United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/600/R-92/060
March 1992
&EPA Wetlands Research
Plan FY92-96
An Integrated
Risk-Based Approach
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March 1992
WETLANDS RESEARCH PLAN FY92-96:
AN INTEGRATED RISK-BASED APPROACH
by
Scott G. Leibowitz1
Eric M. Preston1
Lynn Y. Arnaut2
Naomi E. Detenbeck3
Cynthia A. Hagley4
Mary E. Kentula1
Richard K. Olson2
William D. Sanville3
Richard R. Sumner1
Edited by
Joan P. Baker5
1 U.S. Environmental Protection Agency
USEPA Environmental Research Laboratory, Corvallis, OR
2 Man Tech Environmental Technology, Inc.
USEPA Environmental Research Laboratory, Corvallis, OR
3 U.S. Environmental Protection Agency
USEPA Environmental Research Laboratory, Duluth, MN
4 AScI Corporation
USEPA Environmental Research Laboratory, Duluth, MN
5 Western Aquatics, Inc.
Durham, NC
Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Corvallis, OR 97333
Printed on Recycled Paper
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NOTICE
This document has been subjected to U.S. Environmental Protection Agency peer and
administrative review, and it has been approved for publication as an EPA document.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.
This report should be cited as:
Leibowitz, S.G., E.M. Preston, L.Y. Arnaut, ME. Detenbeck, C.A. Hagley, M.E. Kentula,
R.K. Olson, W.D. Sanville, R.R. Sumner. 1992. Wetland Research Plan FY92:-96: An
Integrated Risk-Based Approach. Edited by Joan P. Baker. EPA/600/R-92/060. U.S.
Environmental Protection Agency, Environmental Research Laboratory, Corvallis, Oregon.
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CONTENTS
Figures vi
Tables - viii
Acronyms ix
Acknowledgments xi
Executive Summary ^ xiii
1. Introduction .'• 1
1.1 Background . 1
1.2 Wetland Research Priorities : . •'. ..... . ...... ' 2
1.2.1 Risk Assessment and Management . . . . 3
1.2.2 National Goal of No Net Loss 3
1.2.3 Major Causes of the Loss of Wetland Function 3
1.2.4 Water Quality Criteria for Wetlands 5
1 .'2.5 Wetland Restoration and Creation 6
1.2.6 Wetland Functions within the Landscape 6
1.2.7 The Role of Wetlands in Reducing Nonpoint Source Pollution ... 7
1.2.8 State Wetland Conservation Plans , . 8
1.2.9 Louisiana Wetland Loss 8
1.3 Priority Wetland Types 9
1.3.1 Freshwater Emergent Wetlands 9
1.3.2 Bottomland Hardwood Forests 10
1.3.3 Western Riparian Systems 10
1.3.4 Other Wetland Resources of Concern 11
1.4 Document Format •.-.•.•. ..12
2. Objectives and Organization of the Wetlands Research Program 13
2.1 Program Goals arid Objectives . ...... ..... 13
2.2 Program Organization .'....' 14
2.3 Program Quality Assurance 17
2.3.1 WRP Quality Assurance Program Plan ......... . 18
2.3.2 Individual QA Project Plans , 18
2.4 Coordination with Other Federal Agencies 18
3. A Risk-based Framework for Wetland Protection 19
3.1 The Concepts of Risk Reduction 19
3.2 Risk Assessment 20
3.2.1 Wetland Function 21
3.2.2 Wetland Value 22
3.2.3 Functional Loss ' 24
3.2.4 Replacement Potential 24
3.3 Risk Management 25
in
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CONTENTS (continued)
3.4 Monitoring and Evaluation 26
3.5 Implementation of the Risk-based Framework 28
4. Wetland Function Project 31
4.1 Background 31
4.2 Approach 33
4.2.1 Literature Synthesis and Conceptual Models 33
4.2.2 Empirical Field Studies 36
4.2.3 Manipulative Experiments , ,. 38
4.2.4 Development of Management Strategies for Protecting
Individual Wetlands and Wetland Complexes 38
4.3 Implementation 42
4.3.1 Functional Responses of Prairie Pothole Wetlands
to Sedimentation .". .".... 42
4.3.2 Effects of Management Practices and Nonpoint Source
Pollution on Bottomland Hardwoods 43
4.3.3 Hydrologic Modification in Urban Wetlands ................ 44
4.3.4 Effects of Stressors on Coastal Seagrass Communities . 44
4.4 Major Contributions 45
5. Characterization and Restoration Project , . . . 47
5.1 Background 47
5.2 Approach - • • •, .......-• 49
5.2.1 Wetland Characterization 49
5.2.2 Performance of Wetland Restoration and Creation Projects ....... 54
5.2.3 Performance Criteria arid Design Guidelines .....;......... 57
5.2.4 Prioritization of Sites for Wetland Restoration and Creation 59
5.3 Implementation 60
5.3.1 Agriculturally Converted Wetlands in the
Prairie Pothole Region 60
5.3.2 Restoration of Western Riparian Systems 61
5.3.3 Creation of Freshwater Marsh 62
5.4 Major Contributions 62
6. Landscape Function Project 65
6.1 Background 65
6.2 Approach 67
6.2.1 Conceptual Models and BPJ Hypotheses 67
6.2.2 Simulation Studies 69
6.2.3 Empirical Landscape Analyses 69
6.2.4 Model Calibration and Applications 71
6.2.5 Low-cost Landscape Assessment Methods 71
6.3 Implementation 75
6.3.1 Landscape Assessment of Prairie Pothole Wetlands 76
6.3.2 Landscape Assessment of Bottomland Hardwoods .......... 77
6.3.3 Effect of Inland Wetlands on Estuarine Water Quality 78
IV
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CONTENTS (continued)
6.4 Major Contributions - - - 78
7. Risk Reduction Project 79
7.1 Approach 79
7.1.1 Framework Development and Review 80
7.1.2 BPJ Risk Assessment 80
7.1.3 Hierarchical Risk Assessment . 80
7.1.4 Technical Support for Risk Management . . . . 84
7.1.5 Monitoring and Evaluation Protocols 84
7.2 Implementation 84
7.2.1 No Net Loss 85
7.2.2 Reduction of Nonpoint Source Pollution 86
7.3 Major Contributions 86
8. Technical Information Transfer ? 89
8.1 Approach < 89
8.2 Additional Activities 90
9. Program Deliverables and Budget . . . 91
10. References 99
Appendix A: Overview of Original Wetlands Research Program . , 107
Appendix B: Wetland Research by Other Federal Agencies 111
Glossary 117
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FIGURES
Figure 2-1. Relationship between the original WRP projects and projects
planned for FY 1992-1996 15
Figure 2-2. Proposed research strategy for the Wetlands Research Program ..... 16
Figure 3-1. Components of the WRP risk-based framework for wetland
protection and management 21
Figure 3-2. Frequency distributions for an indicator of wetland function for
wetlands considered of "high" value by policymakers or
specific user group and wetlands considered to be of "low"
value by the same group . 23
Figure 3-3. Evaluation of restoration potential for wetland functions by
comparing the performance of restored or created wetlands
with that of natural wetlands in the same landscape setting ......... 25
Figure 3-4. Example hypothetical stressor/response curves, illustrating
in this case the relationship between landscape function and
increasing levels of some stressor or multiple stressors' 27
Figure 3-5. The benefits of a risk assessment, measured in terms of the
accuracy of the results, as a function of the assessment costs 29
Figure 4-1. Flow chart for the research strategy for the Wetland Function Project . . 34
Figure 4-2. Conceptual model of the Des Plaines River Wetlands,
developed by William Mitsch and others for the Des Plaines
River Wetlands Demonstration Project examining the response
of constructed wetlands receiving stormwater runoff from the
City of Chicago 35
Figure 4-3. Example of the type of results expected from empirical field
studies relating a gradient of stressors to the response of individual
wetlands 37
Figure 4-4. Chromium assimilation within microcosms containing a heavily
organic freshwater marsh soil or a predominately mineral
bottomland hardwood forest soil as a function of redox
potential, under a loading rate of 50 mg Gr/kg dry soil 39
Figure 5-1. Flow chart for the research strategy for the Characterization
and Restoration Project • 50
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FIGURES (continued)
Figure 5-2. Area of freshwater wetlands involved in Section 404 permitting
in Louisiana from January 1982 through August 1987, by parish 52
Figure 5-3. Illustration of a land use gradient showing the locations of 32
candidate wetlands in a landscape quadrat that extends out
from the urban area of Tampa, FL, and a comparison of land
uses surrounding each candidate wetland showing the change
from predominately urban to increased agricultural and natural
land uses with increasing distance from the urban center 53
Figure 5-4. Hypothetical performance curves illustrating the comparison
of a sample of populations of restored and natural wetlands
in the same land use setting and in different land use settings 55
Figure 5-5. Performance curves illustrating the level of plant diversity in
the emergent marsh component of created and natural
wetlands of different ages in Connecticut, Florida, and Oregon 56
Figure 5-6. Performance curve illustrating the accumulation of soil organic
matter in created and natural freshwater wetlands of different
ages in Oregon . 58
Figure 6-1. Flow chart for the research strategy for the Landscape
Function Project 68
Figure 6-2. Estimated wetland loss rates (percent loss) for landscape
units in the state of Washington 73
Figure 6-3. Weighted annual rate of growth in agricultural and urban land
uses for landscape units in the state of Washington :............. 74
Figure 6-4. Wetland site prioritization for wetlands in the Tensas Basin,
Louisiana, based on a management objective of maximizing
patch size 75
Figure 7-1. Matrix indicating the major sources of information to be used
for each risk assessment component by the Risk Reduction Project
81
VII
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TABLES
Table 9-1.
Table 9-2.
Table 9-3.
Table 9-4.
Table 9-5.
Table 9-6.
WRP Deliverables by Project and by Year
Budget Summary for WRP Projects by Year ....
Wetland Function Project: Timelines and Budgets
Characterization and Restoration Project:
Timelines and Budgets
Landscape Function Project: Timelines and Budgets
Risk Reduction Project: Timelines and Budgets
92
93
94
95
96
97
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ACRONYMS
BOR Bureau of Reclamation
BPJ best professional judgment
COE Corps of Engineers
CWA Clean Water Act
DQO data quality objective
EMAP Environmental Monitoring and Assessment Program
EPA Environmental Protection Agency
ERL Environmental Research Laboratory
FHWA Federal Highways Administration
FTE full-time equivalent
FWS Fish and Wildlife Service
FY fiscal year
GIS Geographic Information System
LDI Landscape Development Index
LULC land use/land cover
NWI National Wetlands Inventory
ORD Office of Research and Development
OST Office of Science and Technology
OWRS Office of Water Regulations and Standards
QA quality assurance
QC quality control
SAB Science Advisory Board
SCS Soil Conservation Service
TP total phosphorus
TVA Tennessee Valley Authority
USDA U.S. Department of Agriculture
USGS U.S. Geological Survey
WET Wetland Evaluation Technique
WRP Wetlands Research Program
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ACKNOWLEDGMENTS
The production of this research plan has been funded wholly or in part by the U.S. Environmental
Protection Agency through Contract No. 68-C8-0006 to ManTech Environmental Technology, Inc.,
Contract No. 68033544 to AScI Corporation, and Contract No. 68-CO-0021 to Technical
Resources, Inc.
Personnel from the Wetlands Division of EPA's Office of Wetlands, Oceans, and Watersheds and
the Regions have been extremely supportive throughout the development of this research plan.
They responded to our requests for information, attendance at meetings, lists of research
priorities, and reviews in addition to dealing with the pressing regulatory matters that were before
them. Their efforts have helped to guarantee that the Wetlands Research Program has focused
on issues important to the Agency. We continue to appreciate the personal support of John
Meagher, Director, Wetlands Division. In particular, we want to thank Doreen Robb, Wetlands
Divisions' liaison to the research program, for her efforts to help us communicate Agency needs
effectively and accurately, coordinate input from the Office, and resolve the myriad of questions
that came up.
The Wetlands Research Program (WRP) would also like to acknowledge the contribution of the
people who supported the authors in the production of this plan. Ann Hairston and Perry Suk
provided technical editing; Kristina Miller, word processing and graphics production. William
Norris coordinated the meetings and provided input to the first drafts. Arthur Sherman advised
on quality assurance issues. William Kruczynski and Raymond G. Wilhour of EPA's
Environmental Research Laboratory in Gulf Breeze, FL, developed the section on the pilot study
to develop preliminary technical support for the establishment of water quality criteria for coastal
seagrass systems.
The WRP thanks all those who generously gave of their time to review the various drafts of the
plan. In particular, we would like to recognize those who participated in an early planning
meeting. Their input did much to shape the overall direction of the Program. Participants were
Robert Brooks of Pennsylvania State University, Stephen Cordle, EPA's Office of Environmental
Processes and Effects Research, Michael Durako of the Florida Department of Natural
Resources, Charles DesJardins of the Federal Highway Administration, Gerald Grau of the U.S.
Fish and Wildlife Service's National Wetlands Research Center, Richard Horner of the University
of Washington, Carl Johnston of the University of Minnesota, Jill Miriter of EPA's Office of Science
and Technology, Gordon Thayer of the National Marine Fisheries Beaufort Laboratory, Russell
Theriot of the U.S. Army Corps of Engineers' Waterways Experiment Station, Arnold Van der Valk
of Iowa State University, Gary Williams of the Bureau of Reclamation, Chief Wu of EPA's Office
of Environmental Processes and Effects Research, and Joy Zedler of San Diego State University.
In addition, Carolyn Hunsaker of the Oak Ridge National Laboratory, Joseph Larson of the
University of Massachusetts-Amherst, and William Mitsch of Ohio State University provided
comprehensive written reviews of an early draft.
Finally, the WRP thanks the members of EPA's Science Advisory Board (SAB) for their review
and endorsement of the plan. Their input guided and strengthened the final version of the plan.
Members of the review panel were Allan Hirsch, Chairman; Betty Haak Olson, Vice-Chair;
Members-Donald F. Boesch, George F. Carpenter, and C. Herb Ward; Consultants-Barbara
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Bedford, James Gosselink, Joseph Larson, and Curtis Richardson; Federal Agency Liaisons-Ann
Bartuska (U.S. Forest Service), David E. Chalk (U.S.D.A. Soil Conservation Service), Robert
Stewart (U.S. Fish and Wildlife Service), and Russell Theriot (U.S. Army Corps of [Engineers)- and
SAB Staff-Edward S. Bender, Marcia Jolly, Robert Flaak, and Donald G. Barnes.
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WETLAND RESEARCH PLAN FY92-96:
AN INTEGRATED RISK-BASED APPROACH
EXECUTIVE SUMMARY
The Wetlands Research Program (WRP) was initiated in 1986 within the U.S. Environmental
Protection Agency's (EPA) Office of Research and Development (ORD) This document
presents the research objectives and strategy for the WRP for F.scal Years (FY) 1992-1996.
PROGRAM OBJECTIVES
The WRP is an applied research program. Its primary purpose is to provide technical support
to the EPA programs within the Office of Water and the Regions to improve the Agency s
ability to carry out its regulatory responsibilities relating to wetlands. Thus, the research
conducted by the WRP must be scientifically sound and represent a significant contribution
to wetland science and also directly serve the needs and priorities of the EPA program offices.
Based on the priority research needs identified by the EPA program offices, the specific
objectives for the WRP for FY 1992-1996 are as follows:
• Develop and demonstrate a risk-based framework for wetland protection and management.
• Determine the contribution of individual wetlands to water quality improvement, habitat,
and hydrologic functions, and develop techniques for enhancing these functions.
• Evaluate the role of the aggregate of wetlands in the landscape on water quality, habitat,
and hydrologic functions at a landscape scale, and the influence of wetland characteristics
on these landscape functions.
'• Quantify the effects of environmental stressors and landscape factors on wetland
functions.
• Characterize and compare the functional status of populations of natural, restored, and
created wetlands in different landscape settings.
• Provide technical support for the development of biological criteria for wetlands in support
of the Office of Water.
• Provide technical support for the development of design guidelines and performance
criteria for wetland restoration and creation.
• Using the information and methods listed above, conduct an integrated risk assessment
for at least one major wetland type to provide technical support on two major issues:
-- the national policy of no net loss of wetland area and function, and
-- the role of wetlands in reducing nonpoint source pollution.
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PROGRAM ORGANIZATION
!? 6 °bf ^f^ the WRP Wi" require information Sphered at three spatial scales
studies at Individual wetland sites are needed to better understand the processes
within wetlands that contribute to wetland functions, wetland responses to environment^
o nomLf W, nd, as,sirnllative caPacitv- '"formation also is needed on the characteristics
of Populations of wetlands (,.e, groups of wetlands of the same type) to compare the functions
iJno H H' ""I ', an? Cfeated WStlandS Within different Iandscape settings. Finally, research
s needed on the role of wetlands within regional landscapes. The incorporation of landscape-
are h Sari±nHVhte WRF? 6SSential beCaUSe (1) the formation and ^^tenance of wetlands
that wit £nHP J on landscape processes, such as regional hydrology, and (2) the functions
tha wetlands prov.de often arise from complexes of wetlands and the interactions between
wetlands and other ecosystems in the landscape.
The methods and analyses employed in wetland research tend to vary depending on the spatial
scale .of interest. For this reason. the WRP has been organized into four project areas, three o
±1 n' fhmP^SI2tKStUdl9S 3t a different Spatial scale- Tne fourth Project will synthesize the
results of the other three projects to address more complex, multiple-scale issues (Figure 1):
1.
2.
3.
Wetland Function Project - focuses on processes within individual wetlands or small
groups of wetlands along a gradient of environmental impacts, to quantify wetland
functions, stressor/response relationships, and wetland assimilative capacity.
Characterization and Restoration Project - develops methods and information to
characterize and compare the functional attributes of wetland populations, and also
develops design guidelines and performance criteria for wetland restoration and creation.
Undscape Function Project - examines issues at the landscape scale, studying the
aggregate of wetlands within a given landscape unit to determine how wetlands contribute
to andscape functions (e.g., regional water quality, biodiversity) and how landscape
factors (e.g., regional hydrology) affect wetland functions.
4.
PfOjeCt " '^W^5 to*lW* fr°™ the other three projects to address
hPHfSUeS at ™ltiple,scales- includin9 the development and demonstration
a risk-based framework for wetland protection and management.
nmonof
component of
to
is
°ther researcn projects: Constructed Wetlands and the wetland
Environmental Monitoring and Assessment Program (EMAP-WeHands)
"^ °Vhe WRP' Constructed Wet'ands and EMAP-wJSands are funded
seDaratef;esearch P'ans. The Constructed Wetlands Project also responds
prog!'amIIofflce- ,For the purposes of this document, therefore, the WRP or
^^ ^et'and FunCti°n' Characterization and Restoration,
hcluded °JeCtS; reS6arCh f°r Constructed Wet|ands and EMAP^
Three ORD Laboratories are involved in the WRP. ' The Characterization and Restoration
> F^ RiSK Redr'°n Pr°JeCtS' and Technical "nfor^on^SrS^S
EPA s Environmental Research Laboratory (ERL) at Corvallis. OR,. ERL-Corvallis
XIV
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Risk-Based Framework
Multiple Scale Issues
No Net Loss
Reduction of Nonpoint
Source Pollution
Wetland
Function
Project
Characterization
and Restoration
Project
Risk
Reduction
Project
JK~
Functions of
Individual Wetlands
. . •
Water Quality
Criteria for Wetlands
Functional Characterization
of Wetland Populations
•
Wetland Restoration
and Creation
i — .
Wetland Functions
in the Landscape
*
Rapid Landscape
Assessment Tools
Landscape
Function
Project
Priority Wetland Types
Freshwater
Emergent
Marsh
Bottomland
Hardwood
Forests
Western
Riparian
Systems
Figure 1. Proposed research strategy for the Wetlands Research Program.
xv
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also will act as matrix manager for the Program as a whole and will provide oversight of Program
Quality Assurance. ERL-Duluth (Minnesota) is responsible for the inland component of the
Wetland Function Project. ERL-Gulf Breeze (Florida) will conduct the pilot study for the proposed
coastal component of the Wetland Function Project.
PRIORITY WETLAND TYPES
Based on discussions with EPA program offices and with wetland scientists participating in a
WRP planning workshop in February 1991, three wetland types were identified as priorities for
research in FY 1992-1996: (1) freshwater emergent wetlands, (2) bottomland hardwood forests
and (3) western riparian systems.
Freshwater emergent wetlands are shallow wetlands that form in depressions, lake and stream
edges, and freshwater tidal zones. Prairie potholes, which occur in depressions within the glacial
deposits of the North American prairie, are a specific type of freshwater emergent wetlands that
is of special interest. Prairie potholes are the principal production area for many North American
duck species. Agricultural activities in the area have resulted, however, in significant wetland
losses and large inputs of sediment, nutrients, and agricultural chemicals that may degrade
wetland functions.
Bottomland hardwoods are extensive forested wetlands that occupy the alternating wet and dry
hydrologic zone adjacent to many rivers in the southcentral and southeastern United States.
These forests provide important functions, such as flood storage, water quality improvement, and
wildlife habitat, yet have been degraded by extensive timber clearing, the construction of dams
and levees that have modified the hydrologic regime, and other cumulative impacts.
Riparian systems (i.e., the interface between aquatic and terrestrial systems, in floodplains and
adjacent rivers and streams) contain the principal freshwater wetland type in the arid and semi-
arid regions of the western United States. These systems provide important habitat for wildlife,
and many of the endangered and threatened species in the area occur within riparian habitats'
Water diversions, urbanization, cattle grazing, and other impacts have resulted in extensive and
continuing loss and degradation of these systems and their associated wetlands.
Three other types of wetland resources have also been identified as warranting additional
research: (1) "drier" wetlands that are saturated with water during only some seasons of the year
(2) wetlands in urban landscapes, and (3) wetlands in coastal areas. Research will be conducted
on these wetland resources to the degree possible within the budget constraints of the WRP
Information on drier wetlands is of particular interest because these wetland resources may
provide an important resource for control of nonpoint source pollutants and flood attenuation, but
may no longer be protected under proposed changes in federal wetland policy and wetland
delineation. Wetlands in urban landscapes are used and valued by relatively large segments of
the general public, yet are also subject to high loss rates and a diversity of impacts. Information
on wetlands in coastal areas is needed on (1) the effects of stressors on coastal wetlands- (2) the
role of inland wetlands in moderating the transport of nutrients, sediments, and chemical
contaminants from the landscape to estuaries; and (3) appropriate water quality criteria and
management strategies for the protection of coastal wetlands. All three of the priority wetland
types noted above may include areas of drier wetland or occur within an urban setting- freshwater
emergent wetlands and western riparian systems can occur in coastal areas
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RISK-BASED FRAMEWORK FOR WETLAND PROTECTION
EPA's Science Advisory Board has recommended that EPA focus their environmental protection
efforts on those problems that pose the greatest risk and on the areas and problems in which the
greatest risk reduction can be achieved. Therefore, one of the major objectives of the WRP for
FY 1992-1996 is to develop and demonstrate the utility of a risk-based framework for wetland
protection and management. Eventually, after this framework has been tested and refined, it can
serve two important purposes: (1) to provide a basis for management decisions regarding
wetland protection that incorporate the best available technical information, and (2) to define
future WRP research needs and priorities.
The goal of the risk reduction process, as proposed by the WRP, is to minimize the loss of
valued wetland functions. The proposed WRP risk-based framework includes three basic
components, each of which includes both technical and policy input (Figure 2):
1. Risk Assessment - the estimation of the risks associated with various stressors and
identification of those wetlands of greatest value that are at greatest risk of functional loss
and also have low replacement potential
2. Risk Management - the development and implementation of an effective management
strategy to control and manage the most serious risks
3. Monitoring and Evaluation - follow-up monitoring to evaluate the effectiveness of
management actions and identify new problems that may arise
To serve the needs of wetland managers and regulators, the risk-based framework must be both
technically and programmatically feasible. The types of technical data and analyses required for
any given application must not be prohibitive. Thus, for most management applications, the
framework will be implemented hierarchically, increasing the level of effort at each stage and
continually focusing on those aspects that will contribute the most to improving management
decisions. Frequently, it may also be effective to implement the framework hierarchically on a
spatial scale, conducting assessments initially at a landscape scale (watersheds or ecoregions).
Site-specific data collection may or may not be necessary depending on the management
objectives, desired level of resolution and confidence, and nature and extent of existing data. The
specifics of how best to implement the risk-based framework will vary depending on the
management context and management objective being evaluated.
The risk-based framework will provide a structure for integrating the results from all four of the
WRP projects. The Risk Reduction Project, however, has the primary responsibility for framework
development and demonstration.
WETLAND FUNCTION PROJECT
The Wetland Function Project focuses on those tasks and information needs best provided
through relatively detailed studies of processes and responses in individual wetlands or small
groups of wetlands. Consistent with the EPA program priorities, four studies will be conducted
during FY 1992-1996, evaluating (1) the functional response of prairie pothole wetlands to
sediments and sediment-associated pollutants; (2) the effects of management practices and
xvii
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I
Science
Wetland Function
Functional Loss
Replacement Potential
Policy
Risk Assessment
Wetland Values
Risk Management
Technical Effectiveness
Guidelines for Avoidance,
Restoration, and Creation
Management Decisions
Laws and Regulations
Monitoring and Evaluation
Monitoring: Baseline
Evaluative
Technical Effectiveness
Program Effectiveness
Achievement of Policy
Objectives
Science
Policy
Figure 2. Components of the WRP risk-based framework for wetland protection and
management. All three components require both technical and policy input.
nonpoint source pollution on the water quality and habitat functions of bottomland hardwood
forests in agricultural landscapes of the southeastern United States; (3) the effects of hydrological
modification on the water quality and habitat functions of freshwater emergent marsh in an urban
setting; and (4) a pilot study of the effects of stressors on coastal seagrass communities.
Each study will incorporate, as appropriate, four major types of activities (Figure 3):
1. Develop literature syntheses and conceptual models to identify the wetland sfressors of
concern, potential indicators of wetland condition and function, and hypotheses regarding
wetland processes and stressor effects.
XVIII
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Literature Synthesis and Conceptual Models
Hazard Identification
of Priority Stressors
Identification of Indicators
Manipulative
Experiments
Empirical
Field Studies
Risk Assessment
Stressor/Response
Relationships
Response thresholds
Assimilative capacity
Uncertainties in extrapolations
Exposure Assessment
Pathways ot exposure
Chemical availability
Temporal/spatial variability
Risk Characterization
Synthesis of information
Technical Support for Risk Management
Water Quality
Criteria
Best Management
Practices
Guidelines for
Site-Specific
Monitoring
Figure 3, Flow chart for the research strategy for- the Wetland Function Project. The
hypothetical graphics are provided to illustrate how findings will be integrated into the
project; they are not meant to convey actual or expected results or relationships.
XIX
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2. Conduct empirical field studies to characterize wetland conditions (a) along a gradient of
an environmental stressor(s), (2) before and after the occurrence of a disturbance or
stressor, and/or (3) in wetlands with varying wetland or watershed management strategies,
to evaluate stressor/response relationships, exposure pathways, and the effectiveness of
various management practices for wetland protection.
3. Perform manipulative experiments in the field or laboratory to determine the response of
specific processes and wetland attributes to a controlled range of concentrations or
conditions associated with a specific stressor as well as to a range of modifying factors
(e.g., sediment organic carbon content).
4. Integrate the project results within the risk-based framework to provide technicafsupport
for risk management, including the development of water quality criteria (especially
numeric biocriteria) for wetlands, best management practices, and guidelines for
monitoring.
CHARACTERIZATION AND RESTORATION PROJECT
The Characterization and Restoration Project focuses on those information needs arid objectives
best achieved through field studies of wetland populations. The overall strategy for the project
is illustrated in Figure 4. Four major tasks will be conducted:
1. Characterize wetland populations, including natural, restored, and created wetlands, to
quantify wetland functions and among-wetland variability within specific geographic and
land use settings.
2. Evaluate the performance of wetland restoration and creation projects and determine the
attainable levels of wetland functions in various landscape settings.
3. Develop specific performance criteria and technical design guidelines to enhance the
performance of wetland restoration and creation projects and accelerate project
development.
4. Develop and test an approach for prioritizing sites for wetland restoration, and creation.
Indicators of wetland function will be measured in a representative sample of wetlands for each
wetland population of interest (e.g., natural, restored, or created wetlands within areas dominated
by urban or agricultural land use). Results from these field surveys will be used to characterize
and compare the functional status of wetland populations and to evaluate the performance of
wetland restoration and creation projects. Information on the long-term development of restored
and created wetlands over time, relative to conditions in natural wetlands in similar settings, is
of particular interest. Manipulative experiments may also be conducted to assess alternative
design features that may improve or accelerate the development of valued functions in restored
or created wetlands.
Three priority studies have been targeted for implementation during FY 1992-1996: (1) the
characterization of agriculturally converted wetlands in the Prairie Pothole Region, (2) the
development of objective protocols for selecting priority sites for restoring western riparian
xx
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Functional Characterization of Wetland Populations
if
i*
Restored Natural
Wetlands Wetlands
Indicator of Wetland Function
Performance Evaluation of Wetland Restoration and Creation
o
OT3
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4>
T _ T T T Natural
1 t r- J. Wetlanda
Time
Technical Support for Risk Management
Attainable Function
Performance Criteria
and Design Guidelines
Techniques for
Prioritizing Site
Selection-
Figure 4. Flow chart for the research strategy for the Characterization and Restoration Project.
The hypothetical graphics are provided to illustrate how findings will be integrated into
the project; they are not meant to convey actual or expected results or relationships.
systems and evaluation of approaches for restoring them, and (3) long-term studies of the
development of mitigation projects with a major component of freshwater emergent marsh.
LANDSCAPE FUNCTION PROJECT
The Landscape Function Project examines issues at a landscape scale, studying the aggregate
of wetlands within a given landscape unit, and comparisons among units, to determine how
wetlands contribute to landscape functions (such as regional biodiversity, water quality, and
hydrology) and how landscape processes and factors affect wetlands.
XXI
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For each region/landscape studied, five basic tasks will be conducted:
1. Develop conceptual model(s) and best professional judgment (BPJ) hypotheses regarding
the role of wetlands in landscape functions and the influence of landscape processes on
wetlands.
