequately
Habitat Evaluation                              31                                          North

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preserved if all possible impact scenarios are accounted for. Barring this solution, effective management
measures must be implemented to ensure protection of the habitats of concern.

        In the case of barrens habitats or unique Great Lakes ecosystems, hydrological and contamination
concerns are especially important.  Construction or  resource management activities require the use of
sediment filter strips and other means of intercepting off-site contaminants. Road building and structural
"improvements" must not result in altered hydrological regimes. Where rare plant types exist or where
habitats are unstable (e.g., sand dunes), recreational access associated with nearby development may have
to be limited.

        Amelioration of impacts from land conversion to transportation uses requires special mitigation
measures.   As with all land conversion, the construction of highways and power-line corridors is
primarily a siting issue. Avoidance of sensitive habitats may be accomplished by modifications to the
route design, and the extent of disturbance can be limited by careful construction practices.  However,
fragmentation of the larger area is unavoidable in the case of land conversion to transportation corridors.
Structural mitigations can be used to lessen the impact on animal movement across transportation routes.
Primarily,  these  include the construction of fences  and underpasses.  The goal of these structural
measures should be to  mimic the natural movement and migration patterns of the  affected species.

        Harvesting
        At a minimum, the production of commercial wood products from an area must not exceed the
sustainable level if the ecological integrity of a forested area is to be maintained.  Where sensitive forest
types exist, logging may be completely prohibited or constrained to specific methods to prevent habitat
loss or degradation.  In other areas, more extreme harvesting methods may be allowed or prescribed to
establish or maintain desired forest conditions. Acceptable methods will vary according  to local forest
ecology and the desired future condition of the site.  Analysis of harvesting techniques must be based
upon  an analysis of the structure and diversity of the forest canopy, midstory, and understory.

        A recent directive of the Chief of the U.S. Forest Service acknowledges this fact and points out
that clear cutting is acceptable only when needed to replicate natural ecological  processes.  Although,
selective cutting can preserve forest structural diversity, it can reduce horizontal diversity (NRC 1982).
The harvesting technique employed must be based upon sound silvicuitural prescriptions and demonstrate
its capability to maintain vertical diversity (foliage height diversity), horizontal diversity (interspersion,
edge, juxtaposition, patchiness),  and a mixture  of live and dead  wood.  Specific timber harvesting
operations should be designed to preserve the structure and diversity of the natural forest habitat.

        An  important component of selective cutting should be the preservation of standing dead trees.
Northern  hardwood forests contain 24 species of birds that nest, roost, or forage for invertebrates in
standing trees with decayed  wood.   These cull trees are usually the  first focus of forest-thinning
operations, to the detriment of the birds. Breeding bird abundance declines rapidly following a clear cut,
and the species composition continues to change for 10 to IS years  (DeGraaf 1991).  However, if trees
with cavities are saved, many  of these species can successfully forage on sound boles.  About one large
cavity or den tree per 2 ha is required for populations of large species such as wood ducks; this requires
harvest  rotations of 100 to 125 years  (although  rotations of 65 years produce trees large enough for
species nesting in smaller cavities).
Habitat Evaluation                              32                                         North

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       Responding to die "biodiversity crisis," the U.S. Forest Service is moving toward an ecosystem
approach to forest management (Bob Szaro, personal communication).  Recent forest management plans
have incorporated tenets of the "New  Forestry" espoused by Jerry Franklin.  These progressive plans
require the rigorous implementation of ecological management practices to m«'"tajn forest productivity
and to preserve the functioning of sensitive forest components such as old-growth  or late-successional
forests. Effective mitigations for habitat conservation in forest management require specific management
measures at the  site, watershed, and landscape levels.  For example, the location, and size of timber
harvests should be planned to  minimize reduction of the core area of mature forest (e.g., harvest only
alternate basins until regrowth).  Maintenance  of mature-forest stands in managed landscape can be
achieved by extending rotation (beyond 80) to ISO to 200 years, by leaving some stands unharvested for
old growth, and by linking stands.  Landscape-scale considerations include the provision of buffer zones
and habitat corridors as discussed in the introduction of mis document.  The following management
measures are recommended for conserving habitat within managed forests:

       •      Minimi?* the construction of new roads and close roads not in use either permanently or
              seasonally.

       •      Use best management practices (BMPs), such as filter strips, to minimize erosion during
              harvesting or road construction.

       •      Maintain 100-ft riparian zones with adjacent feathered transition zones to buffer edge
              effects.

       •      Restrict harvesting operations to periods when the ground is either dry or frozen.

       •      Maintain site productivity by retaining large woody material and minimizing mineral soil
              exposure and compaction during harvesting.

       •      Manage for natural disturbance patterns to maintain natural openings and succession^-
              stage composition.

       •      Maintain connections between blocks of interior forest, especially old growth.

       •      Provide for the protection of special areas, including cliffs, caves, taluses, riparian areas,
              and old-growth stands.

       •      Maintain the structural integrity and the native variety of the forest by managing for the
              natural composition of the  following components: vegetative types, serai stages, tree
              types and sizes, standing dead trees and down material, tree snags,  and cavity trees.
Habitat Evaluation                              33                                         North

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Guidelines for Reviewers

        Reviewers of environmental impact assessments will find this document useful if they follow the
steps laid out in the introduction:

        1.     Review the status and trends of habitats in the region.

        2.     Identify the habitats of concern.

        3.     Link the activities involved with impacts to these habitats of concern.

        4.     Devise appropriate mitigations for the impacts.

Each reviewer can then determine the adequacy of the environmental impact assessment in question and
recommend modifications to enhance its effectiveness.

        In identifying the habitats of concern, the reviewer should supplement the information in this
document with detailed locational information on the abundance and distribution of habitats within the
region of interest, and with any historical information on the extent and quality of these habitats. Most
important, the reviewer should characterize the habitats in terms of their ecological values (e.g., use of
wooded wetlands by migratory waterfowl).

        In considering the links between activities and habitats, the reviewer should look beyond direct
impacts to indirect and subtle effects, including cumulative impacts, interactive and synergistic impacts,
and  scale-dependent impacts  (e.g.,  effects of fragmentation on ecosystem integrity and species home
ranges).

        In devising possible mitigations, the reviewer should  follow the seven principles for habitat
mitigation repeated below. The reviewer also should determine whether adequate assurances have been
given that the mitigations proposed will be completed.

        1.     Base mitigation goals and objectives on a landscape-scale analysis that considers the needs
               of the region.

        2.     Mimic natural processes and promote native species.

        3.      Protect rare and ecologically important species and communities.

        4.     Minimize fragmentation of habitat and promote connectivity of natural areas.

        5.     Maintain structural  diversity of habitats and,  where appropriate, species  diversity  to
               promote the natural variety of the area.

        6.     Tailor management  to she-specific environmental conditions and to the unique  impacts
               of the specific degrading activity.

        7.     Monitor for habitat impacts and revise mitigation plans as necessary.
Habitat Evaluation                              34                                         North

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       Finally, the reviewer should consider the proposed activities and mitigations in the context of
relevant regional  program goals and objectives (e.g., whether the outcome of the project will be in
accordance with principles set out by regional planning commissions such as those established for the
New York Bight and the Great Lakes).

Contacts and Information Sources

       When considering habitat conservation issues in an environmental impact assessment for the
Northern Lakes and Forests, the reviewer should consult the following organizations and individuals for
information on habitat impacts and mitigations:

       State Natural Heritage Programs
       U.S.  Fish and Wildlife Service, Regional and Area Offices
       State Fish and Game Departments
       University and Research Programs
       Herbaria and Museums

       Lesley Sneddon, Regional Ecologist, The Nature Conservancy
       Ralph Pisapia, Associate Director, Fish and Wildlife Enhancement, U.S.  Fish and Wildlife
         Service
Habitat Evaluation                             35                                         North

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                   Midwest Habitat Region:  Midwest Croplands
Geographical Description of the Region

       The Habitat Region, Midwest Croplands, contains parts of 13 states. The region includes parts
of Ohio, Indiana, Illinois, Missouri, Iowa, Wisconsin, Minnesota, North Dakota, South Dakota, Iowa,
Nebraska, Kansas, and  Oklahoma.   Parts of EPA  Regions 5,  6, 7, and 8 are  included.  The
accompanying map indicates the boundaries of this habitat region and the states it comprises.

       The Midwest Croplands  comprise eight ecoregions (Omernik  1987).  The vegetation of the
Midwest Croplands includes a range of mosaic of bluestem, prairie (bluestem and indiangrass), oak,
hickory, wheatgrass, needlestem, oak savanna, maple, bass wood, beech, elm, and ash.  The land use
patterns are croplands and croplands with grazing lands.
Habitat Evaluation
37
                                       Midwest

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Habitats of Concern
       The Midwest Croplands contains many habitats of concern; the most obvious fall into the four
general categories of oak savannas, native prairie remnants, wetlands, and old-growth central hardwood
forest. The principal habitats of concern most at risk in the Midwest Croplands are listed below.
                          PRINCIPAL HABITATS OF CONCERN
                              IN THE AflDWEST CROPLANDS

              1.  Oak savannas

              2.  Native prairie remnants
                 •    tallgrass
                 •    little bluestem prairie
                 •    hill prairie

              3.  Wetlands
                 «    bottomland hardwoods of the Mississippi and Platte Rivers
                 •    prairie potholes
                 •    riparian corridors (only a few remaining)

              4.  Remnant central hardwood forest (virtually none left)
Habitat Values and Trends

       The Corn  Belt States of the  Midwest  have sustained the greatest conversion of terrestrial
environments to human land uses in the nation. The elm-ash forest type in Ohio, Indiana, and Michigan
has been reduced by 88% as a result of conversion to agricultural and urban uses (KJopatek et al. 1979).
Bluestem  prairie  and its transition zone with  oak-hickory forest has  declined  by 85% and  78%,
respectively, representing a loss of more than 41 million ha, primarily due to conversion to agriculture.
The agricultural states of Iowa, Illinois, and Indiana have lost the highest amounts of their natural
ecosystems (92, 89, and 82%, respectively).

       As with forest habitats, the spatial pattern and fragmentation of prairie vegetation can negatively
affect native fauna and ecosystem health.  The loss of grassland habitat to agriculture is responsible for
the decline in prairie birds, especially those requiring large continuous habitats, and is analogous to the
reduction  in old-growth forests and its obligate species.   The upland sandpiper, bobolink, dickcissel,
grasshopper sparrow, savannah sparrow, and Henslow's sparrow all declined by 90% between the 1950s
and 1970s (Graber and Graber 1983). Based on 1984 maps (USDA Forest Service 1989), the average
number of endangered and threatened species per county is 2.4 for the Midwest Habitat Region,  the
lowest in  the nation.  Many  historical species, however, have  been extirpated from the Midwest.
Habitat Evaluation
38
                                        Midwest

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Therefore, the few remaining natural areas are the major contributors to the diversity of the region.
These areas include isolated examples of savanna, grasslands, and forests.

Savannji

        Oak  savanna once covered  between 11 and 13 million ba of the Midwest in the states of
Minnesota, Iowa, Missouri, Illinois, Wisconsin, Michigan, Indiana, and Ohio (Nuzzo 1986).  It is now
the rarest major habitat type in the Midwest; in 1985, only 113 sites totaling 2,607 ba of high-quality oak
savanna remained in the Midwest, representing 0.02% of its original extent.  Oak savanna is dominated
by oaks  producing 10 to  80% canopy, with or without a  shrub  layer,  and  has  a herbaceous,
predominantly grassy ground layer of prairie or forest species.  Because savanna  is fire-dependent, h
rapidly converts to  forest without fire or severe droughts.  This occurred over much of its range within
.40 years of settlement. Fire was eliminated by plowing and grazing, and by the construction of roads
.and railroads, which act as firebreaks. Other than a few areas with the appropriate  moderate grazing or
occasional fires, existing savanna occurs only on droughty sandy or rocky soils.

Grasslands

        Prairie habitats constitute another important regional habitat that is .greatly reduced in area. Only
minor remnants of the vast area of tallgrass prairie remain.  Restoration activities, a major component
of prairie conservation efforts, have been attempted  (1) by upgrading existing degraded prairies, and (2)
by establishing prairie communities on sites without existing prairie species (Kline and Howell 1987).
In addition to planting and  site preparation techniques, fire is an essential  tool in prairie  restoration.
Unfortunately, most restored prairies contain unwanted species and require special management involving
site preparation and fire to address exotic herbs and woody species, respectively.

Forests

        Merritt (1980) described the forests of the central region of the United States as comprising 40
million ha of the originally greater than 140 million ha of hardwood forest, or about  15% of the total land
area [however much of these forests occur outside the Midwest Habitat Region in the states of Kentucky
and Arkansas].  These forests have a long history of disturbance from  Indian and  European  slash and
burn systems, plus livestock grazing and Jogging. Throughout the Midwest, both the hilly well-drained
soils and  the more fertile wetter, glaciated areas have been cleared for agriculture.  Woodlands not
cleared for fanning were heavily timbered.  By the 1930s, permanent clearing bad created the most
fragmented forest system in the United States.

        The most extensive forest type, oak-hickory, makes up 72% of the forest acreage, while elm-ash-
cottonwood occupies about 17%.  Today, woodlands are limited in size, are widely dispersed, and occur
primarily in  the portions of the land that cannot be easily  worked for row crops.  Along the prairie
fringes, wooded areas are located on steep bluffs and ravines and along poorly drained bottomlands.
Elsewhere, they are found on rough and rocky land, on poorly drained uplands, along stream banks, and
on bottomlands subject to overflow.  These few remaining  forests are especially important because of
their role as  riparian areas in the ecological functioning of the watershed. Nationwide 70% to 90% of
riparian areas have  been lost to human activities (Ohmart and Anderson 1986).
Habitat Evaluation                              39                                       Midwest

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        Even in the last 25 years, total Midwest forest has continued to decline.  Only 100,000 ha or
0.07% of the original central hardwood old growth remains, mostly in protected areas mat were once
family farms.  The long-term viability*t>f mis forest type is in question due, in part, to the "natural''
change from oak-hickory to sugar maple (perhaps from  reduced fire or climate change) occurring on
mesic sites.  Degradation is continuing from recreational overuse and vandalism, and from adjacent
impacts such as urban construction, soil erosion, agricultural chemicals, land drainage, and strip mining
for minerals (Parker 1989).

Wetlands

        Prairie wetlands, located in the glaciated portion of the states of North Dakota, South Dakota,
Minnesota, and Iowa, constitute the single most important breeding area for waterfowl in North America
(Hubbard 1988). These wetlands support 50% to 80% of the continent's duck populations as well as
many other wildlife species such as nongame birds, muskrat, and mink.   These wetlands, or prairie
potholes, are relatively shallow, water-holding depressions varying in size, water permanence, and water
chemistry.   Refilling usually occurs from  spring precipitation and  runoff, and water levels fluctuate
widely due to climate variability (Poiani and Johnson 1991).

        Other wetlands include diverse shallow wetlands, ponds, and lakes that were glacially formed,
and bottomland hardwoods.  The peak loss in bottomland hardwood habitat occurred in the 1970s and
1980s, and losses have declined since men for economic reasons.

Activities and  Impacts Affecting Habitats

       The following activities result in major impacts on habitats of concern in the Midwest Croplands:

        •      Conversion to agriculture and offsite impacts of cultivation practices (especially to aquatic
               systems).

        •      Urban development, both residential and commercial (particularly in large metropolitan
               areas such as Chicago,  St. Louis, Cleveland, and Minneapolis-St. Paul).

        •      Forest loss and fragmentation (especially to highway development and channelization of
               riparian areas).
Habitat Evaluation                              40                                      Midwest

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        The major impacts of degrading activities on the principal habitats of concern are summarized
 in the table below.
IMPACTS ON HABITATS OF CONCERN IN THE MIDWEST CROPLANDS

Oak savanna
Prairie
Wetlands
Remnant forests
Land
Conversion
Major conversion
to agriculture
Major conversion
to agriculture
Major conversion
to agriculture and
urban uses
Conversion to
agriculture
limber
Harvesting
Moderate
None
None
Removed prior
to agriculture
Grazing
Moderate
Major
None
None
Water
Management
Minor
Minor
Drainage for land
conversion
None
Other
Succession to
forest after
fire
suppression
Invasion of
exotic
species
Minor
Minor
 Land Conversion

        Historically in the Midwest, conversion to agriculture has been a major factor affecting habitat
 loss.  In Illinois and Indian?, more than 80% of the natural ecosystems have been lost to agriculture.
 Conversion to agriculture is continuing on the fence rows and ditch banks that remain. Odd-dimensioned
 plots are now being converted as a result of monetary  incentives in Wisconsin and other states (Todd
 Peterson, personal communication).  During the Illinois state inventory of prairies, lands were disturbed
 for railroad maintenance or converted to agricultural fields faster than they  could be identified.  These
 conversions represent the loss of the only remaining wildlife habitats in many areas (Illinois Department
 of Conservation 1978).  This is especially true of bottomland  hardwoods, which were also affected by
 channelization  and timber harvesting.  Logging continues on the last large tracts of forest, including
 accelerated development via barge canal along the lower Kaskaskia River (the largest remaining tract of
 bottomland timber in Illinois).  The loss of riparian areas  has  resulted in declines among the waterfowl
 of the Mississippi Fiyway.

        Approximately 60% of North Dakota's original 5 million ac of prairie pothole wetlands has been
 Jost (Stromstad and Donovan, 1989).  Agricultural development accounts  for nearly 99% of prairie
 pothole losses.  In  northeastern  Illinois, 20% of wetlands identified by aerial photos were filled  for
construction between 1970 and  1974.  Instances of new wetland drainage  appear to  have dropped
^significantly;  however,   upland   grasslands  adjacent  to wetlands  are still  significantly  at  risk.
 Approximately 50% of the grasslands in the Missouri Coteau of North Dakota were converted to cropland
 between 1965 and 1975.  Loss of grasslands, bayed and grazed for livestock production, adversely affect
 many species, including the elimination of upland nesting cover for ducks.  Some limestone glades are
 being quarried; hill prairies are being used for homesites; railroad prairies face new maintenance threats
 from herbicides and heavy machinery; and new lands are  now being cultivated.
 Habitat Evaluation
41
                                         Midwest

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        Both the extensive coverage and intensive use of agricultural land in the Midwest pose additions]
stresses to habitats through cultivation practices (NRC 1982).  The use of fertilizers and pesticides,
irrigation and drainage, double cropping and increased field size all contribute to increased pollutant loads
and severe impacts on habitats.  Agricultural chemicals are toxic to many species and can negatively
affect population levels, community composition, and ecosystem dynamics.  Other intensive cultivation
practices directly reduce important hedgerow and riparian habitat and usually produce severe offsite
impacts.

        on Au
        The intensive use of midwestern lands converted to human uses has resulted in a high level of
pollution  discharge  and other negative impacts on aquatic  systems.   A  historical example is the
degradation of the Illinois River through intensive human use from Chicago, including sewage discharge,
dredging, damming, barge traffic, and introduction of carp. As a result, half of the original 400,000 ac
were drained, and the other half of the sand-bottom backwaters of the river were covered with mud.

        Smaller streams throughout the  Midwest have also been severely degraded through the impacts
of agricultural practices and urban expansion. In particular, fish populations have been extirpated by the
following factors (in order of relative importance):

               S illation.
               Drainage of wetlands.
               Stream desiccation due to lowered water tables.
               Competition and hybridization due to habitat changes and introduction of exotic species.
               Pollution.
               Dams and impoundments.
               Raised water temperatures with removal of streamside vegetation.

Mitigation of Impacts

        The conservation of habitats requires consideration  of mitigations for the major  activities
impacting habitats of concern.  In the Midwest Habitat Region, the primary habitat impacts are due to
the following:

        •       Conversion to agriculture and offsite impacts of cultivation practices.
        •       Urban development, both residential and commercial.
        •       Forest loss and fragmentation.

        In the Midwest, habitat conservation of oak savannas and prairie types is essentially a restoration
and creation effort.  Less habitat of high ecological integrity remains in the Midwest than in any other
region except the central valley of California and parts of Florida  (Steve Chaplin, TNC,  personal
communication).  Restoration of grassland systems concentrates on revegetation and borrows largely from
agriculture and horticulture (Jordan et al. 1988). The most commonly measured parameters at restoration
sites are the survival and growth of planted vegetation for the first few growing seasons,  generally too
short a period to evaluate the ultimate species diversity or the presence of self-regeneration.  More
Habitat Evaluation                              42                                       Midwest

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successful has been the use of a "prairie matrix" (developed by Robert F. Betz) of a few aggressive and
tolerant native species that survive weed competition too intense for many other native plants (Packard
1988).  Restorationists follow mis matrix with less aggressive species to effectively shorten the natural
ecological succession of prairies.

        Degradation of remnant forest is continuing from recreational overuse and vandalism and from
adjacent land-use practices such as urban construction, soD erosion, agricultural chenucals, land drainage,
and strip mining for minerals. Research is needed to determine whether important  mitigation factors
(e.g., adjacent harvest, increased access through new roads, different harvest systems, and width of
buffers) can be applied (Parker 1989).

Land Conversion

        Effective mitigation of land conversion activities can sometimes be obtained only by avoiding
impacts on rare or unusual habitat types.  Rarely, if ever, is restoration or compensation an adequate
mitigation for the loss of these habitats.  In these cases, mitigation is a siting issue, where construction
and degrading activities are located at a distance from the habitats of concern. The habitat is adequately
preserved if all possible impact scenarios are accounted for. Barring mis solution, effective management
measures must be implemented to ensure the protection of the habitats of concern.

       In the case  of unique riparian or wetland habitats, hydrologies! and contamination concerns are
especially important. Construction or resource management activities require the  use of sediment filter
strips and other means of intercepting offsite contaminants. Road building and structural  "improvements"
must not result in altered hydrological regimes.   Where rare plant types exist or where habitats are
unstable, recreational access  may have  to  be limited.  These mitigations can be  best  implemented by
creation of a regional land-use plan (through a coordinating council like the Waterfowl Flyway Council)
and landowner incentives (like the Conservation Reserve Program).

       Conversion  to agricultural  land is a  special concern in the  Midwest.   Land conversion to
agriculture can cause ground water  overdraft, salinization of topsoil and water,  reduction  of surface
water, high soil erosion, and destruction of native vegetation.  Mitigations include more conservative
irrigation techniques and improved drainage systems.  Soil conservation techniques vary from windbreaks
to contour plowing, stripcropping, rotation of crops, conversion to grass, and/or minimum tillage.

Agricultural Impacts

       Maintenance of riparian areas  and habitat  corridors  is effective mitigation for intensive
agriculture. Implementation of integrated pest management (IPM) practices can reduce the load of toxic
agricultural chemicals entering both  terrestrial and aquatic  systems.   In general, institution  of best
management practices (BMPs) that address nonpoint source pollution are appropriate mitigations for
impacts caused by cultivation practices.

Wetlands

        Mitigation of wetlands destruction and degradation is the subject of a growing body of literature
(Kusler and Kentula 1989).  Restoration and  mitigation banking concepts are still being evaluated as
effective mitigation measures for  direct wetlands alterations.
Habitat Evaluation                              43                                       Midwest

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Guidelines for Reviewers

        Reviewers of environmental impact assessments will find this document useful if they follow the
steps laid out in the introduction:

        1.     Review the status and trends of habitats in the region.

        2.     Identify the habitats of concern.

        3.     Link the activities involved with impacts to these habitats of concern.

        4.     Devise appropriate mitigations for the impacts.

Each reviewer can then determine the adequacy of the environmental impact assessment in question and
recommend modifications to enhance its effectiveness.

        In identifying the habitats of concern, the reviewer should supplement the information in mis
document with detailed locational information on the abundance and distribution of habitats within the
region of interest, and with any historical information on the extent and quality of these habitats.  Most
important, the reviewer should characterize the habitats in terms of their ecological  values (e.g., use of
wooded wetlands by migratory waterfowl).

        In considering the links between activities and habitats, the reviewer should look beyond direct
impacts to indirect and subtle effects, including cumulative impacts, interactive and synergistic impacts,
and scale-dependent impacts  (e.g.,  effects of fragmentation on ecosystem integrity and species home
ranges).

        In devising possible mitigations, the reviewer  should follow the seven principles for habitat
mitigation repeated  below. The reviewer should also determine whether adequate assurances have been
given that the mitigations proposed will be completed.

        1.     Base mitigation goals and objectives on a landscape-scale analysis that considers the needs
              of the region.

        2.     Mimic  natural processes and promote native species.

        3.     Protect rare and ecologically important species and communities.

        4.     Minimize fragmentation of habitat and promote connectivity of natural areas.

        5.     Maintain structural  diversity of habitats and  species diversity, where appropriate, to
              promote the natural variety of the area.

        6.     Tailor management  to site-specific environmental conditions and to  the unique impacts
              of the specific degrading activity.

        7.     Monitor for habitat impacts and revise mitigation plans as necessary.
Habitat Evaluation                              44                                       Midwest

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       Finally, the reviewer should consider the proposed activities and mitigations in the context of
relevant regional  program goals and objectives (e.g., whether the outcome of the project will be in
accordance with principles set out by regional planning commissions).

Contacts and Information Sources

       When considering habitat conservation issues in an environmental impact assessment for the
Midwest Croplands, the reviewer should  consult  the  following  organizations  and  individuals for
information on habitat impacts and mitigations:

       State Natural Heritage Programs
       U.S.  Fish and Wildlife Service, Regional and Area Offices
       State Fish and Game Departments
       University and Research Programs
       Herbaria and Museums

       Steve Chaplin, Regional Zoologist, The Nature Conservancy
       Mamie Parker, Division of Federal Activities, U.S. Fish and Wildlife Service Region 3
Habitat Evaluation                             45                                      Midwest

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         Southeast Habitat Region: Southeastern Forests and Croplands
Geographical Description or the Region

       The Southeast Habitat Region, Southeastern Forests and Croplands, contains all of 14 states (and
the District of Columbia) and parts of 9 states.  The region includes all of Maryland, Delaware, District
of Columbia, Virginia, West Virginia, Kentucky, Tennessee, North Carolina, South Carolina,  Georgia,
Alabama,  Mississippi, Florida,  Louisiana, Arkansas, and parts of New  Jersey, Pennsylvania, Ohio,
Indiana, Illinois, Iowa, Missouri, Oklahoma, and Texas. EPA Region 4 is included in its entirety, and
parts  of EPA Regions  2, 3, 5, 6,  and 7 also are included.  The accompanying map indicates the
boundaries of this habitat region and the states it comprises.

       The Southeastern Forests and Croplands is perhaps the most diverse in the nation comprising 20
ecoregions (Otnernik 1987). The vegetation of the region includes a wide range of forest types, including
Appalachian oak, oak/hickory /pine, mixed mesophytic forest, southern mixed forest, southern floodplain
forest, as well  as palmetto prairie  and everglades.  Northern hardwoods  and southern mixed and
floodplain forests are also present. The land use pattern is mostly a mosaic of forest and cropland with
substantial woodland, pasture, swampland, marshland, and urban components.
Habitat Evaluation
47
                                       Southeast

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Habitats of Concern
       The Southern Forests and Croplands contains many habitats of concern; the most obvious fall into
eight general categories.  The principal habitats of concern most at risk in the Southern Forests and
Croplands are listed below.
                         PRINCIPAL HABITATS OF CONCERN
                  IN THE SOUTHEASTERN FORESTS AND CROPLANDS

                    1. Bottomland hardwoods
                           oak/gum/cypress

                    2. Scrub habitat
                           Florida aandpine scrub
                           aoutheastem savanna and bogs

                    3. Spruce-fir forest in the Appalachians

                    4. Old-growth pine forest
                           longleaf pine-wiregrass
                           New Jersey pine barrens

                    5. Everglades ecosystem
                           other wetlands

                    6. Maritime forest of coastal barriers

                    7. Contiguous upland hardwood forests

                    8. Mature mixed mesopbytic Appalachian and dark forest
                           sabalpree, barrens, and caves
                           old-growth forest
       Ecosystems of concern include the Chesapeake Bay and major river systems, abundant freshwater
and coastal wetlands, relict closed boreal subalpine forest communities, limestone barrens, remnant alpine
peat bogs, and the Great Dismal Swamp.  Also, me endemic communities in the Southern Appalachians,
high-elevation spruce-fir forests (boreal subalpine), bottomland hardwood forests, coastal live oak forests,
long-leaf pine wiregrass hardwood hammocks, and the Everglades.  Oak-gum-cypress forests of the
lower Mississippi drainage are important overwintering habitats for avian species.
Habitat Evaluation
48
                                      Southeast

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Habitat Values and Trends

        Two to three centuries ago, almost all of the land area in the South was forested.  Since that time,
agricultural land has  become an increasingly'prominent part of the landscape (USD A Forest Service
1989).  The loss of forested area accelerated in the late 1800s with the harvesting of old-growth forests.
However, after  1920 forest area began to increase with the abandonment of agricultural land, reduced
timber  harvesting, and efforts  to regenerate forests.  This trend continued until the  1960s, when
abandonment slowed and new clearing for agriculture and pastureland began (at first among bottomland
hardwoods and later more uniformly across the South). Concomitant increases in population and industry
saw large areas converted to residential and commercial uses. Future  economic conditions will likely
determine whether high rates of conversion continue. Projections for the next SO years show urban area
increases of 14 million ac leading to losses of several million ac each in cropland and pastureland. These
losses may stimulate forest conversions for additional agricultural land; in particular, forests of the Ozarks
are expected to be converted to pasture (NRC  1982).

Forests

        The Southeast contains 200 million ac of forest land with 62 million ac in pine forest (loblolly-
shortleaf pine,  longleaf-slash pine, and oak-pine), 71 million ac in oaL-hickory, and 31  million ac in
bottomland hardwood types (USDA  Forest Service  1989).  Since 1963, losses in the Southeast have
occurred in longleaf-slash pine (40%),  oak-gum-cypress (24%),  and  loblolly-shortleaf pine (15%).
Bottomland hardwoods have been lost to agricultural clearing, and most  remain only as strips along
streams where the soil is too wet for cropping or grazing.  They are further endangered  by dams and
drainage modifications. The loss of longleaf pine habitat can be attributed to the logging of nearly all
original forest from the Atlantic coast to the Piney Woods of Texas and the replacement with loblolly and
slash pine.  Losses of other pine species are the result of poor pine  regeneration and less farmland
abandonment.

        The forests of the Southeastern Forests and Croplands contain a particularly diverse fauna and
flora. Many northern species complexes reach their most southern extent in the southern Appalachians,
while many southern  species reach their most northern extent at Cape Hatteras.  Based on 1984 maps
(Flather and Hoekstra 1989), the average number of endangered and threatened species per county is 5.7
for the Southeastern Forests and Croplands.  The following listing of southeastern forest types illustrates
some characteristic ecological values of the region:

        •       Loblolly-shortleaf pine - much of the ecosystem has been converted to pine plantations,
               often  mixed with pasture  or row crops.

        •       Longleaf-slash pine - covers the coastal region and has an extensive grassy understory
               that varies with site  and  geographic location; it supports many endemic plants and
               endangered  animals  including red-cockaded woodpecker and Florida panther; nearly
               eradicated in logging boom of the early 1900s, it was replanted in loblolly or shortleaf
               pines; slash pine now dominates mis ecosystem.

        •       Oak pine - often occurs on cutover sites with poor pine regeneration; supports white-
               tailed deer and wild turkey.
Habitat Evaluation                              49                                      Southeast

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        •      Oak hickory - supports southern bald eagle, red wolf, red-cockaded woodpecker; i
               widespread with at least six distinct associations.

        •      Bottomland hardwood- principally oak-gum-cypress and elm-ash-cottonwood ecosystems;
               mangrove swamps  in Florida  support Florida manatee, brown pelican,  bald eagle,
               hawksbill sea turtle, and Atlantic Ridley sea turtle;  cypress savanna has been mostly
               converted to pasture and  cropland, but remaining areas support fox squirrel, ibises,
               cormorants, herons, egrets, kingfishers, Bachman's warbler, Florida panther, and bald
               eagle; elm-ash-cottonwood supports many waterfowl species.

        Although the logging of mature forests may increase she diversity by creating forest edge, these
timber harvesting activities usually increase the number of species that are not in need of protection (e.g.,
white-tailed deer, bobwbite quail, cottontail rabbit, gray squirrel, wild turkey) at the expense of species
that are regionally, as well as locally, rare or vulnerable.  As is die case with old-growth Douglas fir in
the Northwest, the decline  of subalpine Appalachian forests threatens the last remnants of historical
ecosystems, the loss of which would dramatically lower regional and global diversity.

        Of particular concern in the Southeast are  (1) old-growth-dependent species (such  as  the red-
cockaded woodpecker in coastal plain pine forests), and (2) forest-interior-dependent species (including
many neotropical migrant songbirds in mixed  deciduous forests). Because of their ecological complexity
and relative isolation,  southeastern forest ecosystems contain many rare and  endangered  species mat
require mature trees for nesting and foraging.  Mature trees are at serious risk from logging in the
Southeastern Forests and Croplands', though sustainable short-rotation plantation forestry dominates the
region, remaining areas of mature forest are still being sought and exploited for short-term profits.

        The habitat of the red-cockaded woodpecker, which exists in the southern  pine forests ranging
from Maryland to Texas, has been reduced and will continue to decline under current timber harvesting
management practices (Roise et al. 1990).  The causal factor in habitat loss is the cutting of loblolly pine-
dominated stands greater than 75 years of age, and the cutting of all longleaf pine stands greater than 95
years of age. Lennartz et al. (1983) estimates that pines required by the red-cockaded woodpecker have
declined by 13% in 25 years. In Texas, clear-cut logging has been restricted because of concerns for the
red-cockaded woodpecker (Larmer  1989).

        Species described as interior forest  birds  (Terborgb 1989) are of special concern in  forest
environments suffering from fragmentation.   Songbirds, in particular, are declining to number because
of the loss  and fragmentation of forest habitat along their migratory path from  New  Hampshire to
Mexico.  Forest  conversion and fragmentation leads to an increased likelihood of starvation and  an
increased likelihood of predation due to an increase in the numbers of songbird predators  (Terborgh
1974).  Robbins et al. (1989) summarized  the breeding habitat losses and requirements of forest birds of
the Middle  Atlantic States in light  of the  negative effects occurring from forest  fragmentation (due to
suburban expansion) to that region (Lynch  and Whitcomb 1978).  They concluded that in relatively
undisturbed mature forests, the degree of isolation and the area of forest were better predictors of relative
abundance of bird species than were any habitat variables. Forest reserves of thousands of hectares are
required to have the highest probability of providing for the least common species of forest birds in a
region.
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        Bottomland hardwood forests represent a third important forest habitat of the Southeast, one mat
 supports many bird species during the critical over-wintering period.  The oak-gum-cypress ecosystem
 of the southern states also includes a diverse resident avifauna (Dickson 1988).  For example, this habitat
 was the historical range of the ivory-billed woodpecker. The forests of the Appalachian and the Ozark
 regions also contain valuable habitats.

        The Appalachian Plateau has special value because its  cool, wet climate at 2,400 ft allows
 northern species to live at lower latitude. Encompassing more than 230 terrestrial vertebrate species, mis
 region has the richest floral, breeding bird, mammal, and amphibian communities of any upland eastern
 U.S. forest type (Hinkle el al. 1989).  More than 60% of the breeding birds are neotropical migrants.
 The  mature mixed mesophytic forest  contains many old-growth  areas and  unique habitats such  as
 subalpine, montane grasslands, serpentine areas, shale barrens, mountain peatlands (supporting unusual
 plants  and  animals:  larch, wild calla, cotton grass and  northern  water  shrew), vernal  ponds (rare
 amphibians and  invertebrates), sandstone ridgecrests (rare plants), and caves (globally  rare aquatic
 amphipods) (The Nature Conservancy,  Maryland Chapter 1991.)

        The forests of the Ozark region (encompassing southern Missouri and northern Arkansas) were
 once vast tracts of white oaks and  sbortleaf pines, but today they exist as a mosaic of relatively young
 vegetation in various stages of succession (Smith and Petit 1988). At the turn of the century, the region
 experienced perhaps the most extensive destruction of forest through clearcutting on the continent. This
 resulted in the loss of many bird species dependent on mature forest and the increase of species adapted
 to open environments.  Of the forest birds that have survived the transformation to a mosaic of young
 forest,  the broad-winged hawk and hooded warbler are at risk from increased habitat fragmentation and
 conversion of hardwood forest to pine plantations.

 grasslands. Barrens, and Scrub Habitats

        In addition to mature forests, terrestrial habitats of significance in Maryland and other mid-
 Atlantic states are shale barrens, barrier islands, serpentine areas (rock outcrops), peat lands, floodplains,
.and sandstone glades.  Serpentine  sites represent the kind of unusual  local environments that produce
 unique habitats throughout the region.  A relatively high percentage of vascular species on  state natural
 heritage program lists and on the candidate lists of threatened and endangered species of the United States
 are serpentine endemics.  Currently, more than 400 communities are listed in the Maryland Natural
 Heritage Program database with another 200 species having been extirpated (Janet McKegg,  Maryland
 Natural Heritage Program, personal communication). Many other important communities are aquatic or
 riparian (e.g., the Delmarva bays),  but  are often better protected by federal and  state  wetlands
 regulations.  The New  Jersey Pine Barrens is another region with many important local habitats. This
 pinelands ecosystem  comprises  a mosaic of upland, aquatic, and wetland environments covering more
 than 400,000 ha (McKenzie  1981).

        Sandpine scrub is one of the nation's most threatened habitats; it is found only on scattered knolls
of coastal and inland Florida and adjoining Alabama and Georgia (Bass 1988).  It has been reduced to
•one-fifth of its original acreage by expanding agriculture and industry. Along with mahogany hammock,
xandpine scrub is also the least recoverable of habitats in Florida.  It has  perhaps the highest concentration
 of endemic plants (including many  that are endangered or threatened) of any place in the United States.
 Development is the principal threat, and landowners are bulldozing areas to prevent federal protection
 of undisturbed scrub. The scrub is already vulnerable because the natural burn cycle of the scrub has
 Habitat Evaluation                              51                                      Southeast

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been disrupted by fire suppression practices. This vegetation type requires burn cycles of 30 to 80 yean
to allow dominants to reproduce but at the tame time to prevent canopy closure.

        Savannas and  bogs  of the southeastern coastal  plains are  also  habitats  sensitive to fire
management.  Without fire they are invaded by fire-intolerant trees. These ecosystems are home to many
endemics, such as carnivorous plants.  Approximately 97% of southeastern savannas and bogs no longer
exist, having been converted to pine plantations or pastures through drainage or to farm ponds in hillside
bogs.

        The only substantial rangelands in the Southeast (4 million ac or  13* of the total area) are the
wet prairies and marshes along Atlantic and Gulf coasts that include the Everglades and palmettos prairie
of southern Florida.  Louisiana and Texas also possess significant portions of this ecosystem; unique
species include the golden-cheeked warbler, Texas red wolf, Attwater's prairie chicken, Florida panther,
Florida great white heron, Everglades kite, plus the more  common collared peccary,  coatimundi, and
pronghorn antelope. Species of concern include subtropical natives suffering population declines due to
the loss of habitat and invasion by exotic species. The region also contains many freshwater and marine
habitats, and is unique in the number and diversity of its wetland habitats.

Wetlands

        Specific southeastern wetland problem areas identified by Tiner (1984) include the following:

               Estuarine wetlands of the U.S. Coastal Zone.
               Louisiana's coastal marshes.
               Chesapeake Bay's submergent aquatic beds.
               South Florida's palustrine wetlands.
               Forested wetlands of the Lower Mississippi Alluvial Plain.
               North Carolina's pocosins.

        In the Southeast, 86% of the forested wetlands are in the coastal plain (Tansey and Cost 1990).
In the  last 10 years, 16% of the area has been converted to nonwetlands  through changes in  species or
hydrology, including harvesting. Large losses of forested wetlands in the Lower Mississippi Valley have
occurred with the conversion of bottomland hardwood forests to cropland.  Of the 11.8  million ac of
bottomland hardwood forest in 1937,  only 5.2 million ac remain, including 60% in seasonally flooded
basins  or flats and 40%  in wooded and shrub swamps.  These decreases in acreage  were matched  by
increases in croplands,  principally soybeans,  and corresponded to the completion of major  Corps  of
Engineers flood control projects and  smaller watershed projects.   Indirect effects of these projects
(clearing by landowners in anticipation of flood protection) exceeded  losses  to direct construction. The
rate of loss continues to increase in Louisiana.

        Shrub wetland losses are greatest in North  Carolina owing to the conversion of pocosins to
cropland and pine plantations and their mining for peat.  The drainage of inland marshes is greatest for
the Florida Everglades.  Indeed, die modifications to the water drainage patterns  beginning in  the
headwaters of Kissimmee basin through  Lake Okeechobee to the Everglades are some of  the most
extensive in the country. Additional losses of mucky bottomlands, marshes, and dunes across the coastal
plain have decreased duck populations, flood control, and water supply.  More than 50% of Texas
wetlands (including bottomland hardwoods and coastal marshes) have been lost (Loftis 1991). In the Gulf
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 Prairies and Marshes  region, much of cordgrass marshes are drained and barrier islands overgrazed
 resulting in severe soil erosion.
 Auatic
        Approximately 24 million ac of water area are contained in the lower Mississippi River and
tributaries, the lakes and waterways of the Mississippi Delta, the large number of small and large lakes
In Florida, the numerous large water impoundments, the small ponds and streams, and the Atlantic and
Gulf coastal waters (one-fifth of mis area) of the Southeastern Forests and Croplands. The many unique
aquatic habitats make this region the most diverse in the nation.

        The marine systems in the Southeast are exceptional and include the unique coral reefs of Florida.
A 5-year study on the  Florida  Keys coral reef by  University of Georgia and Florida  Institute of
Oceanography indicates a 10% per year decline in some parts of the reef and predicts possibly irreversible
endangerment in the next decade (Keating 1991).  Threats include pollution (especially nutrients from
sewage and agriculture that stimulate algae overgrowing), sedimentation (from erosion via forest and
shoreline conversion that smothers corals), diseases (possibly aggravated by water quality stresses), and
weather (including global warming).

Activities and Impacts Affecting Habitats

        The  major sources  impacting  habitats in die Southeastern  Forests and Croplands include
residential,  industrial, and  commercial developments, logging  and  silviculture practices,  agricultural
activities, mining  practices, and  interstate highway or expressway construction.  These activities have
produced adverse  impacts on species populations and their behavior, as well as on ecosystem processes
such as energy flow and nutrient cycling.  They have also contributed to the proliferation of nuisance
plants and  animals.  In its comparative risk analysis for the mid-Atlantic states, EPA Region 3 (1988)
ranked adverse effects  on ecosystems as high from silviculture, coal mining, and conversion to urban uses
through  residential  construction;  as  moderate from agriculture, mineral mining,  second homes
development, dam construction, and recreation; and as low from oil and gas development, bridge
construction,  and  water use.  In  the more southern states, timber harvesting and agriculture have even
greater impacts on habitats.  In the Gulf Coast States, oil and gas production is a major activity degrading
coastal environments.
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        The following activities result in die major impacts on habitats of concern in the Southeast Forests
and Croplands.
IMPACTS ON HABITATS OF CONCERN IN THE SOUTHEASTERN FORESTS AND CROPLANDS

Bottomland
hardwoods
Scrub habitat
Spruce-fir forest
Old-growth pine
forest
Everglades and
wetlands
Maritime habitats
Contiguous forest
Appalachian and
Ozark forests
Und
Conversion
Conversion to
agriculture
Conversion and
fragmentation for
residential
development
Conversion for resort
development
Moderate
Urban and
agricultural
conversion
Conversion for
coastal development
Fragmentation from
urban sprawl and
highway development
Conversion to
plantation silviculture
Timber
Harvesting
Moderate
None
Moderate
Conversion to
short rotation
plantations
Minor
Minor
Fragmentation
Major
Mining
None
None
None
None
Peat mining of
pocosin
wetlands
None
Fragmentation
Major impacts
of coal mining
Water
]L
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amphibians (Crowder  1974).   Conversion of bottomland hardwoods to agriculture continues to be a
significant cause of habitat loss that has detrimental effects on the waterfowl of the Mississippi Flyway.
 Agricultural and Grazing

        The use  of agricultural land  in the Southeast poses  additional  stresses to habitats through
 cultivation practices (NRC 1982).  The use of fertilizers and pesticides, irrigation and drainage, double
 cropping, and  increased field size all contribute to increased  pollutant loads  and severe impacts on
 habitats.  Agricultural chemicals are toxic to many species and  can negatively affect population levels,
 community composition, and ecosystem dynamics. Other intensive cultivation practices directly reduce
 important hedgerow and riparian habitat and usually produce severe offsite impacts. Grazing has a lesser
impact on the region as a whole but is increasing in the south Florida prairies and oak hammocks west
of the Everglades.

 Timber
        Timber harvesting activities are another major cause of habitat loss in the Southeastern Forests
and Croplands, affecting many sensitive forest types. For example, the southeastern mixed forest and
the Ozark forests are being converted to pine  monocultures.  Logging also  continues in the southern
Appalachian subalpine forest and some bottomland hardwood forests. These  impacts affect 90% of the
total bird,  amphibian, and  fish species and 80%  of mammal  and reptile species  that utilize forest
ecosystems (U.S. Forest Service 1989).

        In addition to the direct destruction of forests through land conversion, timber harvesting activities
can fragment, simplify, and degrade forest habitats.  The fauna! communities inhabiting forests vary with
the successional, or serai,  stage. Because the principal impact of timbering practices is to convert forest
stands from latter to earlier serai stages, logging has a major impact on resident animal as well as plant
species.  Timber harvesting telescopes plant succession,  shortens rotations, compresses serai stages, and
decreases the proportion of old  growth. The conversion of hardwoods to conifers creates structurally
simplified plantations that  reduce structural diversity and wildlife. This has produced a trend away from
declining habitat types and toward common habitat types. Management for monotypic even-aged stands
causes increases in forest pest damage that  can result  in  large-scale  spraying and the accompanying
impacts. Logging activities  also impact nearby  aquatic systems through erosion and sediment transport.

        Logging in the national forests of Texas relied exclusively on clearcutting and its variations until
1988.  The general practice  was to convert the  natural complex forest systems (tall pines with oak,  ash,
and hickory underneath in diverse groves of 100 broadleaf tree and shrub species) into single-species
loblolly pine plantations.  Site preparation (including the clearing of all  vegetation, concomitant removal
of topsoil, application of herbicides, and burning) was conducted to eliminate competition with planted
species.  This homogenization threatened the  long-term health and productivity of the forest by reducing
the quality of the gene pool.  Because of the susceptibility of monocultures to insect infestation, additional
clearcutting was conducted to provide buffer areas around the pine plantations. Between 1978 and 1988,
the number of colonies of the endangered red-cockaded woodpecker fell from 455 to 174.  Recent court
decisions and enlightened foresters are  moving away from clearcutting and instituting selective timber
harvesting in national forests containing the red-cockaded woodpecker: Texas,  Louisiana, Alabama,
Mississippi, South Carolina, North Carolina, and Kentucky (Larmer 1989).
Habitat Evaluation                             55                                      Southeast

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        Unlike the Pacific Northwest, little research has been conducted on mature eastern hardwood
forest (virtually no old growth remains).  However, results do show correlations between older forest and
the abundance of several species,  including great horned and barred owls, plicated ind red-cockaded
woodpeckers, and common ravens. Declines in other species have been attributed to brood parasitism
(by brown-headed cowbirds) and nest predation (by common crows, striped  skunks, opossums, black
racers,  and rat snakes) that occurs along clear-cut edges and in thinned stands.  These edge effects are
a prominent impact of forest fragmentation. Fragmentation is second only to the decrease in old-growtk
species as a major impact of timber harvesting activities. The fauna! significance of this fragmentation
includes discrimination against large-bodied species (e.g., Florida panther, red wolves, mink), genetic
swamping by invading species, inbreeding through isolation of populations, and ecological release of
middle-sized omnivores.

        In addition,  (here has been the general decline  in neotropical migrants mat breed in eastern
hardwood forests.  Although the situation is complicated by losses of wintering habitats for long-distance
migrants in Latin America, results indicate that species still present in large blocks of forest are absent
from  small patches (Robbins et al. 1989).  Fragmentation of forest habitat from timber harvesting and
from  land conversions, especially for transportation, appears to be the major cause of these declines
(Terborgh 1989) and has been especially severe in southeastern bottomland forests.