2. Refine these hypotheses through simulation analyses with existing models.
3. Conduct empirical landscape analyses for hypothesis testing and indicator development,
examining the association between (a) indicators of landscape function and wetland and
landscape characteristics and (b) indicators of wetland function and various landscape
factors and processes. . -
4. Calibrate model(s) for specific landscapes, using the results from the empirical landscape
analyses as well as from other WRP projects, and conduct model simulations to evaluate
management options.
5. Develop low-cost landscape assessment methods (such as the Synoptic Approach,
Landscape Development Index, and landscape criteria) that can be readily applied to
provide technical support for wetland protection and management in other areas.
The Landscape Function Project will rely primarily on information obtained by compiling and
analyzing existing data bases, maps, and other available data sources. Field data collected by
the Wetland Function Project, Characterization and Restoration Project, and EMAP-Wetlands also
will be incorporated into these landscape-level analyses as appropriate. The overall project
strategy is illustrated in Figure 5.
The specific studies to be implemented by the Landscape Function Project are (1) a landscape
assessment of prairie potholes; (2) a landscape assessment of bottomland hardwood forests; and
(3) an evaluation of the influence of inland wetlands on estuarine water quality.
RISK REDUCTION PROJECT
The Risk Reduction Project will integrate the results from the other three WRP projects to
demonstrate the application and utility of the proposed risk-based framework for wetland
protection and management. The Risk Reduction Project will conduct no new field work or
landscape analyses, but will work directly with the Wetland Function, Characterization and
Restoration, and Landscape Function Projects, as well as EMAP-Wetlands, to ensure that these
projects provide the types of methods, data, and analyses needed as input to a risk reduction
analysis (Figure 6).
Further work is needed to evaluate, refine, and demonstrate the risk-based framework.
Therefore, the following five tasks will be completed in sequence:
1. Review and evaluate the conceptual framework (described above), modifying and
augmenting it as necessary.- •
XXII
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BPJ Landscape Assessment
Conceptual Models .
Hypotheses
Simulations with
Existing Models
Empirical Landscape Analyses
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.Landscape/Wetland
Characteristic
• . ... ,• :- ..•••.•••••••.„••••••••• :• •'"••;
Landscape Models ,
Functions of Wetlands
in the Landscape
Effects of Landscape Factors
;.in Wetland .Functions :
i
Technical Support for Risk Management
Rapid Landscape
Assessment
Techniques
Role of Isolated
. We.ilands ,
Technical Evaluation of
Managenient Strategies
Figures. Flow chart for the research strategy for the Landscape Function Project. The
hypothetical graphics are provided to illustrate how findings will be integrated into the
project; they are not meant to convey actual or expected results or relationships. The
graphic at the bottom of the figure is used to represent the Synoptic Approach and
other low-cost landscape assessment methods.
XXIII
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WRP Project
I Assessment
Compononl
Wetland
Function
Characterization
and Restoration
Landscape
Function
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JO
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C
Walland Inventory
Wetland Capacity
Landscape Input
Wetland Value
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tn
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Conversion
Degradation
Replacement
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Figure 6. Matrix indicating the major sources of information to be used for each risk assessment
component by the Risk Reduction Project. The hypothetical graphics represent the
general types of analyses and outputs expected from the other three WRP projects.
as illustrated in Figures 3 through 5; they are not meant to convey actual or expected
results or relationships.
XXIV
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2. Conduct a BPJ risk assessment, to further evaluate and refine the basic framework,
demonstrate the utility of the approach, and provide interim project deliverables.
3. Synthesize the WRP research results into a comprehensive, hierarchical risk assessment
for selected regions and Issues.
4. Apply the risk assessment to provide technical support for risk management.
5. Develop a monitoring and evaluation protocol.
Consistent with the WRP research priorities and studies proposed by other WRP projects, the
Risk Reduction Project will focus on two wetland types: (1) prairie potholes and (2) bottomland
hardwood forests. The utility of the risk-based framework will be demonstrated by addressing two
major issues: (1) the national policy of no net wetland loss and (2) the role of wetlands in
reducing nonpoint source pollution.
QUALITY ASSURANCE
It is essential that data collected by the WRP are scientifically sound, legally defensible, and of
known and documented quality. To ensure the collection of high quality data, the WRP will
participate in a centrally managed quality assurance (QA) program that complies with the QA
policies of EPA and of each of the participating ORD Laboratories.
A member of the WRP staff will serve as WRP's QA Coordinator. The QA Coordinator will
prepare a QA Program Plan for the WRP, describing the Program's overall QA goals, methods
for achieving these goals, and QA responsibilities within the Program. In addition, individual QA
Project Plans will be developed as part of the detailed work plans prepared for each study within
the WRP. These QA Project Plans will define specific data quality objectives for the study, along
with the research design, sample collection procedures, analytical protocols, data analysis
methods, and quality assurance/quality control procedures. Each QA Project Plan will be
reviewed and approved by the WRP QA Coordinator and by the appropriate Laboratory QA staff
prior to the collection of any project data.
TECHNICAL INFORMATION TRANSFER
Technical information transfer is a Program strategy to ensure that WRP research is relevant to
EPA policy and regulatory needs and that innovations developed by the WRP will be adopted and
widely used by wetland managers. In 1988, a Regional Liaison Officer position was established
within the WRP to foster direct communication between WRP scientists and wetland experts in
states and EPA Regional Offices. The responsibilities of the Regional Liaison are to (1) identify
and communicate to the WRP the technical support needs of the EPA Regions and states; (2)
work to ensure that WRP studies address these priority technical support needs to the degree
possible; (3) encourage and coordinate the implementation of cooperative projects, involving
shared expertise and/or funding from both the WRP and EPA Regions or states; and (4) distribute
information on WRP projects and results to interested agencies, firms, and individuals. WRP
results are also presented in scientific journals, workshops, and symposia, and summarized in
the "Wetlands Research Update," published at least once per year and distributed widely to all
interested parties.
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PROGRAM DELIVERABLES
The research plans outlined in this document assume a five-year program with a budget of
approximately $2.5 million.annually. Major deliverables-for the WRP for FY 1992-1996, by project
and year, are listed in Table 1.
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Table 1. WRP Deliverables by Project and by Year
: WETLAND FUNCTION PROJECT
State-of-the-science review of stressors, impacts, and indicators of function for FY 1993
priority wetland types
Risk-based approach to setting water quality criteria, especially biocriteria, for FY 1996
wetlands
Handbook for the protection of wetland functions through the implementation of FY 1996
best management practices
Guidelines for site-specific monitoring of ecological integrity in individual wetlands FY 1996
and wetland complexes
Preliminary technical support on establishment of water quality criteria required for FY 1993
survival, growth, and re-establishment of coastal seagrass systems
CHARACTERIZATION AND RESTORATION PROJECT
State-of-the-science approach to selecting sites for restoring western riparian FY 1994
wetlands
An approach to selecting sites for wetland restoration FY 1996
Technical framework for the restoration and creation of wetlands: An evaluation FY 1997
of performance and design
LANDSCAPE FUNCTION PROJECT
An assessment of the function and value of isolated wetlands, with management FY 1995
recommendations
Rapid techniques for landscape assessment of wetlands FY 1996
An evaluation of the functions of wetlands in the landscape FY 1996
RISK REDUCTION PROJECT
The use of a risk-based framework with best professional judgment for wetland FY 1993
risk assessment
A protocol for monitoring and evaluating the effectiveness of risk management FY 1995
Application of a risk-based framework to no net loss of wetlands FY 1996
Application of a risk-based framework to reduction of nonpojnt source pollution FY 1996
XXVII
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
OFFICE OF
WATER
201992
MEMORANDUM
SUBJECT: Wetlands Research Program FY 1992-1996 Research Plan
FROM:
John W. Meagher, Director
Wetlands Division
TO:
Roger Blair, Chief
Watershed Branch
Corvallis Environmental Research Laboratory
I would like to take this opportunity to strongly endorse
the Research Plan entitled, "Wetlands Research: An Integrated
Risk-Based Research Strategy, FY 1992-1996 Research Plan." The
plan reflects the tremendous amount of hard work that went into
identifying and exploring the latest needs in wetlands research.
I feel the plan is at the forefront of where the Agency is headed
with risk-based research efforts, and I commend your continued
leadership role in pioneering wetlands research.
The shifts in emphasis within the current projects and the
continuing efforts toward integration are timely and will result
in a stronger program. I appreciate the opportunities you have
provided our Division to influence the directions of the plan.
We look forward to continued participation in the implementation
of the plan's projects. We also recognize that there are
specific projects within the plan that require input from other
offices in the Office of Water. Specifically, we look forward to
working jointly with the Wetlands Research Program and the Health
and Ecological Criteria Division of the Office of Science and
Technology to plan the work related to the development of
biological criteria for wetlands.
I trust over the next five years our offices will continue
this level of cooperation. We appreciate the contributions of
the Wetlands Research Program to EPA's wetlands protection goals.
Please count us among your strong supporters.
xxvm
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1. INTRODUCTION
This document presents the research strategy developed by the U.S. Environmental Protection
Agency's (EPA) Wetlands Research Program (WRP) for Fiscal Years (FY) 1992-1996. The
purpose of this research is to address the technical needs that have been identified by the EPA
programs within the Office of Water1 and the EPA Regions having legal authority over wetlands.
This research plan is intended, therefore, for two main audiences: the EPA program offices and
the wetlands research community. The objectives of the document are to describe the WRP
research strategy so that (1) the program offices can evaluate whether their priorities are being
met and (2) the wetlands research community can determine whether the proposed research is
scientifically sound. Because this is a strategic planning document, specific studies are not
described at the level of detail required for actual implementation. Detailed research plans will
be prepared and peer reviewed before studies are initiated. .
This section presents (1) a brief background on wetlands and the WRP, (2) the priority issues and
technical needs identified by the EPA program offices, (3) the priority wetland types for research,
and (4) a description of the document format. ,
1.1 BACKGROUND
As the interface between terrestrial and aquatic ecosystems, wetlands are an integral component
of the landscape, contributing in many ways to overall environmental quality. Wetlands comprise
only about 5% of the land area in the conterminous United States (Dahl 1990), but they have a
significant influence on the landscape because of their roles in regulating watershed hydrology
and water quality and in providing habitat for a diverse flora and fauna that includes over one-third
of the Nation's endangered species (U.S. Fish and Wildlife Service 1990). During the last 200
years, more than half of all wetlands have been lost in the United States due to human activities,
primarily the conversion of wetlands for agricultural uses. Losses in some states have been on
the order of 90% (Tiner 1984, Dahl 1990).
The objective of the Clean Water Act (CWA) is to restore and protect the physical, chemical, and
biological integrity of waters in the United States. Wetlands are included in the definition of the
Nation's waters. Thus, the CWA is the primary legislative basis for federal wetland protection.
The EPA is responsible for implementing the CWA and associated regulations.
The WRP was initiated in 1986 within EPA's Office of Research and Development (ORD) to assist
the Agency in carrying out its responsibilities under Section 404 of the CWA, which pertains to
the disposal of dredge and fill materials within the Nation's waters. Originally, the WRP
concentrated on three research areas: Water Quality, Mitigation, and Cumulative Impacts (Zedler
and Kentula 1986). Two more projects, Constructed Wetlands and the wetland component of the
Environmental Monitoring and Assessment Program (EMAP-Wetlands), were added later. All five
projects are described in Appendix A.
1 Relevant programs in the Office of Water include the Wetlands Division within the Office of
Wetlands, Oceans, and Watersheds; the Standards and Applied Science Division within the Office
of Science and Technology; and the Health and Ecological Criteria Division, also within the Office
of Science and Technology.
1
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The research strategy presented builds upon the existing research base. Shite in research
emphasis proposed for FY 1992-1996 reflect changes in Agency priorities, emerging
environmental issues and research needs, advancements in wetland science, and an expansion
of the WRP mandate to provide technical support for administration of other aspects of the CWA
that relate to wetlands. It is important to note that the WRP is an applied research program. The
research conducted must be scientifically sound and represent a significant contribution to
wetland science. At the same time, however, it must serve directly the needs and priorities of the
EPA program offices.
1.2 WETLAND RESEARCH PRIORITIES
The EPA program offices identified the following concerns and major technical needs relating to
wetlands as priority issues for the period FY 1992-1996:
National Concerns
• Implementation of a comprehensive risk-based approach to wetland protection and
management
• Evaluation of the national goal of no net loss of wetland area and function
Programmatic Priorities
Office of Water
• Water quality standards and criteria for wetlands
• Design guidelines and performance criteria for wetland restoration and creation
• The role of wetlands in water quality improvement
• The functions and values of "isolated" wetlands in the landscape
EPA Regions
• Water quality standards and criteria for wetlands
• The role of wetlands in urban stormwater control and associated concerns with wetland
protection
• The role of wetlands in reducing nonpoint source pollution in an agricultural setting and
the potential effects of agricultural runoff on wetland functions and values
• Guidance for State Wetland Conservation Plans
• The functions and values of "isolated" wetlands in the landscape
• Causes of Louisiana wetland loss ,
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Background information on these and related issues is provided below, grouped into the following
categories for ease of discussion: (1) risk assessment and management; (2) the national goal
of no net loss of wetland area and function; (3) a general discussion of the major causes of loss
of wetland function (background information relating to no net loss as well as water quality
standards and criteria); (4) water quality standards for wetlands; (5) wetland restoration and
creation; (6) wetland functions in the landscape, including the role of isolated wetlands; (7) the
role of wetlands in reducing nonpoint source pollution; (8) State Wetland Conservation Plans; and
(9) Louisiana wetland loss.
1.2.1 Risk Assessment and Management
A landmark EPA study conducted in 1987 found that the environmental problems considered by
experts as posing the most serious risk were not those targeted most aggressively by Congress
or the EPA (U.S. EPA 1987). A follow-up study by EPA's Science Advisory Board (SAB)
suggested ways in which the EPA could reduce environmental risk, recommending that
environmental protection efforts be focused on areas in which the greatest risk reduction could
be achieved. In particular, the SAB recommended that "...EPA should improve the data and
analytical methodologies that support the assessment, comparison, and reduction of different
environmental risks" (SAB 1990, p. 18). The President's 1992 budget for the first time
recommended that funding of programs be reoriented toward the reduction of the greatest
environmental risks (Inside EPA, February 9, 1991).
Wetland management must be considered within a risk-based framework to ensure that the most
valued wetland functions are protected. Thus, the EPA Administrator has asked for studies "...
to identify and develop environmentally sound ways to classify wetlands according to their values
and to set priorities for wetlands protection" (Reilly 1991, p. 4).
1.2.2 National Goal of No Net Loss
A national goal of no net loss of wetland area and function was recommended by the National
Wetlands Policy Forum in 1988 (The Conservation Foundation 1988). This goal has been
endorsed by both the President and the EPA. Such an approach advocates comprehensive
resource management instead of regulation on an issue-by-issue basis.
Technical information will be needed for no net loss to be achieved. The concept implies that the
loss of wetlands must be reciprocated by replacement of wetlands with equivalent area and
function. However, as pointed out by the National Wetlands Policy Forum, "...there is a paucity
of information on how to measure the different benefits wetlands provide, how to manage
wetlands to support these functions, and how to restore and create wetlands to provide the
desired benefits on a sustainable basis" (The Conservation Foundation 1988, p. 5). The
development of strategies to achieve no net loss will require, therefore, research to support the
evaluation of wetland function, characterization and prioritization of wetlands by function,
performance criteria for wetland restoration and creation, and the development of regional
assessment methodologies. ' , -
1.2.3 Major Causes of the Loss of Wetland Function
The primary reason for wetland loss in the United States has been conversion of wetlands to
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other uses. The causes of these particular losses are known: 87% of the loss of wetland area
between the 1950s and 1970s and 54% of the loss from the mid 1970s to mid 1980s was due
to agricultural conversion. An additional 8% of the loss between the 1950s and 1970s and 5%
from the mid 1970s to mid 1980s was caused by urban development (Tiner 1984, Dahl and
Johnson 1991). Research into this process is not critical, because the cause is understood and
regulations have been enacted to limit further loss, e.g., Section 404 of the Clean Water Act and
the "swampbuster" provisions of both the 1985 and 1990 Food Securities Act (the "Farm Bill").
Less well understood,are the ways in which environmental stressors2 degrade wetland function.
Five important categories of stressors are (1) hydrologic modification, (2) physical alteration,
(3) sedimentation, (4) nutrient loading, and (5) toxic contaminants.
1.2.3.1 Hvdrologic modification
Hydrology is perhaps the single most important determinant for establishing and sustaining
wetlands and their functions (Mitsch and Gosselink 1986). Subtle changes in the hydrologic
regime of a site, therefore, can have profound consequences. Examples of hydroiogic
modification range from extensive flooding or major water withdrawals and diversions to changes
in local runoff patterns as a result of construction and increases in impermeable surfaces in the
watershed. These alterations can result in outright wetland loss or varying degrees of
degradation. Because the effects of small hydrologic changes, and the cumulative effects that
result from the many such changes that occur, are seldom assessed, hydrologic modifications
may represent the largest unquantified and least understood stressor that affects wetlands.
1.2.3.2 Physical alteration
Physical alterations of wetlands result from dredge and fill operations, changes in land cover type,
timber harvesting, and other activities. As with hydrologic modifications, these actions can result
in the degradation of wetland function as well as the direct loss of wetland area. The
fragmentation of wetland habitat is of particular concern. Both the amount of habitat and its
placement on the landscape can have a profound influence on biodiversity and the suitability of
the landscape to support various wildlife species. As an example, Gosselink et al. (1990)
concluded that maximum wetland patch size was an important criterion for protecting black bear
in bottomland hardwood wetlands. Black bears require large, contiguous forested areas to
sustain viable populations. Likewise, the distance between wetlands is believed to be an
important factor limiting waterfowl success in the prairie pothole region of the central United
States and Canada.
1.2.3.3 Sedimentation
Sediment accretion and trapping are characteristic of most wetlands and are an important aspect
of wetland biogeochemistry. For coastal wetlands, sediment accretion may be critical to
2 We use the term "stressor" to refer to any material or process caused by people that can
stress a wetland and thus degrade wetland function(s). This includes the addition of harmful
agents, such as pollutants, and the removal of beneficial factors (e.g., stream diversions that alter
the hydrology).
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countering subsidence or sea level rise and, thus, for maintaining the system above water. The
removal of a sediment source can drown the wetland. Conversely, increasing sediment loading
rates can decrease the life of a wetland. Therefore, wetlands may be adversely affected by
receiving either too much or too little sediment. Additional information is needed on the
sedimentation rates necessary for sustaining various types of wetlands and on the quantities of
sediments that wetlands can receive and retain without degrading wetland functions.
1.2.3.4 Nutrient loading
Wetlands can be effective at using, retaining, and transforming nutrients and thereby improving
water quality. Wetland function can be impaired, however, by either too much or too little
nutrients. For example, Langis et al. (1991) found that low levels of nitrogen in a created salt
marsh in southern California resulted in low aboveground biomass, as compared with an adjacent
natural marsh. Conversely, Giblin (1982) showed that the capacity of freshwater marshes to
retain iron, zinc, copper, and cadmium can be reduced by adding nutrients. Information is needed
on the total quantity of nutrients that wetlands can retain (i.e., nutrient assimilative capacity) and
also the levels of nutrients that can be discharged into wetlands without impairing their condition
or functions.
1.2.3.5 Toxic contaminants
Significant bioaccumulation of organic toxics and heavy metals can occur within wetlands as a
result of exposure to contaminated sediments, heavy metals in urban runoff, or pesticides in
agricultural runoff. For example, Horner et al. (1988) found high levels of lead, zinc, and
cadmium in the sediments of wetlands receiving stormwater runoff from urban areas. The
concentrations of lead and zinc in these sediments were correlated with toxic responses as
determined by the Microtox bioassay, an indicator of toxic effects on several common bacteria
(Blum and Speece 1991). Toxic contaminants can affect not only the quality of wetland habitat,
but also can interfere with processes critical to the water quality improvement function, such as
nitrogen transformations in wetland soils. Commonly used agricultural pesticides have been
shown to inhibit nitrification in agricultural soils (Lin et al. 1972), and would likely have similar
effects in wetlands. Additional information is needed, however, on the specific effects of toxic
contaminants on wetland ecosystems.
1.2.4 Water Quality Standards for Wetlands
The EPA has a legal mandate to ensure that water quality standards are established that prevent
the degradation of the Nation's waters. In fulfilling this mandate, EPA is requiring that states
develop and implement water quality standards for wetlands (Office of Water Regulations and
Standards, OWRS, 1990a), using a two-phased approach. For Phase 1, water quality standards
for wetlands must be instituted by the end of 1993 based primarily on existing information and
science. In Phase 2, additional research and new approaches will be used to further standards
development.
Wetland standards development requires that all wetlands have uses designated that meet the
goals of the Clean Water Act, Section 101 (a) (2), and that states adopt criteria sufficient to protect
these designated uses. States will be responsible for designating uses for wetlands within their
states. The Office of Water has requested that ORD and the WRP provide technical support for
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the development by the states of wetland water quality criteria, particularly biological criteria
(biocriteria). Biocriteria are considered a subset of water quality criteria.
Phase 1 requires that states adopt existing criteria for wetlands (including chemical criteria) and
adopt new narrative biocriteria. EPA has traditionally emphasized chemical-specific criteria for
water column contaminants (OWRS 1990b). In most cases, chemical criteria developed for other
surface waters are probably protective of wetland-dependent organisms (Hagley and Taylor
1990). Information needs are limited primarily to field-verifying the adequacy of existing criteria
under wetland conditions.
Phase 2 will require that states implement numeric biocriteria. Biocriteria are critical to protect
wetlands from stressors such as hydrologic modification, physical alteration, sedimentation, and
nutrient loading, as well as from chemical contamination (OWRS 1990 a,b). Biocriteria include
not only biological endpoints, but also the habitat and hydrological conditions necessary to sustain
designated aquatic life uses. The development of biocriteria, particularly numeric biocriteria, will
require a great deal of research and field testing.
1.2.5 Wetland Restoration and Creation
Although wetlands are protected from certain impacts by federal law, economic pressures to
develop wetlands remain high. Government agencies will continue, therefore, to decide when and
where wetland impacts can be allowed and when and where wetland restoration arid creation will
be implemented. Wetland restoration and creation projects will undoubtedly remain as options
for compensating losses permitted under Section 404 of the Clean Water Act. In addition, as
discussed above, the role of wetland restoration and creation was recently highlighted by the
National Wetlands Policy Forum as an important element in achieving no net loss of wetlands
(The Conservation Foundation 1988). The restoration of thousands of acres of degraded
wetlands anticipated under the 1990 reauthorization of the Farm Bill has further focused attention
on this practice.
A number of important questions remain to be addressed, however, regarding the success and
design of wetland restoration and creation projects, ranging from "What constitutes appropriate
compensation?" to "Are ecological functions of natural wetlands replaced by created and restored
wetlands?" The amount of information available in the literature on wetland restoration and
creation varies by region and topic. In particular, relatively few studies have been conducted on
inland freshwater wetlands (Kusler and Kentula 1990a). Additional information is needed on
wetland functions to know when and where restoration or creation is appropriate and how to
maximize ecological functions in the design and implementation of wetland restoration and
creation projects.
1.2.6 Wetland Functions within the Landscape
Wetland research has traditionally examined the characteristics of individual wetland sites or, in
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some cases, populations of individual wetlands.3 However, certain regulatory and management
issues can only be addressed by considering wetlands within the context of the landscape in
which they are located. For example, impacts to individual wetlands that are not considered
significant by themselves may cause substantial environmental effects when taken together.
Cumulative impacts are the sum of all of the impacts that have occurred over the entire landscape
and over time. Cumulative effects refer to the net change in the overall landscape function that
results from these impacts. By landscape function, we mean the combination of environmental
processes operating within a landscape unit that account for the overall environmental
characteristics of that unit. Thus, the term wetland function refers to the functions and benefits
provided by individual wetlands, while landscape function refers to the functions and benefits
provided by the landscape unit as a whole, including the complex of wetlands and other
ecosystems within that landscape unit. Examples of landscape function are regional biodiversity,
overall water quality, and the hydrologic integrity of a watershed. Determining the cumulative
effects of wetland loss requires an understanding of how wetlands contribute to landscape
function, both individually and collectively.
Landscape context also can influence whether management goals, such as the ability to restore
a wetland, will be realized. Wetland restoration will be difficult if the environmental processes that
maintain wetlands within a landscape have been disrupted. For example, restoring a forested
swamp within a floodplain may not be possible if flooding has been reduced by the construction
of dams upstream.
One issue of particular interest is the role of isolated wetlands in landscape function. Current
regulatory policies assume that small isolated wetlands less than 10 acres in size are not
functionally significant. The functions and values of these wetlands, however, are not well
understood. In addition, the proportion of the total wetland resource represented by these
wetlands is not known. Research is needed to determine how these wetlands function individually
and whether the cumulative loss of isolated wetlands has or will lead to a significant decline in
landscape function.
1.2.7 The Role of Wetlands In Reducing Nonpoint Source Pollution
Because of internal processes that retain and transform nutrients, heavy metals, and many other
pollutants, wetlands often result in a net improvement in water quality. For this reason, there is
interest in constructing and restoring wetlands as a means of controlling nonpoint source pollution.
In addition, although stormwater cannot be directed into natural wetlands without prior treatment,
natural wetlands are being considered as a means of "polishing" urban stormwater and also may
serve to mitigate nonpoint source pollution.
Additional quantitative information is needed, however, on the role of natural, restored, and
created wetlands in reducing nonpoint source pollution and on the consistency and sustainability
of this function over time, on both site-specific and landscape scales. The rate and capacity of
wetlands to assimilate different pollutants will determine the magnitude and duration of pollutant
3 Unless stated otherwise, we use the phrase "wetland population" in a statistical sense,
referring to a collection of individual wetlands, rather than in a biological sense (i.e., species within
a wetland).
7
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inputs that a wetland can receive without degrading water quality improvement functions. It is
equally important to assess the secondary effects of nonpoint source pollution or urban
stormwater on overall wetland functions and characteristics. For example, habitat quality,
productivity, and species diversity may be adversely affected as a result of the bioaccumulation
of toxic substances.
Because agriculture is a dominant land use'over much of the country, the ability of wetlands to
retain nutrients in agricultural runoff is a research area of particular interest. The role of wetlands
in assimilating nonpoint source pollutants from agricultural sources needs to be determined, as
do the effects of agriculture-related stressors on wetland functions and value. Ecological criteria
are needed for siting and for the design of wetland restoration projects in agricultural landscapes.
Finally, technical support is needed regarding the role of buffers in protecting wetland water
quality and wetland-dependent wildlife. Buffers are vegetated strips of land surrounding a
wetland. Established buffers can at least partially filter pollutants and sediments from overland
and subsurface flow, thereby decreasing the input of these materials into the wetland. Additional
information is needed on the degree to which buffers decrease loading rates and on the
characteristics of buffers that influence the efficiency with which they remove sediments and
pollutants from overland and subsurface flow. I
1.2.8 State Wetland Conservation Plans
The development of State Wetland Conservation Plans was recommended by the National
Wetlands Policy Forum (The Conservation Foundation 1988). As part of an increased emphasis
on advance planning, the purpose of State Wetland Conservation Plans is to provide a basis for
all subsequent acquisition, regulation, and other wetland protection and management activities
in the state. Often, the responsibility for wetland protection and management falls within multiple
state agencies. A single statewide plan can serve as a vehicle for coordinating the efforts of
different wetland authorities and for developing consensus on state wetland protection goals. As
envisioned by the National Wetlands Policy Forum, State Wetland Conservation Plans are to
(1) set forth a state's goals and objectives with respect to its wetland plans and programs;
(2) describe specifically how the state will implement its policies and achieve the goal(s);
(3) identify and describe all wetlands in the state in sufficient detail to support the policy
framework and define processes for collecting sufficient information for management decisions;
and (4) describe the relationship, if any, between the Plan and other local, state, federal, and
international plans. Plans should cover both the land and water on which wetlands depend,
consider the economic and ecological benefits of wetlands, explore the compatibility of different
uses, and integrate wetland protection and management programs with other societal goals (The
Conservation Foundation 1989).
1.2.9 Louisiana Wetland Loss
Forty-one percent of the Nation's coastal marshes are found in Louisiana (Turner and Gosselink
1975), primarily as a result of the Mississippi River. The subtropical climate and nutrient-rich
sediments of the Mississippi combine to make this coast one of the most productive environments
in the Nation. For example, Louisiana's commercial fishery landings in 1984 were the largest in
the Nation's history, accounting for 30% of the total 4J.S. catch (U.S. Department of Commerce
1986). The importance of Louisiana's coastal marshes to maintaining these high fishery yields
8
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is evidenced by the spatial correlation between Gulf shrimp yields and the area of intertidal
vegetation (Turner 1977). In addition, Louisiana's marshes represent the richest fur-producing
region in North America, providing 40-65% of the nation's annual harvest (Larson et al. 1980).
It has been known for decades that Louisiana is experiencing a loss of its coastal wetlands
(Russell 1936, Fisk 1944); loss rates as high as 100 km2/yr have been estimated (Gagliano et al.
1981). Although many factors have been proposed as contributing elements, there is still no
consensus on the causes of this loss, nor their relative importance. To obtain further insight, a
better understanding is needed of the significance of natural delta switching, compared to the
human-related impacts on the river system and on the coastal wetlands. The cause(s) of coastal
wetland loss will ultimately determine whether the loss of Louisiana wetlands can be halted and
eventually reversed.
1.3 PRIORITY WETLAND TYPES
Based on discussions with the EPA program offices and with wetland scientists participating in
a WRP planning workshop held in February 1991, three wetland types were identified as priorities
for research in FY 1992-1996: (1) freshwater emergent wetlands, (2) bottomland hardwood
forests, and (3) western riparian systems. Selection of these wetland types was based on four
criteria: (1) the national significance of the wetland type; (2) the applicability of results to other
wetland types; (3) the need for additional research to improve overall wetland protection, as
identified by the EPA program offices; and (4) a consideration of research being conducted by
other federal agencies, to avoid duplication of efforts and to maximize interagency cooperation.