Mining

        The greatest single threat to terrestrial  habitat in West Virginia and Kentucky is coal  mining,
projected to increase from 2.4 million ac to 3.4 million ac (4%  of total land area) by  the year 2000
(McComb et al. 1991).  The profitability of timber harvesting will be increased by the transportation
infrastructure built for coal mining and the tact that large acreages have reached sawtimber age.  This
transition sets the stage  for  an unprecedented combination of  cumulative impacts in the central
Appalachians in the next 20 to 30 years.  Surface mining will be conducted on ridge tops and side slopes;
development of single-family housing will occur  in valley bottoms;  and mature hardwood  will be
harvested in midslopes and coves.  In addition to the direct destruction of forests, the potential for severe
soil erosion and offsite impacts is great.

        Oil and gas extraction is important on the Gulf coast but rare in other parts of mis region.  Gold
mining  is currently causing habitat degradation in South Carolina.

Water Management

        Historically, water management activities such as damming and diversion of rivers have bad a
major impact on the habitats of the Tennessee Valley, the Mississippi River floodplain, and other regions
of the Southeast.  For example, man's efforts to control the Mississippi River's flooding regime, enhance
its  navigation, and  extract its  minerals have led to  a rapid deterioration of  Louisiana's coastal
environment, Wetland loss in Louisiana is more than 400,000 ac since 1900; only 45%  of the original
forested wetlands in  Louisiana remain. The primary causal factor in this loss is subsidence of wetlands
that are receiving inadequate amounts of sediment from the Mississippi.  An accretion deficit results when
levee systems and control structures transport sediments to deep Gulf waters.

        In  the Mississippi Basin  (mid-south  Alabama,  Tennessee, eastern  Texas, and  Oklahoma),
considerable acreages of bottomland hardwoods were lost to reservoir development between 1962 and


Habitat Evaluation                              56                                     Southeast

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 1985 (Gosselink and Lee 1987).  Dam construction in general changes water flow patterns, causes
 flooding, and changes salinity patterns; this kills tree seedlings  and can convert forest to salt marsh.
 Water diversion, another activity degrading southeastern habitats, is severely impacting the Everglades.
 This diversion stems from the competition for water by agriculture and urban expansion.

 Military Activities

        The large number of military training areas located in the southeastern coastal plain results in
significant impacts on old-growth pine forest. Both a reduction in vegetative ground cover and changes
 in species composition can result from routine operations and military training activities.  Concerns for
 the impacts of tracked vehicle  activity and artillery and aircraft noise on the red-cockaded woodpecker
 recently prompted a Department of Defense conference on the management of this endangered species
 (Doug Ripley, personal communication).

 Mitigations of Impacts

        The conservation of habitats requires  consideration of mitigations for the major  activities
 impacting habitats of concern.  In the Southeastern Forests and Croplands, the primary habitat impacts
 are caused by the following:

        •      Timber harvesting of old-growth or mature forests.
        •      Land conversion of scrub,  coastal, and wetland habitats.
        •      Fragmentation of contiguous forest.
        •      Mining and acidification of Appalachian forest.

Timber Harvesting

        At a minimum, the production of commercial wood products from an area must not exceed the
sustainable level if the ecological integrity of a forested area is to  be maintained.  Where sensitive forest
types exist, logging may be completely prohibited or constrained to specific methods to prevent habitat
loss or degradation. In other areas, more extreme harvesting methods may be allowed or prescribed to
establish or maintain desired forest conditions.  Acceptable methods will vary according to local forest
ecology and the desired  future condition of the  site.  Analysis of harvesting techniques must be based
upon an analysis of the structure and  diversity of the forest canopy, midstory, and understory.

        A recent directive of the Chief of the U.S. Forest Service acknowledges mis fact and points out
that clear cutting  is acceptable only when needed to replicate natural ecological processes.   Selective
cutting can preserve forest structural diversity, the primary determinant of wildlife habitat (Harris et al.
 1979).  However, h can reduce horizontal diversity (NRC 1982).  The harvesting technique employed
must be based upon sound silvicultural prescriptions and demonstrate its capability to maintain vertical
diversity  (foliage height  diversity), horizontal diversity (interspersion, edge, juxtaposition, patchiness),
and  a mixture of live and dead wood.  Specific timber harvesting  operations should be designed to
preserve the structure and diversity of the natural forest habitat.

        An  important component of selective cutting should be the preservation of standing dead trees.
 Many species  of birds nest, roost, or forage for invertebrates in standing trees with decayed wood. These
cull trees are usually the first focus of forest thinning operations to the detriment of the birds. Breeding
Habitat Evaluation                              57                                      Southeast

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bird abundance declines rapidly following a clear cut, and the species composition continues to change
for 10 to 15 years (DeGraaf 1991). However, if trees with cavities are saved, many of these species can
successfully forage on sound boles.  About one large cavity or den tree per 2 ha  is required  for
populations of large species such as wood ducks; this  requires harvest rotations of 100 to  125 years
(although rotations of 65 years produce trees large enough for smaller cavity species).

       Timber harvesting practices modified to reduce the impacts of simplificatiqn  must also address
fragmentation.  As an example, fragmentation has been  especially severe in southeastern bottomland
forests (Gosselink and Lee 1987). In this case, the setting aside of undisturbed tracts  will not suffice to
achieve viable populations of the larger, wider-ranging  species.  Not only do some  species require
specific habitat conditions (such as forest-interior species like Bachman's warbler), but others require
particular arrangements of several communities.  Therefore, a successful fauna! conservation strategy
must emphasize the landscape configuration, not just the structural content of the communities themselves.

       Responding to the "biodiversity crisis," the U.S. Forest Service is moving toward an  ecosystem
approach to forest management (Bob Szaro, personal communication).  Recent forest management plans
have incorporated tenets of the "New Forestry" espoused by Jerry Franklin. These  progressive plans
require the rigorous implementation of ecological management practices to maintain forest productivity
and preserve the functioning of sensitive forest components such as old-growth or late-successional
forests.  Effective mitigations for habitat conservation in  forest management require specific management
measures at the site, watershed, and landscape levels.  For example, the location and size of timber
harvests  should  be planned  to minimize reduction of core area  of mature forest (e.g., harvest only
alternate basins  until regrowth).  Maintenance of mature-forest stands in managed  landscape  can be
achieved by extending rotation (beyond 80) to 150 to 200 years, by leaving some stands unharvested for
old growth, and by linking stands. Landscape-scale considerations  include the provision of buffer zones
and  habitat corridors  as  discussed  in the  introduction  of this document.  Management measures
recommended for conserving habitat within managed forests include the following:

       •       Minimize the construction of new roads  and close roads not in use either permanently or
               seasonally.

       •       Use best management practices (BMPs) such as filter strips to minimi^ erosion during
               harvesting or road construction.

       •       Maintain 100-ft riparian zones with adjacent feathered transition zones  to buffer edge
               effects.

       •       Restrict harvesting operations to periods when the ground is either dry or frozen.

       •      Maintain site productivity by  retaining large woody material and minimizing mineral  soil
               exposure and compaction during harvesting.

       •       Manage for natural disturbance patterns to maintain natural openings and successional-
               stage composition.

       •      Maintain connections between blocks of interior forest, especially old growth.
Habitat Evaluation                              58                                     Southeast

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        •       Provide for the protection of special areas, including cliffs, caves, taluses, riparian areas,
                and old-growth stands.

        •       Maintain the structural integrity and the native variety of the forest by managing for the
                natural composition of the following components: vegetative types, serai  stages, tree
                types and sizes, standing dead trees  and down material, tree snags, and cavity trees.

 Land Conversion

        Effective mitigation of land conversion activities can sometimes be obtained only by avoiding
 impacts on rare or unusual habitat types.  Rarely, if ever, is restoration or compensation an adequate
 mitigation for the loss of these habitats. In these cases, mitigation is a siting issue, where construction
 and degrading activities are located at a distance from the habitats of concern. The habitat is adequately
 preserved if all possible impact scenarios are accounted for. Barring mis solution, effective management
 measures must be implemented to ensure the  protection of the habitats of concern.

        In the case of unique scrub habitats or coastal systems, hydrological and contamination concerns
 are especially important.  Construction or resource management activities  require the use  of sediment
 filter strips  and other means of intercepting offsite contaminants.   Road building and structural
 "improvements" must not result in altered hydrological regimes. Where rare plant types exist or where
 habitats are unstable (e.g., bogs and sand dunes), recreational access associated with nearby development
 may have to be limited.

        Amelioration of impacts from land conversion to transportation uses requires special mitigation
 measures.  As  with all  land  conversion, the construction of highways and power-line corridors is
 primarily a siting issue.  Avoidance of sensitive habitats may be accomplished by modifications to the
 route design,  and the extent of disturbance can be limited by careful  construction practices.   However,
 fragmentation of the larger area is unavoidable in the case of land conversion to transportation corridors.
 Many  structural mitigation strategies can be used  to lessen the impact on animal movement  across
 transportation routes.  Primarily, these include the construction offences and underpasses.  The goal of
4hese structural measures  should be to mimic the natural movement and migration patterns of the affected
 species.

 Mining

        Mitigation  of  mining  impacts involves siting  issues, technological  solutions to eliminate
 contamination, and restoration programs. The major mitigations for oil and gas extraction and production
 are the proper sitings of rigs, reserve pits, processing facilities, and roads where they will have minimal
 impacts on habitats of concern. Most important for  coal and  mineral mining is the siting .of mining
 operations and tailing ponds to avoid habitats of concern, wetlands, riparian areas, and recharge areas.
 Specific mitigation measures depend on the type of mining and the specific process causing impacts. It
 is generally best to minimize the area affected as it is unlikely that even the disrupted soils and sediments
 can  be restored.   In addition to minimizing the area disturbed,  activities should be timed to  avoid
 disturbing nearby plants and  animals during crucial periods of their life cycle.  Possible mitigation
 measures for  mining operations include the following (SA1C 1991a, 1991b):
 Habitat Evaluation                              59                                       Southeast

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        •      Design of mine entrances and workings to minimi** future mine drainage.

        •      Ruuon and runoff control measures such as berms and ditches.

        •      Adequate depth and lining of pits for containment of muds and leacbate.

        •      Elimination of fluid migration through casings and dewatering.

        •      Separation of wastes and contaminated soils with proper disposal.

        •      Treatment of leach heaps and neutral or acidic wastewaters to reduce the load of cyanide,
               nitrates, and heavy metals.

        •      Closure  planning that addresses hydrology,  geochemical  controls, treatment,  and
               restoration.

        •      Nets or other covers over process ponds.

        •      Maintenance of an anaerobic environment in the tailing pile during periods of inactivity.

        •      Secondary  containment of  tanks  and contingency plans for sudden or catastrophic
               releases.

        •      Backfilling and sealing of the mine workings during mine reclamation/closure.

        •      Recycling of process water, smelter slag,  and air pollution control dust.

        •      Monitoring and elimination of discharges to surface water, groundwater, soils, and air.

        •      Replenishment of surface and ground waters with treated effluents.

        •      Road closure and reclamation  (following recontouring) with revegetation of  native
               species.

Although the reclamation  of mined  lands  is often unsatisfactory for ecological habitat restoration,
reforestation with native trees has been demonstrated (Plass  1973)  and would serve to reduce the
abundance of nest parasitic brown-headed cowbirds and restrict their access to mature forest.


Military Activities

        Mitigation of the impacts of military activities on habitats has only recently received attention.
The Army Corps of Engineers' Construction Engineering Research Laboratory in Champaign,  IL, is
developing a Land Condition-Trend Analysis (LCTA) Program (Diersing et al. 1992) as a comprehensive
means of matching military training mission objectives with effective natural resource management.  If
such a plan is instituted, h is likely that careful coordination of the siting and timing of training operations
will dramatically reduce habitat  impacts.  An  awareness of the ecological consequences of specific


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•divides is essential to effective mitigation.  The following general mitigation measures apply to the
primary impacts of military activity:

       •       Timing  and siting of operations - The noise and disturbance associated with aircraft
               flights   and large  troop  maneuvers cannot  be  eliminated.    However,  sensitive
               environments can be avoided and operations can be timed to avoid critical nesting and
               migratory periods.

       •       Calculation of allowable use  for tracked vehicles - Tracked vehicle movements are a
               major cause  of habitat degradation.   Vegetation  destruction and  soil erosion and
               compaction are the primary impacts. Precise equations can be developed that estimate
               sustained tracked vehicle use based on physical properties of the environment, vegetative
               cover, and  changes in vegetative cover caused by the passage of tracked vehicles. For
               example, tracked vehicle use should be restricted to all-weather roads when possible.

       •       Fire  suppression  during artillery practice  - Fires created by artillery pose a major
               problem in  certain environments. Rapid identification and suppression by helicopter can
               virtually eliminate the spread  of large-scale fires.

Guidelines for Reviewers

       Reviewers of environmental impact assessments will find this document useful if they follow the
steps laid out in the introduction:

       1.      Review  the status and trends of habitats in the region.

       2.      Identify the habitats of concern.

       3.      Link the activities involved with impacts to these habitats of concern.

       4.      Devise appropriate mitigations for the impacts.

Each reviewer can then  determine the adequacy of the environmental impact assessment in question and
recommend modifications to enhance its effectiveness.

       In identifying the habitats of concern, the reviewer should supplement the information in this
document with detailed  locational information on the abundance and distribution of habitats within the
region of interest, and with any historical information on the extent and quality of these habitats. Most
important, the reviewer should characterize the habitats in terms of their ecological values (e.g., use of
wooded wetlands by migratory waterfowl).

       In considering the links between activities and habitats, the reviewer should look beyond direct
impacts to indirect and subtle effects, including cumulative impacts, interactive and synergistic impacts,
and  scale-dependent impacts (e.g., effects of fragmentation on ecosystem integrity and species home
ranges).
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        In devising possible mitigations, the reviewer should follow the seven principles for habitat
mitigation repeated below.  The reviewer should also determine whether adequate assurances have been
given that the mitigations proposed will "be completed.

        1.      Base mitigation goals and objectives on a landscape-scale analysis mat considers the needs
               of the region.

        2.      Mimic natural processes and promote native species.

        3.      Protect rare and ecologically important species and communities.

        4.      Minimize fragmentation of habitat and promote connectivity of natural areas.

        5.      Maintain structural  diversity of habitats and,  where appropriate, species diversity to
               promote the natural  variety of the area.

        6.      Tailor management  to she-specific environmental conditions and to the unique impacts
               of the specific degrading activity.

        7.      Monitor for habitat impacts and revise mitigation plans as necessary.

        Finally, the reviewer should consider the proposed activities and mitigations in the context of
relevant regional  program  goals and objectives (e.g.,  whether the outcome of the project will be in
accordance with principles  set out by  regional planning commissions such as those established for the
Chesapeake Bay and the Gulf of Mexico).

Contacts and Information Sources

        When considering habitat conservation issues in an environmental  impact assessment for the
Southeastern  Forests and  Croplands,  the  reviewer should consult  the  following  organizations and
individuals for information  on habitat impacts and mitigations:

        State  Natural Heritage Programs
        U.S.  Fish and Wildlife Service,  Regional and Area Offices
        State  Fish and Game Departments
        University and Research Programs
        Herbaria and Museums

        Dorothy Allard, Regional Ecologist, The Nature Conservancy
        W.T. Olds, Associate Regional Director, Fish and Wildlife Enhancement, U.S. Fish and Wildlife
        Service
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              Great Plains Habitat Region: Great Plains and Prairies
Geographical Description of the Region

       The Great Plains Habitat Region, Great Plains and Prairies, contains pans of 10 states.  The
region includes parts of North Dakota, South Dakota, Montana, Wyoming, Colorado, Nebraska, Kansas,
Oklahoma, New Mexico, and Texas. Parts of EPA Regions 6,7, and 8 are included. The accompanying
map indicates the boundaries of this habitat region and the states it comprises.

       The Great Plains and Prairies comprises 14 ecoregions (Omernik 1987). The vegetation of the
region includes a range of grama, needlegrass, wheatgrass, Nebraska sand hills prairie, bluestem, buffalo
grass, indiangrass, bluestem prairie (bluestem, panic, indiangrass), cross timbers (oak, bluestem), mosaic
{bluestem, oak,  hickory), Blacldand prairies of wheatgrass,  fescue, sandsage, juniper, oak savanna,
mesquite acacia, and savanna bristlegrass.  The land use patterns comprise croplands, croplands  with
grazing lands, cropland  with pastures, subhumid grasslands, and semi-arid grazing lands, irrigated
agriculture, woodlands, forests, and open woodlands grazed.
Habitat Evaluation
63
                                     Great Plains

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Habitats of Concern
       The Great Plains and Prairies contains many habitats of concern, of which the most obvious fall
into four general categories: riparian habitats, prairies, brushland, and wetlands. The principal habitats
of concern most at risk in the Great Plains and Prairies are listed below.
                          PRINCIPAL HABITATS OF CONCERN
                          IN THE GREAT PLAINS AND PRAIRIES
I . Riparian habitats
  •    hardwood draws

2. Prairies
  •    'tallgrass prairie
                                             n
                *    short and midgrass prairie (North Dakota, South Dakota,
                     Colorado, Nebraska, Kansas)
                •    Texas blackland prairie and other types

             3. South Texas bnishlands

             4. Wetlands
                •    prairie potholes (Montana, North Dakota, South Dakota)
Habitat Values and Trends

       The term "rangeland"  describes the lands with climate or soil conditions unsuitable for tree
growth. Rangeland comprises nearly a billion ac (34% of land area) in the United States, including some
of the world's most productive rangeland (Box 1989).

Grasslands

       The Great Plains and Prairies contain 78 million ac of rangeland (USDA Forest Service  1989),
including both the true prairie (tallgrass) and plains grassland (shortgrass). Tallgrass prairie is dominated
by bluestem grasses and includes prairie potholes important for waterfowl breeding. Most of the original
tallgrass prairie was plowed under,  and the remaining areas were invaded by trees following fire
suppression.  The largest existing area of tallgrass prairie (1.5 million ha) covers the Flints Hills of
Kansas and the Osage Hill of Oklahoma. Plains grassland is dominated by short warm-season grasses
of blue grama and buffalo grass and supports pronghorn, mule deer, white-tailed deer, jackrabbit, prairie
dog, greater prairie chicken, and sharptailed grouse.  The decline of the long-billed curlew is associated
with the decrease in this habitat.

       About 84% of mammal  species and  74% of avian species  are associated with  rangeland
ecosystems during at least part of the year.  Thirty-eight percent of the nation's fish species and 58 % of
the amphibians are represented in the relatively arid rangeland ecosystems (Flather and Hoekstra 1979).
Habitat Evaluation
                                 64
                                                                     Great Plains

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Based on 1984 maps, the average number of endangered and threatened species per county is 3.3 for the
Great Plains and Prairies.  Perhaps the most important habitat for animals in the Great Plains and
Prairies are riparian areas where the juxtaposition of terrestrial and wetland or aquatic systems enhances
the value of the habitat.

        By the beginning of the 20th century, the American range was generally overgrazed and depleted.
Severe droughts also contributed to the deterioration of rangeland.  Although the total area of rangeland
has remained relatively constant,  the condition of the range ecosystems has varied considerably with
competition by livestock for forage and other factors.  Cattle, sheep, and wild  horses and burros have
contributed to reduced forage  and  to changes in vegetation composition  on the majority  of U.S.
rangelands.  Many native prairie types have been  lost to overgrazing or agricultural conversion.   The
loss of grassland habitat has been responsible for declines in many bird populations.  The mixed prairie
or shortgrass prairie is  subject to drought, grasshoppers  and jackrabbit attacks, and  cacti invasion.
However, native sbortgrasses are outstanding in their resistance to grazing (perhaps developed in response
to grazing by bison) and have shown remarkable improvement in certain areas. An increase in rangeland
area in the Great Plains of 11 million ac is predicted for  the next 50 years as a result of the natural
succession of agricultural land in the Conservation Reserve Program  (Joyce 1989). Rangeland in Texas
and Oklahoma will likely increase by 14 million ac or 11% during mis period.

Texas Habitats

        Within the Great Plains  and Prairies, Texas contains a greater variety of habitats than any other
state.  However, virtually all of the blackland and tallgrass prairie, coastal bottomlands, and low hills in
Texas have been converted to farms, cities, and suburbs (Loftis 1991). Less man 1 % of blackland prairie
remains  in north-central  Texas.  In the Lower Rio Grande Valley, mere remains less than 1%  of the
native scrubby, hot delta mat once was nearly as rich in wildlife as the Everglades. In particular, duck
populations have declined, bird variety in the valley has decreased, and  the ancient gene  pools  of
blackland prairie  plants are being lost.   Brushlands in  south Texas still support endangered  cats
(jaguarundi and ocelot) and numerous subtropical bird species. Past brush clearing activities have greatly
impacted this habitat, although the U.S. Fish and Wildlife Service is currently preserving and restoring
brush habitat in the Lower Rio Grand Valley.

        Within Texas the greatest loss of natural vegetation has occurred in the state's High Plains and
Blackland Prairies regions. The following describes the status of the natural regions of Texas within the
Great Plains and Prairies (Loftis 1991):

        •      High  Plains - Lost the buffalo and pronghorn with conversion to cattle and crops.
               Damming of rivers has eliminated the willow and cottonwood and replaced them with the
               Old World exotics, salt cedar, and Russian olive.

        •      Rolling Plains - Low bills and broad  flats with  headwaters of major rivers.  Native
               grasses have been cleared and replaced with mesquite, snakeweed,  and prickly pear.

        •      Edwards Plateau - Limestone hills, springs, and  rivers support endangered wildlife;
               ranches and big  cities compete with wildlife for ground water.
Habitat Evaluation                              65                                    Gteal

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        •      Cross-Timbers and Prairies - Strips of prairie crossed by oak forests have been changed
               by farming and urban development.

        •      Blackland Prairies - Originally 12 million ac, the tallgrasses, big bluestem, Indiangrass,
               little bluestem and gammagrass are near extinction at 5,000 ac.

        •      Post Oak Savannah - Nearly all of original grasslands have been plowed under or invaded
               by thickets.

        •      Rio Grande Plain - Open grasslands have been converted to thorn forest by overgrazing,
               and less than 1 % of the natural habitat remains.

Riparian Areas

        Riparian areas in the Great Plains and Prairies constitute perhaps the region's most important
habitat type.  Although they represent only 2% to 4% of the land area in the United States, they make
up 80% of the wildlife habitat. It has been demonstrated that most endangered  species require riparian
areas (Johnson  1989).  Many neotropical migrants also rely on western riparian areas as critical nesting
sites. The value of riparian habitat extends at least 0.25 miles into adjacent areas and can support a
density  of pairs of breeding birds up to  1,000 per  100 ac (Carotbers and Johnson 1975).

        Riparian  areas provide  habitat for more species of birds man  all other western rangeland
vegetation types combined (Chancy et al. 1990). Although riparian areas cover less than 1 % of the West,
they also serve important ecosystem functions (Gillis 1991).  They keep watersheds healthy by storing
and releasing water from spring runoff of snowmelt and summer storms, and by providing watering holes'
for wildlife as well as cattle.  They filter sediment and aid floodplain development, improve floodwater
retention and groundwater recharge, develop plant root masses that stabilize streambanks, develop channel
characteristics that provide appropriate habitat for fish, and support greater biodiversity.

        The linear nature of riparian areas contributes to their value (Gregory et al. 1991). River valleys
connect montane headwaters with lowland habitats, and provide for the transfer of water, nutrients,
sediment, paniculate organic matter, and organisms. Riparian areas transfer these materials laterally onto
floodplains and create complex mosaics of landforms and heterogeneous ecosystems.  Wildlife utilize
riparian areas for food, cover, nesting,  and rearing of young. Riparian habitats are frequently used by
wildlife as  migration routes  (Thomas et al. 1978). The greater heterogeneity of vegetation in unaltered
riparian habitat increases the available ecological niches and increases the number of species that can be
supported.

        Johnson (1978) estimates that only 10% of the original riparian habitat in United States remains,
and that 6%  is lost annually.  In the Great Plains, less than 1% of land is riparian vegetation (Crouch
1978).   Major  losses resulted  from  drainage for conversion to agriculture; other causes include
channelization for navigation and flood  control, flooding caused by dam construction, and diversion of
streamflow for irrigation.  Alterations include grazing, timber harvesting, road construction, mining, and
other impacts.
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Wetlands

        Specific national wetland problem areas identified by Tiner (1984) in the Great Plains and
Prairies include the following:

        •      The emergent wetlands of the Prairie Pothole Region.

        •      Wetlands of the Nebraska Sandhills and Rainwater Basin.