The following subsections provide a brief summary of current conditions, problems, and major
research needs for each of these priority wetland types; other wetland resources of interest are
also addressed.
•r
1.3.1 Freshwater Emergent Wetlands
Freshwater emergent marshes are shallow wetlands that form in areas such as depressions, lake
and stream edges, and in freshwater tidal zones. The hydrologic condition of these communities
ranges from intermittently to permanently flooded. Between the 1950s and 1970s, over 4.5 million
acres of freshwater emergent wetlands were lost (Tiner 1984). Furthermore, freshwater emergent
wetlands accounted for nearly 25% of the Nation's remaining wetland area in the mid 1980s (Dahl
and Johnson 1991). Thus, these wetlands are considered high priority for research for two
reasons - their wide distribution and high rate of loss.
Prairie potholes are a specific type of freshwater emergent wetland that is of special interest.
These wetlands have formed in depressions within glacial deposits of the North American prairie
(Winter 1989). The Prairie Pothole Region, an important breeding and stopover habitat for
migratory bird species, is considered to be the principal production area for many North American
duck species (Batt et al. 1989).
Agriculture is the primary social and economic force in the Prairie Pothole Region, and agronomic
conversions have caused significant loss of wetland area through government-sanctioned
drainage (Leitch 1989). The prairie pothole wetlands that have not been drained are embedded
in a matrix of agricultural land and are frequently exposed to large inputs of sediment, nutrients,
and agricultural chemicals. Little is known about the ability of prairie pothole wetlands to maintain
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their functions under sustained loadings of these stressors (Kantrud et al. 1989). Several factors,
such as the loss of buffers between farms and aquatic systems, a dramatic increase in the use
of chemical fertilizers, herbicides, and insecticides, and some of the highest soil erosion rates in
the Nation, have resulted in poor surface and groundwater quality in the intensively farmed
sections of the Prairie Pothole Region (Omernik 1977, Hallberg 1985, Kelley et al. 1986).
Prairie potholes are ideal for studying the effects of nonpoint source pollution sources on
emergent wetlands, because they are dominated by plant species that are widespread in North
America and they are well-defined in the landscape. Thus, results from research on prairie
pothole wetlands can be extrapolated to many similar systems. Additional information on how
to improve the local and landscape function of these wetlands could also aid ongoing restoration
and research efforts in the area by other federal agencies, such as the U.S. Department of
Agriculture's (USDA) Soil Conservation Service and the U.S. Fish and Wildlife Service.
1.3.2 Bottomland Hardwood Forests
Bottomland hardwoods are extensive forested wetlands that occupy the alternating wet and dry
hydrologic zone adjacent to many rivers in the southcentral and southeastern United States
(Wharton et al. 1982). These forests provide important functions, including flood storage, water
quality improvement, and wildlife habitat, and are of direct economic value as sources of
harvestable timber (Gosselink and Lee 1989). Nonpoint source pollution is a major contributor
to the degradation of surface water quality in agricultural areas in these regions. Bottomland
hardwoods are often forested "fingers" in riparian areas along low order streams within an
otherwise agricultural landscape. The efficiency of these wetlands in removing nutrients
(Lowrance et al. 1984), combined with the high risk to surface waters and riparian wetlands from
nonpoint source pollution in this region, make them a logical focus for study.
Cumulative impacts to this resource have included extensive timber clearing (loss rates as high
as 80% for the Mississippi River alluvial plain) and the construction of dams and levees that have
modified the hydrologic regime (Gosselink and Lee 1989). Such impacts can degrade wetland
functions, causing a loss of flood control capacity and ecological structure (e.g., biodiversity) as
well as other adverse effects. Through improved management practices, it may be possible to
log and farm such wetlands in a manner that lessens the adverse effects (Cairns et al. 1981).
Thus, information is needed on the effects of environmental stressors on the functions of
bottomland hardwoods and on alternative management techniques that may reduce these effects.
Protection of this resource is especially critical because creation of bottomland hardwoods is
difficult, and replacement, if it can be accomplished, would take decades (Kusler and Kentula
1990a).
1.3.3 Western Riparian Systems
Western riparian systems contain the principal freshwater wetland type in the arid and semi-arid
regions of the western United States. Interest in protecting and restoring these systems is on the
rise (e.g., Abell 1989, Baird 1989, Faber et al. 1989). A number of environmental groups,
including the National Audubon Society, the Sierra Club, and The Nature Conservancy, have
made the protection and restoration of riparian habitat a high priority (Faber et al. 1989).
Furthermore, in 1986, the Arizona Riparian Council was formally organized to provide an annual
forum for local coordination of management and research (Patten and Hunter 1989).
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Even though wetlands are protected under Section 404 of the Clean Water Act, at least three
factors have contributed to the continued loss of western riparian systems and their associated
wetlands. First* water supply policies have undervalued natural uses of water. As a result,
waters have been diverted from natural ecosystems and the availability of water for wetland
restoration and creation is limited (Lee and Gross 1988). Because Section 404, regulates the
disposal of dredged and fill materials in navigable waters, such water diversion is not prohibited.
Second, delineation of the wetlands within western riparian systems under Section 404 is difficult
(Lee and Gross 1988). Finally, cattle grazing is common on western arid lands and also not
regulated under Section 404. Cattle grazing can eliminate streambank vegetation and cause
physical alterations, such as bank erosion (Armour et al. 1991). Other factors contributing to the
decline of riparian areas include (1) mining (physical destruction, sediment runoff from tailings,
acid mine drainage) and (2) urbanization (direct alteration of flood plains and channelization, plus
secondary influences such as gravel mining, etc.). ,
Because riparian systems in the western United States have been extensively altered and
degraded, methods for wetland restoration and creation are of particular interest to states, the
EPA regions (Regions 8 and 9), and federal agencies (e.g., Bureau of Reclamation, Bureau of
Land Management, Corps of Engineers) with responsibilities for wetland management. Technical
guidelines are needed for site selection and project design to improve the success and
performance of these restoration programs.
1.3.4 Other Wetland Resources of Concern
Three other types of wetland resources have also been identified as warranting additional
research: (1) wetlands in coastal areas, (2) drier wetlands that are saturated with water during
only some seasons of the year, and (3) wetlands in urban landscapes.
Coastal wetlands were excluded from past WRP research because more information existed for
coastal than inland wetlands (Zedler and Kentula 1986). Furthermore, several federal agencies
have research and management responsibilities related to coastal areas and wetlands (e.g., U.S.
Fish and Wildlife Service, National Oceanic and Atmospheric Administration). However, three
issues in particular require further research: (1) the effects of stressors, in particular inputs of
sediments, nutrients, and toxic contaminants, on the area and quality of coastal wetlands; (2) the
role of inland wetlands in moderating the transport of nutrients, sediments, and chemical
contaminants from the landscape to estuaries; and (3) the development of water quality criteria
for coastal wetlands.
Most wetland research has focused on systems dominated by permanent surface water and/or
high groundwater and containing obligate wetland plants. The term "drier" wetlands is used here
to refer to wetland areas that are only infrequently saturated or flooded, with facultative wetland
vegetation. "Drier" wetlands may occur, therefore, within many wetland types or classes. While
the functions and value of Vet" wetlands are widely recognized, the role of drier wetlands
remains controversial. Although it is likely that these wetlands also play important roles in flood
attenuation, water quality improvement, and habitat, little research has been conducted to confirm
and quantify the functions of these systems. Under the proposed changes in federal wetland
policy and wetland delineation, large areas of these drier wetlands would no longer be protected
and would be opened for development or conversion to agricultural use. Thus, although not a
priority wetland type, per se, further information is needed on .the role of drier wetland areas within
each of the priority wetland types discussed above.
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A final area of interest is wetlands in urban settings. Because these systems occur in areas with
high human population densities, they are used and valued by relatively large segments of the
general public. Yet, wetlands in urban areas are subject to high loss rates and a diversity of
impacts. For example, wetlands are increasingly being considered for use in urban stormwater
management systems (see Section 1.2.7). Additional information is needed on the ability of
wetlands in these landscapes to sustain their functions and value given the level of stressors to
which they are exposed. As for the drier wetlands discussed above, many wetland types and
classes occur within urban areas; thus, issues relating to wetlands in urban areas are not specific
to one or a few wetland types.
1.4 DOCUMENT FORMAT
The research priorities and priority wetland types presented in Sections 1.2 and 1.3 define the
major research directions for the WRP. As noted in Section 1.1, research within the WRP is
intended to directly serve the needs and priorities of the EPA program offices. The remainder of
this document describes the proposed strategy of the WRP to address these needs over the next
five years, FY 1992-1996:
• Section 2 provides an overview of the WRP objectives and organization.
Section 3 introduces the risk-based framework proposed for wetland management and
protection.
• Sections 4-7 describe the specific objectives, research approaches, and expected
contributions of the four WRP project areas: Wetland Function, Characterization and
Restoration, Landscape Function, and Risk Reduction, respectively.
Section 8 discusses the objectives and approach for technical information transfer, an
integral component of the WRP designed to ensure that the research conducted by the
Program is relevant to policy and regulatory needs and that the techniques and
information developed by the Program are readily available to and adopted by the
appropriate EPA program offices and regions.
• Section 9 summarizes the Program deliverables and budgets.
• Section 10 lists the references cited in the text.
• Appendix A provides brief descriptions of the WRP projects pre-1992 and also the
Constructed Wetlands project and EMAP-Wetlands. ;
• Appendix B briefly describes wetland research and technical support programs in other
federal agencies.
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2. OBJECTIVES AND ORGANIZATION OF THE
WETLANDS RESEARCH PROGRAM
This section provides an overview of the WRP: Program goals and objectives for FY 1992-
1996 (Section 2.1), Program organization and responsibilities of the participating ORD
laboratories (Section 2.2), the approach to quality assurance (Section 2.3), and coordination
with other federal agencies (Section .2.4).
2.1 PROGRAM GOALS AND OBJECTIVES
The basic goals of the WRP are as follows:
• Provide the EPA program offices with technical support on issues that they have
identified as priorities, thus improving the Agency's ability to carry out its regulatory
responsibilities.
• Develop methodologies and, through case studies,, illustrate how these methodologies
can be used to support program office objectives and to facilitate the incorporation of
technical information into management decisions and planning.
• Increase the understanding of wetlands and make significant contributions to wetland
science by furthering the development and application of methods for studying wetland
functions, wetland characterization, landscape functions, and wetland restoration.
Based on the EPA programmatic priorities delineated in Section 1.2, the following specific
research objectives were selected for the WRP for FY 1992-1996:
• Develop and demonstrate a risk-based framework for wetland protection and
management.
• Determine the contribution of individual wetlands to water quality improvement,
habitat, and hydrologic functions, and develop techniques for enhancing and protecting
these functions.
• Evaluate the role of the aggregate of wetlands in the landscape on water quality,
habitat, and hydrologic functions at a landscape scale, and the influence of wetland
characteristics on these landscape functions.
• Quantify the effects of environmental stressors and landscape factors on wetland
functions.
• Describe and compare the functional status of populations of natural, restored, and
created wetlands in different landscape settings.
• , Provide technical support for the development of biological criteria for wetlands in
support of the Office of Water.
, • Provide technical support for the development of design guidelines and performance
criteria for wetland restoration and creation.
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• Using the information and methods listed above, conduct an integrated risk assessment
for at least one major wetland type to provide technical support on two major issues:
the national policy of no net loss of wetland area and function, and
the role of wetlands in reducing nonpoint source pollution.
In designing a research program aimed at providing resource managers with information on
wetlands, two constraints must be considered. First, because wetlands continue to be lost at high
rates, the regulatory process must continue despite the fact that not all issues have been
unequivocally resolved. Management decisions must be made using best professional judgment
if better information is not available. Second, methods are needed that can be used within the
actual regulatory arena, e.g., within the permit review process. As Hirsch (1988) has noted, this
effort requires simple protocols, analytical procedures, or "rules of thumb," because time and
resources often do not allow extensive data collection. The WRP research results will provide
regulators with such tools.
2.2 PROGRAM ORGANIZATION
To achieve the objectives identified in Section 2.1 will require information gathered at three
different spatial scales. Detailed studies at Individual wetland sites are needed to better
understand the processes within wetlands that contribute to wetland functions, wetland responses
to environmental stressors, and wetland assimilative capacity. Information is also needed on the
characteristics of populations of individual wetlands to compare the functions of natural,
restored, and created wetlands within different landscape settings. Finally, research is needed
on the interaction of wetlands with other wetlands and ecosystems within regional landscapes.
Cumulative impacts within the landscape can degrade individual wetland functions; also wetlands
provide off-site benefits and contribute to landscape functions.
The methods and analyses employed in wetlands research tend to vary depending on the spatial
scale of interest. For this reason, the WRP has been organized into four major project areas,
each of which will emphasize studies at a different spatial scale:
1. Wetland Function Project -- focuses on processes within individual wetlands or small
groups of wetlands along a gradient of environmental impacts, to quantify wetland
functions, stressor/response relationships, and wetland assimilative capacity.
2. Characterization and Restoration Project - develops methods and Information to
characterize and compare the functional attributes of wetland populations, and also
provides technical support for the development of design guidelines and performance
criteria for wetland restoration and creation.
3. Landscape Function Project - examines issues at the landscape scale, studying the
aggregate of wetlands within a given landscape unit to determine how wetlands contribute
to landscape functions (e.g., biodiversity and regional water quality) and how landscape
factors (e.g., regional hydrology) affect wetland functions.
4. Risk Reduction Project -- integrates findings from the other three projects to address
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comprehensive issues (e.g., no net loss) at multiple scales, including the development and
demonstration of a risk-based framework for wetland protection and management.
The first three of these projects are modifications of the three original WRP projects: Water
Quality, Mitigation, and Cumulative Impacts, respectively (Figure 2-1). The fourth project has
been added to emphasize the shift towards program integration and the risk-based framework for
wetland protection and management. A major objective over the next five years is the
development, demonstration, and implementation of this framework. The Wetland Function,
Gharacterization and Restoration, and Landscape Function Projects are primarily responsible for
research; the Risk Reduction Project will synthesize these results into integrated program
deliverables (Figure 2-2). To ensure that these integrated deliverables are produced, the Risk
Reduction Project will be responsible for coordination among projects.
In addition to the four projects listed above, the WRP includes two other research projects,
Constructed Wetlands and EMAP-Wetlands (Figure 2-1; Appendix A), which are funded
separately, respond to different program offices, and have separate research plans (Olson 1990
and Leibowitz et al. 1991, respectively). For these reasons, the research to be conducted under
these two projects is not included as part of this plan, although important project interactions and
cooperative efforts are noted. For the purposes of this document, reference to WRP or the
"Program" refers only to the Wetland Function, Characterization and Restoration, Landscape
Function, and Risk Reduction Projects.
Original Project
Water Quality
Constructed Wetlands
Mitigation
Cumulative Impacts
EMAP-Wetlands
Projects Planned
f or FY 1992-1 996
Wetland Function
Constructed Wetlands
Characterization
and Restoration
Landscape Function
Risk Reduction
EMAP-Wetlands
Scale of Study
Individual Wetlands
and Watersheds
Populations of
Individual Wetlands
Regional Landscapes
Multiple Scales
Figure 2-1. Relationship between the original WRP projects and projects planned for FY 1992-
1996; the primary spatial scale studied by each project is indicated.
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Risk-Based Framework
Multiple Scale Issues
No Net Loss
Reduction of Nonpoint
Source Pollution
Wetland
Function
Project
Characterization
and Restoration
Project
Risk
Reduction
Project
Functions of
Individual Wetlands
•
Water Quality
Criteria for Wetlands
Functional Characterization
of Wetland Populations
•
Wetland Restoration
and Creation
Wetland Functions
in the Landscape
•
Rapid Landscape
Assessment Tools
Landscape
Function
Project
Freshwater
Emergent
Marsh
Priority Wetland Types
Bottomland
Hardwood
Forests
1
Western
Riparian
Systems
Figure 2-2. Proposed research strategy for the Wetlands Research Program.
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Three ORD Laboratories are involved in the WRP. The Characterization and Restoration Project,
Landscape Function Project, Risk Reduction Project, Technical Information Transfer (see Section
8), and Quality Assurance (see Section 2.3) will be the responsibility of EPA's Environmental
Research Laboratory (ERL) at Corvallis, OR. ERL-Corvallis also will act as matrix manager for
the Program as a whole. ERL-Duluth (Minnesota) will be responsible for the inland component
of the Wetland Function Project. ERL-Gulf Breeze (Florida) will conduct the pilot study for the
proposed coastal component of the Wetland Function Project. This plan and the deliverables
contained within it assume a budget of about $2.5 million per year for five years. Further
information on project budgets and deliverables is presented in Section 9.
2.3 PROGRAM QUALITY ASSURANCE
Policies initiated by the EPA Administrator in memoranda of May 30 and June 14, 1979, require
that all EPA Laboratories, program offices, and regional offices participate in a centrally managed
quality assurance (QA) program. This policy extends to those monitoring and measurement
efforts supported or mandated through contracts, cooperative agreements, regulations, and other
formal agreements. The intent is to develop a unified approach to QA that ensures the collection
of data that are scientifically sound, legally defensible, and of known and documented quality.
The WRP QA Coordinator will provide 0.5 full-time equivalent (FTE) for the QA support function.
Key elements of a QA program include the following:
Data Quality Objectives (DQOs): DQOs must be developed as part of the planning
process before data collection. They are intended to help guide the design of sampling
and analytical protocols and to ensure that the data collected are adequate for the
proposed use. They also provide an objective basis for evaluating the quality of the data
actually collected.
QA Project Plan: A QA Project Plan must be based on the data quality requirements and
include QA and quality control (QC) procedures. Resources needed to accomplish project
objectives must be specified.
• Audits: Audits are conducted to evaluate the conformance of data collection, analysis,
and management to the DQOs and QA Project Plan.
• Reporting: All data must be reported at a quality level adequate for the intended use.
Journal articles and reports developed as products must include QC information
supporting the data.
To comply with the QA policies of EPA and of each of the participating ORD Laboratories (ERL-
Corvallis, ERL-Duluth, and ERL-Gulf Breeze), the WRP will address QA at two different levels:
1. A QA Program Plan will be prepared that describes the Program's overall QA philosophy
and approach.
2. Individual QA Project Plans will be developed as part of the detailed work plans prepared
for each study.
Both of these QA planning documents will be revised annually.
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2.3.1 WRP Quality Assurance Program Plan
The WRP QA Coordinator will prepare the QA Program Plan, in consultation with the WRP
Project Leaders and QA staff from each of the three participating Laboratories. The purpose of
this document will be to provide overall guidance on QA activities that is consistent with the QA
policies of the Agency and each Laboratory. The document will define the QA goals, outline
methods for achieving these goals, and describe QA responsibilities within the Program. The QA
Program Plan will build upon QA practices developed during the first five years of the WRP. This
Plan will be updated and revised annually as experience is gained through implementation and
as project objectives change. The QA Program Plan also will identify existing approved QA
Project Plans and future planned research that will require QA Project Plans.
As discussed earlier, WRP research activities will be diverse, encompassing three different spatial
scales. Chemical, physical, biological, and landscape data will be measured, sampled, collected,
and analyzed, both by the WRP staff and by cooperators. The QA Program Plan will address QA
issues with respect to each of the kinds of data to be collected and also data management.
2.3.2 Individual QA Project Plans
Individual QA Project Plans will be prepared for each study as part of the detailed work plan
developed for that research. These individual QA Project Plans will follow the QA requirements
specified in the document "Interim Guidelines and Specifications for Preparing Quality Assurance
Project Plans" (U.S. EPA 1980). The QA Project Plan will define specific DQOs for the study,
along with the research design, sample collection procedures, analytical protocols, and data
analysis methods. The purpose of these plans is to ensure that data quality is adequate for the
intended use within the budgetary constraints of the particular study. To assure that WRP studies
meet the QA requirements of the Agency and each Laboratory, QA Project Plans will be reviewed
by the WRP QA Coordinator and by the appropriate Laboratory QA staff. These plans must be
approved by an EPA QA Officer prior to the collection of any project data.
2.4 COORDINATION WITH OTHER FEDERAL AGENCIES
Many federal agencies conduct research on wetlands or provide technical support for wetland
management. Federal agencies that have a major wetland research role include the Army Corps
of Engineers, the U.S. Fish and Wildlife Service, the USDA Soil Conservation Service, the Federal
Highway Administration, the Bureau of Reclamation, the USDA Forest Service, and the
Tennessee Valley Authority. Appendix B contains a brief summary of the research or technical
support objectives for each of these agencies.
The WRP research objectives and priority wetland types (Section 1.3) have been selected to both
avoid duplication and foster cooperation with other federal agencies in areas of mutual interest.
Coordination of efforts among federal agencies will lead to a better technical base for managing
the Nation's wetlands. Specific areas of cooperation are noted in the discussions of WRP
implementation within Sections 4-7.
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3. A RISK-BASED FRAMEWORK FOR WETLAND PROTECTION
One of the major objectives of the WRP for FY 1992-1996 is to develop and demonstrate a risk-
based framework for wetland protection and management. An introduction to this framework is
provided here, because the terms, approaches, and issues raised provide context for all aspects
of the WRP. Eventually, after the framework has been refined and tested, it can serve two
important purposes: (1) providing a basis for management decisions regarding wetland protection
that incorporates the best available technical information, and (2) defining future WRP research
needs and priorities that focus on those issues of greatest benefit to management decisions. This
section describes the basic components of the WRP risk-based framework. Specific plans for
developing, demonstrating, and implementing the framework over the next five years are
presented in Section 7, as part of the Risk Reduction Project.
3.1 THE CONCEPTS OF RISK REDUCTION
All environmental problems pose some risk - risks to human health, the quality of life, the
economy, or ecosystems that provide basic life support. The goal of risk reduction is to focus
environmental management and protection efforts on those environmental problems that pose the
greatest risk and on those areas and problems in which the greatest risk reduction can be
achieved (SAB 1990). Risk reduction includes, therefore, two basic elements:
1. Risk Assessment - the identification and estimation of the risks associated with various
stressors and environmental hazards
2. Risk Management - the development and implementation of a specific management
strategy to control and manage the most serious risks
Traditionally, risk assessments have involved only technical input and analyses and included four
steps (U.S. EPA 1991):
1. Hazard Identification - characterization of the specific stressors of concern for the
ecosystem(s), landscape, or region being evaluated as part of the risk assessment
2. Stressor/Response Relationships - quantification of the relationship between the level
of stressor and the magnitude of response or probability of adverse effects on one or
more important attributes of the ecosystem(s) or landscape, for each stressor of concern
3. Exposure Assessment -- quantification of the actual magnitude of stressor exposure, or
potential exposure in the future given various management options, for each
ecosystem/landscape attribute of interest and each stressor of concern
4. Risk Characterization -- integration of the information (and uncertainties) in the three
preceding steps to estimate the probability (risk) of occurrence of specific events, such as
the loss or degradation of an important ecosystem/landscape attribute
Policy analyses and decisions and the implementation of management actions to reduce risk
constitute the risk management component of risk reduction. Under this scenario, the separation
between technical and policy input is distinct: technical input and analyses are associated with
risk assessment and policy input and analyses occur within risk management.
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3. Hydrology - moderating surface and groundwater flows, including flood attenuation,
maintenance of base flow, etc.
For example, the process of denitrification (the biochemical reduction of nitrate into gaseous
nitrogen) in a wetland may reduce the quantity of nitrogen transported into downstream waters,
thereby improving streamwater quality. Thus, the wetland in this example provides a water quality
function as a result of the process of denitrification.
Wetland functions depend on two factors: wetland capacity and landscape Input. The capacity
of a wetland to perform a given function depends on the characteristics of the particular wetland,
for example, wetland type (e.g., marsh or swamp), hydrologic regime, soil and vegetative
properties, geomorphological conditions, etc. In the example above, denitri/ication is dependent
on anaerobic soil conditions, which are controlled primarily by the amount.of soil moisture.
Capacity alone, however, cannot define wetland functions; these processes also frequently
depend on factors originating outside of the wetland. Thus, the actual water quality improvement
depends on both the ability of wetlands to transform and retain pollutants and the rate and
amount of pollutants input from the surrounding landscape. Similarly, flood attenuation assumes
an input of floodwater. Many wetland functions depend on input from the surrounding locale. For
functions that are linked to water, this "locale" would be the surface water drainage area and the
extent of any groundwater aquifer associated with the wetland. For habitat functions, landscape
input could be the regional gene pool of organisms that are wetland dependent.
3.2.2 Wetland Value
The identification of wetland functions is a technical endeavor, based on objective criteria and
analyses. Wetland values, on the other hand, are determined by subjective choices; different
individuals may value the same wetland or wetland function differently. Thus, the assessment
of wetland values is the responsibility of wetland managers and policymakers (see Figure 3-1).
Value is determined by the perceived benefits of wetland functions that are realized and
recognized by society. Values refer to tangible benefits, such as clean water, as well as
intangibles, such as aesthetics, and both current and potential future values should be
considered.
The value of an individual wetland or group of wetlands may be viewed holistically, considering
simultaneously all of the potential benefits that a wetland may provide and the overall value of
the wetland(s) as a unit. Alternatively, values may be assigned separately to each distinct
wetland function, for example, the value of a wetland for flood control or as habitat for wildlife or
for a particular endangered species. The latter approach is easier to implement because it
couples value with explicit functions that can be measured. Such an approach also, however,
tends to fragment our view of wetlands. As a consequence, important functions may be
overlooked or undervalued.
While the assessment of wetland values is the responsibility of policymakers and wetland
managers, technical input and objective analyses can1 still play a critical role. For example, for
holistic assessments of wetland values, wetland managers could identify sets of "reference"
wetlands considered of overall "high" value and of overall "low" value. Wetland characterization
22
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techniques, such as those described in Section 5 for the Characterization and Restoration Project,
could be applied to identify specific wetland attributes useful for distinguishing between "high" and
"low" value wetlands (Figure 3-2). The results from these objective analyses could then be used
to classify other wetlands with similar attributes as high- or low-value wetlands.
As an example of how technical input could be used in the assessment of function-specific
values, the value of reduced peak discharge would depend on both how much the average
person values a reduction in flooding (a subjective choice) and how many individuals living
downstream would benefit from added flood control protection. The latter can be objectively
determined.
The process of establishing wetland values is complex and controversial. In particular, societal
values are often based on incomplete information and, as a result, society may undervalue
important wetland functions. Because of this uncertainty, both societal values and technical
information on, the ecological importance of wetlands will be included in the prioritization process
within the WRP risk-based framework. Furthermore, by explicitly including both function and
value in the framework, the resultant dialogue between technical experts and wetland managers
may reduce the chance of undervaluing important functions, thereby improving management
decisions.
.
II
Low Value
Wetlands
High Value
Wetlands
Indicator(s) of Wetland Function
Figure 3-2. Frequency distributions for an indicator of wetland function for wetlands considered
of "high" value by policymakers or specific user group (solid line) and wetlands
considered to be of "low" value by the same group (dashed line). Based on the
measured value for the indicator, wetland "A" would be classified as a high-value
wetland. In practice, multiple indicators would be used to distinguish between
high- and low-value wetlands.
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3.2.3 Functional Loss
The National Wetlands Policy Forum recommended that analyses of wetland loss consider loss
of area and loss of wetland function (The Conservation Foundation 1988). Thus, functional loss
can result from two factors4:
1. Conversion - transforming a wetland into a different land cover or land use (e.g., filling
in a wetland for construction)
2. Degradation - loss of function resulting from a stressor. Wetland degradation can be
caused by the addition of harmful agents and/or by the removal of beneficial factors (e.g.,
damage to the environmental infrastructure that maintains a wetland as a result of
hydrological modifications caused by dam construction or stream diversion).
With conversion, all or almost all wetland functions are lost. Thus, analyses of functional loss for
wetland conversion require only an assessment of the total area of wetland at risk. For wetland
degradation, the functional loss element may be qualitative (relative risk) or quantitative.
Quantitative analyses would include the four traditional risk assessment activities: (I) identifying
the major hazards or stressors of concern, (2) quantifying the relationship between the level of
stressor and magnitude of the wetland response, (3) quantifying the actual stressor exposure or
the likelihood of stressor exposure given various management scenarios, and finally
(4) synthesizing these results into an overall characterization of risk(s). Quantitative techniques
for assessing wetland functional loss are discussed further in Section 4.
As mentioned previously, the assessment of functional loss would focus specifically on valued
wetland functions. Both losses to date and potential future losses must be considered.
Depending on the spatial scale of the assessment (see Section 3.5), functional loss can be
evaluated for individual wetlands (wetland function) or for the landscape unit as a whole
(landscape function).
3.2.4 Replacement Potential
Replacement potential refers to the ability to replace a wetland and its valued functions through
wetland restoration and creation. Replacement potential depends on the type of wetland, the
function to be restored, the geographical region, and, in the case of restoration, the type of
stressor that altered the original wetland (Kusler and Kentula 1990a). Wetlands with a high
replacement potential, by definition, can be restored or created to achieve conditions nearly
identical to those in natural wetlands within an acceptable amount of time (Figure 3-3). For some
restored wetlands, such as salt marshes, recovery may be rapid because of short turnover times
and low ecological complexity. Other wetland types, however, such as bottomland hardwood
forests, are complex communities with very long turnover times. Such systems probably require
decades to centuries for full functional restoration and, as a result, are likely to have low
replacement potential.
4 Although loss of wetland function can result from'natural processes, this discussion will be
limited to environmental impacts caused by people.
24
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Time
Figure 3-3. Evaluation of restoration potential for wetland functions by comparing the
performance of restored or created wetlands with that of natural wetlands in the
same landscape setting. The broken line represents the average value of an
indicator of wetland function in natural wetlands over time. The heavy curve
represents a situation with high restoration potential, because the level of the
indicator of wetland function approaches that of the natural wetland within an
acceptable amount of time. The situation represented by the lighter line has low
restoration potential.
Replacement potential also depends on landscape condition. It is harder to restore or create a
wetland if the landscape processes that maintain wetlands have been disrupted. If restoration
or creation does take place in such a setting, the wetland will probably not be sustainable.
3.3 RISK MANAGEMENT
Risk assessments estimate risks, identifying those wetlands of greatest value that are at greatest
risk of functional loss and also have low replacement potential. Such assessments also
determine the major stressor(s) responsible for the risk of functional loss. The results from the
risk assessment provide the basis for the selection and implementation of a risk management
plan. Other information, such as the financial and societal costs associated with various
management options, also plays a role in the selection process.
In practice, risk management plans will be developed by policymakers and regulators and will
depend on particular policy objectives. However, technical input is needed to ensure that the
selected management options are technically feasible and effective (see Figure 3-1). As
previously mentioned, the goal of risk reduction is to focus environmental management and
protection efforts where the greatest risk reduction can be achieved (SAB 1990). The WRP risk-
based framework provides a conceptual basis for identifying those wetlands and landscapes for
which a given unit of management effort will provide the largest marginal return (e.g., increase
in function due to wetland restoration and creation or avoidance of future functional loss through
wetland protection).
25
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For example, Figure 3-4 provides several hypothetical examples of stressor/response
relationships for landscape function. The figure depicts the expected level of landscape function
(e.g., the magnitude of flood reduction provided by a given landscape unit) associated with a
given level of stressor(s) (e.g., land use changes or wetland drainage) to which the landscape is
exposed or subjected. Wetland protection efforts would be most effective (largest reduction in
risk) if focused on those landscapes where current conditions are in the area of the curve with
the steepest slope. Similar relationships can be developed and applied for decisions regarding
individual wetlands and also for wetland restoration and creation (see Figure 3-3).
Curves such as those in Figure 3-4, or, at a minimum, a general understanding of the shape of
the curve(s) and positions of the inflection points, also can provide a basis for defining broad
categories of landscape condition:
• Pristine Landscapes - natural landscapes in which landscape function is at or near
maximum. If impacts have occurred, they are small in magnitude and widely dispersed,
both over time and space, and the resiliency of the landscape unit has buffered it from
functional losses.
• Transitional Landscapes - where stressors have resulted in some loss of landscape
function(s), although the impacts are mostly localized and have not yet disrupted the
fundamental landscape processes that create and maintain wetlands. Generally, these
landscapes contain individual wetlands that are still fully functional as well as degraded
wetlands.
Dysfunctional Landscapes - where the environmental infrastructure has been damaged
to the point where it can no longer provide significant natural landscape functions. The
fundamental landscape processes that create and maintain wetlands have been disrupted
and/or replaced by human activities and structures. Stressor impacts are extensive and
greatly exceed the natural assimilative capacities of these systems. Wetlands in these
units are fragmented and degraded, although they may still have significant local (on-site)
value, for example, the presence of endangered species.
Depending on the nature of the stressor/response relationship, the greatest marginal returns
(increase in function) per unit of management effort often coincide with one category of landscape
condition, for instance, in the illustrative curves in Figure 3-4, in transitional landscapes. The
nature of the management/restoration effort may vary depending on landscape condition; for
example, wetlands in a truly dysfunctional landscape would require extensive off-site mitigation
to restore basic landscape processes for restored or created wetlands to be sustainable. Thus,
if easy-to-apply protocols can be developed for classifying landscape units, the approach and
conceptual tools described above can be used to expedite both risk assessments and risk
management decisions.
3.4 MONITORING AND EVALUATION
After a management plan is developed and implemented, two types of monitoring can be
employed: evaluative and baseline. Evaluative monitoring examines the effectiveness of the
management plan. Trends in loss, degree of success of restoration/creation, and compliance with
the wetland management plan are evaluated. The specific objective of this type of monitoring is
26
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(a)
(b)
"D
C
CO
Stressor(s)
Stressor(s)
(c)
A
"^ S.
o Q-
^s
C CO
~T3
C
ra
D
Stressor(s)
Figure 3-4. Example hypothetical stressor/response curves, illustrating in this case the
relationship between landscape function (e.g., biodiversity or overall water quality
improvement) and increasing levels of some stressor or multiple stressors (e.g.,
hydrolbgical modification, toxic contaminants, etc.). In curve (a), landscape
function declines sharply even with low levels of stressor(s), while curves (b) and
(c) suggest that, because of the system's resiliency, it can initially absorb some
level of stressor(s) without a measurable loss of function. The portion of the curve
with the steepest slope can be used to identify those landscapes where the
greatest return (increase in function) could be achieved per unit of wetland
protection effort (reduction of stressor). Labels A-D indicate categories of
landscape condition (defined in Section 3.5). Landscapes falling in the zone
defined by A to B are considered pristine landscapes; those in the zone defined
by B to C are transitional landscapes; and landscapes in the zone defined by C
to D are considered dysfunctional.
27
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to determine whether risk reduction goals are being met so that the management plan can be
amended if necessary. Thus, this type of monitoring has a relatively narrow focus.
Baseline monitoring is used to determine whether new wetland problems have arisen or whether
old problems were overlooked, either of which could result in a change in relative risk. Such
monitoring would consider broad trends in the extent and health of the wetland resource, using
a variety of indicators. The management plan would be updated periodically to reflect any
changes in relative risk, as determined by this type of monitoring. The EMAP-Wetlands project
(see Appendix A) will be a major source of information for baseline monitoring of wetland
condition.
3.5 IMPLEMENTATION OF THE RISK-BASED FRAMEWORK
To serve the needs of wetland managers and regulators, the risk-based framework must be both
technically and programmatically feasible. The framework and risk reduction approach must be
consistent with policy objectives and existing laws and regulations. In addition, the types of
technical data and analyses required for any given application must not be prohibitive. Thus, to
the degree possible, the framework will rely on relatively simple protocols, analytical procedures,
and "rules of thumb," to minimize the need for extensive data collection.
All risk management decisions have some accompanying level of uncertainty. Risk assessments
need not provide perfectly accurate answers to be successful, since this would require more
information than is normally available to the regulator. Rather the framework must simply provide
• managers with better information and approaches than are currently available, thereby improving
the effectiveness of environmental protection efforts and reducing risk. Ultimately, the objective
is to select the optimal level of technical input required to achieve the desired level of confidence
in management decisions at reasonable cost (see Figure 3-5).
For most management applications, the risk-based framework will be implemented hierarchically,
increasing the level of effort at each stage and continually focusing on those aspects that will
contribute the most to reducing uncertainties and decreasing the chance of making an erroneous
management decision. For example, the four elements of a risk assessment generally will be
evaluated sequentially to improve the efficiency of the assessment process. By first considering
wetland function, the assessment of wetland value can focus on the subset of functions that
are actually present within that region, rather than considering all possible functions. The
assessment of functional loss is then limited to valued wetland functions. Finally, replacement
potential is only considered if that valued wetland function is actually undergoing functional loss.
An initial risk assessment may be conducted based solely on best professional judgment (BPJ).
Many management decisions currently rely on expert opinion alone. Formulating this expert
judgment within the risk-based framework will better define the issues and uncertainties and, as
a result, should improve decisionmaking. Depending on the results and desired level of
confidence, it may or may not be necessary to proceed with more quantitative analyses. The next
phase, if needed, could rely on existing information and data that can be readily obtained from
available maps or aerial photography. Finally, if additional information is needed to further reduce
uncertainties, a site visit or even field sampling could be conducted. Again, data would be
collected specifically for those sites that previous analyses (based on BPJ or existing data)
suggest ace at greatest risk or of most uncertain status. Thus, fewer wetlands need to be
evaluated at each step.
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Less Than
Adequate
Useful
Information
Redundancy
Minimum
Threshold
High
Analysis Cost
Figure 3-5. The benefits of a risk assessment, measured in terms of the accuracy of the
results, as a function of the assessment costs. At the very minimum, the risk
assessment must provide results that are better than chance alone, e.g., greater
than 50:50 for binary decisions.
Frequently, it may also be effective to implement the framework hierarchically on a spatial scale.
Assessments would focus first on landscape functions and landscape units, for example, ranking
watersheds or ecoregions within a state. For some management objectives, landscape-level
assessments may be sufficient, especially in areas that are relatively homogeneous. Analyses
of smaller scale units (e.g., subbasins or wetland complexes) or individual wetlands within these
landscape units may be necessary, however, in some cases. For instance, such analyses would
be conducted in areas that are heterogeneous or where site-specific information is desired to
reduce the chance of wetland misclassification or of errors in decisionmaking. If funds are limited,
it may be appropriate for individual wetland assessments to be limited to or conducted first in
those landscape units considered at greatest risk (for example, based on an assessment of
landscape condition as discussed in Section 3.3).
In all cases, risk assessments for wetland protection and management must consider the
condition of the surrounding landscape (in addition to on-site wetland condition) for two reasons:
(1) ignoring landscape considerations will omit important environmental factors that contribute to
wetland function and value, thereby reducing the likelihood of achieving policy objectives; and
(2) including landscape information can expedite the assessment process, as it is generally not
feasible to evaluate every wetland individually.
The specifics of how best to implement the risk-based framework will vary depending on the
management context and management objective being evaluated. The framework could be
applied, for example, to assist with the development of State Wetland Conservation Plans, with
the implementation of Section 404 of the Clean Water Act, or with decisions regarding wetland
29
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acquisition. As part of the Risk Reduction Project, the results from the other three WRP projects
will be combined to demonstrate the application and usefulness of this framework for two major
issues: the national policy of no net loss and the role of wetlands in water quality improvement
In addition, components of the risk-based framework will be applied to provide technical support
for the development of water quality criteria for wetlands, as part of the Wetland Function Project.
Further details on these applications are provided in Sections 7 and 4, respectively.
30
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4. WETLAND FUNCTION PROJECT
The Wetland Function Project focuses on those tasks and information needs best provided
through relatively detailed studies of processes and responses in individual wetlands or small
groups of wetlands. Work, within this project will contribute primarily to three of the WRP
research objectives:
1. Determine the contribution of individual wetlands to water quality improvement,
habitat, and hydrologic functions, and develop techniques for enhancing and protecting
these functions (e.g., best management practices).
2. Quantify the effects of environmental stressors and landscape factors on wetland
functions.
3. Provide technical support for the development of biological criteria for wetlands in
support of the Office of Water.
This section presents background information on the Wetland Function Project and the
research issues to be addressed (Section 4.1); an overview of the basic approach to be used
to achieve the research objectives (Section 4.2); brief descriptions of the proposed studies for
project implementation (Section 4.3); and a summary of the major expected contributions of
the project relative to the overall goals and objectives of the WRP (Section 4.4).
4.1 BACKGROUND
^
The Wetland Function Project is an outgrowth of the original WRP Water Quality Project (see
Appendix A). Research within the Water Quality Project focused on the role of wetlands in
water quality improvement. This research direction was emphasized because water quality
functions were (1) more poorly quantified than other wetland functions; (2) a logical research
focus for EPA, given the Agency's responsibilities under the Clean Water Act and its historic
research strengths in the area of water quality; and (3) not a primary focus of research by
other federal agencies (Zedler and Kentula 1986, Adamus 1989).
During FY 1992-1996, the Wetland Function Project will broaden its research to encompass
all three major categories of wetland functions (hydrologic, habitat, and water quality
improvement) and also address the full suite of major environmental stressors: hydrologic
modification, physical alteration, sedimentation, nutrient loading, and toxic contaminants.
This expansion of the project scope is necessitated by both the shift to a risk-based
framework and the need for innovative biological criteria fo wetlands covering the full range
of potential stressors. Biocriteria include hydrological and habitat conditions necessary to
sustain designated aquatic life uses, as well as biological endpoints.
The Wetland Function Project will provide information on (1) wetland functions, emphasizing
the role of individual wetlands in reducing nonpoint source pollution and urban stormwater
management consistent with the priorities of the EPA program offices (see Section 1.2); (2)
the effects of environmental stressors on wetland functions; (3) management techniques that
may be used to mitigate the effects of stressors on wetland functions; and (4) technical
guidance on site-specific wetland monitoring and indicators of wetland condition and function.
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The overall goal of the project is to provide the technical support needed to develop and
evaluate management strategies for protecting the ecological integrity of individual wetlands
and wetland complexes. In particular, one important pbjective of the project is to demonstrate
how both the traditional risk assessment approach (U.S. EPA 1991) and the the WRP risk-
based framework can be used to aid state wetland regulators in the selection of water quality
criteria and best management practices for wetland protection.
The nature, rates, and .levels of wetland functions often vary both spatially, within a given
wetland, and temporally (e.g., Nixon and Lee 1986, Johnston et al. 1990a). For example, a
wetland may be a sink for excess phosphorus during the growing season, thus improving
downstream water quality; that same wetland, however, could become a phosphorus source
in the autumn during plant senescence. In addition, specific wetland characteristics may
influence the nature and magnitude of wetland functions, for example, the degree to which
a given wetland may serve as a phosphorus sink and thus the utility of the wetland for
nonpoint source pollution control. An understanding of these factors and within-wetland
variability is needed to better interpret the patterns and responses observed at the population
and landscape level. Thus, the detailed studies of individual wetlands conducted as part of
the Wetland Function Project are an essential component of the WRP for interpretation of the
results from the Characterization and Restoration and Landscape Function Projects, as well
as the extensive monitoring data collected by EMAP-Wetlands (see Appendix A).
The Wetland Function Project also will be the primary source of quantitative information on
wetland responses to stressors. Comprehensive studies are needed to (1) identify which
structural or functional attributes of wetlands are most sensitive to particular stressors,
(2) distinguish natural variability in wetland functions from changes caused by anthropogenic
stressors, (3) quantify wetland assimilative capacity and threshold levels for response to
stressors, and (4) assess the combined effects of multiple stressors (Adamus and Brandt
1990).
Best management practices provide a means for preventing or reversing wetland degradation.
In particular, as noted in Section 1.2.7, buffers (i.e., vegetated strips of land) around wetlands
may filter pollutants and sediments from overland and subsurface flow, thereby decreasing
the input of these materials into the wetland. Under conditions where point source (e.g.,
stormwater) discharges or hydrological modifications are of concern, the use of buffers may
not be sufficient to moderate effects. Best management practices, such as upland source
reductions through shifts in tillage practices or in usage patterns to less hazardous pesticides
or herbicides, maintenance of historical watershed/wetland area ratios, or upstream treatment
or control of runoff quantity/quality, may be required. Information is needed on (1) the
effectiveness of buffers and other best management practices at mitigating the effects of
stressors on wetland functions; (2) the critical features of buffers (e.g., size and structure)
that may influence their effectiveness; and (3) the types of stressors and impacts for which
the implementation of best management practices may be most appropriate. The
development of technical guidance for best management practices will rely on and
complement the approaches being developed by the Landscape Function Project (see Section
6).
Finally, as discussed in Section 1.2.4, EPA's Office of Water will be providing guidance to
states for developing biological criteria for wetlands. The Wetland Function Project will
32
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provide technical expertise in support of this effort. Major technical needs include (1)
quantification of stressor/response relationships, as discussed above; (2) an improved
understanding of exposure pathways in wetlands and the influence of the wetland
environment on chemical availability and toxicity; and (3) the identification of suitable
indicators of wetland condition and functions, and information on the range of indicator values
in natural and impacted wetlands, as a basis for defining biocriteria. This information can be
integrated through the traditional risk assessment approach to provide support for developing
water quality criteria and best management plans, with known uncertainties and an
appropriate margin of safety. In addition, incorporation of results into the functional loss
element of the WRP risk-based framework (Section 3.2.3) will facilitate the integration of
water quality criteria and best management practices into large-scale (e.g., ecoregions,
landscapes) wetland protection and management strategies. Use of the risk-based framework
for criteria development also will facilitate the integration of water quality criteria into the
broader context of risk management and the selection of optimal management strategies for
wetland protection.
4.2 APPROACH
To address the objectives and data needs outlined above, the Wetland Function Project will
conduct four major types of activities: (1) literature synthesis and development of conceptual
models, (2) empirical field studies, (3) manipulative experiments, and (4) development of
management strategies within the risk-based framework for protecting individual wetlands and
wetland complexes. Each of these efforts is described in greater detail below. The overall
research strategy is presented diagrammatically in Figure 4-1.
4.2.1 Literature Synthesis and Conceptual Models
For each of the regions and wetland types studied (see Section 4.3), the relevant literature
will be reviewed and synthesized; wetland experts will be consulted; and conceptual models,
such as the model of the Des Plaines River wetland presented in Figure 4-2, will be developed.
The following will be identified:
• the major stressors of concern for the particular system being studied, that is, the
stressor(s) considered to have the most critical or severe effects on the wetland type
of interest (e.g., excessive sedimentation caused by high erosion and the loss of buffer
strips might be considered critical for prairie pothole wetlands);
• the most important wetland functions that are threatened by each stressor (e.g., loss
of habitat and depletion of food resources for waterfowl that rely on the prairie pothole
wetlands);
• major ecosystem components and processes, in particular those components or
processes that may serve as indicators of impaired function caused by different
stressors (e.g., seed bank viability of critical plant species, macroinvertebrate
dynamics, etc.); and
• linkages among these stressors, ecosystem components, processes, and wetland
functions.
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Literature Synthesis and Conceptual Models
Hazard Identification
of Priority Stressors
Identification of Indicators
Empirical
Field Studies
Manipulative
Experiments
Risk Assessment
Stressor/Response
Relationships
Response thresholds
Assimilative capacity
Uncertainties in extrapolations
Exposure, Assessment
Pathways of exposure
Chemical availability
Temporal/spatial variability
Risk Characterization
Synthesis of information
Technical Support for Risk Management
Water Quality
Criteria
Best Management
Practices
Guidelines for
Site-Specific
Monitoring
Figure 4-1. Flow chart for the research strategy for the Wetland Function Project. The
hypothetical graphics are provided to illustrate how findings will be integrated into
the project; they are not meant to convey actual or expected results or
relationships.
34
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Active
Sediment
Layer
Energy/Water
Nu trients/B iomass
Permanent
Sediments
Figure 4-2. Conceptual model of the Des Plaines River Wetlands, developed by William Mitsch
and others for the Des Plaines River Wetlands Demonstration Project examining
the response of constructed wetlands receiving stormwater runoff from the City of
Chicago. This project was funded through the WRP Water Quality Project.
35
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The results from the literature review, expert consultation, and conceptual models will be used
for several purposes:
• to limit the scope of study by focusing on those functional and structural attributes
considered most sensitive to particular stressors of concern;
to develop specific research hypotheses to be tested during the empirical and
manipulative studies;
• to define hypothetical or preliminary stressor/response relationships based on the best
available data;
to aid in the design of experiments that will verify stressor/response relationships and
separate natural variability from stress-induced responses;
• to identify potentially useful indicators of wetland functions and responses to stressors that
can then be evaluated in the empirical and manipulative studies; and
• ultimately, to assist in the interpretation of study results, which may be complicated by
system interactions and the indirect effects of stressors on wetland functions.
The conceptual models will be revised and enhanced as needed as additional information is
obtained through the field and laboratory studies conducted by the Wetland Function Project.
4.2.2 Empirical Field Studies
Detailed studies of individual wetlands or small groups of wetlands will be conducted to
characterize wetland conditions (1) along a gradient of an environmental stressor or disturbance,
(2) before and after the occurrence of a disturbance or stressor, and/or (3) in wetlands with
varying wetland or watershed management strategies, such as buffers, that may be used to
mitigate the effect of stressors on wetland functions. Indicators of wetland function will be
measured in each wetland and the correlation between indicator values and stressor levels will
be examined to help define exposure pathways and stressor/response relationships.
The recently completed two-year study of Minnesota wetlands by Detenbeck et al. (1991) for the
Water Quality Project provides an example of the type of study envisioned. The objective was
to evaluate the effects of stressors associated with urbanization on wetland water quality, as well
as the ability of these wetlands to improve downstream water quality. Within the 8-county
Minneapolis/St. Paul metropolitan area, 31 wetlands were identified that would be disturbed during
the time frame of the study (September 1988 to September 1990). Disturbances included
dredging, fill, impoundment, drainage, and inputs of urban stormwater or pumped groundwater.
Water quality and hydrologic data were collected seasonally at the inflow to, mid-wetland, and
outflow from each site before, during, and after disturbances. Relationships between wetland
response (e.g., the change in total phosphorus pre- and post-disturbance) and indicators of the
disturbance intensity (e.g., the change in wetland type or water depth) were examined using
stepwise multiple regression (see Figure 4-3). Stormwater or pumped groundwater inputs,
construction, dredging and/or impoundment, wetland fill, and an increase in the watershed area
or urban/residential land use relative to wetland area all had a significant effect on wetland water
quality.
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1.2-
1.0-
0.8-
_j 0.6-
CL
O)
£0.41
H-
« 0.2-j
O)
ra
6 o.o
-0.2-
-0.4-
-0.6-
Y = 1.1 - 1 .OTypediff + 0.0053Wished, f2 = 0.98
-0.8-ur-r
-2
-1 0
Index of change in wetland depth
(adjusted for watershed size)
Figure 4-3. Example of the type of results expected from empirical field studies relating a
gradient of stressors to the response of individual wetlands. In this study, changes
in wetland depth (TYPEDIFF) were used as an indicator of hydrologic disturbance
to urban wetlands in the Minneapolis/St. Paul area. Springtime concentrations of
total phosphorus (TP) decreased following disturbance as wetlands were
deepened by dredging and/or impoundment (Detenbeck et al. 1991). The
relationship illustrated in the plot has been adjusted for correlations between
watershed size (Wtshed) and the change in total phosphorus or in wetland depth.
For studies involving spatial gradients, land use, topography, soils, groundwater quality, and other
existing data will be used to select wetlands with varying degrees of stressor exposure, from non-
impacted reference sites to severely impacted sites. Studies will also examine the role of buffers
and other wetland or watershed characteristics (e.g., wetland morphology, hydrologic regime,
watershed/wetland area ratios) that may influence wetland responses to stressors.
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4.2.3 Manipulative Experiments
Selected stressor/response relationships will be evaluated under controlled conditions using
experimental manipulations of portions of natural wetlands (mesocosms) in the field or of artificial
experimental units (microcosms) in the field or laboratory. Changes in wetland functions and
processes will be quantified in response to a controlled range of levels of specific stressor(s).
Sufficient levels of each stressor will be'included in the experimental design to allow for
development of a stressor-response curve or response surface (for exposures to multiple
stressors). In addition, a range of modifying factors (e.g., salinity, redox potential, sediment
organic carbon content) will be incorporated into a factorial design to assess exposure pathways
and so that results can be extrapolated to a wider range of wetland conditions. When possible,
experiments will be run for several years so that stressor effects over time and/or recovery times
can be assessed directly. Based on the results from these experiments, threshold levels for
adverse effects can be identified, that is, the level of stressor beyond which a detectable and
ecologically significant loss of function occurs.
An ongoing study by R.D. Delaune, W.H. Patrick, and others at Louisiana State University,
initiated as part of the Water Quality Project, provides an example of the type of work planned.
The effects of waterborne contaminants on important functions and characteristics of bottomland
hardwood forests and Panicum marsh in Louisiana, wetland types with predominately mineral and
organic sediments, respectively, are being examined. Experimental microcosms are being used
to evaluate assimilation processes and rates for toxic organics and metals that are known
problems in this region (see Figure 4-4). Assimilation rates are being measured along a gradient
of sediment redox potentials. Mesocosm experiments are being used to define indicator
responses at a range of contaminant levels. Such process-level experimentation provides rate
measurements that may be incorporated into predictive models to estimate the risks associated
with continued or increased contaminant loading (e.g., as part of risk characterization; see Section
4.2.4).
4.2.4 Development of Management Strategies for Protecting Individual Wetlands and
Wetland Complexes
The Wetland Function Project will demonstrate how a traditional risk assessment approach
(introduced in Section 3.2.3) can facilitate and improve the development of management
strategies for protecting individual wetlands and wetland complexes. The goal is to provide state
regulatory agencies responsible for implementing standards and best management practices with
an approach that they can use to develop a comprehensive, well integrated combination of
protective strategies to protect their wetland resources. Results from the empirical and
manipulative studies conducted by the Wetland Function Project will be used to demonstrate and
test the usefulness of this approach and, ultimately, to contribute to the functional loss element
of the risk-based framework.
The four steps of a traditional risk assessment (hazard identification, quantification of
stressor/response relationships, exposure assessments, and risk characterization) provide a basis
for characterizing the most critical risks to wetlands. Using this information, wetland managers
can then manage those risks through wetland standards, including an appropriate combination
of narrative and numeric biological, physical, and chemical criteria and best management
practices. «
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Cr (VI) load: 50 mg/kg dry soil
50
=- 40-
o
co
CD
e,
T3
CD
30-
20 -
CD
oc
10 -
500
200 0
Redox Potential (mV)
-200
H Freshwater Marsh Soil
U Bottomland Hardwood Soil
Figure 4-4. Chromium assimilation within microcosms containing a heavily organic freshwater
marsh soil or a predominately mineral bottomland hardwood forest soil as a
function of redox potential, under a loading rate of 50 mg Cr/kg dry soil (Delaune
et al., unpublished data, Louisiana State University; project funded through the
WRP Water Quality Project).
Hazard identification involves a qualitative, preliminary assessment of risks and the identification
of appropriate endpoints and indicators, so that subsequent efforts can be focused on the priority
stressors and responses of greatest concern. In most cases, this step can rely on existing
information, and the Wetland Function Project will demonstrate how the literature syntheses and
conceptual models described in Section 4.2.1 can serve as the primary basis for hazard
identification. ;
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Knowledge of stressor/response relationships, exposure pathways, and natural variability is critical
to the development of criteria with known levels of uncertainty and sensitivities. The Wetland
Function Project will rely on both the empirical studies and manipulative experiments to quantify
stressor/response relationships and conduct exposure assessments. Experimental manipulations
demonstrate cause-and-effect and can be used to quantify the effects of individual stressors in
a controlled environment. By including modifying factors in the experimental design, information
will also be provided on chemical availability and exposure pathways. The empirical field studies
examine wetland responses to real-world conditions that cannot be adequately simulated in small-
scale experiments. The two approaches together are complementary and necessary to determine
with confidence how important wetland functions and characteristics respond to stressors.
Through risk characterization, the information described above can be synthesized and presented
to wetland managers in a manner that can facilitate decisions regarding appropriate water quality
criteria, especially numeric biocriteria, to protect the ecological integrity of wetlands. Uncertainties
can be explicitly recognized and accounted for through margins of safety or other means. Many
wetland mosaics have already been seriously degraded by a complex of anthropogenic stressors,
from point and nonpoint sources. In such cases, the implementation of best management
practices, along with water quality criteria, may be an appropriate management strategy to arrest
and reverse wetland degradation. The risk-based approach described in this section provides an
objective basis for selecting the most appropriate combination of protective measures and also
for extrapolating the assessment results to other regions or wetland types. To apply these
recommendations to larger management scales (e.g., ecoregions, landscapes), the Wetland
Function Project will provide information to the Landscape Function and Risk Reduction Projects.
The risk-based approach described above for the development of water quality criteria and best
management practices will be demonstrated for one wetland type and region, specifically the
Prairie Pothole Region (see Section 4.3.1). Because this will be a demonstration project, no
attempt will be made to provide all of the data needed to develop a full set of criteria; efforts will
concentrate on (1) developing and refining the approach itself and (2) providing technical support
for criteria and best management practices relevant to excess sediments and sediment-associated
contaminants. Data from the other primary studies (bottomland hardwoods arid freshwater
emergent wetlands in urban areas; see Section 4.3) also will be used to provide technical support
for water quality criteria, focusing primarily on the development of biocriteria and best
management practices relevant to the primary stressors being considered in each system.
The sequence of tasks to be completed is as follows:
1. Through the hazard identification process, a proposed set of biological, physical, and
chemical criteria appropriate to the chemical and nonchemical stressors of greatest
concern will be developed.
2. The degree to which existing stressor/response data and criteria (primarily chemical
criteria, developed for lakes and streams) may be relevant to the wetlands of interest will
be evaluated.
Substantial information already exists on the' toxic effects of chemical stressors and
conventional pollutants on aquatic and terrestrial biota, and many chemical-specific criteria
are already available for lakes and streams. Furthermore, the collection of data for
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quantifying stressor/response relationships and exposure is expensive. Thus, states will
need to make efforts to reduce the need for additional chemical-specific toxicity testing,
while still ensuring that the final criteria are adequately protective of wetlands. For criteria
relevant to prairie pothole wetlands, the Wetland Function Project will test a simple
procedure, based on available data, to determine whether existing criteria are sufficient
to protect wetland-dependent organisms under wetland conditions (Hagley and Taylor
1991).
3. Empirical and manipulative studies will be used to (1) field verify trje relevance of existing
criteria and (2) develop new stressor/response relationships and exposure data, focusing
primarily on developing and testing biological indicators of chemical and nonchemical
stressors, from which both narrative and numeric biocriteria can be developed.
States may find that site-specific adjustments are needed in select cases. Limited
additional testing may be warranted for classes of chemical contaminants (e.g., heavy
metals) expected to have altered toxicity under wetland conditions of low and/or variable
dissolved oxygen or pH. The Wetland Function Project will conduct actual toxicity tests
only in the context of research already planned for prairie potholes and southeastern
bottomland hardwoods (see Sections 4.3.1 and 4.3.2); all tests Will be conducted under
conditions appropriate for wetland ecosystems.
For nonchemical stressors, such as a change in hydrologic regime or physical alteration,
both the direct and indirect effects on wetland ecosystems can be significant and must be
evaluated. In some cases, the effects may be nonlinear or may involve an irreversible
shift to an alternate state (Niemi et al. 1990). Information will be collected on the level
and range of critical driving factors, such as hydrologic regime and physical structure,
within which wetland functions can be maintained at the levels expected for natural,
unaltered wetlands.
Data collected within the Wetland Function and other WRP Projects on indicators of
wetland functions in natural and impacted wetlands will provide the basis for developing
biocriteria. Biocriteria can be used to indicate when the cumulative effects of both
chemical and nonchemical stressors have induced significant changes in community
structure or other important wetland attributes. To date, biocriteria have been developed
and applied only for lotic systems in some states (e.g., Ohio EPA 1988). Data suitable
for biocriteria development will be collected in each of the wetland types studied by the
Wetland Function Project (see Section 4.3).
4. Seriously degraded wetlands and wetland complexes will be identified for which
development of best management practices might be especially appropriate.
Retrospective functional loss assessments will be used to determine when best
management practices are most appropriate. Literature reviews as well as the empirical
and manipulative studies will provide information on the best methods for implementing
best management practices.