        The drainage of inland marshes for range and agriculture has been the greatest in the prairies of
-the Dakotas and Minnesota, the sandhills of Nebraska, and the Florida Everglades.  In Texas, wetlands
covering 8.4 million ac or 52% of the original extent have been lost. One-third loss of this loss (296,132
AC) has been in the playa lake complexes that are especially important for waterfowl and migratory
species.   In general, emergent wetlands have  high  priority in this region owing to their functional
importance and the constant threat of degradation.

Activities and Impacts Affecting Habitats
IMPACTS ON HABITATS OF CONCERN IN THE GREAT PLAINS AND PRAIRIES

Riparian habitats
Prairies
Brushlands
Wetlands
Land
Conversion
Residential development and
construction of pipeline and
transportation corridors
Convenion to agriculture
Conversion to urban uses
Conversion to agriculture and
urban uses
Timber
Harvesting
Minor
None
None
None
Grazing
Sever
overgrazing
and physical
habitat
degradation
Severe
overgrazing
Minor
Minor
Water
Management
Impacts of damming
and water diversions
Moderate
Minor
Major
       The Great Plains and Prairies rangeland areas are at risk principally from grazing and water
management projects.   Dam construction in the Platte River area has also been a major source of
modification to terrestrial habitat in that area. Of special concern are the remnants of the tallgrass prairie
ecosystem, which has suffered extensive conversion. The rarest of all North America's major biomes,
only 10% of the original 142 million ac of tallgrass remains. Much of the 10% represents fragments of
old railway rights-of-way, pioneer cemeteries, and various preserves.  This prairie habitat is at risk from
human encroachment and cattle grazing.

       This region is experiencing rapid population growth as part of the westward migration.  Highway
construction, in particular, has expanded and is creating substantial cumulative impacts on natural areas.
The Texas hill country is being rapidly converted to urban uses.  Riparian areas  are being degraded
Habitat Evaluation
67
                                     Great Plains

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through overgrazing, and prairie potholes are being converted to agriculture.  Although the region has
a relatively small population, urban areas such as Denver, CO, and central Texas are experiencing rapid
growth while second-home and time-share development is occurring in previously pristine areas (e.g.,
Montana, Flatbead Mountains in Wyoming, and Colorado prairie river systems).

       Grazing and water projects especially threaten riparian environments throughout the region. For
example, overgrazing and phreatopbyte control are destroying riparian vegetation. W.ater diversions have
caused major iosses of riparian and wetland habitats and are contributing to the declines of waterfowl
along the Mississippi Flyway.

      Conversion
        To date, the most fertile soils within the Great Plains and Prairies have been converted to
croplands; these same areas have historically supported the greatest abundance of wildlife (Mayer and
Laudenslayer 1988).  In addition, urban development has been a major source of rangeland conversions.
Pressure on local governments to convert open space to residential, commercial,  and industrial uses to
accommodate growth has been intense, and will continue to destroy rangeland habitats where population
growth is most pronounced.

        Conversion of rangelands to cropland will increase with  the availability of ground water for
irrigation (USDA Forest Service 1989).  In particular, sandy rangeland in Texas, Colorado, New Mexico,
and Nebraska has been converted to farmland (Sheridan 1981).  Abandonment of these farms can lead
to desertification if the ground water has been depleted. Areas of concern for desertification include
Kiowa and Crowley  Counties in Colorado.   In these semiarid lands, land conversion to  agriculture,
grazing, and water management can cause groundwater overdraft, salinization of topsoil  and water,
reduction of surface water, high soil erosion, and destruction of native vegetation.

        As with  forest habitats, the spatial pattern and fragmentation of rangeland vegetation can
negatively  affect native fauna and  ecosystem health.   The loss of grassland  habitat to agriculture is
responsible for the  decline in prairie birds, especially those requiring large continuous habitats, and is
analogous to the reduction in old-growth forests and the decline  in its obligate  species.  The upland
sandpiper,  bobolink,  dickcissel, grasshopper sparrow,  savannah sparrow, and Henslow's sparrow all
declined by 90% between the 1950s and 1970s (Graber and Graber 1983).

Agricultural Impacts

        The intensive use of agricultural land in certain areas of the Great Plains and Prairies pose
additional stresses to habitats through  cultivation and  irrigation practices (NRC 1982).  The use of
fertilizers and pesticides, irrigation and drainage, double cropping and increased field size all contribute
to increased pollutant loads and severe impacts on habitats.  Agricultural chemicals are toxic to many
species and can negatively affect population levels, community composition, and  ecosystem dynamics.
Other intensive cultivation practices directly reduce important hedgerow and riparian habitat and usually
produce severe offsite impacts.
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 Grazing

        Widespread devastation of rangeiand resulted from uncontrolled overgrazing between  1880 and
 1935, and the damage was amplified by the drought years of the 1930s (Branson 1985). The enactment
 of the Taylor Grazing Act of 1934 reduced grazing pressure at mat time. With the advancement of range
 management science and the moist years following 1960, considerable improvement occurred in range
 vegetation.  However, the USDA Forest Service (1989) reports mat 21% of its rangelands are still in
 "unsatisfactory" condition.  The Bureau of Land Management (1989) reports mat BLM rangeland
 condition is 33% good or better, 38% fair, and 13% poor.

        The management of public land grazing is shared between the land management agency and the
 grazing permittee.  Grazing permits are issued,  and allotments are inspected for use, condition, and
 compliance by  the management agency;  actual management of the livestock and maintenance  of
 improvements is the responsibility of the permittee.  Attempts to reduce grazing allotments in national
 forests to allow improvements on lands in poor or fair condition has caused resentment among graziers.
 However, federal permit fees are only one-fifth the rate for private lands.  As private grasslands continue
 to decline in acreage as a result of urban and agricultural conversion, there will be increased pressure on
 public lands.

        Grazing poses the following threats to rangeland habitats (Cooperrider 1990):

        •      Competition with ungulates and small herbivores (e.g., desert tortoise) and limits on the
               populations of free-roaming pronghorn antelope, mule deer, elk, and bighorn sheep.

        •      Transmission of disease (e.g., dramatic diebacks in bighorn sheep  with domestic sheep
               grazing).

        •      Loss of cover for birds.

        •      Spread of exotics and noxious weeds.

        •      Desertification, or serious degradation.

        •      The conversion  of lands with sagebrush and pinyon-juniper to reseeded  grassland for
               more forage.

Riparian Areas

        The most  severe impact in terms of supporting healthy ecosystems  and native faunas  on
rangelands has been the loss of 70% to 90% of riparian areas to human activities (Ohmart and Anderson
4986).  Losses  of riparian areas have caused the endangerment of habitat-dependent species and likely
will cause the extirpation of many species if the last remaining areas of individual habitat  types are lost
 (e.g., 10 species may go extinct if the cottonwcod-willow association  disappears).  Johnson  (1978)
 estimates that 6%  of riparian areas continue to be lost annually through water management activity,
 grazing, sand and gravel  extraction, and development activities.
Habitat Evaluation                             (9                                  Great Plains

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        On average, the riparian zone is only 2% of a grazing allotment, but it produces 20% of the
forage, and the cattle consume 80% of their forage from these riparian areas. Stream bottoms are natural
concentration areas for livestock seeking succulent forage, shade, reliable water supply, and favorable
microclimate.  Only when access is limited by steep slopes are livestock absent from unfenced riparian
areas.  Grazing impacts riparian areas both by removing vegetation and by trampling. By affecting the
spacing of plants, width of the riparian corridor, seedling establishment, and species composition, floristic
diversity is often lower in grazed areas.  Trampling increases soil compaction, erodes streambanks,
decreases water quality, widens and shallows channels, and physically destroys vegetation (Kauffman and
Krueger 1984).  Riparian degradation causes accelerated runoff and erosion of downcut streambeds,
lowered water tables, and desertification of the land.  It has a negative impact on wildlife habitats and
leads to declines in willows and native grasses. In addition, degraded riparian areas are more susceptible
to upland inputs as healthy riparian areas can filter out upland degradation. While  the condition of all
rangelands has improved since 1980, riparian areas are in their worst historical condition.

        Although the values and functions of riparian areas have been widely and severely impacted by
cultivation, road building, mining  urbanization, logging, and damming of rivers, grazing has caused the
most geographically extensive impacts (Chancy et al. 1990). Impacts of grazing on riparian areas include
the following:

               Little vegetation to stabilize streambank and shade stream.
               Lowered  water table and subsurface water storage.
               Reduced or absent  summer flow.
               Warm water in summer  and icing in winter.
               Poor habitat for fish and aquatics.
               Poor habitat for wildlife.
               Reduced amount and quality of forage.

Water  Management

        The regulation and  damming of  streams are often performed to control flooding and drain land,
resulting  in the impoverishment of riparian  vegetation (Szaro  1991).   Dams and water  diversion
significantly change downstream flow regimes, levels of winter floodwater, dry-season  flow rates, and
riparian-zone soil moisture. Downstream areas lose pulse-stimulated responses, while upstream areas are
affected by water  impoundment and salt accumulation.  Native riparian plants are usually unable to
colonize the shore of reservoirs because of the altered hydrologic regime. For example, high water levels
are maintained  much longer  in reservoirs than in rivers and streams; changes  in  the  level  are  more
drastic; and  the large  winter/spring floods  required for alluvial seedbeds (e.g.,  cottonwood) are
eliminated.
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Mitigations of
        The  conservation of habitats «fequires consideration of mitigations for the major activities
 impacting habitats of concern. In the Great Plains and Prairies, the primary habitat impacts are caused
 by the following:

        •      Land conversion of riparian and wetland habitats.
        •      Grazing of riparian areas.
        •      Water management impacts of diversion and damming on riparian and wetland areas.

 It is likely mat certain areas will see additional conversions to cropland or pasture, and that more open
Tanges will be fenced and thus restrict whiter grazing by native ungulates. Increased irrigation will likely
 follow higher demand for water and adversely affect water tables and stream flow on rangelands. These
 and other activities will pose a complex of interrelated  effects on habitats of concern and will require a
 holistic, ecosystem-level approach to mitigation. The effects of future management and mitigations on
 riparian areas will have the greatest impact on wildlife  and native ecosystem health (NRC 1982).

 Land Conversion

        Effective mitigation of land conversion activities can sometimes be obtained  only by avoiding
 impacts on rare or unusual habitat types. Rarely, if ever,  is restoration or compensation an adequate
 mitigation for the loss of these habitats.  In these cases, mitigation is a siting issue, where construction
 and degrading activities are  located a distance from the habitats of concern. The habitat is adequately
 preserved if all possible impact scenarios are accounted for.  Barring mis solution, effective management
 measures must be implemented to ensure the protection of the habitats of concern.

        In the case of unique riparian or wetland habitats, hydrological and contamination concerns are
 especially important.  Construction or resource management activities require the use of sediment filter
 strips and other means of intercepting offsite contaminants. Road building and structural "improvements"
must  not result in  altered hydrological regimes.   Where rare plant  types exist  or where habitats are
unstable, recreational access may have to be limited.  These mitigations can be best implemented by
creation of a regional land-use plan (through a coordinating council like the Waterfowl Flyway Council)
 and  landowner incentives (like the Conservation Reserve Program).

        Conversion to  agricultural land is a special concern in rangelands with increasing irrigation
 potential.  Land conversion  to agriculture can cause ground water overdraft, salinization of topsoil and
 water, reduction of surface water, high soil erosion, and destruction of native vegetation. Mitigations
 include more conservative irrigation techniques and  improved drainage systems.  Soil conservation
techniques vary from windbreaks  to contour plowing, stripcropping, rotation of crops, conversion  to
grass, and/or minimum tillage.

Crazing

        Future management of grazing on rangelands will determine whether range conditions worsen or
 improve from their currently degraded state (NRC 1982).  In the past, range condition has been estimated
 by (1) forage production relative to a mythical average,  and (2) production of livestock.  Recently, some
 range managers have begun to base condition estimates on deviation from an ideal range or ecological
Habitat Evaluation                              71                                   Great Plains

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climax. These and other improvements in range science provide for consideration of objectives beyond
livestock production.  For example,  the widely used model of E.J. Dyksterhuis (1949) is based on
reversible and gradual community change and is now viewed as inaccurate, as it does not incorporate
threshold community shifts (Jahn 1991).  The problem for habitat conservation is that the proportion of
rangeland climax habitats has greatly decreased,  similar to the  case with old-growth forest.  Although
mere remain disagreements over proper management methods,  it is anticipated that more effective use
of ecological analyses of range condition will improve the management of rangelands.

        Specific methods  of mitigating grazing impacts on rangelands include the following (Branson
1985):

               Proper intensity  and season of grazing.
               Practices that improve livestock distribution.
               Control of undesirable species using fire or other appropriate methods.
               Land-surface modification to retain soil moisture for forage production.
               Ecologically based management plans for each site using adequate field data.

        Proper grazing management can restore the long-term productivity of most rangelands, but
obstacles are grazing tradition, the geographical extent of problem, and the difference between short-term
costs and  long-term benefits.  Successful management requires that traditional intensive measures to
increase forage be replaced by different management practices.  For example,  rest-rotation grazing can
improve range conditions, while intensified chemical use and mechanical brush removal to improve forage
will likely further degrade range habitats.   Certainly, successful rangeland mitigation  requires time,
flexibility, commitment by graziers, and monitoring and evaluation.

        Improvements in die condition of riparian areas will provide the greatest proportional benefit to
rangeland integrity and functioning. Szaro (1991) argues strongly for an overall ecosystem approach to
research and management of riparian areas.  This  includes the use of reference sites,  a watershed
(ecosystem) scale approach, and  long time scale considerations  (greater than 5 years).  Mitigation must
consider the following factors:

        •       Riparian floristic (plant species) diversity should  take precedence over structural diversity
               (vegetation layers and patches) as descriptors of the habitat.

        •       Wildlife species  depend both on floristic composition and on the relationship of riparian
               areas to animal movement patterns and migratory pathways.

        •       The distribution  of riparian vegetative communities varies with topography and depends
               principally on elevation.

        •       Flooding  and other  natural disturbances are  important to riparian  systems.   They
               contribute to  their status  as distinct and  highly  integrated pockets  within  other
               communities.
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Successful riparian management requires unique solutions to the specific condition at each site (Chancy
et.al. 1990). However, general principles include die following:

        •      Include riparian areas in separate pastures with separate objectives and strategies.

        •      Fence or herd stock out of riparian areas to let vegetation recover.

        •      Control the timing of grazing (1) to keep the stock off streambanks  mat are most
               vulnerable to erosion, and (2) to coincide with the physiological needs of plants.

        •      Provide more rest to the grazing  cycle to increase plant vigor or to encourage more
               desirable species.

        •      Limit grazing intensity.

        •      Change from cattle to sheep to get better animal distribution through herding.

        •      Permanently exclude livestock from high-risk and poor recovery areas.

Wetlands

        Mitigation of wetlands destruction and degradation is the subject of a growing literature (Kusler
and Kentula 1989).  Restoration and mitigation banking concepts are still being evaluated as effective
mitigation measures for direct wetlands alterations.

Guidelines for Reviewers

        Reviewers of environmental impact assessments will find this document useful if they follow the
steps laid out in the introduction:

        1.      Review the status and trends of habitats in the region.

        2.      Identify the habitats of concern.

        3.      Link the activities involved with impacts to these habitats of concern.

        4.      Devise appropriate mitigations for the impacts.

Each reviewer can then determine the adequacy of the environmental impact assessment in question and
recommend modifications to  enhance its effectiveness.

        In identifying the habitats  of concern, the reviewer should supplement the information in this
document with detailed locational information on the abundance and distribution of habitats within the
region of interest, and with any historical information on the extent and quality of these habitats.  Most
important, the reviewer should characterize the habitats in terms of their ecological values (e.g., use of
wooded wetlands by migratory waterfowl).
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        ID considering the links between activities and habitats, the reviewer should look beyond direct
impacts to indirect and subtle effects, including cumulative impacts, interactive and synergistic impacts,
and scale-dependent impacts  (e.g., effects of fragmentation on ecosystem integrity and species home
ranges).

        In devising possible mitigations, the reviewer should follow the seven principles for habitat
mitigation repeated below.  The reviewer should also determine whether adequate assurances have been
given that the mitigations proposed will be completed.


        1.      Base mitigation goals and objectives on a landscape-scale analysis that considers the needs
               of the region.

        2.      Mimic natural processes and promote native species.

        3.      Protect rare and ecologically important species and communities.

        4.      Minimize fragmentation of habitat and promote connectivity of natural areas.

        5.      Maintain structural diversity  of habitats  and,  where appropriate, species diversity to
               promote the natural variety of the area.

        6.      Tailor management to she-specific environmental conditions and to the  unique impacts
               of the specific degrading activity.

        7.      Monitor for habitat impacts and revise mitigation plans as necessary.

        Finally, the reviewer should consider the proposed activities and mitigations in the context of
relevant regional  program  goals and objectives  (e.g.,  whether the outcome of the project  will be in
accordance with principles  set out by regional planning commissions).

Contacts and Information Sources

        When considering habitat conservation issues in an environmental impact assessment for the Great
Plains and  Prairies, the  reviewer should consult the  following organizations  and  individuals for
information  on  habitat impacts and mitigations:

        State Natural Heritage Programs
        U.S. Fish and Wildlife Service, Regional and Area Offices
        State Fish and Game Departments
        University and Research Programs
        Herbaria  and Museums

        Patrick Bourgeron, Regional Ecologist, The Nature Conservancy
        Robert Jacobsen, Regional Associate Director, Fish and Wildlife Enhancement,  U.S. Fish and
         Wildlife Service
Habitat Evaluation                              74                                   Great Plains

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     Western Rangelands Habitat Region:  Western Deserts and Grasslands
"Geographical Description of the Region

       The Western Rangelands Habitat Region, Western Deserts and Grasslands, contains parts of 12
 states. The region includes parts of Texas, New Mexico, Arizona, California, Nevada, Utah, Colorado,
•Wyoming, Idaho, Montana, Oregon, and Washington.  Parts of EPA Regions 6,  8, 9, and  10 are
 included.   The accompanying map  indicates the boundaries of this habitat region and the states h
 comprises.

       The Western Deserts and Grasslands comprises 11 ecoregions (Omernik,  1987).  The natural
 vegetation included in the Region consists of a variety of sagebrush steppe (sagebrush and wheatgrass),
 saltbush, grease wood, creosote bush, bur  sage, needlegrass shrub steppe, juniper, pinyon woodlands,
blackbusb, Great Basin sagebrush, grama, tobosa shrub steppe, Trans-Pecos shrub  savanna (tarbush,
 creosote), chaparral (manzanita, ceanothus, chamise), and tule marshes (bulrush and cattails). The land
 use pattern is mostly desert shrublands both grazed and ungrazed, irrigated agriculture, open woodlands
 grazed, subbumid grasslands, semi-arid grazing lands,  forests and woodlands  mostly ungrazed,  and
 croplands with grazing land.
 Habitat Evaluation
75
Western Rangdands

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Habitats of Concern

        Hie Western Deserts and Grasslands contains many habitats of concern, of which the most
obvious fall into five general categories: riparian habitats, wetlands, desert complexes and scrub habitats,
grasslands, and forested habitats. The principal habitats of concern most at risk in the Western Deserts
and Grasslands are listed below.
                          PRINCIPAL HABITATS OF CONCERN
                     IN THE WESTERN DESERTS AND GRASSLANDS
              1. Riparian habitats

             2. Wetlands
               «    shallow emergent wetlands In pluvial lake basins
               *    cold desert and steppe in Great Basin and Intermountain regions
               •    saline desert wetlands

             3. Desert complexes and scrub habitats
               *    Sonoran and Mojave desert communities
               •    sagebrush type
               »    salt desert shrub type

             4. Grasslands
               *    mixed prairie or shortgrass prairie
               •    California grassland
               •    Palouse grassland of the Northwest
               •    southwest semidesert grassland

             5. Forested habitats
               •    pinyon-juniper woodland
               •    ponderosa pine-bunchgrass type
               •    chaparral vegetation of Arizona and California
Habitat Values and Trends

       The term "rangeland" describes the lands with climate or soil conditions unsuitable for tree
growth.  Rahgelands encompass nearly a billion ac (34% of land area) in the United States, including
some of the world's most productive rangeland (Box 1989).  Western Deserts and Grasslands habitats
traverse the entire range of life zones from the alpine communities of high mountains to the subtropical
Sonoran Desert scrub plains and valley of the lower Gila and Colorado Rivers.  In the Rocky Mountain
region, rangelands (including pinyon-juniper and chaparral-mountain scrub forests) comprise about 336
million ac.  Sagebrush alone constitutes the second largest habitat type in United States with 105 million
Habitat Evaluation
76
Western Rangelands

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•ac, while other habitats include southwestern shrubsteppe, desert shrub, mountain grasslands, mountain
meadows, desert grasslands, and plains grasslands. Rangelands in die Pacific States total 68 million ac
with 23 million ac in grassland and 45 million ac in shrubland (USDA Forest Service 1989).

        By the beginning of the 20th century the American range was generally overgrazed and depleted.
Severe droughts also contributed to the deterioration of rangeland.  The majority of rangeland is in the
West, where declines in area have been minor-4% in the Rocky Mountains and 5% in the Pacific States
(USDA Forest Service 1989).  Although the total area of rangeland has remained  relatively constant, the
condition of the range ecosystems has varied considerably with competition by livestock for forage and
other factors.  Cattle,  sheep,  and wild  horses and burros have contributed  to  reduced forage and to
changes in vegetation composition on the majority of U.S. rangelands.  Many native prairie types have
been  lost to overgrazing or agricultural  conversion. Grazing and fire suppression have allowed brush
Species to  replace many of the grass forage species  on 200 million ac of  the Southwest  (National
Association of Conservation Districts  1979), negatively impacting bighorn sheep, pronghom, sage grouse,
masked bobwhite quail, and northern aplomado falcon. At the same time, range management activities
(such as pinyon-juniper removal,  exotic species plantings, predator  and native ungulate control) and
development along valleys  and lower slopes have affected wildlife community composition and critical
winter range for wild ungulates. The loss of grassland  habitat has been responsible for declines hi many
bird populations.

        No data exist on the  extent of area! changes, but the range of pinyon-juniper has certainly
increased since settlement as a result  of overgrazing, fire suppression, and climate changes.  Projections
for the next 50 years indicate that rangeland area will  increase by 7 million ac in the Rocky Mountains
and 3 million ac  in the Pacific States as a result of conversion of agricultural lands through the
Conservation Reserve Program (USDA  Forest Service 1989).   However, even  where there have been
increases in total area,  the  condition  of these rangelands has been severely degraded. The majority of
rangeland on nonfederal and Bureau of Land Management lands is in fair to poor condition (Joyce 1989).
In the 11 western states, range conditions on public lands are rated as 2% excellent, 29% good, 42% fair,
and 26% poor (Wald and Alberswerth 1989).

        KJopatek « al. (1979) demonstrated that the rule marsh ecosystem in California, Nevada, and
Utah  has suffered the greatest loss of any habitat since presettlement tunes (89%), primarily owing to
agricultural conversion. However, in general, vegetation in the western United States has exhibited the
least losses due to land conversion and suffer primarily from degradation.  Alpine meadows and barrens
have undergone the least change because of their nigged topographical setting.  In contrast, riparian areas
are especially important to wildlife, and losses of this type of vegetation to human activities are estimated
at 70% to 90% (Swift and  Barclay 1980). In Texas, important rangelands include the rocky landscape
along the Big Bend in the Trans Pecos Region and the extremely diverse Mountains and Basins Region,
where overgrazing has damaged most of the desert grasslands and  small streams (Loftis  1991).

        About  84%  of mammal species  and 74% of avian  species  are associated with rangeland
ecosystems during at least part of the  year, and  38% of the nation's fish species and 58% of the
amphibians are represented in the relatively arid rangeland ecosystems (Flather and Hoekstra 1989).
Based on 1984 maps, the average number of endangered  and threatened species per county is 6.1 for the
Western Deserts and Grasslands, the highest in the  nation.  Although most of the value placed on
rangeland habitats centers on the grass and shrub vegetation existing under different climatic conditions,
and the grazing  fauna they  support, many  other values  such as reclusive reptile species and the
Habitat Evaluation                              77                            Western Rangelands

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characteristic cryptogamic crusts of the desert are being recognized. Perhaps most important are riparian
areas where the juxtaposition of terrestrial and wetland or aquatic systems enhances the value of the
habitat.