5. The information, described above will be synthesized in such a way that it can be
extrapolated to the ecosystem level or to other similar systems through empirical or
mechanistic models or the development of expert systems.
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The results from this work will contribute directly to the major deliverables proposed for the
Wetland Function Project (Section 9) and also the integrated program deliverables for the Risk
Reduction Project (see Sections 7 and 9). Research efforts by the Wetland Function Project
concerning water quality criteria and best management practices will be closely coordinated with
programs ongoing within EPA's Office of Science and Technology and the Office of Wetlands,
Oceans, and Watersheds dealing with the development of sediment criteria, new water quality
and biological criteria, and wildlife criteria; nonppint source pollution; and coastal zone
management
4.3 IMPLEMENTATION
Consistent with the EPA program priorities identified in Sections 1.2 and 1.3, the Wetland
Function Project has selected four areas of emphasis for FY 1992-1996: (1) the functional
responses of prairie pothole wetlands to sediments and sediment-associated pollutants, (2) the
effects of management practices and nonpoint source pollution on the water quality and habitat
functions of bottomland hardwood forests in agricultural landscapes of the southeastern United
States, (3) the effects of hydrologic modification on the water quality and habitat functions of
freshwater emergent marsh in an urban setting, and (4) a pilot study of the effects of stressors
on coastal seagrass communities: Brief descriptions of these four studies are provided below.
4.3.1 Functional Responses of Prairie Pothole Wetlands to Sedimentation
Work conducted on prairie pothole wetlands will provide technical support for (1) developing water
quality criteria to protect freshwater emergent marshes from the effects of sediment and sediment-
associated pollutants, (2) developing guidelines for buffer widths of nonagricultural land to protect
these wetlands from nonpoint source pollution, and (3) determining the role of isolated wetlands
in performing habitat, water quality, and hydrologic functions (see Section 1.2.6). Tasks will be
coordinated with concurrent efforts in these wetlands conducted by the Characterization and
Restoration (Section 5.3.1) and Landscape Function (Section 6.3.1) Projects and EMAP-
Wetlands, and the results will be integrated by the Risk Reduction Project into the risk-based
framework (Section 7.2). Results from the prairie pothole studies also will be used to
demonstrate a risk-based approach for setting water quality criteria, as described in Section 4.2.4.
The general hypotheses to be tested include the following:
The habitat function and water quality improvement capacity of wetlands in
agricultural landscapes have been degraded by nonpoint source pollution.
Sediment from agricultural watersheds is a major cause of habitat degradation and
declines in the water quality improvement capacity of prairie pothole wetlands.
Buffers surrounding wetlands in agricultural watersheds can reduce sediment input
and preserve the wetland water quality improvement and habitat functions.
Isolated wetlands in agricultural landscapes function as sinks and/or transformers
of contaminants associated with nonpoint source pollution.
The study will be initiated by conducting a literature review and assessing expert opinion to define
the state of the science on the effects of sedimentation and associated nutrients and toxics on
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the habitat and water quality improvement functions of prairie pothole wetlands. Conceptual
model(s) will be developed and potential indicators of deleterious effects identified. Specific
hypotheses regarding stressor/response relationships will be developed, focusing on the
relationship between sedimentation and wetland habitat functions. Degradation of hydrologic
functions will also be considered in the state-of-the-science review, though to a lesser degree.
Both empirical and manipulative studies will be conducted. Wetlands with a range of adjacent
upland buffer widths and upland agricultural practices will be selected for field sampling.
Indicators of wetland function, identified through the literature review, will be measured in each
wetland. Wetland condition will be examined as a function of surrounding land uses (as an index
of nonpoint source pollutant loadings) and buffer widths. Concurrently, wetland mesocosm
experiments will be conducted to evaluate the effects of increased loads of sediment and
associated contaminants on important wetland components and processes (e.g., the growth and
survival of plants and invertebrates, seed bank viability, rates of litter decomposition). The results
from the empirical and manipulative studies will provide information on (1) the effects of sediment
and sediment-associated contaminants on the wetland habitat function, (2) stressor/response
relationships for the development of water quality criteria, (3) the development of best
management practices (e.g., guidelines for tillage practices or buffer widths), and (4) uncertainties
associated with monitoring strategies for detecting the effects of stressors on prairie potholes.
4.3.2 Effects of Best Management Practices and Nonpoint Source Pollution
on Bottomland Hardwoods
Both the Wetland Function and Landscape Function Projects (see Section 6.3;2) will be
conducting research on bottomland hardwoods; the results from these studies will be integrated
into the risk-based framework by the Risk Reduction Project (Section 7.2).
Studies by the Wetland Function Project will focus on (1) the effects of nonpoint source pollution
and buffer management on the. functions of bottomland hardwood wetlands and (2) the
effectiveness of these riparian wetlands at reducing nonpoint source loadings to downstream
surface waters. Technical guidance will be developed for riparian buffer widths needed to protect
the water quality of low order streams (i.e., upstream tributaries having low discharge relative to
the main stem) and buffer widths of nontilled land needed to protect the riparian forest habitat
functions from upland inputs. The general hypotheses to be evaluated include the following:
The width and structure of riparian bottomland hardwood forests are important
determinants of the water quality improvement functions of these wetlands,
reducing pollutant loadings to low order streams.
Nontilled buffers adjacent to bottomland hardwood wetlands will protect the habitat
function of these riparian forests from upland inputs of nonpoint source pollutants.
The relationships between wetland condition, land use, and buffer widths provide
useful management guidelines for protecting low order streams and riparian forests
from nonpoint source pollution.
A literature review will be conducted and expert opinion assessed to (1) identify and evaluate
existing conceptual and quantitative models of riparian forest wetland structure and function;
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(2) summarize existing information characterizing baseline sediment, nutrient, and pesticide
assimilation curves and buffer widths for undisturbed riparian forests under different nonpoint
source loading scenarios; (3) select indicators of riparian forest water quality and habitat
functions; and (4) generate preliminary stressor/response curves for two major stressors of these
systems, physical alteration and sedimentation.
Empirical and manipulative studies will be conducted. Bottomland hardwood stands with a range
of upland buffer widths and upland disturbance regimes will be selected for field sampling.
Experimental bottomland hardwood stands will be evaluated after being subjected to several
different management regimes that represent a range of severity of effects. Overland and
groundwater flows of materials will be monitored to develop assimilation curves for the various
management practices and to determine riparian buffer widths required to protect stream water
quality. Management practices, both best management practices and current detrimental
management practices, also will be correlated with changes in indicators of wetland habitat
functions.
The relationships between buffer widths, the surrounding land use, wetland condition, and stream
water quality, from both the empirical and manipulative studies, will provide the basis for
management guidelines. Response thresholds identified from stressor/response curves will
support the development of criteria for wetland water quality standards.
4.3.3 Hydrologlc Modification in Urban Wetlands
The objective of this study is to determine the effects of hydrologic modification caused by
urbanization on the water quality and habitat functions of freshwater emergent wetlands. Given
the current budget for FY 1992-1996, efforts will be limited to a literature review, synthesis and
expansion of ongoing projects funded through the Water Quality Project, and potential research
on the effects of stormwater on urban wetlands funded jointly by the EPA Regions and the WRP.
The literature review will focus on the types, levels, and mechanisms of effects generally
associated with urban hydrologic modification. Ongoing research includes (1) the study by
Detenbeck et al. (1991) evaluating the effects of physical and chemical disturbances on urban
wetland water quality functions, (2) the development of macroinvertebrate indices of wetland
integrity along a gradient of urban stormwater effects, and (3) a study being conducted in King
County (Seattle metropolitan area), WA, examining the response of vegetation and amphibian
indicators to hydrological stressors in urban wetlands. Follow-up surveys of wetland water quality
and habitat functions will be conducted at disturbance sites in the Minneapolis/St. Paul
metropolitan area to evaluate the rate of recovery of wetlands following physical disturbances.
A regional workshop on urban wetlands to be held in early 1992 in New York City will provide the
framework for planning additional studies of urban wetlands to address regional issues (e.g.,
stormwater inputs).
4.3.4 Effects of Stressors on Coastal Seagrass Communities
Coastal seagrass communities, one of the major categories of coastal wetland habitat, are highly
productive ecosystems that furnish food and shelter to ecologically and commercially important
fisheries (Thayer et al. 1984). Significant declines in both the area and quality of seagrass
communities have been documented in many coastal areas of the United States. However, the
nature of seagrass responses to important stressors is not well understood, nor have the
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tolerance limits of seagrass communities to individual and combined stressors been defined.
Empirical field studies and microcosm and mesocosm experiments are needed to characterize
stressor/response relationships and to determine the effects of known quantities of stressors on
the structure and function of seagrass communities.
During FY 1992, a pilot study will be initiated on the effects of stressors on seagrass communities
along the Gulf Coast. A workshop was held in January 1992, including representatives from the
National Oceanic and Atmospheric Administration, the U.S. Fish and Wildlife Service, the Corps
of Engineers, and state agencies. Based on the information and research discussed at this
workshop, a detailed plan of study is being developed to examine the effects of land use and
watershed management practices on seagrass systems. The results from the pilot study, together
with long-term data sets for estuaries in Texas and Florida, will be used to identify variables and
conditions associated with the absence or loss of seagrass communities. Field studies by EMAP-
Wetlands and the EMAP-Near Coastal monitoring programs also will aid.in generation of testable
hypotheses and in field verification.
If additional funding is obtained, research will continue in FY 1993 and beyond, studying seagrass
communities in the Atlantic and Pacific as well as in the Gulf of Mexico. In addition to field
studies, laboratory mesocosm experiments will be conducted, manipulating variables singly and
in combination, to measure the effects of stressors on seagrass survival, growth, and community
structure. Major stressors of concern include nutrients, toxics, light levels, and sediment loads.
An important objective is to determine the optimal water quality conditions for the establishment
and growth of seagrasses. This information will be used to support the development of water
quality criteria for the protection of seagrass communities.
4.4 MAJOR CONTRIBUTIONS
The major contributions of the Wetland Function Project to the WRP will include the following:
quantification of wetland stressor/response relationships and changes in wetland functions
and attributes over time in response to important environmental stressors;
• quantification of wetland assimilative capacities and response thresholds for selected
stressors;
• development and application of a risk-based approach to setting water quality criteria for
wetlands;
• technical guidelines for wetland protection, including the role of buffers and best
management practices;
• technical guidance on the role of individual wetlands for water quality improvement, in
particular for nonpoint source pollution control or urban stormwater management; and
• technical guidance on wetland monitoring and indicators of wetland condition and
functions.
The specific program deliverables for the Wetland Function Project are listed in Section 9.
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5. CHARACTERIZATION AND RESTORATION PROJECT
The Characterization and Restoration Project focuses on those information needs and objectives
best achieved through field studies of wetland populations. Work within this project will contribute
primarily to two of the WRP research objectives:
1. Describe and compare the functional status of populations of natural, restored, and
created wetlands in different landscape settings.
2. Provide technical support for the development of design guidelines and performance
criteria for wetland restoration and creation.
This section presents background information on the project and the research issues addressed
(Section 5.1); an overview of the basic approach to be used to achieve the research objectives
(Section 5.2); brief descriptions of the specific studies to be implemented (Section 5.3); and a
summary of the major expected contributions of the project relative to the overall goals and
objectives of the WRP (Section 5.4).
5.1 BACKGROUND
A cohesive management and regulatory program requires information not only on the ecological
functions of wetlands, both individually and in the landscape, but also on the ability to create and
restore those functions. Over the past five years, the WRP Mitigation Project focused on
research to evaluate how well restored and created wetlands replace the functions of natural
wetlands (Zedler and Kentula 1986). Based on this research, an approach was developed for
establishing regional performance criteria and design guidelines for mitigation projects with open
water and emergent marsh (Appendix A). The Characterization and Restoration Project, an
outgrowth of the original Mitigation Project, will continue this research. In addition, the scope of
the project has been expanded to include the development of methods and data for characterizing
wetland populations. Characterizations can then be used to (1) test and refine the approach
developed to assess the success of wetland restoration and creation projects of additional
wetland types and (2) provide basic information on attainable wetland functions and among-
wetland variability needed for regional-scale wetland management and implementation of the risk-
based framework.
The strategy of the Mitigation Project always centered on wetland populations, comparing the
characteristics of a sample of restored or created wetlands to, an analogous population of natural
wetlands5 of the same type, occurring in similar landscape settings. This approach is in contrast
to most wetland studies that have considered only a single site or paired sites (natural versus
restored or created). Case studies of individual sites or comparisons of pairs of sites do not
provide information that can be extrapolated with known confidence to the wetland population as
a whole. Variations among natural wetlands, and among restored or created wetlands, must be
5 We use the term "natural" to refer to wetlands that occur naturally in the landscape, that is,
excluding created, restored, enhanced, rehabilitated, co'nstructed, and other types of wetlands that
have been manipulated by humans. Natural wetlands are not, however, necessarily minimally
impacted, but may be subject to a range of impacts and stressors.
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considered when evaluating the success of wetland restoration or creation efforts, especially for
setting design and performance criteria. The population frame used in the Characterization and
Restoration Project is not only an outgrowth of historical and ongoing activities of the project, but
is regarded as an effective approach for evaluating the overall success of mitigation projects.
The characterization of wetland populations is also a primary objective of EMAP-VVetlands. It is
essential, therefore, that the Characterization and Restoration Project and EMAP-Wetlands work
closely together to avoid duplication and ensure comparability of results. EMAP-Wetlands is
charged with characterizing wetlands over large spatial and temporal scales, implementing a long-
term monitoring network that will eventually cover the entire United States and all major wetland
types. The Characterization and Restoration Project, by contrast, will sample only certain regions
and wetland types to address specific WRP research objectives. The types of measurements and
sampling methods in the two projects will be similar, although additional project-specific indicators
will likely be measured within the Characterization and Restoration Project. Appendix A provides
further discussion of the interactions between EMAP-Wetlands and the WRP projects.
The evaluation of wetland restoration and creation projects will remain an important component
of the research in the Characterization and Restoration Project. The amount of existing literature
on this issue varies by region and topic. Much of the research has been based on case studies,
with no natural sites for comparison (Quammen 1986). If reference sites were used, typically a
paired approach was taken. Consequently, the majority of research to date has been site
specific.
To determine the adequacy of current information, the Mitigation Project assembled a team of
experts to compile and document the status of science on wetland restoration and creation
(Kusler and Kentula 1990b). The major findings of this group follow:
• Practical experience and available information vary by wetland type, ecological function,
and region. The most extensive and best documented data are available for Atlantic
coastal wetlands. Much less is known about restoring and creating inland wetlands.
• Most restoration and creation projects do not have specific goals, complicating efforts to
evaluate "success." Success is often evaluated only in terms of compliance with permit
requirements or establishment of vegetation. Such measurements are not indicative of
the occurrence or level of function, nor the persistence of those functions over time.
• Monitoring of restoration and creation projects has been uncommon. Monitoring of sites
and quantitative comparisons with natural wetlands over time would provide a variety of
information, including how projects develop and how they compare with natural wetlands
in the region (Kusler and Kentula 1990a).
The research to be conducted as part of the Characterization and Restoration Project will address
these major data gaps by (1) studying the restoration and creation of inland wetlands;
(2) developing approaches for establishing performance criteria and for evaluating project
success, especially success in terms of establishing or restoring important wetland functions;
(3) evaluating regional patterns and long-term trends in the performance of mitigation projects;
and (4) developing an approach for prioritizing sites for wetland restoration and creation.
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5.2 APPROACH
Four major tasks will be conducted as part of the Characterization and Restoration Project:
1. Describe (characterize) wetland populations, including natural, restored, and created
wetlands, to quantify wetland functions and among-wetland variability within specific
geographic and land use settings.
2. Evaluate the performance of wetland restoration and creation projects and the attainable
levels of wetland functions in various landscape settings.
3. Provide technical support for the development of specific performance criteria and
technical design guidelines to enhance performance and accelerate project development.
4. Develop and test an approach for prioritizing sites for wetland restoration and creation.
The approach to be employed for each of these tasks is described in the subsections that follow.
The overall project strategy is presented diagrammatically in Figure 5-1. ..
5.2.1 Wetland Characterization
To characterize wetland populations requires three subtasks: (1) selecting the specific sites to
be sampled, (2) deciding which wetland attributes to measure and how and when to sample, and
(3) analyzing the sample results to provide an effective characterization of the population of
interest. Each of these subtasks is described in turn.
5.2.1.1 Site selection
Data will be collected on a representative sample of natural, restored and/or created wetlands
within specific region and land use setting(s) of interest. Ecological and landscape settings are
considered important determinants of wetland characteristics and attainable levels of wetland
functions. It is important that restored and created wetlands be compared to natural wetlands
occupying similar landscapes, and thus exposed to similar stressors, to ensure that the expected
attributes of a wetland restoration or creation project are within the bounds of possible
performance given the setting (Brown 1991). For this reason, the sites sampled will be stratified
by ecoregion and land use. Brooks and Hughes (1988) suggested Omernik's (1987) ecoregions
as a framework for wetland selection because the ecoregion boundaries were selected to reflect
regional patterns of land surface form, potential natural vegetation, and soils. In addition, the
effects of land use and landscape position will be accounted for by grouping wetlands in similar
land use settings (e.g., urban, agricultural).
For each study region, a list of all restored and created wetlands in the area will be compiled or
obtained (e.g., using a listing of Section 404 permits that required compensatory mitigation). This
list will define the population of restored and created wetlands. Depending on the study
objectives and size of the population (i.e., total number of mitigation projects in the area), either
all or a random subset of these wetlands will be sampled. If projects within the area are of
varying age (i.e., time since completion of the wetland restoration or creation activities), then the
sample may be stratified by age to provide a basis for evaluating how projects develop over time.
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Functional Characterization of Wetland Populations
Restored Natural
Wetlands Wetlands
Indicator of Wetland Function
Performance Evaluation of Wetland Restoration and Creation
_ I L _ JL Natural
Wetlands
Restored
Wetlands
Time
Technical Support for Risk Management
Attainable Function
Performance Criteria
and Design Guidelines
Techniques for
Prioritizing Site
Selection
Figure 5-1. Flow chart for the research strategy for the Characterization and Restoration
Project. The hypothetical graphics are provided to illustrate how findings will be
integrated into the project; they are not meant to convey actual or expected results
or relationships.
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Analysis of the list of sites also can be used to describe patterns and trends in wetland restoration
and creation (e.g., acreage of impacted,or created wetlands, wetland type(s) affected, mitigation
ratios, etc.), as illustrated in Figure 5-2 (Kentula et al., in press; Holland and Kentula, in press;
Sifneos et al., in press).
The next step is to select the natural wetlands that will be used to establish the level of wetland
function(s) that is attainable for a given region and land use setting. For example, a landscape
quadrat may be established along a gradient of interest, such as the urbanization gradient shown
in Figure 5-3. The total population of wetlands within the quadrat can be identified using either
National Wetland Inventory maps or aerial photography. The population may then be stratified
according to land use, degree of impact, or major stressor using a procedure such as the
Landscape Development Index (Brown 1991), which is discussed further in Section 6. As is the
case for restored and created wetlands, either all or a random sample of natural wetlands can be
surveyed, depending on the size of the wetland population and desired sample size and
stratification.
Finally, the suitability of the sites needs to be verified in the field, and the list of sites to be
sampled finalized. Sites will be rejected if they are the wrong wetland type or size, if conditions
at or adjacent to the site would be hazardous to the field team, or if access is denied.
Contingencies for site rejection will be factored into the preliminary site lists, to ensure that the
final sample size is adequate.
5.2.1.2 Site characterization
At each of the sites selected, field measurements will be collected to assess wetland
characteristics. Indicators of wetland functions are of particular interest, because an important
objective of wetland restoration/creation is to replace losses of wetland area or function. At
present, there are no universally accepted indicators of wetland function. Indicators of potential
utility have been identified, however, by consulting wetland scientists and the literature. Adamus
and Brandt (1990) completed such a review for the WRP. In addition, a list of potential indicators
for use in regional wetland monitoring has been developed for EMAP-Wetlands (Leibowitz et al.
1991). Finally, studies conducted over the last five years as part of the Mitigation Project have
resulted in the identification of useful indicators, especially for comparing natural and
restored/created wetlands (e.g., Confer and Niering, in press; Sherman 1991; Sherman et al.
1991).
To the extent possible and to ensure comparability/exchangeability of data, the indicators and
sampling methods employed will be consistent with those used for EMAP-Wetlands. In some
cases, additional indicators and more intensive sampling may be needed to satisfy specific
objectives of the Characterization and Restoration Project. In general, wetlands will be described
through measurements of important biological, physical, and chemical parameters. Sites will be
mapped to scale, and the maps will be annotated with features of the site and the surrounding
area. Basin morphology will be described; other measured variables (e.g., vegetation patterns)
will then be related to relative elevations within the site. Surveys of vegetation and animals will
be conducted. Site hydrology, soils, and water quality will be described.
The Characterization and Restoration Project will contribute to indicator development, testing, and
improvement by evaluating the utility of proposed indicators in extensive surveys in different
51
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LEGEND
Area of Wetland (acres)
~w
0-100 101- 501- 1,001- 5,001-
500 1,000 5,000 10,000+
Wetlands
Compensatory
Figure 5-2. Area of freshwater wetlands involved in Section 404 permitting in Louissiana from
January 1982 through August 1987, by parish (Sifneos et al., in press).
52
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(a)
(b)
PERCENT LAND AREA
1OO
INCREASING DISTANCE FROM URBAN CENTER >
URBAN D AGRICULTURAL ® NATURAL
Figure 5-3. Illustration of a land use gradient showing (a) the locations of 32 candidate
wetlands in a landscape quadrat that extends out from the urban area of Tampa,
FL, and (b) a comparison of land uses surrounding each candidate wetland
showing the change from predominately urban to increased agricultural and natural
land uses with increasing distance from the urban center (adapted from Brown 1991).
53
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wetland types and regions. The results will complement, and provide a population context for,
the intensive field studies and mesocosm and microcosm experiments conducted as part of the
Wetland Function Project (see Section 4.2.2).
5.2.1.3 Population characterization
The major output from this task will be characterization curves, describing the frequency
distributions of functional indicators (or a multivariate, integrated index of wetland function) for the
wetland populations of interest. Separate curves will be developed and compared for natural and
restored or created wetlands (top of Figure 5-1), for wetlands in different landscape settings, and,
where possible, for mitigation projects (restored or created wetlands) of different ages.
5.2.2 Performance of Wetland Restoration and Creation Projects
Data collected in the field studies described above also will be used to document the ecological
performance of restored and created wetland projects.. The two main analytical tools used to
assess the success of wetland restoration and creation efforts within a region will be (1) snapshot
comparisons of the characterization curves for functional indicators in natural and restored or
created wetlands (top of Figure 5-1) and'(2) performance curves, which track the development
of ecological functions of restored or created wetlands over time relative to natural wetlands
(middle of Figure 5-1; also Figure 5-4). As noted above, it is important that wetlands be
compared within the same landscape setting; natural wetlands provide the basis for defining the
level of function that can be attained by restored or created wetlands within a specific landscape
setting. Questions to be addressed by these analyses include the following:
• What is the achievable level of wetland function in a particular environmental/land use
setting? (What is the time-averaged mean for natural sites?)
• How long does it take for restored or created wetlands to achieve their maximum level of
function? (What is the slope of the performance curve during the period of
establishment?)
• Do restored and created wetlands achieve, on average, the same level of function as
natural wetlands? (Is the average value for any specific functional indicator, at some time
after establishment of the mitigation project, equal to the mean value of that functional
indicator in natural sites in the same landscape setting?)
• How can natural and degraded wetlands best be distinguished? (What indicator(s) of
wetland function have the least overlap between the characterization curves for the two
groups of wetlands and what is the value of this indicator(s) where the two
characterization curves intersect?)
Figure 5-5 illustrates the type of results expected from these analyses using recently completed
Mitigation Project studies. Measurements of an index of plant diversity in created freshwater
wetlands of different ages in Connecticut, Florida, and Oregon are compared to the mean and
standard error for the diversity index for comparable populations of natural wetlands. Note that
most of the wetlands studied during this project were less than five years old. Furthermore, very
few studies have evaluated changes in restored or created wetlands over time (Kusler and
54
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(a)
o
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Functional Level
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Functional Level of
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o
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Figure 5-4. Hypothetical performance curves illustrating (a) the comparison of a sample of
populations of restored and natural wetlands in the same land use setting and
(b) in different land use settings. In figure (a), "A" minus "B" is equal to the
difference in the level of function between the restored and natural wetlands. "C"
is the time needed to develop the maximum level of function on the restored sites.
55
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Connecticut Field Study
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Figure 5-5.
Performance curves illustrating the level of plant diversity in the emergent marsh
component of created and natural wetlands of different ages in Connecticut,
Florida, and Oregon. The dashed line represents the mean plant diversity of the
population of natural wetlands; the errors bars indicate one standard error. An
asterisk indicates the value for an individual created wetland.
56
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Kentula 1990b). For this reason, during FY 1992-1996 the sites from one or more of the earlier
studies will be re-examined to track their development five years later and further characterize
the apparent temporal trends identified (Figure 5-5). In addition, mitigation projects constructed
since the last study will be included in the sample to see if their pattern of development repeats
that of the projects studied earlier (see Section 5.3.3).
The field data collected as part of the wetland characterization studies described in Section 5.2.1
also provide documentation on the "as-built" conditions of restored or created wetlands. These
data will be compared to the original planning documents, such as the construction plans and
Section 404 permit conditions, to determine if the project was constructed as planned and
permitted (e.g., Gwin and Kentula 1990).
5.2.3 Performance Criteria and Design Guidelines
Based on the data and results described in Sections 5.2.1 and 5.2.2, specific technical guidelines
will be developed to aid in the design and evaluation of wetland restoration and creation projects.
Performance and characterization curves will be produced for each indicator measured and will
be used to suggest performance criteria. For example, based on the information in Figure 5-5,
we can suggest a check on the status of the plant community development at a created site.
Within five years after construction, the plant diversity of the site is expected to be greater than
or equal to that of natural wetlands within comparable settings. Sites having plant diversities
more than one standard error less than the average value for natural wetlands may need a
correction in design.
Information on the structural features of restored or created wetlands, relative to the functional
level attained, will suggest design guidelines and generate testable hypotheses concerning critical
design features that influence the likelihood of a successful wetland restoration or creation project.
For example, Figure 5-6 illustrates, from the same Mitigation Project study discussed in Section
5.2.2, the concentration of soil organic matter in created wetlands of varying ages in Oregon,
relative to the mean soil organic matter content in a comparable population of natural wetlands.
Site 'A1 has more soil organic matter than both the other created wetlands and the vast majority
of natural wetlands. Examination of this site could suggest insights into how to design a created
wetland to accelerate the accumulation of organic matter. This accumulation should concurrently
increase wetland functions related to soil organic matter content, such as water quality
improvement. The validity of such hypotheses will be evaluated by (1) looking for similar patterns
and relationships in other groups of restored, created, and natural wetlands; and/or (2) conducting
field experiments (e.g., mesocosm studies) that evaluate specific cause-and-effect relationships.
Studies and analyses will be carried out to identify design features that are critical to wetland
functions and can be manipulated to accelerate the development of these functions over time.
The objectives of the Characterization and Restoration Project are not only to develop technical
guidelines for the specific wetland types and areas studied, but also to demonstrate a general
process that can be applied by wetland managers in other regions and other wetland types. This
approach, proposed initially as part of the Mitigation Project, will provide a framework for the
development of ecologically defensible mitigation strategies that are tailored to local and regional
needs. The major features of this approach include the following: ,
Existing information in project files on wetland restoration and creation activities in the
area is used to guide planning and decisionmaking.
57
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58
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• Areas at greatest risk are identified and targeted for monitoring efforts to evaluate the
performance of wetland restoration and creation projects.
» Ecological (ecoregion) and land use settings are considered in the selection of sites for
monitoring.
The characteristics of natural wetlands, of the same type and in the same landscape
setting, are used to define the attainable conditions for restored and created wetlands.
• Characterization and performance curves are used to set objective, realistic performance
criteria, develop design guidelines for maximizing function, and identify critical checkpoints
in project development.
• The process of developing design guidelines and setting performance criteria is iterative.
During the next five years, this framework will be tested and refined as needed to ensure that the
approach and specific techniques are broadly applicable to a variety of wetland types, regions,
and management concerns.
5.2.4 Prioritlzation of Sites for Wetland Restoration and Creation
Another important management need is the development of objective guidelines and techniques
for identifying and prioritizing sites for wetland restoration and creation. Critical issues for project
siting include (1) identifying locations where wetlands are needed to improve the ecological
functions of the landscape, (2) selecting those sites that are most suitable for wetland restoration
or creation, and (3) protecting restored and created wetlands from further impacts associated with
surrounding land uses and stressors.
Four subtasks are proposed to develop an approach for prioritization:
1.
2.
Identify target locales where wetland restoration and creation projects are planned.
Conduct a literature review to (a) determine the wetland types that occur in that area,
(b) identify experts on restoring and creating those wetland types, and (c) assess the
available information on wetland functions and factors that may influence the success of
wetland restoration.
3. Commission a group of experts to develop a state-of-the-science approach for prioritizing
sites for restoration and creation.
4. Test the proposed approach by conducting field studies to evaluate the success of
wetland restoration and creation projects implemented at the recommended sites, and
refine the approach as needed. The ability to complete this final step may be constrained,
however, by the timing of these follow-on mitigation projects.
As part of the state-of-the-science approach for site selection, landscape-level assessment tools
will be developed. The utility of the Landscape Development Index (Brown 1991) and the
Synoptic Approach (Abbruzzese et al. 1990a,b) will be examined as a first step in developing a
59
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decision support system for selecting sites for restoration and creation. This work will be
coordinated with the Landscape Function Project (Section 6).
5.3 IMPLEMENTATION
The components of the approach described above can be combined in different ways to assess
a diversity of wetland types in different parts of the country. In general, .the goal of the project
is to demonstrate the approach in typical wetlands and regions, so that the techniques can be
adopted and applied by others. Research on wetland restoration and creation is dependent on
the existence of completed or soon to be constructed projects. Thus, to some degree, the
Characterization and Restoration Project must focus on opportunities for research that currently
exist or have a high probability of occurring. Sites with existing monitoring data, for which
temporal trends information can be obtained, are of particular interest. Cooperative effort with
other WRP projects, to provide a basis for conducting an integrated risk assessment and
demonstrating the risk-based framework, is an additional consideration in selecting areas and
wetland types for study.
Under the Characterization and Restoration Project, three priority studies have been targeted for
implementation during FY1992-1996: (1) the characterization of agriculturally converted wetlands
in the Prairie Pothole Region, which will be conducted as part of an integrated study with the
other WRP projects and EMAP-Wetlands; (2) the development of objective protocols for selecting
sites for restoring western riparian systems and evaluation of approaches for restoring them; and
(3) long-term studies of the development of mitigation projects with a major component of
freshwater marsh. Brief descriptions of each of these studies are presented below.
5.3.1 Agriculturally Converted Wetlands in the Prairie Pothole Region
Research by the Characterization and Restoration Project on prairie pothole wetlands will focus
on those data and studies required by trie Risk Reduction Project to demonstrate the risk-based
framework (see Section 7.2). The objectives are twofold: (1) to characterize populations of
natural and restored wetlands in the Prairie Pothole Region and (2) to evaluate the recovery of
function in restored wetlands previously converted to agriculture. The first of these objectives will
be conducted in cooperation with EMAP-Wetlands, which is currently planning a pilot study in the
Prairie Pothole Region in 1992 and 1993 (see Appendix A). The Characterization and Restoration
Project will conduct additional field sampling for characterization of natural and restored wetlands,
supplementing the EMAP sampling and analyses as needed.
Hundreds of agriculturally converted wetlands, primarily prairie potholes, have been restored in
the Midwest and represent a source of information that could be tapped on the effectiveness of
wetland restoration and creation. An examination of the success of prairie pothole restorations,
in terms of specific wetland functions, is particularly important because the 1990 Farm Bill has
a provision for farmers to restore and enroll up to 600,000 acres of degraded wetlands in the
Wetlands Reserve Program. The USDA Soil Conservation Service (SCS), which has
responsibility for implementing the Farm Bill, is interested in cooperating with the WRP in the
evaluation of existing restoration projects to refine and, where possible, improve the design of
new projects.
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The methods described in Sections 5.2.1 to 5.2.3 will be used to evaluate the performance of
restoration and creation projects in the Prairie Pothole Region and to develop performance criteria
and design guidelines. The underlying hypothesis is as follows:
Restored agriculturally converted wetlands have the same level of ecological
function as natural wetlands in the same landscape setting.
If funding allows, at least two ecologically different areas will be studied to test whether the
approach and results can be generalized to other landscape settings. If possible, sites will be
stratified by different agricultural stressors to (1) evaluate differences in attainable function and
(2) test hypotheses such as the following:
Wetlands in landscapes dominated by the cultivation of a certain commodity have
a lower level of ecological function than wetlands in landscapes dominated by
natural systems.
Studies of projects of various ages and monitoring data over time, if available, will provide
information on rates of revegetation, repopulation by animals, and redevelopment of soil profiles;
patterns of succession; and wetland persistence.
A potential secondary project, if funding allows, will be to compile and summarize SCS records
to report on patterns and trends in wetland restoration and preservation in the Prairie Pothole
Region.
5.3.2 Restoration of Western Riparian Systems
As discussed in Section 1.3.3, interest in protecting and restoring riparian systems in the arid and
semi-arid west has been on the rise (Abell 1989, Baird 1989, Faber et al. 1989). Several
agencies (e.g., Bureau of Reclamation, Bureau of Land Management, Federal Highways
Administration) are involved in the restoration of these systems, and all of these agencies have
expressed an interest in cooperative studies with the WRP. In addition, EPA Regions 8 and 9
have asked the WRP to provide technical support for the restoration and management of western
riparian systems.
The principal focus of the Characterization and Restoration Project will be the development of a
methodology for selecting and prioritizing sites for restoring or creating western riparian systems.
One or more watersheds will be selected for a demonstration study. The basic approach will be
as described in Section 5.2.4. To the degree possible, the proposed guidelines and protocols for
site selection will rely on existing or easy to obtain information on watershed characteristics to
facilitate management applications. Several of the low-cost landscape assessment methods
described in Section 6.2.5 will be included in these assessments of landscape factors that
influence the sustainability and functions of restored wetlands.
The Characterization and Restoration Project also will evaluate the performance and design of
existing restoration projects. By sampling and characterizing populations of restored and natural
riparian systems, the following hypothesis will be tested:
Restored western riparian systems have the same level of function as similar
natural systems in the same landscape setting.
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If funding allows, at least two ecologically different areas will be studied and/or sites will be
stratified by land use, to (1) evaluate the relationship between attainable function and the
landscape setting and (2) test hypotheses such as the following:
Western riparian systems in landscapes dominated by a particular land use (e.g.,
urban, agricultural) have a lower ecological function than do western riparian
systems in landscapes dominated by natural systems.
In addition, information on project siting in relationship to project success will contribute to the
development of the guidelines and protocols discussed above for selecting priority sites for
restoration.
Finally, if an appropriate opportunity arises and funding allows, manipulative experiments (see
Section 5.2.3) will be conducted to evaluate ways for improving project design and performance.
5.3.3 Creation of Freshwater Marsh
As part of the Mitigation Project, the performance of created wetland mitigation projects with a
major component of freshwater marsh was assessed in studies in Connecticut, Florida, and
Oregon. At least one of these studies will be repeated during FY1992-1996 to provide additional
data on the development of created wetlands as they mature over time (see Section 5.2.2). If
possible, more recently constructed mitigation projects and additional natural sites will be
sampled, stratified by land use or other important stressors, to examine differences in attainable
function in relationship to the landscape setting.
If funding allows, manipulative studies also will be conducted to evaluate design features or
construction techniques that may enhance the success of wetland restoration or creation projects
(see Section 5.2.3). Specifically, substrate development is an emerging issue of importance.
Research in salt marshes has shown that low soil organic matter in created marshes impairs
nutrient cycling and may have effects throughout the food chain (Langis et al. 1991). Approaches
to accelerate substrate development through additions of organic matter are being investigated
for saltwater marshes (J.B. Zedler, San Diego State University, personal communication). Parallel
studies in freshwater marshes may be appropriate to test hypotheses such as the following:
A created freshwater marsh with at least X% of the average soil organic matter
content of similar natural freshwater marshes sustains a level of nutrient cycling
comparable to that in natural marshes.
5.4 MAJOR CONTRIBUTIONS
The Characterization and Restoration Project will make several important contributions to the
goals and objectives of the WRP and the priority needs of the EPA program offices, including the
following:
a characterization of wetland populations in different landscape settings, including
information on among-wetland variability in wetland characteristics and functions;
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an assessment of the utility of indicators of wetland functions in extensive surveys of
different wetland types in different regions and landscape settings;
an approach for selecting and prioritizing sites for wetland restoration and creation;
• performance criteria and technical design guidelines that can be used to evaluate and
improve the success of wetland restoration and creation projects; and
• a general framework that can be broadly applied for collecting and using information on
wetlands to guide management decisions regarding wetland restoration and creation.
The specific program deliverables for the Characterization and Restoration Project are listed in
Section 9.
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6. LANDSCAPE FUNCTION PROJECT
The Landscape Function Project examines issues at a landscape scale, studying the aggregate
of wetlands within a given landscape unit. Research focuses on how wetlands contribute to
landscape functions (such as regional biodiversity, water quality, and hydrology) and how
landscape processes and factors affect wetlands. The incorporation of landscape-level research
into the WRP is essential because (1) the formation and maintenance of wetlands are highly
dependent on landscape processes and (2) the functions that wetlands provide often arise from
complexes of wetlands and the interactions between wetlands and other ecosystems in the
landscape.
Work within the Landscape Function Project will contribute primarily to two of the WRP research
objectives (Section 2.1):
1. Evaluate the role of the aggregate of wetlands in the landscape on water quality, habitat,
and hydrologic functions at a landscape scale, and the influence of wetland characteristics
on these landscape functions.
2. Quantify the effects of environmental stressors and landscape factors on wetland
functions.
The first of these two objectives will be the major focus of the Landscape Function Project.
Relative to Objective 2, of particular interest to the Landscape Function Project are (1) landscape
factors, such as regional hydrology and geomorphology, that are critical to creating and
maintaining wetlands, and (2) the effects of cumulative impacts on wetland and landscape
functions (see Section 1.2.6). The Landscape Function and Wetland Function (Section 4)
Projects will work together on the second objective to assess how landscape factors and
environmental stressors affect wetlands.
The remainder of this section presents (1) background information on the Landscape Function
Project (Section 6.1); (2) an overview of the basic approach to be used to achieve the research
objectives (Section 6.2); (3) brief descriptions of the specific studies to be implemented (Section
6.3); and (4) a summary of the major expected contributions of the project relative to the overall
goals and objectives of the WRP (Section 6.4).
6.1 BACKGROUND
The Landscape Function Project is an outgrowth of the Cumulative Impacts Project conducted
during the first five years of the WRP (see Appendix A). To evaluate cumulative impacts requires
studies at temporal and spatial scales beyond those of an individual disturbance, specific project,
or individual wetland. The role of component wetlands in the functioning of the entire landscape
system must be determined (Preston and Bedford 1988). Furthermore, the importance of
wetlands may depend not just on their area or individual characteristics, but on the mosaic of
wetland types and conditions in the landscape (Whigham et al. 1988). For these reasons, the
study of cumulative impacts requires analyses at the watershed or regional landscape level.
Thus, the Landscape Function Project is a natural extension of the Cumulative Impacts Project.
65
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Three basic approaches have been used to study landscape functions: (1) empirical analyses,
(2) case studies, and (3) modeling. Empirical analyses examine the relationship between the
level of function achieved by individual landscape units and the characteristics of those units. The
number of landscape units involved must be sufficient to identify statistically valid relationships.
Because controlled landscape-scale experiments are typically not feasible, this approach is the
most rigorous alternative for the study of landscape processes. The boundaries of the landscape
units and total study area are defined relative to the landscape function of interest and study
objectives. For example, for water quality improvement functions, landscape boundaries are
generally delineated by watersheds. For habitat functions, landscape boundaries could be
defined by the range and distribution of the biota of interest. Examples of results from empirical
analyses include the following:
• An analysis of 33 Minnesota watersheds found that stream water quality (including nitrates
and inorganic suspended solids) was related to wetland characteristics within the
watershed (Johnston et al. 1990b).
• Dissolved organic carbon levels in 42 streams in southern Quebec were correlated with
the percentage of each catchment that was wetland (Eckhardt and Moore 1990).
• Smith and Higgins (1990) found that areas with avian cholera epizootics had a significantly
lower density of semipermanent wetlands, compared to areas without epizootics.
Case studies, by contrast, involve too few sites for statistical testing of hypotheses,, Such studies
do, however, provide a first-order assessment of whether the findings are consistent with
proposed hypotheses and relationships. For example, Childers and Gosselink (1990) found that
downstream levels of. total phosphorus, total suspended solids, and turbidity were significantly
related to water level at three sites in the Tensas Basin in northern Louisiana. Noting that
elevated levels of nutrients and suspended solids were characteristic of cleared watersheds, the
authors concluded that stream enrichment in the Tensas could have been caused by the logging
of bottomland hardwood. The number of streams was not large enough to test whether other
factors might have caused these water quality trends. When considered with other findings (e.g.,
Gosselink et al. 1990), however, a reasonable conclusion is that the landscape function of the
Tensas had declined as a result of the loss of forested wetlands. Case studies such as this and
others (e.g., Brooks et al. 1989) can be used to refine hypotheses about important landscape
processes and functions when a more rigorous study is not possible.
Modeling, a third approach to landscape analysis, is often the only way to study complex systems
that would require extensive and costly field sampling programs to characterize landscape
conditions and functions adequately. The validation of model results with empirical data can be
a form of hypothesis testing. Furthermore, once developed, calibrated, and tested, models
provide a means of exploring management options before implementation. For example, the
CELSS model, developed for coastal Louisiana (Costanza et al. 1990), simulates land loss and
marsh succession based on factors such as river discharge, sedimentation, subsidence, and
ecosystem productivity. The model has been used to examine various management scenarios,
such as the construction of a levee extension. In some cases, relatively simple models may also
be useful. For example, Rhoads and Miller (1990) developed an input/output stream channel
model to study the effects of created wetlands on channel stability.
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Work within the Landscape Function Project will focus on empirical analyses and modeling as the
primary approaches to assessing landscape functions. Results from case studies conducted by
other research programs also will be used to aid in model development and calibration.
6.2 APPROACH
For each region/landscape studied, five basic tasks will be conducted:
1. Conceptual models and best professional judgment (BPJ) hypotheses regarding the role
of wetlands in landscape functions and the influence of landscape processes on wetlands
will be developed.
2. These hypotheses will be refined through simulation analyses with existing models.
3. Empirical landscape analyses will be performed for hypothesis testing and indicator
development.
4. Models will be calibrated for specific landscapes, and simulations will be used to evaluate
various management options.
5. Low-cost assessment methods will be developed that can be readily applied to provide
technical support for wetland protection and management.
The approach for each of these tasks is described in the subsections that follow. The overall
project strategy is illustrated in Figure 6-1.
The Landscape Function Project will rely primarily, on information on wetland and landscape
characteristics obtained by compiling and analyzing existing data bases, maps, and other
available data sources. Field data collected by the Wetland Function and Characterization and
Restoration Projects and EMAP-Wetlands also will be incorporated into these landscape-level
analyses as appropriate. ,
6.2.1 Conceptual Models and BPJ Hypotheses
As part of the Cumulative Impacts Project, a generic model of landscape processes was
developed that considers individual ecosystems as sources or sinks6 of materials linked within
a larger landscape unit. Consistent with the discussion of wetland functions in Section 3.2.1, the
amount of material removed by a sink is determined by both the sink's capacity to remove
material and the landscape input of material received by the sink. The effect of any individual
ecosystem component on the overall landscape function depends, therefore, on three factors:
(1) the magnitude of the ecosystem as a source or sink; (2) the transport mechanism for. the
material (e.g., diffusion, gravity, channelized flow, or migration); and (3) the spatial relationship
6 An ecosystem can reduce the amount of material passing through it in several ways, for
example, chemical transformation, filtration, etc. The term "sink" is used here in a generic sense
to refer to any reduction in material transport resulting from an ecosystem process. The model
also recognizes neutral ecosystems, which neither add to nor remove the particular material.
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BPJ Landscape Assessment
Conceptual Models
Hypotheses
Simulations with
Existing Models
Empirical Landscape Analyses
Landscape/Wetland
Characteristic
Landscape Models
Functions of Wetlands
in the Landscape
Effects of Landscape Factors
in Wetland Functions
Technical Support for Risk Management
Rapid Landscape
Assessment
Techniques
Role of Isolated
Wetlands
Technical Evaluation of
Management Strategies
Figure 6-1. Flow chart for the research strategy for the Landscape Function Project. The
hypothetical graphics are provided to illustrate how findings will be integrated into
the project; they are not meant to convey actual or expected results or
relationships. The graphic at the bottom of the figure is used to represent the
Synoptic Approach and other low-cost landscape assessment methods.
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between the sources and sinks in the landscape. The model also provides a theoretical basis
for assessing values, by incorporating utility functions that represent the usefulness of the material
to end users (e.g., the importance of flood control for downstream population centers).
This generic model provides a framework for evaluating ecosystem interactions, landscape
processes, and the role of wetlands in landscape functions. It will be used as a frame for defining
formal hypotheses and associated conceptual model(s) for each of the wetland landscapes to be
studied as part of the Landscape Function Project (see Section 6.3). A literature review will be
conducted, and experts familiar with the Specific landscape will be consulted. The purpose of this
review will be to identify the major environmental factors that contribute to the formation and
sustainability of wetlands within the particular landscape (e.g., hydrology, geology, and soils) as
well as stressors that may affect these landscape processes or the wetland directly. Based on
these results, BPJ conceptual models and hypotheses will be developed. Regional workshops
will then be held to review and further refine these hypotheses and models. Synthesis documents
summarizing management recommendations, derived from the workshop discussions, and BPJ
hypotheses will be produced as interim deliverables.
6.2.2 Simulation Studies
Several models already exist for evaluating the effects of land use (including the occurrence and
extent of wetlands) on selected landscape functions. For example, the Soil Conservation
Service's TR-55 (SCS 1986), and the USDA Agricultural Research Service's AGNPS model
(Young et al. 1987) can be used to examine how land use and wetland location affect peak
discharge and agricultural nonpoint source pollution, respectively. Model simulations could
examine, for example, whether adding a unit of headwater wetland is more effective at lowering
peak discharge than is a unit of isolated (basin) wetland. Although these models include relatively
simple representations of complex processes, their application is considered worthwhile for
exploring alternative hypotheses regarding landscape processes because (1) they are general
enough to be applied over a wide geographic range; (2) they are available and can be used with
minimal start-up time, compared to more complex models or models developed from scratch; and
(3) they can aid in the definition and refinement of specific hypotheses to be examined in the
empirical landscape analyses.
A literature review will be conducted to identify environmental models that include land use as a
variable and that may be used to evaluate the role of wetlands in landscape functions. A subset
of these models will then be adapted to conduct simulation studies of the particular landscapes
being researched. The results from these simulations will be used to refine the BPJ hypotheses
and conceptual model(s) and will assist in the design and interpretation of the empirical landscape
analyses.
6.2.3 Empirical Landscape Analyses
As discussed in Section 6.1, empirical analyses evaluate the relationship(s) between landscape
function(s) and the characteristics of wetlands and other ecosystems within each landscape unit
(see Figure 6-1). These studies will be used to (1) test hypotheses regarding how wetlands
function within the landscape and (2) evaluate the utility of various indicators of landscape
function. .
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In most analyses, the emphasis will be on how wetlands affect landscape function. Thus, the
dependent variable in statistical analyses will be indicator(s) of landscape function(s). For
example, downstream water quality'(e.g., nitrate.or phosphorus concentrations) may serve as an
indicator of the water quality function of a watershed, or peak discharge as an indicator of a
landscape's hydrologic function. The independent variables will be one or more indicators of the
characteristics of wetlands (and perhaps other types of ecosystems) within each landscape unit.
Examples of potentially useful indicators include total wetland area, average wetland patch size,
wetland type (e.g., swamp or marsh), wetland position (e.g., distance from stream), or an indicator
of wetland shape. ' • - •
In some cases, empirical analyses may also be conducted to examine how landscape factors
affect wetlands. In this instance, indicators of wetland function would be the dependent variables,
while the characteristics of the landscape outside of the wetland become the independent
variables. The optimal landscape unit for these analyses would be the drainage area of an
individual wetland. It may not be feasible to use such a unit, however, because watershed
delineations for individual wetlands are typically not available; completion of these delineations
for the large number of sites required for an empirical landscape analysis would be extremely time
consuming. Thus, analyses will generally be conducted using a watershed or ecoregion
containing a population(s) of wetlands as the landscape unit. Landscape factors that could be
used as independent variables include land use, hydrologic modifications, and point: and nonpoint
source pollutant estimates. Wetland attributes that could be used as dependent variables
(indicators of wetland function and condition) include plant biomass, biodiversity indices,
measures of primary and secondary productivity, and others.
The relationships between dependent and independent variables will be explored using a variety
of statistical techniques, including multiple regression and principal components analysis (for
example, see Johnston et al. 1990b).
Data sources for landscape analyses will vary depending on the specific areas being studied.
Wetland and land use data are needed in a spatial format so that a Geographic Information
System (GIS) can be used to derive the various landscape parameters. U.S. Geological Survey
(USGS) Land Use/Land Cover (LULG) data are available in digital format for much of the country.
Most wetland areas have been mapped by the National Wetlands Inventory (NWI), but these
maps have been digitized for a limited number of states. The Soil Conservation Service's
STATSGO digital soils maps will soon be available for most of the United States. In addition,
many states have their own GIS data that could be used for landscape analyses. County census
data from the U.S. Census or the Agricultural Census can also be applied to these analyses.
Sources of information that can be used to summarize landscape function include the USGS
Water Resources data (includes stream discharge and water quality parameters); U.S. Fish and
Wildlife Service (FWS) Breeding Bird Surveys; and rare, threatened, and endangered species lists
compiled by the FWS or State Heritage programs. Although data on wetland condition (e.g.,
biomass or biodiversity) are available for many wetlands, a statistical characterization of specific
wetland populations is not readily available and would be expensive to collect. The Landscape
Function Project will make use of such data when available from the Characterization and
Restoration Project, EMAP-Wetlands, and other sources.
In addition to evaluating various hypotheses about the relationship between wetlands and the
surrounding landscape, the empirical analyses will assist in the identification and evaluation of
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indicators of landscape function. Cost-effective indicators are needed so that scientific findings
can be applied in daily management decisions. Thus, analyses will be conducted to evaluate the
relative utility of alternative indicators that are simpler and/or require less effort and cost to obtain.
For example, landscape analyses based on a 1:24,000-scale NWi map may indicate a significant
relationship between certain landscape and wetland characteristics. These analyses could then
be repeated, substituting similar information obtained using a 1:250,000-scale USGS LULC map.
If the latter also describes a significant relationship and similar results, indicators based on the
USGS LULC maps may be preferable for wetland management because the labor requirements
and computer costs for obtaining these data are lower and the USGS LULC maps are more
widely available.
The EMAP-Wetlands project also will conduct landscape characterizations and develop and use
landscape-level indicators (see Appendix A). Thus, the development and testing of indicators of
landscape function as part of the Landscape Function Project will be carefully coordinated with
efforts conducted by EMAP-Wetlands. For EMAP-Wetlands, a subset of the sites analyzed using
remote sensing and mapped data will be sampled in the field, providing partial field verification
of the landscape assessments.
6.2.4 Model Calibration and Applications
Once the hypotheses developed as part of the tasks described in Sections 6.2.1 and 6.2.2 have
been tested and revised, the generic landscape model will be adapted and calibrated for the
specific landscape being studied. Two sources of information will be used to parameterize these
models: (1) regression coefficients from the empirical landscape analyses and, where available,
(2) data from the Wetland Function Project on wetland assimilative capacity and
stressor/response relationships (Section 4.2).
After parameterization, the models can be used to rank wetlands based on their relative
contribution to landscape function. Potential candidate sites for wetland restoration or creation
could also be similarly evaluated, leading to recommendations for siting wetlands in the
landscape. A set of management maps, showing the locations of these ranked wetlands and
candidate sites for wetland restoration and creation, could also be prepared. This work will
contribute to the effort of the Characterization and Restoration Project to develop method(s) for
prioritizing sites for restoration (Section 5.2.4). Finally, the models could also be used to evaluate
different management scenarios and to support the development of specific management
guidelines. Many of these simulations and applications will be conducted in conjunction with the
Risk Reduction Project (Section 7).
6.2.5 Low-Cost Landscape Assessment Methods
The landscape models described in Section 6.2.4 will give wetland managers a powerful
management tool. Unfortunately, because of the intensive efforts and costs required to develop
these models, it will not be possible to repeat these analyses in all areas where needed.
Therefore, the final task of the Landscape Function Project will be to develop low-cost landscape
assessment methods, which can be easily applied to other regions and management needs.
Three types of landscape assessment tools will be used: (1) synoptic landscape assessments,
(2) general landscape criteria, and (3) the Landscape Development Index (LDI). The Synoptic
Approach and LDI were developed initially as part of the Cumulative Impacts and Mitigation
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Projects, respectively. Over the next five years, these methods will be further tested, improved,
and modified as needed for broader applicability.
6.2.5.1 Synoptic landscape assessment
The Synoptic Approach was developed by the WRP for assessing cumulative impacts to
wetlands. Case studies have been applied in Louisiana (Abbruzzese et al. 1990a) and
Washington (Abbruzzese et al. 1990b), and a first version is to be released in 1992. It involves
the mapping, at large scales, of indicators of wetland function, wetland value, functional loss, and
replacement potential. Based on these maps, areas within a state or region can be prioritized
for protection or further study. For example, Figures 6-2 and 6-3 illustrate two maps developed
for the state of Washington. The initial distribution of wetlands in the state was estimated by the
occurrence of hydric soils. The difference between the total area with hydric soils and current
wetland acreage (mapped in Figure 6-2) provides an indicator of the wetland loss rate. In the
United States as a whole, 95% of the historical wetland loss (from the 1950s to 1970s) has been
due to conversion to agricultural and urban land uses (Tiner 1984; 59% from the mid 1970s to
mid 1980s, Dahl and Johnson 1991). Therefore, recent trends in agricultural and urban growth
(in Figure 6-3) can be used as an indicator of potential future stressors related to land use
changes. Other stressor indicators could also be mapped, e.g., the percent of channelized
stream as an indicator of hydrological modification. For the Synoptic Approach, mapping at larger
scales, such as regions or the statewide maps illustrated in Figures 6-2 and 6-3, is most
appropriate.
Over the next five years, the Synoptic Approach will be updated, focusing on the risk-based
framework, the needs of the Risk Reduction Project, and priority regional issues. The
development and testing of landscape indicators, discussed in Section 6.2.3, will result in more
accurate assessments of landscape and wetland functions. The parameterized landscape model
(Section 6.2.4) will allow functional weighting factors to be developed for different wetland types.
6.2.5.2 General landscape criteria
Forman and Godron (1986) described several structural components of landscapes, including
patches, corridors, and the background matrix, many or all of which may influence landscape
functions. Indices, such as patch size, connectivity, and porosity, can be used to quantify and
characterize these landscape components and may provide useful landscape criteria for wetland
protection. For example, the black bear requires large forested areas as habitat. The Tensas
Basin in northern Louisiana initially consisted of extensive bottomland hardwood swamps. Much
of this wetland area has been logged and converted to agricultural land, however, leaving small
fragmented patches in the center of the unit and only a few larger patches. An appropriate
landscape criterion for protecting the black bear would be to maximize wetland patch size. Given
such a criterion, wetlands within the landscape unit could be evaluated according to how their loss
(or gain) would affect the maximum patch size (see Figure 6-4).
In developing these criteria, the objective is to identify fairly simple and easily measured
landscape characteristics that can be used to prioritize wetlands for protection or to rank sites for
wetland restoration and creation. As part of developing the BPJ hypotheses (Section 6.2.1),
consideration will be give to landscape characteristics that are critical to maintaining important
landscape and wetland functions (e.g., what is the optimal distance between ponds or the optimal
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Canada
0<-egon
Ketland Loss /
Hydric Area (fraction]
| 1 -1.00 - 0.63
[iff] 0.63 - 0.86
(Hi 0.86 - 0.99
0.99 - 1.00
Figure 6-2. Estimated wetland loss rates (percent loss) for landscape units in the state of
Washington. Initial wetland area was estimated from the area with hydric soils;
current wetland area estimated from the U.S. Geological Survey Land Use/Land
Cover maps (Source: Abbruzzese et al. 1990b).
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Canada
Ife i jb led Grow th
(A«r'87/95 + Pop'B/S5)
I | -I.I2E-2 - -1 . 96E-3
|| -1.96E-3 - 3.08E-3
3. 08E-3 - 7.75E-3
7.75E-3 - 4 . 98E-2
Figure 6-3. Weighted annual rate of growth in agricultural and urban land uses for landscape
units in the state of Washington. Historically, agricultural and urban land uses
accounted for 87% and 8% of wetland loss, respectively. Therefore, recent trends
in agricultural and urban growth were weighted by 87 and 8, respectively, to
provide a first-order indicator of potential future stressors on wetlands related to
land use changes (adapted from Abbruzzese et al. 1990b).
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LEGEND
BLHF Patch Priority
High CID
Intermediate K$fr3
Corridors liliU
Figure 6-4. Wetland site prioritization for wetlands in the Tensas Basin, Louisiana, based on
a management objective of maximizing patch size (modified from Gosselink et al.
1990). Loss of wetland area from patch MA,M which is not the largest patch in the
basin, would have no effect on the maximum patch size and thus is given a low
priority for protection (dark shading). On the other hand, loss of wetland area from
the largest patch, "B," would have a proportionate effect on the maximum patch
size. Patch "B," therefore, is ranked as high priority for protection. Finally, loss
of wetland area could have a disproportionately large effect if the area affected
was a corridor that linked two large patches ("C"). Patch "C," therefore, is ranked
as the highest priority for protection.
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frequency distribution for pond depths for waterfowl production in prairie potholes?). These
hypotheses will be tested with the empirical landscape analyses and the results used to select
general landscape criteria.
Wetlands are typically found in one of three landscape configurations: (1) extensive (e.g., the
Atchafalaya Basin or the Everglades), (2) patchy (e.g., prairie potholes), and (3) dendritic or
branched (e.g., the Pearl River Basin in Mississippi or Georgia's Savannah River). Studies to
develop landscape criteria will be conducted for patchy and dendritic landscapes. Little work will
be conducted for extensive wetlands, because the study by Gosselink et al. (1990) provides initial
guidance for these systems.
6.2.5.3 Landscape Development Index
The LDI is an indicator of the intensity of landscape stressors that may degrade wetlands, based
on land uses in the surrounding area (Brown 1991). For each land use type (urban, agricultural,
natural), a land use intensity factor (weight) is defined that reflects the expected severity of the
impacts on wetlands associated with that land use. The LDI was first developed for use in
Florida, where urban land use was given greater weight than agricultural or .natural land uses,
because groundwater withdrawal for urban populations was considered the most important factor
causing wetland degradation.
Over the next five years, the LDI will be adapted for other regions by adjusting the land use types
included and the relative weighting factors for each land use. Weighting factors can be derived
from the empirical landscape analyses and applied to other similar landscapes outside of the
study area. Where limited information exists, BPJ could be used to determine which land uses
to include and how they should be weighted.
The LDI can be used for both small- and large-scale landscape assessments. LDI values for
areas around individual wetlands may be useful for permit evaluations or in selecting reference
wetlands. Because the LDI weights more heavily those land uses that are expected to impact
and degrade wetlands, the LDI could also be used as an indicator of functional loss within the
risk-based framework.
6.3 IMPLEMENTATION
Consistent with the priority wetland types identified in Section 1.3, the Landscape Function Project
will focus on studies in freshwater emergent marshes in the Prairie Pothole Region and
bottomland hardwood forests. A third study also is planned to evaluate the effect of inland
wetlands on estuarine water quality. Brief descriptions of these studies are provided below.