Woodland and Shrubland

        Pinyon-juniper woodland is a widely distributed vegetation type that supports mule deer, mountain
lion, coyote, bobcat, jackrabbit, and  numerous birds.  Pinyon-woodland has invaded grassland areas
owing to lack of fire, seed spread by livestock, overgrazing and reduced competition from grasses, and
shirts in climate (Branson 1985). Woodland invasion of big sagebrush has occurred more slowly, usually
where pinyon-juniper is often adjacent to sagebrush on the dissections of western basins and mountains.
Fire management in now  being used to encourage the reestablishment of natural vegetation  and native
diversity in  these areas.

        In Arizona and California, chaparral vegetation consists of dense stands of evergreen shrubby
vegetation.  In California, the sparse herbaceous understory of chaparral is less affected by livestock
grazing than grasslands, but alien herbaceous species have largely replaced native perennials in both
systems (Branson  1985).   Areas in Arizona with high grass  were converted to dense chaparral with
intensive  grazing following mineral prospecting in 1890; other chaparral  in the Sierra Nevada is a
subclimax of forest maintained by frequent fires. This habitat provides watershed protection and critical
habitat for the California condor.

Grasslands

        Mountain grasslands provide critical winter range for big game.  These mountain meadows are
sensitive to  abuse, as some are destroyed by roads  and camping as -well as grazing.  Desert grasslands
consist of blue and black grama grasses and invading shrubs resulting from increased livestock grazing,
climatic change, increased competition among plant species, rabbits and rodents, and fire control.   They
support pronghorn and collared peccary.

        The mixed prairie or shortgrass prairie is subject to drought, grasshopper and jackrabbit attack,
and cacti invasion.  Native shortgrasses are outstanding in their resistance to grazing (perhaps developed
in response  to grazing by  bison) and have shown remarkable improvement in certain areas.

        Nowhere else in the  West has the native vegetation been as completely replaced as in the 30-
mOlion-ac extent of grasslands in California (Branson 1985). Native perennials were largely replaced by
introduced Mediterranean annuals by the 1860s, so mat now less man 5% of the current species are
perennials.  This has been attributed to past overgrazing or perhaps fire.  Most of the open grassland in
the Sacramento and San Joaquin Valleys is now cultivated or in urban or industrial use. Adjacent grass-
woodland and chaparral are grazed by livestock.

        The Palouse grassland of the Northwest is dominated by bluebunch wheatgrass on 12 million ha
of the Columbia Basin Province of Oregon, Washington, and Montana.   Because few ungulates  were
present before the introduction of domestic stock, native grass species were not resistent to grazing and
were strongly impacted by livestock grazing and the invasion of Mediterranean annuals (Branson 1985).
The most fertile areas have been cultivated, including some drier lands now irrigated.  Grazing is now
much reduced in the Palouse grassland, and some improvement in range conditions has occurred.
Habitat Evaluation                              78                            Western Rangelands

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        The widespread change of southwestern semidesert grassland to shrubland is one of the greatest
modifications of vegetation on western rangelands.  Cited causes include excessive use by domestic stock
and the reduction of range fires; the loss of topsoil may prevent ever restoring the original grasslands
(Branson 1985). Over the last 100 years; mesquhe, creosote bush, and tarbush have expanded to cover
the entire range.

Deserts

        Four major deserts occur in the western United States: the Sonoran, Mojave, Chihuahuan, and
Great Basin Deserts.  Among desert habitats, the desert riparian  and palm oasis habitats support the
greatest number and densities of bird species (Mayer and Laudenslayer 1988).  The Sonoran and Mojave
Deserts, in particular, support unusual plant and animal communities mat are threatened by increased
human activities in these regions.  Cold desert types of the Great Basin support mule deer, pronghorn,
coyote, collared peccary, and feral horses.  Hot desert shrublands support desert mule deer,  collared
peccary, antelope, and desert bighorn .sheep.

       Both decreased rainfall in mis century and effects of grazing have impacted the widely spaced
woody plants and cacti of the Sonoran Desert, including the cessation of reproduction in saguaro cactus.
The Mojave Desert is suffering degradation from offroad vehicles, whicjb resulted in the cessation of the
annual Barstow to Vegas motorcross (The Washington Post 1990).  Desert habitats in general support
many  populations  of unique and  endangered species, including the  desert tortoise.    Unique
geomorphological  features such as desert buttes and the Utah salt flats are also facing  threats  from
recreational activity, air pollution, and water withdrawal (Lancaster 1991).

       The sagebrush habitat type is unusually susceptible to change when grazed. Many bunchgrasses
in the sagebrush type lack resistance, and the historical response has been the following: (1) an increase
in native shrubs undesirable for browsing, (2) reduction in grasses and forbs, and (3) exploitation of voids
by alien annual weeds adapted to heavy grazing.  A history of grazing and cultivation has led to
encroachment and takeover by annual grasses, primarily cheatgrass.  Mitigation includes burning of
annuals but is effective only where there is sufficient annual precipitation.  The success of cheatgrass has
facilitated the successful introduction of exotic chukar partridge and supports the majority of wild horse
and burro herds.  The sagebrush types also support sage grouse, pronghorn, and mule deer. It is likely
that the original sagebrush habitat can never be restored to pristine conditions even with removal of
domestic animals (Branson 1985).

       The salt desert shrub type is often called the sbadescale zone because of hs  sparse vegetation and
usually widely spaced shrubs with essentially no understory or interstitial species. In general, where  there
is an understory (such as black sage),  historical overgrazing has reduced grasses and promoted shrub
growth and invasion by the exotics balogeton and Russian thistle.

Riparian Areas

        Riparian areas in the West constitute perhaps the region's most important habitat type. Although
they represent only 2% to 4% of the land area in the United States, they make up 80% of the wildlife
habitat.  It has been demonstrated that most endangered species require riparian areas (Johnson 1989).
Many  neotropical  migrants also rely on western riparian areas as  critical nesting sites.  The value of
Habitat Evaluation                              79                            Western Rangelands

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riparian habitat extends at least 0.25 miles  into adjacent areas and can support a density of pairs of
breeding birds up to 1,000 per 100 ac (Carotfaers and Johnson 1975).

       Riparian areas provide  habitat  for  more  species of birds than all other western nngeland
vegetation types combined (Chancy et al. 1990). Within the Great Basin of southeastern Oregon and in
southeastern Wyoming, more man 75% of terrestrial wildlife species depend on riparian systems.  In
Arizona and New Mexico, 80*  of all vertebrates use mem for at least half of their, life cycle and more
than 40% of the species are totally dependent on riparian areas.  Although riparian areas cover less than
1% of the West, they  also serve important ecosystem functions (GUIis 1991).  They keep watersheds
healthy by storing  and releasing water from spring runoff of snowmelt and summer storms and by
providing watering holes for wildlife as well as cattle.  They  filter sediment and  aid floodplain
development, improve fioodwater retention and groundwater  recharge, develop plant root masses that
stabilize streambanks,  develop channel characteristics mat provide  appropriate habitat  for fish,  and
support greater biodiversity.

       The linear nature of riparian areas contributes to their value (Gregory et al. 1991). River valleys
connect montane headwaters with lowland habitats, and provide for the transfer of water, nutrients,
sediment, paniculate organic matter, and organisms. Riparian areas transfer these materials laterally onto
floodplains and create  complex mosaics of landforms and heterogeneous ecosystems.  Wildlife utilize
riparian areas for food, cover, nesting, and rearing of young.   Riparian habitats are frequently used by
wildlife as migration routes (Thomas et al. 1978).  The greater heterogeneity of vegetation in unaltered
riparian habitat increases the available ecological niches and increases the number of species that can be
supported.

       Of the 175 million ac of floodplains along streams and riven in the conterminous  United States,
20% are considered to be rangeland (Johnson 1978). Valley trenching starting in the 1880s resulted in
the loss of many riparian meadows through massive sheet and  rill erosion.  The introduction and spread
of saltcedar, or tamarisk, became common in most drainages in the Southwest after 1920.  Saltcedar
displaces native vegetation upon which certain species depend; it reduces the diversity of native shrubs
and cottonwoods and transpires large quantities of water. Attempts to increase water yields by reduction
of phreatophytes  (such as saltcedar) have included root plows, dozer blades, various mowers and
choppers, and chemical spraying. These treatments have declined significantly in recent years as a result
of concerns  about their efficacy and environmental impact.

       Johnson (1978) estimates that only 10% of the original riparian habitat in United States remains,
and that 6% is lost annually. Major losses resulted from drainage for conversion to agriculture; other
causes include channelization for navigation and flood control,  flooding caused by dam construction, and
diversion of streamflow for irrigation. Alterations include grazing, timbering, road construction, mining,
and other impacts.  In  Arizona, 95% of the woody riparian habitat has been lost or degraded since pre-
settlement.  In Utah, settlement patterns saw riparian areas converted to farmland, frequently hay fields.
They continue to be threatened by water management activity, grazing, sand and gravel extraction, and
development activities.
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 Wetlands

        Specific western wetland problem areas identified by Tiner (1984) include the following:

        •      Estuarine wetlands of die U.S. Coastal Zone.
        •      Western riparian wetlands.

 Wetlands in the Western Great Basin and Intermountain regions include riparian wetlands and shallow
 wetlands in pluvial lake basins. These shallow wetlands are often saline or alkaline as a result of high
 evaporation.  Important large wetlands include me Bear River Marshes, UT,  Malheur Lake Marshes,
 OR, Stillwater Marsh in the Carson Sink, NV, Tule-Klamath Basin  in CA  and  OR, and the  marsh
 .systems of the California central valleys. Nesting habitat for Canada geese has been lost as much of the
 marshlands of the Great Salt Lake have been inundated with rising lake  level (Thomas 1990). Important
 coastal estuary habitats include the large Gulf of California estuary and the fringing marshes along San
 Diego and Tomales Bays.

 Aquatic Systems

        The water area in Western Grasslands and Deserts is generally restricted to large bodies of water
 such as the Great Salt Lake (one-third of all water in the region), and the upper Missouri, Snake, and
 Colorado River systems.

 Activities and Impacts Affecting Habitats

        The Western Deserts and Grasslands has suffered extensive degradation and loss of rangelands
 through conversion to cropland; urban expansion; domestic and feral equine competition with indigenous
 populations for range resources; grazing-pressure effects from  the introduction  of  shrub species to
 grasslands; and range management activities, including the use of herbicides and the exclusion of natural
 inhabitants (U.S. Forest Service  1989).  Other activities negatively affecting rangelands include water
 management projects that dam or divert water supplies, mining impacts,  and the use of remote rangelands
as targets for waste disposal.

        For example,  in California more than 17 million ac of natural habitat have been lost through
 conversion to urban and agricultural land, including nearly 90% of riparian habitats in the Central Valley
 (California DFFP 1988). Major habitats mat have lost  significant acreages in the last 30 years include
 grasslands and coastal scrub.  The use of grasslands for grazing also  results  in  habitat loss and
 fragmentation, including excessive surface  soil erosion on nearly 25% of western rangelands.

        Grazing and water projects especially threaten riparian environments throughout the region.  For
 example, overgrazing  and phreatophyte control are destroying riparian vegetation in Arizona and New
 Mexico.  Water diversions in the Central Valley and  elsewhere have caused major losses of riparian and
 wetland habitats and are contributing to the declines  of waterfowl along the Pacific Flyway.

        Recreational use of off-road vehicles and military maneuvers are also degrading arid environments
 such as the Mojave.  By one calculation, more than a half million ac have been disturbed by  motor
 vehicles in California (California DFFP 1988). Fragile coastal dune habitats have also been damaged and
 eliminated by development, recreation, and introduced species.
 Habitat Evaluation                             81                            Western Rangelands

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        The following activities result in the major  impacts  on habitats of concern in the Western
Grasslands and Deserts.
IMPACTS ON HABITATS OF CONCERN IN THE WESTERN GRASSLANDS AND DESERTS

Riparian habitats
Wetlands
Desalts
Grasslands
Woodlands and
ahniblands
|«id
Conversion
Residential
development and
construction of
pipeline and
transportation
corridors
Agriculture!
conversion
Urban expansion
Agricultural
conversion
Urban expansion
Grazing
Degradation
from domestic
and feral
unmilatec

Moderate
Degradation
from domestic
and feral
ungulates
Degradation
from domestic
and feral
ungulates
Moderate
M"1*^
Moderate
Moderate
Moderate
Minor
Minor
Water
Management
Historical
impact of
iirnKMindmmt.f
and water
diversions
Historical
impact of
iititvHtndmffaty
and water
diversions
Major impact
of water
diversions
Minor
Minor
Other
Recreational
use
Minor
Off-road
vehicle use
Minor
Moderate
      Conversion
       To date, the most fertile toils within the Western Grasslands and Deserts have been converted
to croplands; these same areas have historically supported the greatest abundance of wildlife (Mayer and
Laudenslayer 1988). In addition, urban development has been a major source of rangeland conversions,
reaching the highest urban densities at lower elevations with the majority of cities of 10,000 in population
occupying areas formerly in grassland or scrub vegetation.

       Urban and suburban expansion have converted large areas around the Los Angeles metropolitan
area. In addition, some of California's fastest growing areas are in rural counties, including those with
significant range resources. Rapid growth from the Sunbelt migration is now occurring around Las Vegas
and other desert cities. In the Las Vegas area, the expansion of bousing development has been facilitated
by land trades  with the Bureau of Land Management.  Riparian areas  in particular are under heavy
pressure from development in New Mexico, Arizona, and Nevada.  Pressure  upon the land and local
governments to convert open space to residential, commercial, and industrial uses to accommodate growth
Habitat Evaluation
82
Western Rangelands

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 has been intense, and will continue to destroy rangeland habitats where population growth is most
 pronounced.

        Conversion  of rangelands to cropland will increase with the availability of ground water for
 irrigation (USDA Forest Service 1989).  For example, sandy rangeland in Texas,  Colorado, New
 Mexico, and Nebraska has already been converted to farmland (Sheridan 1981).  Abandonment of these
/farms can  lead  to  desertification  if the  ground water  has  been depleted.   Areas  of concern for
 desertification include the Challis Planning Unit in Idaho,  the San Jaoquin Basin in California, the Gila,
iSanta Cruz, and  San Pedro River Basins in  Arizona, and  the Sonoran and Chihuahuan Deserts in
^Southwest.   In these  arid  and semiarid lands,  land conversion to agriculture, grazing, and water
•management can cause ground water  overdraft, salinization of topsoil and water, reduction of surface
 water, high soil erosion, and destruction of native vegetation.  Irrigation can also have adverse impacts
 on rangelands  when poor drainage leads to waterlogged areas.

        As  with forest habitats, the  spatial pattern  and fragmentation of rangeland vegetation can
 negatively affect native fauna and  ecosystem health.  The loss of grassland habitat to  agriculture  is
 responsible for the decline in prairie birds, especially those requiring large continuous habitats, and  is
 analogous to the reduction in old-growth forests and its obligate species. The upland sandpiper, bobolink,
 dickcissel, grasshopper sparrow, savannah sparrow, and Henslow's sparrow all declined by 90% between
 the 1950s and  1970s (Graber and Graber 1983).

 Agricultural Impacts

        The intensive use of agricultural land  in certain areas of the Western Grasslands and Deserts
 poses additional stresses to habitats through cultivation and irrigation practices (NRC 1982). The use of
 fertilizers and pesticides, irrigation and drainage, double cropping, and increased field size all contribute
 to increased pollutant loads and severe impacts on habitats.  Agricultural chemicals are toxic to many
 species and can negatively affect population levels, community composition,  and ecosystem dynamics.
 Intensive cultivation practices (e.g., cotton agriculture in deserts) usually produce severe offsite impacts.

Crazing

        Widespread  devastation of rangeland resulted from uncontrolled overgrazing between 1880 and
 1935, and the damage was undoubtedly amplified by the drought years of the 1930s (Branson 1985). The
enactment  of  the Taylor Grazing  Act of 1934  reduced grazing  pressure  at  mat time.  With the
 advancement of range management science and the moist years following 1960, considerable improvement
 occurred in range vegetation. However, the USDA Forest Service (1989) reports 21 % of its rangelands
 were still in "unsatisfactory" condition. The Bureau of Land Management (1989) reports that rangeland
 condition is 33% good or better, 38% fair, and 13% poor.

        Overstocking and overgrazing have historically resulted in severe degradation  and catastrophic
flooding of rangelands. Undesirable and  irreversible changes include  replacement of grassland with
creosote bush  in the arid Southwest; replacement of native perennial buncbgrasses by Mediterranean
 annuals in California grasslands; and conversion of native vegetation in the Great Basin to an artificial
 balance of grasses and shrubs. Many national forest lands now contain different rangeland communities
 (e.g., invasion by Utah juniper into grass-shrub and replacement of grasses by big sagebrush).
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        The management of public land grazing is abared between the land management agency and the
grazing permittee.   Grazing  permits  are issued  and allotments  inspected for use,  condition, and
compliance  by the management agency; actual management of  the  livestock and maintenance  of
improvements is the responsibility of the permittee. Attempts to reduce grazing allotments in national
forests to allow improvements  on lands in poor or fair condition has caused resentment among graziers.
However, federal permit fees  are only one-fifth the rate for private lands.  As the acreage of private
grasslands continues to decline with urban and agricultural conversion, there will be increased pressure
on public lands.

        Grazing poses the following threats to rangeiand habitats (Cooperrider 1990):

        •      Competition with ungulates and small herbivores (e.g., desert tortoise) and limits on the
               populations of free-roaming pronghorn antelope, mule deer, elk,  and bighorn sheep.

        •      Transmission of disease (e.g., dramatic diebacks in bighorn sheep with domestic sheep
               grazing).

        •      Loss of cover for birds.

        •      Spread of exotics and noxious weeds.

        •      Desertification, or serious degradation.

        •      The conversion of lands  with sagebrush and pinyon-juniper to reseeded grassland for
               more forage.

Riparian Areas

        The most  severe impact in terms of  supporting healthy  ecosystems and  native  faunas on
rangelands has been the loss of 70%  to 90% of riparian areas to human activities (Ohmart and Anderson
1986). Losses of riparian areas have caused the endangerment of habitat-dependent species  such as the
Least Bell's vireo and likely will cause the extirpation of many species if the last remaining areas of
individual types are lost (e.g., 10 species may become extinct if the  cottonwood-willow  association
disappears). Johnson (1978) estimates mat 6% of riparian areas continues to be lost annually. Historical
loss estimates include 98% of riparian habitats in the Sacramento Valley of California, 95% in Arizona,
and 90 to 95 % in the Rocky Mountains Region. In Utah, settlement patterns saw riparian areas converted
to farmland, frequently hay fields.   They continue to be threatened by water management activity,
grazing, sand and gravel extraction, and development activities.

        Grazing is so ubiquitous in riparian ecosystems of the Southwest that only a few ungrazed sites
exist (Szaro 1991). On average, the riparian zone is only 2% of a grazing allotment, but it produces 20%
of the forage, and the cattle consume 80% of their forage from these riparian areas. Stream bottoms are
natural  concentration areas for livestock  seeking succulent forage, shade, reliable water supply, and
favorable microclimate. Only  when  access is limited by steep slopes are livestock absent from unfenced
riparian areas.  Grazing impacts riparian areas both by removing vegetation and by trampling.  By
affecting the spacing  of plants, width of the riparian corridor, seedling establishment, and  species
composition, fioristic  diversity is often lower in grazed areas.  Trampling increases soil compaction,
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erodes streambanks, decreases water quality, widens and shallows channels, and physically destroys
vegetation (Kauf&nan and Krueger 1984). Riparian degradation causes accelerated runoff and erosion,
downcut streambeds, lowered water tables, and desertification of the land.  It has a negative impact on
wildlife habitats and leads to declines in willows and native grasses.  In addition, degraded riparian areas
are more susceptible to upland inputs as healthy riparian areas can filter out upland degradation.  While
the condition of all rangelands has improved since 1980, riparian areas are  in their worst historical
condition.

        Although the values and functions of riparian areas have been widely and severely impacted by
cultivation, road building, mining, urbanization, logging, and damming of rivers, grazing has caused the
most geographically extensive impacts (Chancy et al. 1990). Impacts of grazing on riparian areas include
the following:

               Little vegetation to stabilize streambank and shade stream.
               Lowered water table and subsurface water storage.
               Reduced or absent summer flow.
               Warm water in summer and icing in winter.
               Poor habitat for fish and aquatics.
               Poor habitat for wildlife.
               Reduced amount and quality of forage.

Mining

        Surface mining has severely degraded large areas of the Western Grasslands and Deserts. Surface
deposits of minerals are extracted  by removing  successive  layers  of the  terrestrial  environment.
Reclamation efforts have increased, but true restoration success is  .especially difficult in arid habitats.
Establishment of vegetation is problematic even with  fast growing  nonnative species.   Oil and gas
development also pose severe risks to the pristine natural areas of the West. Exploration and production
of both land and off-shore oil reserves are in direct conflict with many wildlife requirements.  The
substantial infrastructure required by mining activities also contributes to habitat degradation.

Water Management

        The regulation and damming of streams are often performed to control flooding and drain land,
resulting  in the impoverishment  of riparian vegetation  (Szaro 1991).   Dams and water diversion
significantly change downstream flow regimes, levels of winter floodwater, dry-season flow rates, and
riparian-zone soil moisture.  Downstream areas lose pulse-stimulated responses while upstream areas are
affected  by  water  impoundment and salt accumulation.  Native riparian plants are  usually unable to
colonize the shore of reservoirs because of the altered hydrologic regime. For example, high water levels
are maintained much longer in reservoirs than in  rivers and streams; changes in the level are more
drastic;  and  the large  winter/spring floods  required  for  alluvial seedbeds  (e.g.,  cottonwcod) are
eliminated.

Recreational Activities

        The characteristics of riparian areas that attract wildlife and livestock also attract human recreation
such as birdwatching, hiking, fishing, camping, hunting, trapping, picnicking, floating, boating, and river
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running (Carothers and Johnson 1975). These activities are increasing as leisure time, personal income,
mobility, and pollution levels increase in the western United States. This will place even greater stress
on these rare and abused ecosystems.

Military Activities

        The large number of military training areas located in the Western Grasslands and Deserts results
in major impacts on arid land environments.  Both a reduction in vegetative ground cover and changes
in species composition result from tracked vehicle activity and troop maneuvers (Diersing et al. 1992).
There is a major shift from perennial warm-season grass (blue grama) to invading annual cool-season
grasses following disturbance by tracked vehicles.  This activity can also reduce densities of shrubs, trees,
and succulent plants; the loss of juniper can exceed its ability to regrow.

Mitigations of Impacts

        The conservation of habitats  requires consideration of mitigations  for  the major activities
impacting habitats of concern. In the Western Deserts and Grasslands, the primary habitat impacts are
caused by the following:

               Grazing of riparian areas.
               Land conversion of riparian and wetland habitats.
               Urban conversion of desert and shrubland habitats.
               Mining impacts on arid lands.
               Water management impacts of diversion and damming on riparian and wetland areas.

It is likely that certain areas will see additional conversions to cropland or pasture, and mat more open
ranges will be fenced and thus restrict winter grazing by native ungulates. Increased irrigation will likely
follow higher demand for water and adversely affect water tables and stream flow on rangelands.  These
and other activities will pose a complex of interrelated effects on habitats of concern and will require a
holistic, ecosystem-level approach to mitigation.  The effects of future management and mitigations on
riparian areas will have the greatest impact on wildlife and  native ecosystem health (NRC 1982).

Grazing

       Future management of grazing on rangelands will determine whether range conditions worsen or
improve from their currently degraded state (NRC 1982).  In the past, range condition has been estimated
by (1) forage production relative to a mythical average, and (2) production of livestock.  Recently, some
range managers have begun  to  base range condition on deviation from an ideal range or ecological
climax. This and other improvements in range science provide for consideration  of objectives beyond
livestock production.   For example, the widely  used model of E.J. Dyksterhuis (1949) is based on
reversible and gradual community change and is  now viewed as inaccurate, as it  does  not incorporate
threshold community shifts (Jahn 1991).  The problem for habitat conservation is that the proportion of
rangeland climax habitats has greatly decreased,  similar to the case with old-growth  forest.  Although
there remain disagreements over  proper management methods, more effective use of ecological analyses
of range condition will likely improve the management of rangelands.
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        Specific methods of mitigating grazing impacts on rangelands include the following (Branson
 1985):

               Proper intensity ar.   reason of grazing.
               Practices that improve livestock distribution.
               Control of undesirable species using fire or other appropriate methods.
               Land-surface modification to retain soil moisture for forage production.
               Ecologically based management plans for each site using adequate field data.