6.3.1 Landscape Assessment of Prairie Pothole Wetlands
All five of the tasks described in Section 6.2 will be conducted in the Prairie Pothole Region. The
work will be coordinated with concurrent efforts by the Wetland Function Project (Section 4.3 1)
Characterization and Restoration Project (Section 5.3.1), and EMAP-Wetlands (Appendix A), and
will contribute directly to the risk assessment and management analyses for the Risk Reduction
Project (Section 7.2).
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The Prairie Pothole Region is a patchy landscape, with many isolated wetlands. Analyses will
focus on two important landscape functions: (1) prairie potholes as habitat for waterfowl and
other biota and (2) the potential for prairie pothole wetlands to improve regional surface water
quality. The general hypothesis to be tested is as follows:
Within the Prairie Pothole Region, these landscape functions (habitat and water
quality improvement) depend on the characteristics of wetlands in that landscape,
such as the distance between wetlands, the frequency distribution of pond depths,
or percent open water.
The Landscape Function Project also will work with the Wetland Function and Characterization
and Restoration Projects to address the following hypotheses:
Prairie pothole wetlands are being degraded by landscape factors, such as
sedimentation and nonpoint source pollution, and the severity of these impacts is
influenced by landscape characteristics, in particular the occurrence of buffers.
The ability to restore wetland functions is dependent on the condition of the
landscape unit.
Specific research hypotheses will be developed based on a literature review and conceptual
model(s) (Section 6.2.1). Simulation studies will be used to further refine these hypotheses
(Section 6.2.2), which will then be tested through empirical landscape analyses (section 6.2.3).
The final calibrated and tested landscape model(s) (Section 6.2.4) will be used to evaluate various
management options for protecting and restoring wetlands to maximize the water quality and
habitat support functions of these wetlands. The synoptic landscape assessment and other
landscape assessment approaches (Section 6.2.5) will be evaluated and applied. Using these
models and landscape assessment techniques, it may be possible to extrapolate the results for
prairie potholes to other patchy landscapes.
6.3.2 Landscape Assessment of Bottomland Hardwoods
All five of the tasks described in Section 6.2 also will be completed for the study of bottomland
hardwoods. These efforts will be coordinated with complementary research being conducted by
the Wetland Function Project (Section 4.3.2) and integrated into the risk-based framework as part
of the Risk Reduction Project (Section 7.2). Two issues, in particular, will be addressed: (1) the
effect of riparian buffers on stream water quality and (2) the effects of habitat alteration (e.g.,
logging) on the habitat functions of bottomland hardwoods. Both of these issues also will be
evaluated by the Wetland Function Project, although at a different spatial scale (individual wetland
versus landscape-level responses and analyses).
Bottomland hardwoods occur in both extensive and dendritic configurations. The Landscape
Function Project will be evaluating dendritic landscapes, including three major wetland types:
headwater wetlands, riverine wetlands, and isolated (basin) wetlands. Analyses will examine the
roles of these three different wetland types in landscape functions (water quality, habitat, and
hydrology), and will provide an opportunity for improved'understanding of the importance of small,
isolated wetlands (see Section 1.2.6). General hypotheses include the following:
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Within a dendritic landscape setting, the contribution of wetlands to different
landscape functions depends on the type of wetland (headwater, riverine, or
isolated).
Riverine wetlands are effective sinks of nonpoint source pollution and, therefore,
can improve stream water quality.
6.3.3 Effect of Inland Wetlands on Estuarine Water Quality
As noted in Section 1.3.4, research is needed on the effects of inland watersheds on estuarine
water quality and how this is moderated by wetlands. This study will examine the effects of
different types of wetlands on agricultural nonpoint source pollution of estuarine waters. In
particular, analyses will focus on comparisons among riverine wetlands, temporarily flooded
wetland forests, and agricultural wetlands (wetlands that have been converted to agriculture, but
still retain hydric soil conditions) and their relative effectiveness at reducing nonpoint source
pollution. The latter two wetland types are examples of drier wetlands, as discussed in Section
1.3.4. This research will build upon a nutrient study to be implemented in early FY 1992 with
funding from the Cumulative Impacts Project. Because funding for this study will be limited, only
the empirical analysis and synoptic landscape assessment components of the Landscape
Function Project will be included.
6,4 MAJOR CONTRIBUTIONS
The major contributions of the Landscape Function Project to the WRP and EPA program office
priorities will include the following:
techniques for rapid landscape-level assessments of wetlands;
an improved understanding of the role of wetlands in the landscape, including methods
for ranking wetlands according to their relative contribution to landscape functions;
an evaluation of the functions of isolated wetlands in the landscape;
an improved understanding of landscape processes and characteristics that are critical to
establishing and maintaining wetlands and of how stressors affect these processes, which
will assist the Characterization and Restoration Project in developing methods for
prioritizing sites for wetland restoration and creation; |
landscape-level methods and data on wetland and landscape functions in the Prairie
Pothole Region and bottomland hardwood forests required for estimating risks and
conducting the Risk Reduction Project; and
an evaluation of the effectiveness of different wetland types at reducing the impact of
nonpoint source pollution on estuarine water quality.
The specific program deliverables for the Landscape Function Project are listed in Section 9.
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7. RISK REDUCTION PROJECT
In Section 3, we proposed a general risk-based framework for wetland protection and
management. The Risk Reduction Project will integrate the results of the other three projects to
demonstrate the application and utility of this framework (see Figure 2-1). Thus, the Risk
Reduction Project will address two of the WRP objectives:
• Develop and demonstrate a risk-based framework for wetland protection and
management.
• Conduct an integrated risk assessment for at least one major wetland type to provide
technical support on two major issues:
the national policy of no net loss of wetland area and function, and
the role of wetlands in reducing nonpoint source pollution.
The Risk Reduction Project will conduct no new field work or landscape analyses, but instead will
work directly with the Wetland Function, Characterization and Restoration, and Landscape
Function Projects to ensure that these projects provide the types of data and analyses needed
as input for a risk reduction analysis. Therefore, within the WRP, the Risk Reduction Project is
responsible for inter-project coordination and for producing integrated program deliverables. The
project approach is described in Section 7.1, plans for project implementation in Section 7.2, and
the major expected contributions of the Risk Reduction Project in Section 7.3.
7.1 APPROACH
The components of the risk-based framework and major elements of a wetland risk assessment
were described in Section 3 (see Figure 3-1). Although this discussion outlines a general
framework for a risk reduction analysis, further work is needed to evaluate, refine, and
demonstrate these techniques and the overall usefulness of the approach. Therefore, the
following tasks will be completed in sequence:
• Review and evaluate the conceptual framework, modifying and augmenting it as
necessary.
Conduct a best professional judgement (BPJ) risk assessment, to further evaluate and
refine the basic framework, demonstrate the utility of the approach, and provide interim
project deliverables.
• Synthesize the WRP research results into a comprehensive, hierarchial risk assessment.
« Apply the risk assessment to provide technical support for risk management.
• Develop a monitoring and evaluation protocol.
These tasks are described in the subsections that follow.
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7.1.1 Framework Development and Review
The proposed risk-based framework will be thoroughly reviewed and evaluated early on during
the five-year research program. The objectives of this effort are to ensure that the framework
(1) has not omitted important factors, (2) is workable 'and'efficient, and (3) considers other EPA
programs and risk assessment guidelines, A comprehensive review of the risk assessment
literature will be completed. Workshops and interagency work group meetings will be held to
discuss the proposed framework and its application to the types of issues and problems that arise
in wetland protection and management. Representatives from other EPA programs involved in
the development of risk assessment protocols (e.g., the Risk Assessment Forum) will be invited
to participate actively in these discussions. Finally, journal articles describing the framework will
be prepared and peer reviewed.
7.1.2 BPJ Risk Assessment
For one or more selected regions and priority issues (see Section 7.2), the risk assessment
process will be completed using BPJ to define the four elements of a risk assessment (wetland
functions, values, functional loss, and replacement potential). The objectives are (1) to test the
framework and refine it as necessary, (2) to identify high priority data and research needs to
reduce uncertainties in the assessment results, and (3) to demonstrate the utility of the risk-based
framework and approach even when applied using strictly BPJ without extensive data collection
and analysis. A BPJ assessment can provide management with preliminary information until a
more rigorous, data-based analysis can be completed. A report summarizing this case "study will
be prepared as an interim deliverable.
The BPJ risk assessment will be based on a literature review and consultation with regional
wetland experts. In addition, indicators that could be used to measure and assess each of the
four risk assessment elements and regional data sources will be identified. The regional experts
also will be asked to propose general landscape criteria (see Section 6.2.5.2).
7.1.3 Hierarchical Risk Assessment
The field sampling, experiments, and analyses to be conducted as part of the Wetland Function,
Characterization and Restoration, and Landscape Function Projects (Sections 4-6) will provide
the basic technical information needed to evaluate wetland functions, values, functional loss, and
replacement potential (Figure 7-1). The Risk Reduction Project will integrate and,synthesize this
technical information, together with subjective input on wetland values from wetland managers
and policymakers, to address,two major management issues: (1) the national goal of-no-net loss
of wetland area and function and (2) the role of wetlands in reducing nonpoint source pollution
(see Section 7.2). The following discussion outlines briefly the major sources and types of
information required for each element of a risk assessment.
7.1.3.1 Wetland function ....;.-••• ,- • •-.. - :; ; .
In Section 3.2.1, the functions of wetlands were .grouped into three major categories: (1) habitat,
(2) water quality improvement, and (3) hydrology. For an assessment of no net loss, all three of
these major functions are of concern, while analyses relating to nonpoint source pollution control
will focus primarily on the water quality improvement function.
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. WRP Project
-^
Assessment
Component
Wetland
Function
Characterization
and Restoration
Landscape
Function
c
o
o
3
Wetland Inventory
Wetland Capacity
Landscape Input
Wetland Value
CO
V)
o
CO
o
o
• c
n
u.
Conversion
Degradation
Replacement
Potential
Figure 7-1. Matrix indicating the major sources of information to be used for each risk
assessment component by the Risk Reduction Project. The hypothetical graphics
represent the general types of analyses and outputs expected from the three other
WRP projects, as illustrated in Figures 4-1, 5-1, and 6-1; they are not meant to
convey actual or expected results or relationships.
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Wetland functions, as discussed in Section 3.2.1, depend on both the wetland capacity and
landscape input Wetland capacity depends on the wetland type. .Thus, to evaluate wetland
functions requires information on (1) the numbers and types of wetlands present in the landscape
(i.e., a wetlands inventory). (2) the capacity of each wetland type, and (3) landscape inputs to
each type or group.
Wetland Inventory. The Landscape Function Project, as part of the synoptic landscape
assessment (Section 6.2.5.1), will determine the extent of the wetland resource and the types of
wetland communities present for each landscape unit in the region(s) of interest. Various sources
of data will be used, depending upon availability, including National Wetlands Inventory maps,
USGS LULC maps, and State resource inventories. The types of wetland communities present
in the region will be determined from existing inventories or by consulting state or federal resource
agencies, State Heritage programs, and regional wetland experts.
Wetland Capacity. Quantitative information on wetland capacity will be provided by the Wetland
Function, Characterization and Restoration, and Landscape Function Projects for individual
wetlands, wetland populations, and landscape units, respectively. The stressor/response
relationships and temporal response curves developed by the Wetland Function Project will be
used to quantify wetland assimilative capacity and also differences in assimilative capacity among
different wetland types (e.g., wetlands of type "A" or with characteristics "A" may, on average, be
able to assimilate more nitrate than wetlands of type HB"). The empirical landscape analyses
conducted by the Landscape Function Project will relate general wetland characteristics to
landscape functions (e.g., reductions in stream nitrate concentrations).
Landscape Input. Information on land use and landscape conditions collected by the Landscape
Function Project, in particular the synoptic landscape assessments, will be used to estimate
landscape inputs. Analyses will be conducted for all three categories of wetland function. For
example, the models described in Section 6.2.2 can provide estimates of nonpoint source
pollutant loadings and peak discharge.
7.1.3.2 Wetland value
The risk-based framework incorporates information on wetland values to help focus subsequent
analyses in the risk assessment on those wetland components and functions considered of
greatest importance. These values, however, will be defined by others, specifically wetland
managers and regulators, not the WRP or the Risk Reduction Project.
As discussed in Section 3.2.2, wetland values can be assessed holistically (i.e., the overall value
of the wetland as a unit) or assessed separately for each distinct wetland function., Given an
explicit listing of valued wetland functions within a particular area, the Landscape Function Project
can provide an analysis of the numbers of individuals who may benefit from these functions. For
example, based on census data from the Bureau of Statistics, human population densities can
be determined for areas downstream that may benefit from flood attenuation. Beneficiaries of
wetland functions will be broadly defined to include people, fish, wildlife, and/or other significant
organisms. Thus, indicators of ecological benefits could include lists of rare, threatened, and
endangered species; numbers of drinking wells; and sales of hunting and fishing licenses.'
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A holistic evaluation of wetland values requires wetland managers or regulators to select
examples of "high" and "low" value wetlands that, as a group, are representative of the full range
of values and benefits that wetlands provide. Characterization curves, as developed by the
Characterization 'and Restoration Project, can then be used to identify specific wetland
characteristics indicative of high or low value for one or more possible wetland functions (see
Figure 3-2).
The specific approach to be applied over the next five years will be determined by the wetland
managers-and regulators involved in the risk assessment and risk management process, working
together with the staff of the'WRP and Risk Reduction Project. ,
7.1.3.3 Functional loss •
Risk assessments must consider losses of wetland area and functipn, through conversion and
degradation, respectively. Declines in landscape function may result from both a1 loss of wetland
area and a decline in individual wetland functions within the landscape unit. Cumulative loss of
these functions will also be considered.
Conversion. The loss of wetland area to date will be estimated as part of the synoptic landscape
assessment (Section 6.2.5.1). Figure 6-3 illustrates such an analysis for the state of Washington
based on the difference between areas with hydric soils (estimate of historic wetland area) and
current wetland areas from USGS LULC maps. The particular methods employed will depend
upon data availability. For example, Figure 5-2 illustrates trends in wetland losses based primarily
on Corps of Engineers Section 404 permit data (e.g., Holland and Kentula, in press; Sifneos et
al., in press). When such information is available, it can be incorporated into the assessment.
If data are available in GIS format, loss trends will be examined by wetland type, geographic area,
and land use or stressor type.
Degradation. The extent and degree of wetland degradation may be determined by (1 j statistical
field surveys to determine the current status and health of wetland populations, as planned by
EMAP-Wetlands, and/or (2) assessing the types and levels of stressors impacting wetlands within
the region (hazard identification and exposure assessment) and the sensitivity of wetland
functions to these stressors (stressor/respdnse relationships). The Wetland Function Project will
quantify the effects of stressors on important wetland processes and functions (Section 4.2).
Empirical landscape analyses conducted by the Landscape Function Project will be used to
quantify the relationship between landscape function and wetland and landscape characteristics
(Section 6.2.3). The Wetland Function and Landscape Function Projects will evaluate data to
estimate the levels of wetland stressors locally and regionally, respectively. Finally, the simulation
models developed by the Landscape Function Project (Section 6.2.4) will provide a basis for
identifying those wetlands and wetland characteristics most important to landscape functions and
the specific wetlands and landscape units at greatest risk of degradation (loss of function) from
specific stressors.
7.1.3.4 Replacement potential ' '
The Characterization and Restoration Project will develop performance curves (Figure 5-5) that
can be used to evaluate the replacement potential of different wetland types and/or specific
wetland functions. In addition, the Landscape Function Project will provide information on
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landscape processes (e.g., regional hydrology) that can be used to determine how replacement
potential is affected by landscape condition (Section 6.2).
7.1.4 Technical Support for Risk Management
A risk assessment quantifies the probability that the loss or decline of valued wetland functions
has or will occur. Using this information, wetland regulators and managers can then develop a
plan for managing that risk. Two complementary approaches can be applied for risk
management:
1. Avoidance ~ Minimize the functional loss of those wetlands with the highest value by
protecting them from conversion and degradation.
2. Restoration/creation — Increase functional values within high risk areas by replacing lost
function through wetland restoration or creation.
The Risk Reduction Project will provide technical support for the development of risk management
plans by EPA Regional personnel within the study areas. Results from the risk assessment will
identify the most significant cause(s) of functional.loss and the areas and wetland types at
greatest risk. The Landscape Function Project simulation model(s) can be used to explore
alternative management options (Section 6.2.4). The replacement potential of high risk wetland
types, as determined from performance curves (Section 5.2.2), will influence whether the
management strategy emphasizes avoidance or restoration/creation. For wetlands with a high
replacement potential, technical support for design guidelines (Section 5.2.3) and methods for site
selection and prioritization (Section 5.2.4; also Section 6.2.4) will be available from the
Characterization and Restoration Project to increase the probability of achieving a successful and
sustainable replacement of wetland function.
7.1.5 Monitoring and Evaluation Protocols
As discussed in Section 3.4, two types of monitoring are needed: (1) evaluative monitoring to
determine the effectiveness of a specific management program and (2) baseline monitoring to
detect new wetland problems that may arise and general trends in wetland status. As part of the
WRP, over the next five years the time frame and budget will not be adequate to implement a
monitoring and evaluation sampling program. It will be possible, however, to develop a
monitoring and evaluation protocol that illustrates these two monitoring schemes using
components of the Characterization and Restoration Project and EMAP-Wetlands as examples.
Empirical studies conducted by the Wetland Function and Landscape Function Projects (Sections
4.2.2 and 6.2.3) will aid in the selection of useful indicators of wetland and landscape function for
both evaluative and baseline monitoring.
7.2 IMPLEMENTATION
The Wetland Function, Characterization and Restoration, and Landscape Function Projects, as
well as EMAP-Wetlands, all will be conducting research in the Prairie Pothole Region during FY
1992-1996 (see Sections 4.3.1, 5.3.1, 6.3.1, and Appendix A). Results from this research will
serve as the basis for an integrated case study by the Risk Reduction Project to demonstrate the
hierarchial implementation of the risk-based framework. The Risk Reduction Project also will
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coordinate with the U.S. Fish and Wildlife Service, the Soil Conservation Service, the Bureau of
Reclamation, the Corps of Engineers, and other agencies and universities working in this area
to determine whether research studies funded by these organizations can contribute to and be
integrated into the Prairie Pothole risk reduction case study.
Information from other WRP research also will be used, as appropriate, by the Risk Reduction
Project to illustrate how differences in regional processes and management goals may influence
the application of a risk-based framework. Both the Wetland Function and Landscape Function
Projects will be working in bottomland hardwood wetlands (Sections 4.3.2 and 6.3.2). The results
from these studies will be integrated into the risk-based framework as a second risk,reduction
case study.
As mentioned previously, the Risk Reduction Project will use the risk-based framework to provide
technical support for two major issues: no net loss (Section 1.2.2) and.the role of wetlands in
reducing nonpoint source pollution (Section 1.2.7). The framework will be implemented
hierarchically as described in Section 3.5. The subsections that follow provide preliminary
research hypotheses that will guide the design and development of these proposed risk
assessments.
7.2.1 No Net Loss
Two case studies will be conducted to illustrate how the risk-based framework can be applied to
support the development of risk management plans for no net loss, one in the Prairie Pothole
Region and the other for bottomland hardwood wetlands. The hypotheses for the Prairie Pothole
Region are as follows:
The most important functions of prairie pothole wetlands are waterfowl habitat and
reduction of nonpoint source pollution.
The habitat function of prairie potholes is dependent on both the condition of
individual wetlands and the characteristics of wetland assemblages (for example,
the statistical distribution of basin depths).
The most significant causes of functional loss in prairie potholes are agricultural
conversion, habitat alteration, and sediment and nutrient loading from nonpoint
source pollution.
The following hypotheses apply to bottomland hardwoods:
The most important functions of bottomland hardwoods are water quality
improvement, wildlife habitat, and flood attenuation.
Fragmentation of the dendritic system would result in the degradation of these
wetland functions.
The most significant causes of functional loss 'have been floodplain conversion,
hydrologic modification, and-habitat alteration.
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Risk-based analyses can provide information relevant to the goal of no net loss by assessing
(1) which valued functions are being lost through conversion or degradation and (2) whether these
functions can and are being replaced. The results from these analyses could be applied through
a number of different mechanisms, for example, by the Office of Water to provide guidelines for
State grants; by EPA Regions to establish regional goals and to prioritize permit activities; and
by States to develop State Wetland Conservation Plans (see Section 1.2.8).
7.2.2 Reduction of Nonpoint Source Pollution
Technical information is needed on the sustainable use of natural, restored, and created wetlands
for water quality improvement (see Section 1.2.7). In particular, the WRP will focus on the use
of wetlands as buffers to reduce nonpoint source pollution loadings to downstream waters. The
specific hypotheses to be examined, in addition to those listed in Section 7.2.1 relating to the
water quality improvement function, are as follows:
Restoration of agricultural wetlands is an effective way to reduce nonpoint source
pollution.
Riparian buffers are effective for water quality improvement.
Optimal siting of restored, created, or constructed wetlands will maximize the level
of water quality improvement.
Wetland habitat function can be degraded by assimilation of nonpoint source
pollution.
The Risk Reduction Project will provide technical support aimed at developing approaches to
maximize the water quality function of wetlands, while minimizing the loss of other valued
functions. Research on the secondary effects of pollution will suggest guidelines and water
quality criteria to avoid wetland degradation (e.g., Section 4.2.4). Simulation studies, as described
in Sections 6.2.2 and 6.2.4, will help identify areas with a high landscape input of nonpoint source
pollution where the water quality improvement function of wetlands may be especially important.
7.3 MAJOR CONTRIBUTIONS
The Risk Reduction Project will produce integrated program deliverables that synthesize the
results of the other WRP projects into reports, guidelines, and management tools useful to
wetland managers and regulators. The major contributions of the project will include the
following:
• a risk-based framework for wetland protection and management, that has been tested and
finalized and can be applied to a range of management issues and needs;
• a methodology, and case study, for risk assessments based on BPJ that can provide for
improved decisionmaking without extensive data collection or new analyses;
technical support for management-plans to implement the policy of no net wetland loss;
86
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<• technical support for maximizing the role of wetlands in reducing nonpoint source pollution
while also avoiding the degradation of other valued wetland functions; and
« protocols for wetland monitoring and evaluation of the success of wetland management
programs.
The specific deliverables for the Risk Reduction Project are listed in Section 9.
87
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8. TECHNICAL INFORMATION TRANSFER
Technical information transfer is a program strategy to ensure that WRP research is relevant to
policy and regulatory needs and that innovations developed by the WRP will be. adopted and
widely used by wetland managers at the regional and state levels. Only by actively involving
regional and state wetland managers and regulators in the process of research planning and
demonstration will the WRP research have the impact necessary to reduce environmental threats
to wetlands. For these reasons, technical information transfer is an important and integrated
component of the WRP.
8.1 APPROACH
Technical information will spread within an organization only if it is first transmitted from its
innovator to a receptive "expert" in an identified user group (Muth and Hendee 1980). While
traditional approaches to technical information transfer, such as publications and symposia, can
successfully generate awareness of and interest in a particular innovation, they do not often lead
to its trial and adoption.
Accordingly, in 1988 a Regional Liaison Officer position was established within the WRP to foster
more direct communication between WRP scientists and wetland experts in states and EPA
Regional Offices. The Regional Liaison is an EPA Regional wetland manager assigned to the
WRP. The responsibilities of the Regional Liaison include the following:
Identify and communicate to the WRP the technical support needs of the EPA Regions
and states that are consistent with the goals and objectives of the WRP, such as the
listing of priority research needs presented in Section 1.2.
• Work to ensure that WRP studies address these priority technical support needs to the
degree possible within the constraints of the mandate and budget of the WRP.
• Encourage and coordinate the implementation of cooperative projects, involving shared
expertise and/or funding from both the WRP and EPA Regions or states.
• Involve the EPA Regions from the beginning of the research process to the end, to ensure
ownership and further technology transfer through direct participation in the research
process.
« Identify Region and State staff who are interested in innovation and piloting research.
Distribute information on WRP projects and results to interested agencies, firms, and
individuals.
Collaborative research studies, in which wetland managers work directly with WRP scientists on
research projects (sharing expertise and/or funding), are an important feature of the WRP strategy
for technical information transfer. Thus, one of the primary responsibilities of the Regional Liaison
is to identify opportunities for WRP scientists to conduct studies that are both relevant to the WRP
Five-Year Research Plan and also support the more immediate needs of the EPA Regions and
states. Besides offering technical assistance to the Regions and states, these collaborative
studies serve two important purposes. First, collaborative efforts provide a forum for WRP
89
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scientists to receive feedback from wetland managers on the relevance of their proposed
research. Second, collaborative studies directly involve Regional and state wetland experts in
the development of new wetland science and innovations, increasing the likelihood that these new
innovations will be adopted and used for wetland management. The WRP can then encourage
further technology transfer with offers of additional technical consultation, as resources allow.
Over the next five years, the Regional Liaison will implement a plan, developed in July 1990 and
endorsed by both the WRP and EPA Regions, for identifying opportunities for collaborative
studies. The plan includes a formal set of provisions for (1) establishing an EPA Regional
research committee; (2) developing collaborative study selection criteria; (3) soliciting proposals
for regional studies from the EPA Regions; and finally (4) ranking, selecting, and implementing
these studies. The Regional Liaison will have an annual budget of about $250,000 (see Section
9) that will be used to provide incentives for WRP participation in collaborative studies that may
not be directly related to project objectives. A series of collaborative reports will result from these
studies.
No formal training programs by the WRP are planned at this time, but opportunities for such
training may arise as results from the WRP research become available. The Regional Liaison
will, however, on occasion organize informal workshops at the EPA Regional Offices.
Copies of all WRP reports and publications will be transmitted by the Regional Liaison to the EPA
Regions, who will in turn notify the states of their availability. The Regional Liaison also will
develop a separate mailing list for the states to,ensure that the information generated by the WRP
is widely distributed.
8.2 ADDITIONAL ACTIVITIES
The WRP recognizes its responsibility to provide visible and technically credible information to
the scientific community, to other federal agencies involved in wetland research, and to the public.
The WRP scientists will continue, therefore, to pursue peer-reviewed publication of their findings
in scientific journals. WRP scientists also will serve as organizers and contributors to national and
regional wetland workshops and symposia, such as those organized by the Society of Wetlands
Scientists.
Another aspect of technology transfer that must be considered is the coordination of WRP
research with wetland research conducted by other federal agencies. This task is the
responsibility of the WRP Manager, in cooperation with the Wetlands Division within the Office
of Water. The WRP Manager, or her delegate, currently serves on a number of interagency
committees and work groups (e.g., with the Army Corps of Engineers, Soil Conservation Service,
and Federal Highways Administration). Additional coordination between the WRP and wetland
research activities in other agencies is achieved through review of major project plans and
reports, and participation in peer review and coordination workshops.
The WRP prepares an informal "Wetlands Research Update" at least once per year. This report
provides a summary of WRP's ongoing research activities, the names of project scientists, and
the conclusions of recently completed studies to any interested individual or group. The WRP
maintains a large, open mailing list for distribution of the Update. Representatives from states,
the EPA, other federal agencies, and many private individuals and consulting firms are included
on the mailing list.
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9. PROGRAM DELIVERABLES AND BUDGET
This planning document assumes a five-year program funded at $2.552 million annually. Major
deliverables from the WRP for FY 1992-1996 will directly address the priority EPA programmatic
needs identified in Section 1 and will include the following:
• a risk-based approach to setting water quality criteria, including biocriteria, for wetlands;
a technical handbook on the protection of wetland functions through the implementation
of best management practices;
• a technical framework for the restoration and creation of wetlands, focusing on an
evaluation of performance and design; '"
• rapid techniques for landscape assessments of wetlands;
• an assessment of the role and functions of isolated wetlands, with management
recommendations;
application of the risk-based framework to the national policy of no net loss of wetlands;
and
• application of the risk-based framework to an evaluation of the role of wetlands for
reducing nonpoint source pollution.
Table 9-1 provides a full list of the WRP major deliverables by project and year. The total
Program budget, assumed for FY 1992-1996, is summarized by year and WRP project in Table
9-2. Individual project budgets, by deliverable and year, are presented in Tables 9-3 to 9-6 for
the Wetland Function, Characterization and Restoration, Landscape Function, and Risk Reduction
Projects, respectively. The budget for Technical Information Transfer is included in Table 9-2.
The outputs from this program element will be collaborative research reports, not major program
deliverables. Therefore, no separate budget table by deliverable is provided for Technical
Information Transfer.
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Table 9-1. WRP Deliverables by Project and by Year
WETLAND FUNCTION PROJECT
State-of-the-science review of stressors, impacts, and indicators of function for FY 1993
priority wetland types
Risk-based approach to setting water quality criteria, especially bipcriteria, for FY 1996
wetlands
Handbook for the protection of wetland functions through the implementation of . , FY 1996
best management practices
Guidelines for site-specific monitoring of ecological integrity in individual wetlands FY 1996
and wetland complexes
Preliminary technical support on establishment of water quality criteria required for FY 1993
survival, growth, and re-establishment of coastal seagrass systems
CHARACTERIZATION AND RESTORATION PROJECT
State-of-the-science approach to selecting sites for restoring western riparian FY 1994
wetlands
An approach to selecting sites for wetland restoration FY 1996
Technical framework for the restoration and creation of wetlands: An evaluation FY 1997
of performance and design
LANDSCAPE FUNCTION PROJECT
An assessment of the function and value of isolated wetlands, with management FY 1995
recommendations
Rapid techniques for landscape assessment of wetlands FY 1996
An evaluation of the functions of wetlands in the landscape FY 1996
RISK REDUCTION PROJECT
The use of a risk-based framework with best professional judgment for wetland FY 1993
risk assessment
A protocol for monitoring and evaluating the effectiveness of risk management FY 1995
Application of a risk-based framework to no net loss of wetlands FY 1996
Application of a risk-based framework to reduction of nonpoint source pollution FY 1996
92
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10. REFERENCES
Abbruzzese, B., S. G. Leibowitz, and R. Sumner. 1990a. Application of the Synoptic Approach
to wetland designation: A case study in Louisiana. Final Technical Report, EPA/600/3-90/066,
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New York.