        Proper grazing management can restore the long-term productivity of most rangelands, but
 obstacles are grazing tradition, geographical extent of problem, and the difference between short-term
 costs and long-term benefits.  Successful management requires mat traditional intensive measures to
increase forage be replaced  by different management practices. For example, rest-rotation grazing can
 improve range conditions, while intensified chemical use and mechanical brush removal to improve forage
 will likely further degrade range habitats. In addition, fire can be used as a management tool to return
 pinyon-juniper areas to their previous savannah condition. As a rule, conversion to cattle from sheep
 requires more management as cattle use bottomland more intensely than sheep. Therefore, summer cattle
 use of desert ranges in an undesirable practice.  Successful rangeland mitigation requires time, flexibility,
 commitment by graziers, and monitoring and evaluation.

        Improvements in the condition of riparian areas will provide the greatest proportional benefit to
rangeland integrity and functioning.  The Bureau of Land Management (BLM) has plans for restoring
 180,000 stream miles within 270 million ac of BLM lands to improve the functioning and status of 23.7
 million ac of riparian/wetland systems to meet demands for protecting watersheds, restoring water quality,
 and enhancing conditions for fish, wildlife, livestock, and outdoor recreation (Jahn 1991).

        Szaro (1991) argues strongly for an overall ecosystem approach to research and management of
 riparian areas. This  includes the use of reference sites, a watershed (ecosystem) scale approach, and
 long time scale considerations  (greater than 5 years).  Mitigation  of impacts to riparian areas should
 consider the following factors:

        •      Riparian floristic (plant species) diversity should take precedence over  structural diversity
               (vegetation layers and patches) as descriptors of the habitat.

        •      Wildlife species depend both on floristic composition and on the relationship of  riparian
               areas  to animal movement patterns and migratory pathways.

        •      The distribution of riparian vegetative communities  varies with topography and depends
               principally on elevation.

        •      Flooding and other  natural disturbances  are important to riparian systems.  They
               contribute to their  status  as distinct and  highly integrated pockets within other
               communities.

 Successful riparian management requires unique solutions to the specific condition at each site (Chancy
 et al. 1990).  However,  general principles include the following:
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        •      Include riparian areas in separate pastures with separate objectives and strategies.

        •      Fence or herd stock oufof riparian areas to let vegetation recover.

        •      Control die timing of grazing (1) to keep the stock off streambanks they are most
               vulnerable to erosion, and (2) to coincide with the physiological needs of plants.

        •      Provide more rest to the grazing cycle to increase plant vigor or  encourage more
               desirable species.

        •      Limit grazing intensity.

        •      Change from cattle to sheep to get better animal distribution through herding.

        •      Permanently exclude livestock from high-risk  and poor-recovery areas.

Land Conversion

        Effective mitigation of land conversion activities can  sometimes be obtained only by avoiding
impacts on rare or unusual habitat types.  Rarely, if ever, is restoration or compensation an adequate
mitigation for the loss of these habitats.  In these cases, mitigation is a siting issue, where construction
and degrading activities are located a distance from the habitats of concern.  The habitat is adequately
preserved if all possible impact scenarios are accounted for. Barring mis solution, effective management
measures must be implemented to ensure the protection of the habitats of concern.

        In the case of unique riparian or wetland habitats, hydrologies! and contamination concerns are
especially important.  Construction or resource management activities require the use of sediment filter
strips and other means of intercepting offsite contaminants.  Road building and structural "improvements"
must not result in altered hydrological regimes.  Desert habitats are especially vulnerable to mechanical
disruption by vehicles and machinery.  Where rare plant types exist or where habitats are unstable (e.g.,
sand dunes), recreational access may have to be limited.  These mitigations can be best implemented by
creation of a regional land-use plan (through a coordinating council like the Waterfowl  Flyway Council)
and landowner incentives like the Conservation Reserve Program.

        Conversion to agricultural land is a  special  concern in rangelands with increasing irrigation
potential. Land conversion to agriculture can cause groundwater overdraft, salinization of topsoil  and
water, reduction of surface water,  high soil erosion,  and destruction of native  vegetation.  Mitigations
include more conservative irrigation techniques and improved drainage systems.  Soil conservation
techniques vary from windbreaks to  contour plowing,  stripcropping, rotation  of crops, conversion to
grass, and/or  minimum tillage.

        Amelioration of impacts from land conversion to transportation uses requires special  mitigation
measures.   As  with  all  land conversion, the construction of highways and  power-line  corridors is
primarily a siting issue.  Avoidance of sensitive habitats may be accomplished by modifications to the
route design,  and the extent of disturbance can be limited by careful  construction practices.  However,
fragmentation of the larger area is unavoidable in the case of land conversion to  transportation corridors.
Many structural  mitigation measures can be used to lessen  the impact on animal movement across


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 transportation routes.  Primarily, these include the construction of fences and underpasses. The goal of
 these structural measures should be to mimic the natural movement and migration patterns of the affected
 species.

 Mining

        Mitigation of  mining impacts involves siting  issues,  technological  solutions to  eliminate
•contamination, and restoration programs. The major mitigations for oil and gas extraction and production
 are the proper sitings of rigs, reserve pits, processing facilities, and roads where they will have minimal
.impacts on habitats of concern.  Most  important for coal and mineral mining  is the siting of mining
 operations and tailing ponds to avoid habitats of concern, wetlands, riparian areas, and recharge areas.
-Specific mitigation measures depend on the type of mining and the specific process causing impacts.  It
ns generally best to minimize the area affected  as h is unlikely mat even the disrupted soils and sediments
 can be restored.   In addition to minimizing the area disturbed, activities  should be timed to avoid
 disturbing nearby plants and animals during crucial periods of their life cycle.

         Possible mitigation measures for mining operations include the following (SAIC  1991a, 1991b):

        •      Design of mine entrances and workings to minimiza future mine drainage.

        •      Runon and runoff control measures  such as benns and ditches.

        •      Adequate depth and lining of pits for containment of muds and leachate.

        •      Elimination of migration of fluids through casings and dewatering.

        •      Separation of wastes and contaminated soils with proper disposal.

        •      Treatment of leach heaps and neutral or acidic wastewaters to  reduce the load of cyanide,
               nitrates, and heavy metals.

        •      Closure planning  that addresses hydrology, geochemical  controls,  treatment,  ana
               restoration.

        •      Nets or other covers over process ponds.

        •      Maintenance of an anaerobic environment in the tailing pile during periods of inactivity.

        •      Secondary containment of tanks and contingency plans  fo:  sudden  or catastrophic
               releases.

        •      Backfilling and sealing  of the  mine workings during mine reclamation/closure.

        •      Recycling of process water, smelter slag, and air pollution control dust.

        •      Monitoring and elimination of discharges to surface water, ground water, soils, and air.
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        •      Replenishment of surface and ground waters with treated effluents.

        •      Road closure and  reclamation (following  recontouring) with revegetation of native
               species.

Although the reclamation of mined lands is often  unsatisfactory  for ecological  habitat restoration,
reforestation with native trees has been demonstrated (Plass  1975)  and would serve to  reduce the
abundance of nest parasitic brown-headed cowbirds and restrict their access to mature forest.

Wetlands

        Mitigation of wetlands destruction and degradation is the subject of a growing body of literature
(Kusler and Kentula 1989).  Restoration and mitigation banking concepts are still being evaluated as
effective mitigation measures for direct wetlands alterations.

Military Activities

        Mitigation of the impacts of military activities on habitats has only recently received attention.
The Army Corps of Engineers' Construction Engineering Research Laboratory  in Champaign, IL, is
developing a Land Condition-Trend Analysis (LCTA) Program (Diersing et al. 1992) as a comprehensive
means of matching military training mission objectives with effective natural resource management. If
such a plan is instituted, it is likely that careful coordination of the siting and timing of training operations
will dramatically reduce habitat impacts.   An awareness of the ecological consequences  of specific
activities is essential to effective mitigation. The following general mitigation measures apply the primary
impacts of military activity.

        •      Timing and siting of operations - The noise and disturbance  associated with aircraft
               flights  and  large  troop  maneuvers  cannot   be  eliminated.    However,  sensitive
               environments can be avoided, and operations can be timed to avoid critical nesting and
               migratory periods.

        •      Calculation of allowable use for tracked vehicles -  Tracked vehicle movements are a
               major  cause  of habitat degradation.   Vegetation  destruction and  soil erosion  and
               compaction are the primary impacts.  Precise equations can be developed that estimate
               sustained tracked vehicle use based on physical properties of the environment, vegetative
               cover, and changes in vegetative cover caused by the passage of tracked vehicles.   For
               example, tracked vehicle use should be restricted to  all-weather roads when  possible.

        •      Fire suppression during artillery practice • Fires created by artillery pose a major
               problem in arid environments.  Rapid identification and suppression by helicopter can
               virtually eliminate the spread of large-scale fires.
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Guidelines for Reviewers

        Reviewers of environmental impact assessments will find mis document useful if they follow the
steps laid out in the introduction:

        1.     Review the status and trends of habitats in the region.

        2.     Identify the habitats of concern.

        3.     Link the activities involved with impacts to these habitats of concern.

        4.     Devise appropriate mitigations for the impacts.

Each reviewer can then determine the adequacy of the environmental impact assessment in question and
recommend modifications to enhance its effectiveness.

        In identifying the habitats of concern, the reviewer should supplement the information in this
document with  detailed locational information on the abundance and distribution of habitats within the
region of interest, and with any historical information on the extent and-quality of these habitats.  Most
important, the reviewer should characterize the habitats in terms of their ecological values (e.g., use of
wooded wetlands by migratory waterfowl).

        In considering the links between activities and  habitats, the reviewer should look beyond direct
impacts to indirect and subtle effects, including cumulative impacts, interactive and synergistic impacts,
and scale-dependent impacts (e.g.,  effects of fragmentation on ecosystem integrity and species home
ranges).

        In devising possible  mitigations, the reviewer should follow the seven principles for habitat
mitigation repeated  below. The reviewer should also determine whether adequate assurances have been
given that the mitigations proposed will be completed.

        1.     Base mitigation goals and objectives on a landscape-scale analysis that considers the needs
               of the region.

        2.      Mimic  natural processes and promote native species.

        3.     Protect rare and ecologically important species and communities.

        4.      Minimize fragmentation of habitat and  promote connectivity of natural areas.

        5.     Maintain structural  diversity of habitats and, where appropriate,  species diversity to
               promote the natural variety of the area.

        6.     Tailor management  to site-specific environmental conditions and to the unique impacts
               of the specific degrading activity.

        7.     Monitor for habitat  impacts and revise mitigation plans as necessary.
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        Finally, the reviewer should consider the proposed activities and mitigations in the context of
relevant regional program goals and objectives  (e.g.,  whether the outcome of the project will be in
accordance with principles set out by "regional  planning commissions such as those established for
southern California).

Contacts and Information Sources

        When considering habitat conservation issues in an environmental  impact assessment  for the
Western Deserts and Grasslands, the reviewer should consult the following organizations and individuals
for information on habitat impacts and mitigations:

        State Natural Heritage Programs
        U.S.  Fish and Wildlife Service, Regional and Area Offices
        State Fish and Game Departments
        University and Research Programs
        Herbaria and Museums

        Patrick Bourgeron, Regional Ecologist, The Nature Conservancy
        R. Langley, Associate Director, Fish and Wildlife Enhancement, U.S. Fish and Wildlife  Service
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                  Western Forests Habitat Region: Western Forests
 Geographical Description of Region

        The Western Forests Habitat Region, Western Forests, contains parts of 11 states. The region
 includes parts of Washington, Oregon, California, Arizona, New Mexico, Colorado, Wyoming, Utah,
 Nevada, Montana, and Idaho. Parts of EPA Regions 6, 8, 9, and 10 are included. The accompanying
 map indicates the boundaries of this habitat region and the states h comprises.

        The Western Forests comprises 12 ecoregions (Omernik, 1987). The vegetation of the Western
forests includes a wide range of forest types, including spruce, cedar, hemlock, cedar hemlock, Douglas
.fir, redwood, silver-fir, western spruce, mixed conifer forest (fir, pine, Douglas fir), red fir, lodgepole,
^subalpine  forest, western  ponderosa pine, grand-fir,  alpine meadows (bent grass,  sedge,  fescue,
 needlegrass), Arizona pine, pinyon woodland, Southwestern spruce, and a mosaic of Oregon oakwoods.
 The land use pattern is  predominantly forest and woodlands that are grazed and ungrazed,  pasture
 croplands, and croplands with some interspersion of pasture, woodlands, and forests.
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Habitats of Concern
       The Western Forests contains many habitats of concern; the most obvious fall into four general
categories: old-growth conifer forests, remnant hardwood forests, alpine communities, and riparian and
aquatic systems. The principal habitats of concern most at risk in the Western Forests are listed below.
                          PRINCIPAL HABITATS OF CONCERN
                               IN THE WESTERN FORESTS
              1. Old growth conifer forests
                *   Douglas fir of Pacific Northwest
                *   ponderosa pine east of the Cascades
                *   ponderosa pine in Arizona and New Mexico
                «   redwood forest in California
                *   old growth in northern Rocky Mountains

             2. Remnant hardwood forests
                *   California oak woodlands
                *   Oregon oakwoods

             2. Alpine communities
               •    alpine talus and barrens

             3. Riparian, wetland, and aquatic systems
               •    riparian forest
               *    salmon fishery habitat
Habitat Values and Trends

       The western United States contains a large area of forested land, including the last substantial
areas of virgin forest (excluding Alaska).  Timber harvesting came to the West with the settlement era
after most of the East had already been logged. The three major regions of western forests are the Rocky
Mountains, California, and the Pacific Northwest.

Rockv Mountain Forests

       In the Middle and Southern Rocky Mountains, intensive exploitation of forest timber began when
railroads opened up the region, producing lumber mills in  1870 (Barrett 1980).  Fire also played  an
important role in this region, promoting lodgepole pine at the expense of Douglas fir.  Logging came
later to the Northern Rocky Mountains, where the forests of Idaho and western Montana represent the
largest area of contiguous  forest in the  United States with more than 80%  of the land forested.
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Agricultural settlement increased rapidly after the Civil War, reaching into the fertile grasslands and open
timbered foothills. Farmland extension is currently slow but continuing into the forest area. About half
of die forest area is grazed.

        Current forestry efforts are directed at die conversion of old-growth and high-graded stands to
commercial timber harvesting.  Although white pines forests were intensively logged between 1910 and
1925, old-growth forests still predominate over much of the Northern Rocky Mountain Region.  A total
of 138 million ac of forest occur in the Rocky Mountain Region, most in pinyon-juniper woodland (47
million ac of dry plateaus and broken tablelands), Douglas-fir (18 million ac), fir-spruce (16 million ac),
ponderosa pine (16 million ac), and  lodgepole pine (15 million ac) (USDA Forest Service 1989). In
recent decades, a modest, steady decline in forest area has occurred as  a result of clearing for roads,
urban development, powerline rightsof-way, and surface mining.  Substantial areas in Montana, Idaho,
and Colorado have been converted to homesites. Data indicate mat forest ecosystem types that have
declined since 1963 include western  white pine (89%), larch (35%), lodgepole pine (29%), ponderosa
pine (27%), and western hardwood (19%).  In the future, forest area is expected to remain stable as
timber harvesting lands decrease and conversions to urban uses increase.

        The Rocky Mountain  region is  a highly dissected series of peaks and  ridges containing bom
forests  and rangeland  (see Western  Rangelands Habitat Region).   Even within forested areas, many
unusual  habitats  exist,  including  old-growth  spruce/skunk  cabbage,  acid   shale  ponderosa pine
communities, intermountain bunchgrass, and various alpine and subalpine communities. Many of these
are uncommon and isolated, representing especially vulnerable habitats in mis region.

California Forests

        California is second only to Alaska in total forest area; forest area constitutes 40% of the state,
or 40 million ac (Barrett 1980). Since 1953, the total commercial forest area in California has decreased
by about 1 million ac because of grazing development, roads, construction of reservoirs and power lines,
urban expansion, and park and wilderness dedication.  The six  major habitat types include redwood,
mixed conifer, true fir, ponderosa  pine, California oak woodland, and California chaparral.  Although
the state has a long history of industrial use of forest, efforts are under way to restrict timber harvesting
throughout the state.

        Losses of forests and woodlands have been less than 1 % per year over the last decade  and are
caused principally by urbanization and construction of roads and reservoirs (USDA Forest Service 1989).
However, the condition of forests has been greatly affected by  logging, which has reduced the  number
of trees by 55% and changed  open stands of large trees to dense stands of small trees.   Forest
composition has changed; hardwoods have replaced coastal conifers, while white fir and incense-cedar
have replaced pine in the interior.  Originally 74% of forest was mature or old growth and 13% was in
sapling or saw timber stages.  Now nearly 40% of mature stands have been cut and are in the sapling
stage.  Predictions are that about 11 % of timberland will be reserved for mature stands (Raphael et al.
1988).  Air pollution, both acid deposition and smog, also have caused extensive damage to these forest
ecosystems, especially to the susceptible granitic watersheds and Southern California forests (California
Department of Forestry and Fire Protection 1988).
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 Pacific Northwest Forests

        The Pacific States, excluding California, comprise about 50 million ac of forest.  Major types
 include western bemlock-sitka spruce, coastal Douglas fir, true fir-mountain hemlock, mixed conifers of
 southwestern Oregon, mixed pine-fir of eastern Oregon and Washington, and northwestern ponderosa pine
 (USDA Forest Service  1989).  Since 1963, many forest ecosystem types have declined: western white
 pine (99%), redwood (31%), ponderosa pine (26%), Douglas fir (20%), and lodgepole pine (17%).

        The Pacific Northwest rainforest (principally spruce, hemlock, and fir) constitutes one of the most
 productive forest regions in the world. The western areas of Washington and Oregon are 80% forested,
 and the eastern portions of these states are 35% to 40% forested. Large-scale settlement began in the
 Pacific Northwest during the middle of the 19th century. Agriculture was restricted to river valleys and
 the steppe vegetation of the East, but adjacent forested areas were used extensively for grazing of both
 sheep  and cattle.  Timber harvesting increased  with the advent of the California Gold Rush and has
 continued to be a major industry ever since.  Forest use west of the Cascades started along waterways
 and progressed inland onto steeper slopes as logging technologies improved. Virgin timber is still being
 cut on the higher slopes of the Olympics and western slopes of the Cascades, but the age classes of the
 second forest follow the original, regional pattern of harvesting.  Qearcut logging has been  almost
 universal west of the Cascades with partial cut logging used to the east (Barrett 1980).

        The Olympic Peninsula of Washington contains one of the best examples of old-growth forests
 remaining in the United States. Of the 390,000 ac of old growth existing in 1940, only 94,000 remained
 in  1988 (Morrison 1990).  Although sitka spruce and western hemlock covered more than 1 million ac
 before European settlement, logging and human-caused fires have reduced the area by 97%.  Additional
 ecological zones include Douglas fir, pacific silver fir, mountain hemlock, subalpine fir, and alpine.  In
 both Oregon and Washington, me most obvious  change in forest cover over the last 10 years has been
 the reduction  in area of old-growth forests by logging.  Major impacts in  both states have been clear
 cutting, road building, edge effects, fragmentation, and human fires, as well as disease and pest mortality
 in eastern Washington.

        Morrison (1988) assessed me amount and condition of ecological old-growth conifer forest that
 still exists on 6 of the  12 westside national forests in the coastal region of Oregon, Washington, and
 northern California and estimated the amount of old growth that will remain in 5 years  if present policy
 continues.   The results  predict that old growth covers less area and is being lost more rapidly than is
-claimed by the U.S. Forest Service.  Factors contributing to the vulnerability of old-growth forest in  the
 Northwest include the following:

        •      Nearly all of the old growth on private lands in the Pacific Northwest has been logged.
        •      Only 31 % of the remaining old growth is in designated wilderness areas.

        Based on 1984 maps  (Flather and  Hoekstra 1989), the  average number of endangered and
 threatened species per county is 5.6 for the Western Forests, among the highest in the nation. The
 following listing of Pacific Northwest forest types illustrates some of their characteristic ecological values:
        Douglas-fir - dense overstory forest of ancient trees supports important plants such as epiphytes
        and yew, and rare species such as spotted owl and marbled murrelet; forest openings and early
      at Evaluation                              %                               Western Forests

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        serai stages support elk, grizzly bear, moose, blue and ruffed grouse, mammalian predators such
        as mountain lions and bobcats, and endangered American peregrine falcon.

        Fir-spruce and hemlock-Shka spruce -dense canopy forest with little understory but interspersed
        with meadows or stream bottoms with willows and aspens; support moose, elk, wolverine, lynx,
        black bear, mountain lion, and some grizzly bear.

        Ponderosa pine - historically, fire kept habitat open  and park-like with ground cover of grasses,
        sedges, and forbs; supports black bear, mule deer, elk, and mountain lion.

        Lodgepole pine - supports moose,  elk, wolverine, lynx, black bear, mountain lion, coyote, and
        some grizzly bear.

        Redwood - dense overstory forest of small geographic extent in California and Oregon; supports
        elk, mountain lion, bobcat, and black bear.

        Western hardwoods - 50% or more of coast live oak, canyon live oak, blue oak, valley oak,
        interior live oak, or aspen; in California supports mule deer, California quail, mountain quail,
        skunk, and endangered San Joaquin kit fox.

        Pinyon-juniper -  often adjacent to sagebrush on dissection of western basins and  mountains;
        supports mule deer,  mountain lion coyote, bobcat, jackrabbit, numerous birds.

        Alpine - above timberline in Rocky Mountain and  Pacific Coast regions; consists  of grasses,
        grasslike species  and forbs; includes lakes and ponds with endemic trout; supports pika, pocket
        gopher, yellow-bellied marmot, mule deer, elk, mountain sheep, and ptarmigan.

Riparian and Wetland Areas

        The original amount of wetland area in the Rocky Mountain Region has been decreased by one-
third  since widespread settlement began  (Windell  et  al.  1986).   The Rocky Mountains comprise a
relatively small area of wetlands, but a wide variety of wetland types, ranging from intermountain basins
to alpine tundra.  Much of the impact results from the concentration of human population within certain
Rocky Mountain areas.  Population tends to be sparse in the high plains, heavy along the junction
between the plains and  mountains,  and  moderate in the  mountains along narrow  valley floodplain
corridors.  The heaviest development is concentrated along  water courses.

        Development  along water courses has dramatically  reduced the area  of wetlands in the  Pacific
States.  As in the Rocky Mountain Region, many Pacific States wetlands occur in rangeland environments
rather than forests.  However, many wetlands do occur in  the Western Forests, including the large
.estuaries of San Francisco and Puget Sound and the forest wetlands along the north coast of Washington.
Perhaps of even greater importance in the Western Forests are riparian areas. These forest zones provide
essential habitat for many forest species,  connect forest to  wetland areas,  and provide filtering and
transport of nutrients for aquatic systems.  The traditional use of riparian areas  for access to  timber
harvesting and transport of logs has severely degraded riparian areas in the Western Forests.
Habitat Evaluation                              97                                Western Forests

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Auatic
        Approximately 6 million ac of -water area occur in the vast Rocky Mountains.  About 4 million
ac of water area occur in the Pacific States, including coastal waterways such as Puget Sound and Strait
of Juan de Fuca, Crater Lake, and rivers such as the Columbia and Willamette. Incomparable salmonid
fisheries were once characteristic of the Western Forests.  Timber harvesting practices and development
on major rivers, especially damming for bydropower and irrigation diversion, have dramatically reduced
fishery habitat and salmonid abundance.

Activities and Impacts Affecting Habitats

        The major sources of degradation and loss to  terrestrial environments in the Western Forests are
timber harvesting practices and mining.  Land conversion and water management activities also affect
both terrestrial and aquatic systems. The ecologically rich old-growth forests of the Pacific Northwest
are under intense logging pressure as private old-growth lands are eliminated.  The total area of old
growth has declined by 80%, and the remaining forests are being fragmented and degraded.  This issue
represents  one of  the  country's most intense  conflicts  of natural area  preservation  and resource
exploitation.

        In addition to timber harvesting, mining and  oil and gas development pose risks to the  pristine
natural areas of the Northwest.  Gold mining is causing habitat degradation in Washington.  Pressure
upon local governments to convert open space to residential,  commercial, and  industrial  uses to
accommodate growth  have  been intense, and have also been responsible for the loss of wildlife habitat
in the area. Losses have been most severe where the effects of urbanization and population growth are
most pronounced.   California habitats that have lost significant acreages in the last 30 years  include
foothill oak woodland, closed-cone pine-cypress, and  redwood forests. Much of the development in the
next decade will occur on hardwood forest lands of California.
Habitat Evaluation                              9g                               Western Forests

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        The following activities result in the major impacts on habitats of concern in the Western Forests.
IMPACTS ON HABITATS OF CONCERN IN THE WESTERN FORESTS

Old-growth
forests
Remnant
hardwood
forests
Alpine
communities
Riparian,
wetland, and
aquatic systems
Land
Conversion
Minor
Urban development
Resort and recreational
development
Residential development
in river bottoms
and construction of
pipeline and
transportation corridors
Timber
harvesting
Qearcutting and
forest
fragmentation
Moderate
Minor
Major impacts
of erosion and
sedimentation
Mining
Moderate
Minor
Moderate
Major
Water
Management
Minor
Minor
Minor
Major impacts of
damming and
water diversion
Timber Harvesting

        Old-growth forests are of special concern for habitat conservation.  Not only do these sensitive
terrestrial environments contain unique assemblages of species but they  are also under intense timber
"harvesting pressure. The only significant remaining area of old-growth forest is the conifer forest of the
Pacific Northwest.  Less than 5 million ac of the original IS million ac of old growth in western
Washington and western Oregon remain.  Some view the altered landscape of the Olympic Peninsula in
western Washington due to timber cutting as the  most drastic ecological  disturbance of the last 10,000
years (Morrison, 1990).  Less than 20% of the original old growth on the peninsula remains, and entire
ecological associations of plants and animals that  once dominated lower elevations on the peninsula are
now rare.  Ancient forests of the Pacific Northwest have been so fragmented by roads and logging mat
the viability of the old-growth ecosystem is in question.

        Forests serve  many  important  ecosystem functions  that can be lost  or degraded by timber
harvesting practices (Norse 1990a).  For example, forests are naturally efficient regulators of water-flow
levels through the retention of surface run-off during high precipitation periods and the maintenance of
moisture levels during low precipitation  periods.  Forest stabilization of soils prevents increases in
sediment loads and maintains water purity for aquatic habitat and human uses. In the Klamath Mountains
of southwestern Oregon, erosion rates  in roaded areas averaged more than 100 times higher than on
undisturbed sites, and  erosion caused by logging alone averaged 6.8 times higher than on undisturbed
sites  (Dyrness  1975).   In  northern California over a  9-year period, stream sediment in a developed
Habitat Evaluation
99
                                  Western Forests

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watershed was more than 80% higher with road building and 275% higher with logging and roads than
in a similar, undisturbed watershed.  Forests also serve to retain nutrients within the ecosystem by a
complex process of litter accumulation and decomposition. Logging often destroys the nutrient retention
ability of the soils and has been implicated in failures to achieve forest regeneration.

        Fragmentation of habitat is another severe impact of timber harvesting on forests.  As roads and
clearcuts  are placed in  virgin forest, landscape fragmentation increases and the.natural buffering of
extremes in temperature, drought, snow pack, and wind decreases. As a result, blowdowns, fires, insect
and disease infestations, snag cutting, and salvage logging increase. Approximately 60 ac of old growth
are destroyed or altered for each new 25-ac clearcut in unfragmented old growth as a result of deleterious
edge effects; for every mile of road built in unfragmented old growth, approximately 97 ac of old-growth
forest are altered  by edge effects (Morrison 1988).

Land Conversion

        Land conversion in the Western Forests has the greatest impact on the remnant woodlands at the
edge of urban centers and on the forest valleys along river courses.  The U.S. Forest Service (1989)
projections over the next 50 yr indicate a loss in forest area of 8 million ac with the conversion to urban
and developed uses in the Seattle-Tacoma areas, numerous areas in California, and the mixed forest-urban
zones of  Oregon.  Conversion  of both uplands and  wetlands  has a profound effect on  the natural
communities in the West. In recent years, the expansion of populations into formerly pristine areas is
fragmenting forest through industrial and residential  development.  Rural areas are also suffering from
"spin-off development" associated with highway development.

Impacts on Riparian  and Wetland Are^s

       In addition to the conversion of lands along water courses, riparian and  wetland areas of the
Western Forests face threats from other offsite and onsite activities.  The primary impacts to wetlands
include the following:

       •       Recreation and other development (especially vacation houses and  resort facilities).

       •       Drainage and filling for buildup and parking areas (impact Of cumulative effects).

       •       Dewatering, diversion, and irrigation (there are many transbasin diversion systems in the
               Rocky Mountains).

       •       Forest clear-cutting and channelization (causing erosion, raster snowmelt, reduced water
               retention, and nutrient loading downstream).

       •       Mineral  mining (aquifer draw down,  channelization, stream diversion, acid and alkaline
               mine drainage, waste disposal sites and tailing areas, erosion and sedimentation).

       •       Sand and gravel mining (expected to  triple or quadruple by the year 2000).
Habitat Evaluation                              100                               Western Forests

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               Road and railroad access (construction of roads, villages, and towns along medium to
               large streams).

               Dams and reservoirs (decreasing the acreage of riverine, riparian, and wetland systems).

       s °p A
        Aquatic resources, especially the anadromous fisheries of the Pacific Northwest, are also suffering
 severe declines. The complex of dams on the Columbia River kill approximately 93% of young salmon
 and have contributed to the listing of the sockeye and chinook salmon as threatened. Recovery plans for
 these and other fish species will have large-scale ramifications on water management and human industry
 planning for the region (Weisskopf 1991).

 Mitigations of Imparts

        The conservation of habitats  requires consideration of mitigations for  the  major activities
 impacting habitats of concern.  In the Western Forests, the primary habitat impacts are caused by the
 following:

        •      Timber harvesting and fragmentation of old-growth forests.
        •      Land  conversion of remnant hardwood forests and alpine communities.
        •      Mining impacts on forests and aquatic systems.
        •      Water management impacts of diversion and damming on rivers.

 Management of the combined effect of these activities on sensitive habitats requires a holistic, ecosystem-
 level approach. The new interagency efforts to manage the Greater Yellowstone Ecosystem in Montana
 and Wyoming (approximately 20 million ac, 69% publicly owned  by five federal agencies) is the premier
 example of an integrated approach to  ecosystem management (Jaho 1991).  In particular, the approach
 pays special attention to the needs of wide-ranging species such as elk  and grizzly bears. It emphasizes
 the need to  look at the landscape scale (not institutional boundaries) for the implications of habitat value
    modification.
Timber Harvesting

        At a minimum, the production of commercial wood products from an area must not exceed the
sustainable level if the ecological integrity of a forested area is to be maintained. Where sensitive forest
types exist, logging may be completely prohibited or constrained to specific methods to prevent habitat
loss or degradation.  In other areas, more extreme harvesting methods may be allowed or prescribed to
establish or maintain desired forest conditions. Acceptable methods will vary according to local forest
ecology and the desired future condition of the site.  Analysis of harvesting techniques must be based
upon an analysis of the structure and diversity of the forest canopy, midstory, and understory.

        A recent directive of the Chief of the U.S. Forest Service acknowledges mis fact and points out
that clear cutting  is acceptable only when  needed to replicate natural ecological processes.   Selective
cutting can preserve forest structural diversity, the primary determinant of wildlife habitat (Harris et al.
 1979). However, it can reduce horizontal  diversity (NRC 1982).  The harvesting technique employed
must be based upon sound silvicultural prescriptions and demonstrate its capability to maintain vertical
 Habitat Evaluation                             101                               Western Forests

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diversity (foliage height diversity), horizontal diversity (interspersion, edge, juxtaposition, patchiness)
and  a mixture of live and dead wood.  Specific timber harvesting operations should be designed to
preserve the structure and diversity of the natural forest habitat.

        An important component of selective cutting should be the preservation of standing dead trees.
Many forest birds nest, roost, or forage for invertebrates in standing trees with decayed wood.  These
cull trees are usually the first focus of forest-Chinning operations to the detriment of the birds.  Breeding
bird abundance declines rapidly following a clear cut, and the species composition continues to change
for 10 to 15 years (DeGraaf 1991). However, if trees with cavities are saved, many of these species can
successfully forage on sound boles.   About one large cavity or den tree per 2 ha is required for
population of large species such as wood ducks; this requires harvest rotations of  100 to 125 years
(although rotations of 65 years produce trees large enough for species nesting in smaller cavities).

        Timber harvesting practices modified to reduce the impacts of simplification  must also address
fragmentation. Toe setting aside of undisturbed tracts will not achieve viable populations of the larger,
wider-ranging  species.  Some species require specific habitat conditions; others  require particular
arrangements  of several  communities.   Therefore,  a successful fauna! conservation strategy must
emphasize the landscape configuration, not just the structural content of the communities themselves.

        Responding to the "biodiversity crisis," the U.S. Forest Service is moving toward an ecosystem
approach to forest management (Bob Szaro, personal communication).  Recent forest management plans
have  incorporated tenets of the "New Forestry" espoused by Jerry Franklin. These progressive plans
require the rigorous implementation of ecological management practices to maintain forest productivity
and preserve  the functioning of sensitive forest  components such as old-growth or late-successional
forests. Effective mitigations for habitat conservation in forest management require specific management
measures  at the site,  watershed, and  landscape levels.  For example, the location and size  of  timber
harvests should be planned to minimize  reduction of core area of mature forest (e.g., harvest only
alternate basins until regrowth).  Maintenance of mature-forest stands in  managed  landscape can be
achieved by extending rotation (beyond 80) to 150 to 200 years, by leaving some stands unharvested for
old growth, and by linking stands.  Landscape-scale considerations include the provision of buffer zones
and  habitat corridors as discussed  in the introduction  to this document.  Management  measures
recommended for conserving habitat within managed forests include the following:

        •      Minimize the construction of new roads and close roads not in use either permanently or
               seasonally.

        •      Use best management practices (BMPs) such as filter strips to minimize erosion during
               harvesting or road construction.

        •      Maintain 100-ft riparian zones with adjacent feathered transition zones  to buffer edge
               effects.

        •      Restrict harvesting operations to periods when the ground is either dry or frozen.

        •      Maintain site productivity by retaining large woody material and minimizing mineral soil
               exposure and compaction during harvesting.
Habitat Evaluation                              102                               Western Forests

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tree
        •      Manage for natural disturbance patterns to maintain natural openings and successional-
               stage composition.

        •      Maintain connections between blocks of interior forest, especially old growth.

        •      Provide for die protection of special areas, including cliffs, caves, taluses, riparian areas,
               and old-growth stands.

        •      Maintain the structural integrity and the native variety of the forest by managing for
               natural composition of the following components: vegetative types, serai  stages,
               types and sizes, standing dead trees and down material, tree snags, and cavity trees

        The preservation of old-growth forest in the Pacific Northwest has been the focus  of intensive
 scientific study. For example, the report of The Scientific Panel on Late-Successional Forest Ecosystems
 provides a model  of  alternatives of forest management  for preservation  of ecosystems and wildlife
 (Johnson et al. 1991).  Using the spotted owls as  an indicator species, the panel derived the following
 recommendations for mitigating the impact of timber harvesting on late-successional/old-growth forest
 in the Northwest:

        •      Late-Successional/Old-Growth (LS/OG) areas should be protected as habitat conservation
               areas (HCAs).  Blocks suitable to  maintain 20 pairs of owl should be not more than 12
               miles apart.  Areas between these  blocks must follow the 50-1 1-40 rule: 50% of forest
               must have an average tree diameter of 1 1 inches and canopy closure of 40 % .  Areas with
               additional owls may be added to the HCAs to meet the goal of preservation.

        •      Provisions for  watersheds and fish include major reductions in  road mileage and  road
               drainage improvements, as well as extended logging rotations. "Problem" roads would
               be improved or removed, and unstable soils would remain unroaded.

        •      Riparian management will include no-harvest areas of varying width (1/4  mi to 50 ft
               depending on the value of the stream).

 In a series of alternatives (from high timber harvest to LS/OG and watershed/fish emphasis), the Panel
 found that "current forest plans do not provide a high level of assurance for maintaining habitat for old-
 growth-dependent species."  No alternative provides abundant timber harvest and high levels of habitat
 protection for species  associated with late-successional forests.

 Land Conversion

        Effective mitigation of land conversion activities can sometimes be obtained only  by avoiding
.impacts on rare or unusual habitat types.  Rarely, if ever, is restoration or compensation  an adequate
 mitigation for the loss of these habitats. In these  cases, mitigation is a siting issue, where  construction
 and degrading activities are located at a distance from the habitats of concern.  The habitat is adequately
 preserved  if all possible impact scenarios are accounted for. Barring this solution, effective management
 measures must be implemented to ensure the protection of the habitats of concern.
 Habitat Evaluation                             103                               Western Forests

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        In the case of unique woodland or wetland habitats," hydrologies] and contamination concerns are
especially important.  Construction or resource management activities require the use of sediment filter
strips and other means of intercepting offsite contaminants. Road building and structural "improvements"
must not result in altered hydrological regimes.  Where rare plant types exist or where habitats are
unstable (e.g., riparian areas), recreational access may have to be limited.  These mitigations can be best
implemented by creation of a regional land-use plan (through a coordinating council like the Waterfowl
Flyway Council) and landowner incentives like the Conservation Reserve Program,

Mininp

        Mitigation of  mining  impacts involves  siting issues, technological  solutions  to  eliminate
contamination, and restoration programs. The major mitigations for oil and gas extraction and production
are the proper sitings of rigs, reserve pits, processing facilities, and roads where they will have minimal
impacts on habitats of concern. Most important for coal and mineral  mining is the siting of mining
operations and tailing ponds to avoid habitats of concern, wetlands, riparian areas, and recharge areas.
Specific mitigation measures depend on the type of mining and the specific process causing impacts.  It
is generally best to minimize the area affected as h is unlikely mat even the disrupted soils and  sediments
can  be restored.   In  addition to minimizing the area  disturbed,  activities should be timed to  avoid
disturbing nearby plants and animals during crucial periods of their life cycle.

        Possible mitigation measures for mining operations include the following (SAIC 1991a, 1991b):

        •       Design of mine entrances and workings to minimi™ future mine drainage.

        •       Runon and runoff control measures such as berms and ditches.

        •       Adequate depth and lining of pits for containment of muds and  leachate.

        •       Elimination of migration of fluids through casings and dewatering.

        •       Separation of wastes and contaminated soils with proper disposal.

        •       Treatment of leach heaps and neutral or acidic wastewaters to reduce the load of cyanide,
               nitrates, and heavy metals.

        •       Closure planning  mat addresses  hydrology,  geocbemical controls, treatment, and
               restoration.

        •       Nets or other covers over process ponds.

        •       Maintenance of an anaerobic environment in the tailing pile during periods of inactivity.

        •       Secondary  containment of tanks and contingency plans  for  sudden or catastrophic
               releases.

        •       Backfilling and sealing of the mine workings  during mine  reclamation/closure.
Habitat Evaluation                              104                               Western Forests

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        •      Recycling of process water, smelter slag, and air pollution control dust.

        •      Monitoring and elimination of discharges to surface water, groundwater, soils, and air.

        •      Replenishment of surface and ground waters with treated effluents.

        «      Road closure and  reclamation  (following  recontouring) with revegetation of native
               species.

Although the reclamation of mined lands is often  unsatisfactory for ecological habitat restoration,
reforestation with native trees has been demonstrated  (Plass 1975)  and would  serve  to  reduce  the
abundance of nest parasitic brown-headed cowbirds and restrict their access to mature forest.

Wetlands

        Mitigation of wetlands destruction and degradation is the subject of a growing body of literature
(Kusler and Kentula  1989).  Restoration and mitigation banking concepts are still being evaluated as
effective mitigation measures for direct wetlands alterations.

Guidelines for Reviewers

        Reviewers of environmental impact assessments will find this document useful if they follow the
steps laid out in the introduction:
        1.      Review the status and trends of habitats in the region.

        2.      Identify the habitats of concern.

        3.      Link the activities involved with impacts to these habitats of concern.

        4.      Devise appropriate mitigations for the impacts.

Each reviewer can then determine the adequacy of the environmental impact assessment in question and
recommend modifications to enhance its effectiveness.

        In  identifying the habitats of concern, the reviewer should supplement the information in this
document with detailed locations] information on the abundance and distribution of habitats within the
region of interest, and with any historical information on the extent and quality of these habitats.  Most
important,  the reviewer should characterize  the habitats in terms of their ecological  values (e.g., use of
wooded wetlands by migratory waterfowl).

        In considering the links between activities and  habitats, the reviewer should look beyond direct
impacts to  indirect and subtle effects, including cumulative impacts, interactive and synergistic impacts,
and  scale-dependent impacts (e.g., effects of fragmentation on ecosystem integrity and species home
ranges).


Habitat Evaluation                             105                                Western Forests

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        In devising possible mitigations,  the reviewer should  follow die seven principles for habitat
mitigation repeated below.  The reviewer should also determine whether adequate assurances have been
given that the mitigations proposed will be completed.

        1.     Base mitigation goals and objectives on a landscape-scale analysis that considers the needs
               of the region.

        2.     Mimic natural processes and promote native species.

        3.     Protect rare and ecologically important species and communities.

        4.     Minimize fragmentation of habitat and promote connectivity of natural areas.

        5.     Maintain structural diversity of habitats and, where appropriate,  species diversity to
               promote the natural variety of the area.

        6.     Tailor  management to site-specific environmental conditions and to the unique impacts
               of the specific degrading activity.

        7.     Monitor for habitat impacts and revise mitigation plans as necessary.

        Finally, the reviewer should consider the  proposed activities and mitigations in the context of
relevant regional  program  goals and objectives (e.g.,  whether the outcome of the  project will be in
accordance with principles set out by regional planning commissions such as those established for the
Columbia River Basin).

Contacts and Information Sources

        When considering  habitat  conservation issues  in  an environmental  impact assessment for the
Western Forests, the reviewer should consult the following organizations and individuals for information
on habitat impacts and mitigations:

        State Natural Heritage Programs
        U.S. Fish  and  Wildlife Service, Regional and Area Offices
        State Fish  and  Game Departments
        University and Research Programs
        Herbaria and Museums

        Patrick Bourgeron, Regional Ecologist, The Nature Conservancy
        Jim Teeter, Associate Director,  Fish and Wildlife Enhancement, U.S. Fish and Wildlife Service
Habitat Evaluation                              106                               Western Forests

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                      ALASKA HABITAT REGION: ALASKA
Geographical Description of the Region

       The Alaska Habitat Region consists of the state of Alaska and is contained in EPA Region 10.
Although only the single state is included, Alaska constitutes one-third  of the land area of the United
States. Also, because it is separated from the conterminous states, Alaska contains a unique set of habitat
types.

       Alaska comprises 5 ecoregions  (Bailey 1980).  The vegetation  of Alaska consists of grasses,
sedges, lichens with willow shrubs, birch-lichen woodland, needleleaf forest, cottongrass-tussock, dwarf
shrubs, lichens, mosses, dwarf birch, Labrador-tea, cinquefoil, white spruce mixed with cottonwood,
balsam poplar, willow rose, dogwood, berry bushes, dwarf arctic birch, crowberry, arctic willow, resin
birch, dwarf blueberry, cottongrass, bluejoint, taiga, green and thinleaf alder, dogwood, sphagnum, bog
rosemary, white mountain-avens, moss-campion, black oxytrope, arctic sandwort, alder thickets, devils
club, mountain ash, and alpine-azalea.

       Alaska is unique among  the regions of the United States in mat  it  still possesses large areas of
pristine landscape. The scale of the state is vast, and changes to the landscape from different land use
patterns, although increasing, are still primarily restricted to urban centers, fishing ports, and oil and gas
producing operations.
Habitat Evaluation
107
                                          Alaska

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Habitats of Concern
       Alaska contains many habitats of concern; the most obvious fall into five general categories: old-
growth forest, riparian watersheds and fisheries, tundra, maritime forest, and boreal forest.  The principal
habitats of concern most at risk in Alaska are listed below.
                           PRINCIPAL HABITATS OF CONCERN
                                         TN ALASKA

              1. Old-growth forest of southeastern Alaska

              2. Riparian watersheds and salmon rivers

              3. Tundra
                •    wetlands (e.g., muskeg and sedge meadow)
                *    arctic tundra foothills and uplands
                *    alpine tundra

              4. Aleutian Island maritime grasslands

              5. Boreal forest of south-central Alaska
Habitat Values and Trends

       The scale and range of habitat types that occur in Alaska are unparalleled in the contiguous United
States.    Large areas  of Alaska are still without  any  ground inventories or meaningful ecological
descriptions.

Jundra

       Alaska contains 173  million ac of rangeland mostly in arctic and alpine  tundra.  By  many
definitions, the tundra of Alaska is wetland and includes many wetland complexes such as muskeg and
sedge meadow.  These areas support large populations of caribou, moose, and about 30,000 reindeer.
Also present are bears, wolves, coyotes, foxes, squirrels, and mice.  Lichen is a primary ground  cover
in Alaska, and it is critical to the survival of reindeer.  Lichen habitat has been seriously degraded by
overgrazing and wildfires.  In the arctic  tundra and Bering tundra provinces, cottongrass-tussock is
widespread; in the Brooks Range region, lower elevations may be  vegetated with  sedges and shrubs
(USDA Forest Service 1989).

       Tundra provides  critical habitat for waterfowl; h also supports fisheries on the  lowlands and
black-tailed deer on the uplands.  In the North Slope foothills, caribou use the uplands for calving and
Habitat Evaluation
108
                                          Alaska

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 are seasonally dependent on tundra vegetation.  The tundra and maritime grasslands of the Aleutian
 system provide one of the outstanding pristine ecosystems in the United States.

 Forests

       Alaska is less man 40% forested.  Today, Alaskan forests consist of 116 million ac of fir-spruce
 and  11 million  ac of hemlock-Shka  spruce  (USDA  Forest Service 1989).   More than 90% of me
 commercial coastal forests are still in old growth; however, in the interior more than 50% are in young
 stands (Barrett 1980).  Except in the immediate vicinity of villages, the native Indians made no impact
 on the coastal forests. However, both aboriginal and modern cultures have  altered the interior forest
 through fire.

       The mainland of coastal Alaska and the island archipelago contain one of the largest pristine
 rainforest and shoreline ecosystems in the world.   Of this,  11,600,000 ba fall within the Tongass and
 Chugach National  Forests and the Glacier Bay National Park and Preserve.  Southeast Alaska  is 46%
 forested, with the remainder in alpine, permanent snow and ice (including broad piedmont glaciers at the
 northern tip), or bog (muskeg). This coastal forest type (Sitka spruce-western hemlock) extends westward
 across south-central Alaska where me state is only 11 % forested.  Similar to the Pacific Northwest,
 Alaska old-growth forest is multi-aged with codominants 200 to 250 years of age.  However, Alaskan
 old-growth forest experiences less frequent natural perturbations (such as fire) and  contains a  greater
 percentage of total closed-canopy cover.  Highly productive old-growth forests usually occur in smaller
 patches man in the Pacific Northwest and are increasingly fragmented toward their northern range limit.
 In general, however,  Alaskan old-growth forest is abundant owing to the relatively low frequency of
 catastrophic disturbance (Alaback and Juday 1989). Coastal Alaskan old  growth supports Sitka black-
tailed deer and other wildlife species.

Alaska Coastal Plain

       The Alaska Coastal Plain is one of the last intact arctic ecosystems.  It supports caribou, musk-ox,
moose, Dall sheep, wolf, arctic fox, brown bear, and 22% of the western arctic population of lesser snow
goose. This area is threatened by oil and minerals exploration and development;  in many cases land is
being leased to oil companies by native corporations (Frazier 1987).   Oil drilling in Prudhoe Bay has
caused erosion, vehicle damage, heavy dust loads from the road system, and water damming and tundra
ponding.

 Aquatic Systems

       About 16 million ac of Alaska is in water area, principally the coastal  waterways, the numerous
 large rivers of the Yukon  system, and  more than 3  million  lakes more  than 20 ac in size.  Alaska
 possesses  the world's most productive salmon fisheries.
Habitat Evaluation                             109                                        Alaska

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Activities and Impart* Affecting Habitats

        The following activities result itf tbe major impacts on habitats of concern in Alaska.
IMPACTS ON HABITATS OF CONCERN IN ALASKA

Old-growth forest
Riparian
watersheds and
fuberiec
Tundra
Maritime
grasslands
Boreal forests
Land
COUVHSKMI
Minor
Urban development in
river bottoms and
development of pipeline
and transportation
corridors
Conversion around urban
centers
Minor
Minor
Timbering
Heavy logging in
the Southeast
Major impact
from logging
practice* and
sedimentation
None
None
Moderate
Mining
Minor
Degradation
from in-stream
placer mining
Impacts of oil
and gas
production
Minor
Minor
Other
Minor
Minor
Impacts of
military
activities
Impacts of
military
activities
Minor
Land Conversion

       Alaska is experiencing rapid development of certain areas, especially around Anchorage and
Fairbanks (Mary Lynn Nation, personal communication). This includes urban sprawl and the building
of infrastructure for tourism. Considerable conflicts with wetland fills have arisen because of the extent
of tundra wetland.  Land conversions include areas for ports and airports infrastructure,  and areas for
harbors and the shipping industry.  Private fish hatcheries and ladders are consuming land in the south-
central region, and the fishing industry in Dutch Harbor has converted  land for processing and storage
operations.  One of the greatest threats is posed by transportation corridors; a recent proposal is to open
the Dalton Highway (the hauling road to the North Slope) to recreation.

Timber Harvesting

       Timbering of Alaska is principally confined to the coastal southeastern area of productive Sitka
spruce-hemlock. It ranks with tourism, behind oil production and fisheries, as the state's major industries
(USDA Forest Service 1989). Considerable research has been conducted on timbering methods for this
area and will likely result in both less national forest area being available for logging and more intensive
timbering of the remaining lands. The increase in privately owned forest will likely result in logging and
a decreased forest area in certain locations. In particular, the leasing of land through native corporations
has resulted in increased logging.
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110
                                           Alaska

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        Timbering activities include clear cuts and conversions for roads, antennas, and other operational
areas.  Severe impacts are also caused by log transfer, staging, and in-water storage.  Negative effects
include erosion and si nation of salmon fishery habitat and loss of habitat for black-tailed deer.

Mining

        In addition to timbering, mining and oil and gas development pose severe .risks to the pristine
natural areas of Alaska.  Exploration and production of oil reserves in Alaska are in direct conflict with
many wildlife requirements. In addition to the production on the Kenai Peninsula oil patches and offshore
oil drilling in Cook Inlet, considerable small-scale drilling exploration is conducted in undeveloped areas.
Discovery of oil in these regions would require substantial infrastructure development, including pipelines
and tinkering. New petroleum and liquid natural gas (LNG) pipelines are also proposed.

        Gold mining is another cause of habitat degradation in Alaska. This includes placer mining and
proposed copper leachate facDities. Impacts include the effects of tailings and runoff, especially the
contribution to erosion and sedimentation that negatively affect salmon fisheries.

Military Activities

        Military  operations constitute another  activity  degrading habitats in Alaska.   This is most
important in the pristine Aleutian maritime grasslands; the fact that these areas are generally inaccessible
has prevented virtually all other degradation.  Impacts include toxic releases and bulldozing operations
causing erosion.

Mitigations of Impacts

        The conservation of  habitats  requires  consideration  of mitigations for  the major activities
impacting habitats of concern.  In Alaska, the primary habitat impacts are caused by the following:

        •      Timbering of old-growth forests in southeastern Alaska.
        •      Mining impacts on tundra and aquatic systems.
        •      Urban expansion and conversion of tundra environments.
        •      Impacts of logging and development on riparian areas and salmon fisheries.

Management of the combined effect of these activities on sensitive habitats requires a holistic, ecosystem-
level approach.  In particular, the approach pays special attention to the needs of wide-ranging species
such as caribou.  It emphasizes the need to look at the landscape scale (not institutional boundaries) for
the implications of habitat value and modification.
Timber Harvesting

        At a minimum, the production of commercial wood products from an area must not exceed the
sustainable level if the ecological integrity of a forested area is to be maintained.  Where sensitive forest
types exist, logging may be completely prohibited or constrained to specific methods to prevent habitat
loss or degradation.  In other areas, more extreme harvesting methods may be allowed or prescribed to
establish or maintain desired forest conditions.  Acceptable methods will vary according to local forest
Habitat Evaluation                              111                                         Alaska

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ecology and die desired future condition of the site.  Analysis of harvesting techniques must be based
upon an analysis of the structure and diversity of the forest canopy, midstory, and understory.

       A recent directive of the Chief of the U.S. Forest Service acknowledges this fact and points out
that clear cutting is acceptable only when needed to replicate natural ecological processes.  Selective
cutting can preserve forest structural diversity, the primary determinant of wildlife habitat (Harris et al.
1979).  However, h can reduce horizontal diversity (NRC 1982).  The harvesting technique employed
must be based upon sound silvicultural prescriptions and demonstrate its capability to F"««nt«in vertical
diversity (foliage height diversity), horizontal diversity (ioterspersion, edge, juxtaposition, patchiness),
and a mixture of live and dead wood.  Specific timber harvesting operations should be designed to
preserve the structure and diversity of the natural forest habitat.

       An important component of selective cutting should be the preservation of standing dead trees.
Many birds nest, roost, or forage for invertebrates in standing trees with decayed wood.  These cull trees
are usually the first focus of forest-thinning operations, to the detriment of the birds.  Breeding bird
abundance declines rapidly following a clear cut, and the species composition continues to change for 10
to IS years (DeGraaf 1991).   However, if trees with  cavities are saved,  many of these species  can
successfully forage on sound boles.   About one large cavity or  den tree per 2  ha is required for
population of large species  such  as wood ducks; this requires harvest rotations of 100 to 125 years
(although rotations of 65 years produce trees large enough for species nesting in smaller cavities).

       Responding to the "biodiversity crisis," the U.S. Forest Service is moving toward an ecosystem
approach to forest management (Bob Szaro, personal communication). Recent forest management plans
have incorporated tenets of the "New Forestry" espoused by Jerry  Franklin.  These progressive plans
require the rigorous implementation of ecological management practices to maintain forest productivity
and to preserve  the functioning of sensitive forest components such as old-growth or late-successional
forests. Effective mitigations for habitat conservation in forest management require specific management
measures at the  site, watershed, and  landscape levels.   For example,  the location and size of timber
harvests should be planned to minimize reduction of the core area of mature forest (e.g., harvest only
alternate basins  until  regrowth).  Maintenance of mature-forest stands in  managed landscape  can be
achieved by extending  rotation (beyond 80) to 150 to 200 years, by leaving some stands unharvested for
old growth, and  by linking stands.  Landscape-scale considerations include the provision of buffer zones
and habitat corridors as were discussed in the  introduction of this  document.  Management  measures
recommended for conserving habitat within managed forests include the following:

       •      Minimize the construction of new roads and close roads not in use either permanently or
              seasonally.

       •      Use best management practices  (BMPs)  such as filter strips to minimize erosion during
              harvesting or road construction.

       •      Maintain 100-ft riparian zones  with adjacent  feathered transition zones to buffer edge
              effects.

       •      Restrict harvesting operations to periods when the ground is either dry or frozen.
Habitat Evaluation                              112                                       Alaska

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        •      Maintain site productivity by retaining large woody material and minimizing mineral soil
               exposure and compaction during harvesting.

        •      Manage for natural disturbance patterns to maintain natural openings and successional-
               itage composition.

        •      Maintain connections between blocks of interior forest, especially o)d growth.

        •      Provide for the protection of special areas, including cliffs, caves, taluses, riparian areas,
               and old-growth stands.

        •      Maintain the structural integrity and the native variety of the forest by managing for the
               natural composition of the following components: vegetative types, serai stages, tree
               types and sizes, standing dead trees and down material, tree snags, and cavity trees.

        The conservation of old-growth forest presents a special  challenge  that  is  currently being
addressed in Alaska.  In southeastern Alaska, the rainforest extends 500 miles long  by  100 miles wide
across a mosaic of offshore islands. The forest supports Sitka spruce 200 feet tall and 400 years old with
a lush undergrowth of evergreen plants, ferns, and mosses. Most of mis rainforest is within the confines
of the Tongass National Forest and is subject to the multiuse management and timber harvesting of the
U.S.  Forest Service.  Forest series with late successional components in the Tongass  include upland,
riparian, and beach Sitka spruce, Sitka spruce-western hemlock, mixed conifer, and subalpine mountain
hemlock.   An old-growth management  prescription for the Tongass prepared by a recent workgroup
(Samson et al. 1991) included the following requirements: (1) define ecological units; (2) establish a
province system that captures representative habitat for  dependent  species; and (3) recommend the size,
shape, and distribution of habitats to maintain viable populations of species. The group recommends that
at least one watershed within each province be left intact for wildlife.  Timber and  timber-wildlife
emphasis alternatives were described.  The latter requires mat forest management in the Tongass include
the following:

        •       Harvest areas from the periphery inward to maintain large continuous blocks.

        •       Harvest areas  so that they are "sloppy" with small  patches  of green trees, brushy
               openings, and  snags to increase the habitat available through time.

        •       Provide edges  that are "feathered'* to reduce vulnerability to windthrow.

        •       Harvest habitat types in a manner that ensures the continued existence of each type and
               relative availability of each type.

        •      Use habitat models for indicator species to prioritize areas to be retained as old-growth
               wildlife habitat.

Based on population models of ermine, islands of less than 2,000 ac of forest habitat should not be
logged.  Alternatively, clusters of smaller islands may  withstand  timbering if species have appropriate
dispersal routes.
Habitat Evaluation                             113                                        Alaska

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Mining

        Mitigation  of mining  impacts'involves  siting issues,  technological solutions  to eliminate
contamination, and restoration programs. The major mitigations for oil and gas extraction and production
are the proper sitings of rigs, reserve pits, processing facilities, and roads where they will have minimal
impacts on habitats of concern. Most important for coal  and mineral mining is  the siting of mining
operations and tailing ponds to avoid habitats of concern, wetlands, riparian areas, and recharge areas.
Specific mitigation  measures  depend on the type of mining and the specific process causing impacts.  It
is generally best to minimize the area affected as h is unlikely that even the disrupted soils and sediments
can be restored.  In addition  to minimizing the area disturbed, activities should be timed to  avoid
disturbing nearby plants and animals during crucial periods of their life cycle.

        Possible mitigation measures for mining operations are listed below (SAIC 1991a, 1991b):

        •       Design of mine entrances and workings to  minimi™ future mine drainage.

        •       Runon and runoff control measures such as berms and ditches.

        •       Adequate depth and lining of pits for containment of muds and leacbate.

        •       Elimination of migration of fluids through casings and dewatering.

        •       Separation of wastes and contaminated soils with proper disposal.

        •       Treatment of leach heaps and neutral or acidic wastewaters to reduce the load of cyanide,
               nitrates, and heavy metals.

        •       Closure planning  that addresses hydrology, geochemical controls, treatment, and
               restoration.

        •       Nets or other covers over process ponds.

        •       Maintenance  of an anaerobic environment in the tailing pile during periods of inactivity.

        •       Secondary  containment  of tanks and contingency plans  for  sudden or  catastrophic
               releases.

        •       Backfilling and sealing of the mine workings during mine reclamation/closure.

        •       Recycling of process water, smelter slag, and air pollution control dust.

        •       Monitoring and elimination of discharges to surface water, groundwater, soils, and air.

        •       Replenishment  of surface and ground waters with treated effluents.

        •       Road closure and reclamation  (following recontouring) with revegetation of native
               species.


Habitat Evaluation                              114                                       Alaska

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 Although  the  reclamation of mined lands is often unsatisfactory for  ecological habitat restoration,
 reforestation with  native trees  has been demonstrated (Plass  1975) and would serve to reduce the
 abundance of edge species and restrict their access to mature forest.

 Land fV>tiversion

        Effective mitigation of land conversion activities can sometimes be obtained only by avoiding
 impacts on rare  or unusual habitat types.  Rarely, if ever, is restoration or compensation an adequate
 mitigation for the loss of these habitats. In these cases, mitigation is a siting issue, where construction
 and degrading  activities are located at a distance from the habitats of concern.  The habitat is adequately
 preserved  if all possible impact scenarios are accounted for.  Barring this  solution, effective management
 measures must be implemented to ensure the protection of the habitats of concern.

        In the  case of unique tundra habitats, hydrological and contamination concerns are especially
 important.  Construction or resource management activities must take special precautions to minimize
 mechanical disturbance of permafrost soils. Road building and structural "improvements" must not result
 in altered hydrological regimes.  Where rare plant types exist or where habitats are unstable, recreational
 access may have  to be limited. These mitigations can be best implemented by creation of a regional land-
 use plan (through a coordinating council like the Waterfowl Flyway Council) and landowner incentives
 like the Conservation Reserve Program.

 Wetlands

        Mitigation of wetlands destruction and degradation is the subject  of a growing body of literature
 (Kusler and Kentula  1989).  Restoration and mitigation banking concepts are still being evaluated as
 effective mitigation measures for direct wetlands alterations.

 Guidelines for Reviewers

        Reviewers of environmental impact assessments will find mis document useful if they follow the
steps laid out in the introduction:

        1.      Review the status and trends of habitats in the region.

        2.      Identify the habitats of concern.

        3.      Link the activities involved with impacts to these habitats of concern.

        4.     Devise appropriate mitigations for the impacts.

>Bach reviewer can then determine the adequacy of the environmental impact assessment in question and
 recommend modifications to enhance its effectiveness.

        In identifying the habitats of concern, the reviewer should supplement the information in mis
 document  with detailed locational information on  the abundance and distribution of habitats  within the
 region  of interest, and with any historical information on the extent and  quality of these habitats.  Most
 Habitat Evaluation                             115                                        Alaska

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important, the reviewer should characterize the habitats in terms of their ecological values (e.g., use of
wooded wetlands by migratory waterfowl).

       In considering the links between activities and habitats, the reviewer should look beyond direct
impacts to indirect and subtle effects, including cumulative impacts, interactive and synergistic impacts,
and scale-dependent impacts (e.g., effects of fragmentation on ecosystem integrity and species home
ranges).

       In devising possible mitigations,  the  reviewer  should  follow the seven principles for habitat
mitigation repeated below.  The reviewer also should determine whether adequate assurances have been
given that the mitigations proposed will be completed.

        1.     Base mitigation goals and objectives on a landscape-scale analysis that considers the needs
               of the region.

       2.     Mimic natural processes and promote native species.

       3.     Protect rare and ecologically important species and communities.

       4.     Minimize fragmentation of habitat and promote connectivity of natural areas.

       S.     Maintain structural diversity of habitats and, where appropriate,  species diversity to
               promote the natural variety of the area.

       6.      Tailor management to site-specific environmental conditions and to the unique impacts
               of the specific degrading activity.

       7.      Monitor for habitat impacts and revise mitigation plans as necessary.

       Finally, the reviewer should consider die proposed activities and mitigations in the context of
relevant regional program  goals and objectives (e.g., whether the outcome of the project will be in
accordance with principles  set out  by regional planning  commissions).

Contacts  and Information Sources

       When considering habitat conservation issues in  an environmental impact assessment for Alaska,
the reviewer should consult the following organizations and individuals for information on habitat impacts
and mitigations:

       State Natural Heritage Programs
       U.S: Fish and Wildlife Service, Regional and Area Offices
       State Fish and Game Departments
       University and Research Programs
       Herbaria and Museums

       Gerry Tande, Regional Ecologist, The Nature Conservancy
       Mary Lynn Nation, Division of Federal Activities, U.S Fish and Wildlife Service, Alaska
Habitat Evaluation                              116                                        Alaska

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                  HAWAII AND THE ISLAND TERRITORIES
       This section briefly discusses Hawaii and the Island Territories.  They comprise a relatively small
land area, but are sufficiently distinct to require discussion separate from the seven major regions of the
United States.

Geographical Description

       The Hawaiian Islands and the Pacific Trust Territories of Guam and the Northern Marianas are
all included in EPA Region 9. Puerto Rico and the U.S. Virgin Islands are included in EPA Region 2.
Hawaii forms its own ecoregion in the Bailey system (1980), a Highland Ecoregion within the Rainforest
Division.  The island territories have not been classified into ecoregions by either the Bailey or Omeraik
systems.

       The vegetation of the Hawaiian Islands comprises tropical shrubs, dense needleleaf and broadleaf
forests,  bogs, and moss lichen communities.  Because of its isolation, Hawaii contains many endemic
species  and possesses a fauna and flora unlike mat found anywhere  else. Although the community
compositions  are different, the vegetation of the Pacific Trust Islands  aad Puerto Rico and the Virgin
Islands contains many of the same elements of tropical forests and island floras.

Habitats of Concern

      The diverse ecosystems of Hawaii can be classified as existing on dry leeward or wet windward
areas. Leeward lowlands consist mostly of introduced plants such as.kiawe and haole koa in grassland
or savanna habitats.  Leeward uplands contain evergreen scrublands and forests with exotics such as
guava, Java plum, and Christmasberry.  Windward evergreen rainforests are dominated by native ohia
and koa, and constitute 0.3 of the  1.7 million ac of forest on Hawaii. Above the rainforest on the highest
islands of Maui and Hawaii are zones of mountain parklands of koa and mamane, alpine scrub, and alpine
tundra (USDA Forest Service  1989).

      Of the 150 vegetation types in the Hawaii Natural Heritage classification, more  than 50% are rare
and nearly all are endemic (Sam Gon, personal communication).  Principal habitats of concern include
the following:

             Brackish anchialine pools along the shore.
             Coastal and lowland wetlands  (below 3000 ft).
             Coastal and lowland forest and shrub ecosystems.
             Upland forest types.
             Wet bog ecosystems within forests.
             Subalpine and alpine zones.

Habitat Values and Trends

       All the major ecological zones are represented in the 6,500 sq mi of Hawaiian  land mass. More
than 10,000 species of plants and animals are endemic to Hawaii.  Extinctions of native species began
with the arrival of Polynesians 1,500 years ago and  accelerated with the arrival of Europeans in the late


Habitat Evaluation                            117                                      Hawaii

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 1700s, reaching rates thousands of times the natural rate.  Of the 140 bird species native to Hawaii, 70
have become extinct and 30 more are endangered.  Currently, 37 species of plants in Hawaii are federally
listed as endangered and 152 more are expected to be listed in the next 2 years (Hawaii State Department
of Land and Natural Resources et al. 1991).

       The aboriginal Hawaiians converted most of the land below the 600-meter elevation to agriculture
on the eight main islands.  Today, nearly two-thirds of Hawaii's original forest cover and 50% of the
rainforest have been lost to land conversion for bousing, agriculture, and ranching.  Ninety percent of
the lowland plains dry forests, 61 % of the mesic forests, and 42% of the wet forests have been destroyed.
The last remnants of Hawaiian  coastal plant communities are on the most remote and arid shores.  The
unique terrestrial environments of Hawaii are also being degraded or lost due to the logging of tropical
forests. Hawaii contains 180 terrestrial ecosystems, of which at least 88 ecosystems will be lost within
20 years unless current losses of habitat are addressed (Tangley 1988).  Similar histories have befallen
the Pacific Trust Territories of Guam and the Northern Marianas and  Puerto Rico and the U.S. Virgin
Islands. For example, the loss of tropical rainforest to timbering and conversion to agriculture is a major
problem in Puerto Rico.

       The invasion of non-native species represents the greatest threat to surviving native species and
natural communities on all the  U.S. islands.  The Hawaiian archipelago has lost more than 75% of its
original endemic land bird fauna through prehistoric and historic extinctions; the comparable Galapagos
archipelago as  a whole is not known to have lost a single land bird species (Loope et al.  1988).  The
absence of native large mammals has left the native fauna and flora vulnerable to the browsing, rooting,
and trampling of introduced pigs, goats, cattle, and deer.  On Hawaii's  1.4 million ac of rangeland,  most
native plants have been replaced by introduced perennials.  Native Hawaiian birds have suffered  from
avian malaria spread by introduced  mosquitos, and native plants have been smothered by  the exotic
banana poka.  In Guam, the introduced brown tree snake has wiped out 9 of the 11 species of native
birds, and Hawaii is now threatened by the repeated reintroduction of this reptile.

Activities and Impacts Affecting Habitats

       The majority of forest land remaining in Hawaii is contained within the state forest  reserves and
conservation districts.  These lands are managed principally for watershed and aquifer protection and
allow little commercial wood harvesting.  However, timbering of native koa and exotic eucalyptus do
occur, and logging  continues to impact private lands.

       A greater threat to forest ecosystems in Hawaii is livestock grazing.  Substantial areas of forest
continue to be cleared to promote forage growth for cattle ranching (USDA Forest Service 1989).  The
current tax structure in Hawaii  encourages clearing of forest for ranching.

       Conversion  of lands for urban and resort construction has a major impact on coastal  and lowland
environments.  In addition, growing commercial  and  residential development contributes to the loss of
dry areas subject to fire.  This  problem is exacerbated on military firing ranges.

       Agriculture  has long been an important industry on Hawaii, and it continues to impact adjacent
terrestrial and aquatic habitats through sedimentation and contamination with pesticides.
Habitat Evaluation                              118                                       Hawaii

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       The primary threat to Hawaii and the Island Territories is alien species.  Introduced species
contributing to habitat destruction include herbivorous mammals, predaceous ants, dogs, cats, mongoose,
alien arthropods, mollusks, and alien plants. Wet ecosystems, in particular, are threatened by invading
non-native animals (principally pigs, goats, deer) mat disrupt the natural vegetation to the extent that
native species are replaced by non-native plants.  The invasion of combustible non-native weeds has
created a cycle of wildfires mat often destroy rare dryland native plants (Hawaii State Department of Land
and Natural Resources et al. 1991).

       The decline and extinction of many endemic Hawaiian bird species can be attributed to  the
unprecedented  invasion  of exotic species.   Among exotic  birds, more introductions (162) and
establishments (between 45 and 67) have occurred in Hawaii man anywhere else in the world (Scott et
al. 1986).  Today, more than 80 introduced vascular plant species currently pose threats to the native
biota in Hawaii.  The inadequacy of detection and control has resulted in continuing invasions, and the
problem of existing exotics requires constant management or additional losses will result.  It is believed
that biological methods offer the best hope of extensive long-term control of the most aggressive alien
plants in natural systems.

Guidelines for Reviewers

       Reviewers of environmental impact assessments for Hawaii and the Island Territories should refer
to other regional discussions for more detailed information on habitat impacts and their mitigations.  The
following section outlines the consideration of habitat conservation in the review process:

       1.      Review the status and trends of habitats in the region.

       2.      Identify the habitats of concern.

       3.      Link the activities involved with impacts to these habitats of concern.

       4.      Devise appropriate mitigations for the impacts.

Each reviewer can then determine the adequacy of the environmental impact assessment in question and
recommend modifications to enhance its effectiveness.

       In identifying the habitats of concern, the reviewer  should supplement the information in this
document with detailed locational information on the abundance and distribution of habitats within the
region of interest, and with any historical information on the extent and quality of these habitats.  Most
important, the reviewer should characterize the habitats in terms of their ecological values (e.g., use of
wooded wetlands by migratory waterfowl).

       In considering the links between activities and habitats, the reviewer should look beyond direct
impacts to indirect and subtle effects, including cumulative impacts,  interactive and synergistic impacts,
and scale-dependent impacts (e.g., effects of fragmentation on ecosystem  integrity and species home
ranges).
Habitat Evaluation                              119                                       Hawaii

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       In devising possible mitigations, the reviewer should follow the seven principles for  habitat
 mitigation repeated below. Hie reviewer should also determine whether adequate assurances have been
 given that the mitigations proposed wilLtoe completed.

       1.     Base mitigation goals and objectives on a landscape-scale analysis mat considers the needs
              of the region.

       2.     Mimic natural processes and promote native species.

       3.     Protect rare and ecologically important species and communities.

       4.     Minimize fragmentation of habitat and promote connectivity of natural areas.

       5.     Maintain structural diversity of habitats and, where appropriate,   species diversity to
              promote the natural variety of the area.

       6.     Tailor management to site-specific environmental conditions and to the unique impacts of
              the specific degrading activity.

       7.     Monitor for habitat impacts and revise mitigation plans as necessary.

       Finally, the reviewer  should  consider the proposed activities and mitigations in the context of
relevant  regional program goals and objectives (e.g.,  whether the outcome of the project will be in
accordance with principles set out by regional planning commissions).

Contacts and Information Sources

       When  considering habitat conservation issues in an environmental impact assessment for the
Hawaii and the Island Territories, the reviewer should consult the following organizations and individuals
for information on habitat impacts and mitigations:

       State Natural Heritage Programs
       U.S. Fish and Wildlife Service, Regional and Area Offices
       State Fish and Game Departments
       University and Research Programs
       Herbaria and Museums

       Sam Gon, Regional Ecologist, The Nature Conservancy
       Jim Teeter,  Associate  Director, Fish and Wildlife Enhancement, U.S. Fish and Wildlife Service
Habitat Evaluation                              120                                       Hawaii

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                                     REFERENCES
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