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78(3): 141-144. . .
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6-8.
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APPENDIX A: OVERVIEW OF ORIGINAL WETLANDS RESEARCH PROGRAM
The original Wetlands Research Program (WRP) developed in 1986 consisted of three semi-
autonomous projects (Zedler and Kentula 1986): (1) Water Quality, (2) Mitigation, and
(3) Cumulative Impacts. During the past five years, these three WRP projects have developed
the basic research methods required to support a risk reduction strategy. Water Quality has
developed techniques to quantify the response of wetlands to environmental stressors. Mitigation
has developed methods for characterizing various wetland populations and assessing the
performance of mitigation projects. Cumulative Impacts has developed techniques for ranking
and mapping landscape units according to function and risk.
These methods contain the basic elements for the more comprehensive research approach
needed to address the FY 1992-1996 research priorities. The WRP objectives are being met
through two basic organizational changes: (1) the missions of the individual projects have been
broadened to address a wider range of issues, and (2) a fourth project has been added whose
specific mission will be to integrate results from the other three projects into synthesis deliverables
on risk reduction. Brief descriptions of the three original WRP projects are provided in the
subsections below.
More recently, two additional research areas have been added to the WRP to address emerging
national priorities: Constructed Wetlands and the wetland component of the Environmental
Monitoring and Assessment Program (EMAP-Wetlands). The Constructed Wetlands and EMAP-
Wetlands projects are not included as a part of this plan, because they were funded separately
and have developed their own research plans (Olson 1990 and Leibowitz et al. 1991,
respectively).1 The Constructed Wetlands project also responds to a different program office.
The research activities described in this document will, however, be closely coordinated with and
mutually supportive of the Constructed Wetlands and EMAP-Wetlands projects, to assure that all
studies are designed to provide maximum benefit to both individual projects and the Program as
a whole. Brief descriptions of the Constructed Wetlands and EMAP-Wetlands projects are also
provided below.
A.1 WATER QUALITY
Wetlands provide three primary functions in the landscape: water quality, hydrology, and habitat
functions. Of these three, the role of wetlands in regulating or modifying water quality is the most
poorly understood. To increase our understanding of this function, the original Water Quality
Project was developed with two goals:
1. Ensure that water quality criteria protect the chemical, hydrological, and biological integrity
of wetland resources adequately by determining the effects of contaminants on wetland
structure and function.
2. Determine quantitative limits for waste assimilation to maintain the long-term structural and
functional integrity of wetlands of different types.
1 For the purposes of this document, reference to the WRP or to the "Program" refers only
to the projects described as a part of this plan. Constructed Wetlands and EMAP-Wetlands are
not included unless stated otherwise.
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Reid surveys and experiments have been conducted as part of this project to determine the
!SfL°! anthr°P°9enic stressors on wetland water quality functions and the capacities of priority
wetland types to assimilate common contaminants.
A.2 MITIGATION
°f, wKetlands have been created to compensate for wetland losses
°f the Clean Water Act (°WA)- Few follow-uP studies have been
nd f, rmil;e Whethef Created wetlands Adequately replaced the valued
wetland functions that were lost. The goal of the Mitigation Project in the last five years has been
,6 S.UC?ess °f mi«9ation projects both in terms of compliance with permit specifications
weunri ±9JtCa Perf°rma^ of wetland "action and creation projects. To what degree has
wetland m.t.at.on successfully compensated for wetland losses? To accomplish this qoal
t'an,dS haVe been treated 3S events in progress. Measurenfem
made on restored and created wetlands have been compared with
°f "reference" wetlands C-e- natural wetlands of the same type and n
^ ^ reSt°red aPd CreatSd SitSS)- Such 'Olsons havTresulted
rt H Performance of current mitigation efforts as well as recommendations
wetland designs in future mitigation projects.
A.3 CUMULATIVE IMPACTS
UndSr SeCti°n 4°4 Of the CWA on|y after measu^s have been
o comPensate for imPacts to wetlands. However, impacts considered
themselv^es ^ cause substantial environmental effects when their combined
ocud othP^rr^6^- Cumu!fve impacts are the sum of a» « ^e impacts that have
occurred over the entire landscape and over time. Cumulative effects refer to the total
n andscape function resulting from these impacts. The goal of the Cumuf^T
in he past five years has been to provide technical support to wetland regulators I
**0 W6tlandS and the consequent cumulative effects on
has been developin9 the
A.4 CONSTRUCTED WETLANDS
. ^etIandS Pr°ject receives fundin9 from outside the WRP base budget to
chnical suPP°rt on ^e role of constructed wetlands in wastewater treatment and
H (2)J V3lUate the relati°nship between water quality and ecdogS
o r P hpr no-tland treatment SyStem is a wetland that has beefl created or
restored
1$ "Sed '° distin9uish th^e wetlands from "created or
under seotion 4°4
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landfill and industrial wastewater, nonpoint source pollution, and urban stormwater. Program
objectives are to evaluate the following:
the relationships between the design and structure of wetland treatment systems and
water quality improvement;
• the relationship between water quality in wetland treatment systems and ecological
condition, including bioaccumulation of toxic substances, productivity, species diversity,
and habitat quality (secondary ecological effects); and
• the relationship between the placement of wetland treatment systems and landscape
water quality functions.
The Constructed Wetlands Project recently produced a document outlining its five-year research
plan (Olson 1990), Coordination with this project will improve the WRP deliverable on the role
of wetlands for reducing nonpoint source pollution.
A.5 EMAP-WETLANDS
EMAP was initiated in 1988 to provide information on the health of the Nation's ecological
resources. Wetlands are one of seven resource categories that will be studied in EMAP. The
goal of EMAP-Wetlands is to provide a quantitative assessment of the current status and
long-term trends in wetland condition at regional and national scales. This goal will be achieved
through estimates of condition based on probabilistic samples of wetlands within regional wetland
populations; health will be assessed by the use of field and remote indicators. The objectives,
statistical design, and approach for EMAP-Wetlands are described in greater detail in the recently
completed and peer-reviewed research and monitoring plan for the project (Leibowitz et al. 1991).
Several opportunities exist for cooperative efforts between the WRP Projects and EMAP-Wetlands
and are currently being pursued. All of these projects will be evaluating and applying indicators
of wetland and/or landscape condition. Thus, current plans call for extensive sharing of
information among projects as well as the coordination of indicator selection and testing activities.
For example, the literature review on indicators prepared by the WRP (Adamus and Brandt 1990)
played an important role in the selection of potential indicators for use in EMAP-Wetlands.
Furthermore, recent efforts and workshops conducted by EMAP-Wetlands on wetland indicators
will be used to help guide future WRP research and indicator development.
The WRP Characterization and Restoration Project will be conducting surveys of wetland
populations, similar jn scope to (although with different objectives than) the surveys and
monitoring planned for EMAP-Wetlands. To the degree possible, the indicators and sampling
methods employed in the Characterization and Restoration Project will be consistent with those
used for EMAP-Wetlands (see Section 5.2.1.2).
The Wetland Function Project will be conducting intensive studies of individual wetlands or small
groups of wetlands (see Section 4.2.2). The resulting information on within-wetland indicator
variability and on changes in wetland indicators in response to stressors will be of value to both
EMAP-Wetlands and other WRP projects, both for indicator selection and for interpreting the
indicator data collected in these more extensive surveys and landscape assessments. Pilot
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studies planned by EMAP-Wetlands also will involve some evaluation of within-wetfand indicator
variability. Results from these efforts will aid both the Wetland Function Project and
Characterization and Restoration Project with indicator selection.
Current plans also call for a joint project on prairie pothole wetlands. EMAP-Wetlands is in the
advance stages of planning a pilot study in this region in 1992-1993. As a result, the WRP will
"piggy-back" its proposed studies of prairie potholes (see Sections 4.3.1, 5.3.1, and 631) onto
the EMAP-Wetlands pilot. WRP will benefit, therefore, from EMAP-Wetlands planning and
Interagency contacts. Data collected by EMAP-Wetlands on the status of wetland populations
m the area will be used directly by the Characterization and Restoration Project and the Risk
Reduction Project. Additional population-level sampling by the Characterization and Restoration
Project will be designed specifically to supplement, as needed, the EMAP-Wetlands pilot study
(see Section 5.3.1). In addition, the development of a working relationship between the WRP and
EMAP-Wetlands through the prairie pothole study will establish a protocol for formal coordination
of joint future activities.
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APPENDIX B: WETLAND RESEARCH BY OTHER FEDERAL AGENCIES
Many federal agencies conduct wetland research or provide technical support on wetland
management. The nature of these activities is dictated by agency mandate. In general, federal
wetland responsibilities fall into three categories: (1) regulatory, (2) resource management, and
(3) public works. In addition, an important factor that controls the kind of research or technical
support activities conducted by an agency is whether that agency's primary involvement with
wetlands is conservational (e.g., management or protection) or compensatory (i.e., the pursuit of
agency objectives causes deleterious effects on wetlands that must be mitigated).
For each federal agency with a major wetland role, the following subsections provide a brief
overview of their overall responsibilities with respect to wetlands and major research or technical
support objectives and strategy. In particular, these discussions focus on three key areas:
wetland function and value, restoration and creation, and the effects of anthropogenic stressors.
Major wetland types of concern to the agency also are identified. The purpose of this appendix
is to demonstrate that the planned research by the Wetlands Research Program (WRP) avoids
duplication and, even more important, will foster cooperation between the WRP and other federal
agencies in areas of mutual interest.
B.1 ARMY CORPS OF ENGINEERS
The Army Corps of Engineers (COE) has wetland responsibilities within all three management
categories: (1) under Section 404 of the Clean Water Act, the Corps has the primary
responsibility for issuance of wetland dredge and fill permits; (2) the COE manages 9 million
acres of federal land as part of its water resources projects, and wetland management is a part
of the Corps' overall land stewardship; and (3) the COE causes adverse effects on wetlands
through dredging operations and must mitigate, therefore, for wetland loss.
The Corps has committed $22 million during FY 1991-1993 for wetland research. A recent draft
planning document describes six technical task areas for planned research (COE 1990):
(1) critical processes, (2) delineation and evaluation, (3) restoration and development,
(4) predicting and minimizing impacts, (5) change assessment, and (6) stewardship and
management. The primary focus of the Corps' wetland research activities is the development of
techniques for conserving, establishing, and managing the Nation's wetlands. The Corps'
expanded research program for FY 1991-1993 will emphasize field research and demonstrations
aimed at restoring, establishing, and managing numerous wetland types, including wooded
wetlands, freshwater marshes, and coastal intertidal wetlands. The work will involve
interdisciplinary undertakings in environmental engineering, hydrology, hydric soils, biological
techniques, structures, and design criteria. Considerable effort also will be expended on
improving the accuracy and range of wetland delineation and evaluation techniques, with major
emphasis on wetland functions and values. The application of remote sensing for wetland change
assessment will be evaluated, as well as techniques to predict and avoid wetland impacts. The
three-year program is responding to the Administration's challenge of no net loss of wetlands.
The WRP is working with the Corps to assure coordination of the two research programs.
B.2 U.S. FISH AND WILDLIFE SERVICE
The U.S. Fish and Wildlife Service's (FWS) mission is to conserve, protect, and enhance fish and
wildlife along with their habitat. Although it is mostly a resource management agency, with over
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half of the Service's funding directed towards wetland conservation, it also has regulatory
responsibilities (for example, under the Endangered Species Act). The FWS manages 90 million
acres of wildlife refuges throughout the nation, 37% of which are wetlands (U.S. FWS 1990). The
FWS is responsible for restoring and enhancing wetlands under programs such as the North
American Waterfowl Management Plan and as a part of the Conservation Reserve Program. The
Service also is responsible for evaluating wetland status and trends through its National Wetlands
Inventory (NWI) program.
A 1990 FWS Wetlands Action Plan lists several key research areas (U.S. FWS 1990), including
(1) the ecological consequences of management practices; '(2) habitat requirements of
wetland-dependent species; (3) evaluation of assessment methods for management and
restoration; (4) assessment of the function, wildlife value, and stability of wetland ecosystems;
(5) the effects of large-scale environmental change (e.g., global warming) on wetlands;
(6) assessment of the effectiveness of alternative mitigation strategies; (7) assessment of the
long-term impacts of chemical contamination; and (8) evaluation of the role of hydrology in habitat
maintenance. The FWS has been involved in evaluating wetland functions and values at both
site-specific and landscape scales. Wetland restoration and creation research has similarly
occurred at both of these spatial scales. Priority stressors have included chemical contaminants
and global climate change. Research has been conducted on several wetland types, including
bottomland hardwoods, prairie potholes, and coastal/estuarine systems such as seagrass
communities. The experience of the FWS in these areas, especially regarding the use of the
Prairie Pothole Region by waterfowl, can complement planned WRP studies.
B.3 SOIL CONSERVATION SERVICE
The U.S. Department of Agriculture's (USDA) Soil Conservation Service (SCS) has both resource
management and public works responsibilities. Under the 1990 Farm Bill, SCS provides technical
assistance for the Wetlands Reserve Program; the objective of this program is to restore up to
600,000 acres of degraded wetlands. The SCS also makes wetland determinations for the
"swampbuster" provisions of both the 1985 and 1990 Farm Bills. The Service's major
responsibility in the area of public works is flood prevention. Main areas of interest to the SCS
include (1) the value of prior converted cropland and cropped wetlands; (2) improved wetland
delineation; (3) an evaluation of the functions and value of wetland restorations, along with
methods for improvement; and (4) the environmental factors that cause anaerobic soil conditions.
While the SCS is not involved directly with research, it has a need to provide personnel in state
offices with technical support for meeting SCS responsibilities. In addition, the SCS has
considerable experience in restoring wetlands on agricultural lands, mostly focusing on
engineering requirements and the management of vegetation for waterfowl production. The plant
materials used for increasing the function and success of restored and created wetlands are
selected at SCS plant materials centers. The effects of nonpoint source pollution on wetlands
(both nutrients and sediments) is another area that the SCS has investigated.
The importance of working closely with SCS is illustrated by the fact that 87% of the historical
wetland losses from the 1950s to 1970s and 54% from the mid 1970s to mid 1980s resulted from
agricultural conversion (Tiner 1984, Dahl and Johnson 1991). The technical assistance provided
by the SCS for the Wetlands Reserve Program offers a major avenue for redressing these losses.
WRP's proposed research on prioritization of -restoration sites could help ensure that the
ecological benefits of this program are maximized.
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B.4 FEDERAL HIGHWAYS ADMINISTRATION
The Federal Highways Administration (FHWA) is a public works agency. FHWA policy is to
mitigate for the adverse effects on wetlands occurring as a result of highway construction
(Isaacson 1988). Thus, FHWA research has focused on two areas: (1) evaluating the effects of
highway projects on wetlands, including both direct losses of wetland area as a result of highway
construction and wetland degradation caused by runoff from highway projects, and (2) developing
guidance on site-specific mitigation, including minimization and compensation (restoration or
creation). The FHWA is funding an FY 1992 research initiative which includes wetland research.
Priority research areas will include (1) functional assessments of wetlands, (2) cost-effectiveness
of wetland creation, (3) identification of hydric soils, and (4) short-term impacts from construction
in wetlands.
The assessment of the functions and value of individual wetland sites has been a major interest
of the FHWA. In fact, the FHWA was responsible for the original development of the Wetland
Evaluation Technique (WET; Adamus 1983, Adamus and Stockwell 1983). Restoration and
creation activities have focused on engineering approaches to successful mitigation. The
construction of highways itself has been the major impact considered by this agency. The FHWA
has expressed particular interest in the mitigation of western riparian wetlands.
B.5 BUREAU OF RECLAMATION
The Bureau of Reclamation (BOR) is primarily a public water resources agency, serving the
western United States. BOR water projects provide irrigation water for over 10 million acres of
farmland and drinking water for more than 25 million people (Grossman 1990). BOR dams also
provide hydroelectric power. The BOR owns over 8 million acres of land and, therefore, also has
resource management responsibilities.
Because BOR water projects have impacted wetlands, the BOR has had a policy of avoidance,
minimization, and wetland mitigation. In 1987, however, the BOR announced an expanded
emphasis on its role as a resource management agency (Grossman 1990). To fully realize the
water resource benefits of wetlands, wetland protection and management have been integrated
into the Bureau's water resource management initiatives. The BOR recognizes that wetlands can
serve as integrators and indicators of overall basin conditions. Thus, four major research needs
have been identified: (1) siting of wetlands to realize water resource and fish and wildlife benefits,
(2) design criteria for different wetland functions, (3) the hydrologic regime required to support
different wetland functions, and (4) operating and maintenance requirements for sustaining
wetland systems.
The BOR initiated a five year multi-million dollar wetland program in FY 1991 that emphasizes
three activities: (1) inventorying wetlands on BOR lands, (2) developing projects to support the
North American Waterfowl Management Plan, and (3) specific research and demonstration
projects. Short-term research priorities are to develop scientific and engineering guidelines and
procedures for wetland restoration and creation.
BOR's main interests in wetlands relate to wetland functions for flood storage, reducing nonpoint
source pollution, and habitat. Restoration and creatidn activities have focused on engineering
design criteria, including hydrologic requirements of wetlands. Likewise, hydrologic modification
js the major wetland stressor of concern to the BOR.
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The BOR also has a major interest in western riparian systems. Research by the
Characterization and Restoration Project could assist the BOR in their efforts to increase the
ecological functions of their wetland restoration and creation projects. BOR's experience with
western riparian systems also could benefit the study planned by the WRP on these systems (see
Section 5.3.2). '
B.6 USDA FOREST SERVICE
The USDA Forest Service is responsible for the management of 191 million acres of forest and
range lands, of which 12 million acres are classified as wetlands. National Forest System land
is managed to achieve multiple objectives, including timber and mining production, enhancement
of water quality and quantity through watershed protection, and other goals such as fish and
wildlife habitat preservation. The mission of Forest Service research is to serve society by
developing and communicating the scientific information and technology needed to protect,
manage, and use the natural resources of forest and range lands. Forest Service research has
the authority to address information needs on private and public lands, including industrial and
non-industrial land owners. Research is carried out through a network of eight .Experiment
Stations and the Forest Products Laboratory, encompassing 74 locations and $170 million in FY
1991.
Wetland and water quality research in the Forest Service has been underway for decades in
many parts of the country. In the North Central region, long-term, process-based studies in
peatland ecosystems have been conducted since the 1950s. Bottomland hardwood management
in the South, especially in Mississippi and Louisiana, has been studied since 1937. Techniques
to manage riparian areas in the western United States have been an essential part of Forest
Service research for 20 years, including increased emphasis on the fundamental functions of
these systems. Under the Center for Forested Wetlands in Charleston, SC, environmental
controls on the growth and productivity of major wetland species are being studied, with some
emphasis on soil chemistry and plant physiology. Projects in Louisiana and North Carolina are
examining the legislative, regulatory, and economic controls on forest wetland management
practices. Studies of wetland ecosystems as wildlife and fish habitat and as areas to maintain
and enhance biological diversity are underway in all Stations.
To meet the management challenges of wetland ecosystems, "Wetlands" has been identified as
a National Research Problem Area for FY 1993; a staff specialist will coordinate research efforts
across the country. The program will continue to cover the full range of research needs
previously described, and will focus on areas of critical uncertainties (e.g., best management
practices). Research categories that will be emphasized include fundamental understanding of
ecosystem dynamics in disturbed and undisturbed landscapes; development of methods and
evaluation of the success of wetland restoration and rehabilitation; management of the wetland
resource; socioeconomic values of wetlands and legislative/regulatory controls on management
decisions; and landscape-scale linkages of wetlands to upland and adjoining ecosystems.
The WRP will contact the Forest Service to coordinate studies on bottomland hardwood forests
(Sections 4.3.2 and 6.3.2) and western riparian systems (Section 5.3.2).
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B.7 TENNESSEE VALLEY AUTHORITY
As described in its enabling legislation, the Tennessee Valley Authority (TVA) is both a public
works and resource management agency. Historically, its widely publicized flood control,
navigation, and power generation programs have greatly overshadowed its natural resources
management and development activities. Recent organizational and policy changes have,
however, prompted many new initiatives for improved stewardship of public lands and natural
resources under its control. Research areas of interest to JVA include classification, delineation,
mapping, and inventory; restoration and creation for water quality improvements and habitat
development; effects of flooding on ecological function; and habitat valu,e of wetlands.
tVA's major interests in wetland functions, are the role of constructed and natural wetlands for
restoring and maintaining water quality and the habitat values associated with such systems.
Restoration and creation has centered on the role of constructed wetlands for treating wastewater,
acid drainage, and agricultural and industrial waste. Hydrologic modification has been the major
stressor of concern. Because of its geographic location, bottomland hardwood forests are of
particular interest to TVA. The WRP will contact TVA to coordinate their studies on bottomland
hardwood forests (Sections 4.3.2 and 6.3.2).
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GLOSSARY1
Assimilative capacity - the total quantity of a material (such as sediments, nutrients, or toxic
contaminants) that a wetland (or other ecosystem) can remove through filtration, transformation,
retention, etc.
Avoidance - when used in the context of wetland management, the prevention of the loss of,
wetland area or function by implementing regulations or management strategies to protect
wetlands.
Baseline monitoring - periodic measurements or observations of ecosystem attributes over time
used to assess trends in ecosystem condition and to identify new environmental problems as they
arise.
Bioaccumulation - the process by which a compound is taken up and concentrated by an
organism, both from the surrounding media (water, soil, or air) and through the food chain.
Biocriteria - numerical values or narrative expressions that describe the reference biological
integrity of aquatic communities inhabiting or relying on wetlands of a given designated use, and
the habitat and hydrological conditions necessary to sustain that use. Biological criteria are
considered to be a subset of water quality criteria.
Buffer - vegetated strips of land surrounding ecosystems. Established buffers can at least
partially filter pollutants and sediments from overland and subsurface flow, thereby decreasing
the input of these materials into the ecosystem. Buffers can occur around wetlands, protecting
the wetland from external loading, or a wetland can serve as a buffer to protect other ecosystems,
such as streams.
Characterization curve - a histogram or curve representing the frequency distribution of a
wetland attribute (e.g., an indicator of wetland function) for a wetland population within a given
landscape setting.
Conceptual model - a simplified or symbolic representation of a system's behavior and
responses, identifying important stressors, major ecosystem components, processes, and
functions, and the linkages among these stressors, components, processes, and functions.
Constructed wetland - a wetland that has been created or restored specifically to treat either
point or nonpoint source pollution wastewater.
Conversion - the transformation of a wetland into a different land cover or land use (e.g., filling
in a wetland for building construction), resulting in the complete or near complete loss of the
original wetland functions.
1 Terms are defined specifically as they are used in this document.
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Created wetland - a wetland that has been constructed on a non-wetland site specifically to
compensate for wetland losses permitted under Section 404 of the Clean Water,Act.
Cumulative effects - the net change in the overall landscape function that results from
cumulative Impacts.
Cumulative Impacts - the sum of all of the Impacts that have occurred over the entire landscape
of interest and over time.
Data quality objectives - the desired level or standard of data quality (e.g., minimum acceptable
levels of precision and accuracy) established during the project planning process and used to
(1) help guide the sampling design and selection of analytical protocols and (2) provide an
objective basis for evaluating the adequacy of the data collected.
Degradation - the loss of function (in this case, wetland or landscape functions) resulting from
exposure to a stressor. Wetland degradation would include direct and indirect effects resulting
from the addition of harmful agents and/or the removal of beneficial factors (e.g., damage to the
environmental infrastructure that maintains a wetland as a result of hydrological modifications
caused by dam construction or stream diversion).
Denltrlflcation - biologically mediated reduction of nitrate to gaseous forms of nitrogen (NO, N2O,
and N.,). Nitrate is used as an electron acceptor in the absence of free oxygen (e.g., in wetland
soils and sediments); denitrification occurs in association with the decomposition of organic
matter.
Ecoreglon - a mapped classification of ecosystem regions. Ecoregions are geographic areas that
have relatively homogeneous ecological systems and homogeneous relationships between
organisms and their environment.
Ecosystem - a complex of biological communities and the physical and chemical environment
forming a functioning whole in nature. Wetlands, upland forests, lakes, and streams are
examples of types of ecosystems.
Effect - a change in wetland structure and/or function in response to some causal agent (i.e.,
some Impact or stressor).
Empirical study - relying on experience or observation alone (as opposed to a controlled
experiment). In this document, an empirical study refers to field observations and measurements
collected for wetlands along a gradient of stressor(s) or surrounding management practices.
Environmental stressors - see stressor.
Evaluative monitoring - measurements or observations of ecosystem attributes collected
specifically to determine the effectiveness of a risk management plan.
Exposure assessment - a component of a traditional risk assessment, involving the
quantification of the magnitude of one or more stressors to which the organism, biological
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population, or ecosystem is exposed or may be exposed to in the future given various
management scenarios.
Function - see wetland function and landscape function.
Functional loss - the loss or decline of a valued wetland function as a result of wetland
conversion or degradation. ,
Hazard identification - a component of a traditional risk assessment, involving the
characterization of the specific stressors of concern for the ecosystem(s), landscape, or region
being evaluated as part of the risk assessment.
Hydrologic modification - a change in the timing, duration, frequency, quantity, location, or
distribution of water flows as a result of human activities. Hydrologic modifications may result
from dam or levee construction, water withdrawals, stream diversions, 'changes in local runoff
patterns due to construction activities or increases in impermeable surfaces in the watershed, etc.
Hydrology - the study of waters of the earth: the properties, circulation, and distribution of water
on the surface of the land, in the soil and underlying rocks, and in the atmosphere. -Hydrology
is a major determinant of the occurrence and condition of wetlands.
Impact - an action that adversely affects a wetland or other ecosystem, for example, dam
construction, timber clearing, agricultural activities that result in wetland conversion or
degradation.
Indicator - one of the specific environmental attributes measured or quantified through field
sampling, remote sensing, or, in some cas'es, compilation of existing data (e.g., existing maps or
land use information) to assess ecosystem condition or functions, or exposure to environmental
stressors.
Isolated wetlands - wetlands that are small (e.g., less than 10 acres) and have no connection
to other surface water bodies. The term "isolated wetlands" is used in this document to refer
specifically to those small, isolated wetlands that are covered under Nationwide Permit 26.
Landscape Development Index - an index of the intensity of landscape stressors that may
degrade wetlands, based on land uses in the surrounding area and their known or suspected
effects on wetlands.
Landscape function - the combination of environmental processes operating within a landscape
unit that account for the overall environmental characteristics of that unit. The term wetland
function refers to the functions and benefits provided by individual wetlands, while landscape
function refers to the functions and benefits provided by the landscape unit as a whole, including
the complex of wetlands and other ecosystems within that landscape unit. Examples of
landscape function are regional biodiversity and the overall water quality and hydrologic integrity
of a watershed.
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Landscape unit - a contiguous area of land used in landscape-level analyses. The scale and
boundaries of landscape units can vary depending on the landscape function of interest and
study objectives. Often, watersheds or ecoregions are used as landscape units.
Loading rate - the amount of material received by a wetland or other ecosystem per unit of time.
Manipulative studies - controlled experiments in which a wetland/ecosystem component of
interest is exposed to a controlled set of conditions or levels of some stressor.
Mesocosm - a portion of a wetland or other ecosystem enclosed in the field for the purpose of
a manipulative study.
Microcosm - an artificial experimental unit including one or more wetland/ecosystem components
used in a manipulative study in either the laboratory or field.
Mitigation project - wetland enhancement, restoration, or creation activities required to
compensate for wetland losses permitted under Section 404 of the Clean Water Act.
Natural wetland - a wetland that occurs naturally in the landscape and has not been manipulated
to recover or increase wetland functions.
Nitrification - the oxidation of ammonium to nitrite or nitrate by microorganisms.
Nonpolnt source pollution - impurities or contaminants derived from diffuse origins (e.g.,
agricultural runoff), as opposed to pollutants that are introduced into a wetland or ecosystem at
one or more discrete locations (point source pollution).
Nutrients - chemicals required for biological maintenance. Nitrogen and phosphorus are
examples of plant nutrients.
Nutrient loading - the input of nutrients into a wetland or other ecosystem from external
sources.
Performance curve - a curve tracking the change in an Indicator of wetland function over time
in a population of restored or created wetlands compared to trends through time of the same
indicator in natural wetlands in similar landscape settings.
Physical alteration - a change in the physical structure or characteristics of a wetland or other
ecosystem as a result of human activities, for example, as a result of dredge and fill operations
changes in land cover type, timber harvesting, etc.
Population - the entire group of wetlands of a given wetland type occurring within a
geographically defined area. Unless otherwise stated, the phrase "wetland population" is used
in this document to refer to statistical populations, rather than biological populations (i.e., an
assemblage of organisms of the same species inhabiting a given wetland or other ecosystem).
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Process(es) - a natural phenomenon involving the biological, chemical, or physical conversion
or transfer of some material. For example, nitrification and denitrification are processes within
wetlands that contribute to the water quality function.
Replacement potential - the ability to recover a wetland and its valued functions through
wetland restoration or creation.
Response threshold - the level of stressor above which a significant change will occur in some
wetland/ecosystem attribute of interest (see stressor/response relationship).
Restored wetland - a wetland that has been returned from a disturbed or altered condition to a
previously existing natural or altered condition by some action of man.
Riparian system - ecosystems occurring in the interface between aquatic and terrestrial systems,
in floodplains and adjacent to rivers and streams. Riparian systems are subject to direct
influences of ground and/or surface waters (e.g., occasional flooding, root zones extending into
the groundwater table). Riparian systems are valued for diverse functions, such as flood
attenuation, groundwater supply, streambank stabilization, habitat and migration corridors for
wildlife (including many endangered species), and modification of surface water habitats (e.g.,
shading, or organic matter inputs).
Risk - the possibility of some loss or adverse effect.
Risk assessment - the identification and estimation of the risks associated with various
stressors and environmental hazards.
Risk-based framework - an organized approach for identifying and quantifying risks (risk
assessment), developing management strategies to reduce risks (risk management), and
monitoring the effectiveness of these management actions and identifying new problems and risks
that may arise (monitoring and evaluation).
Risk characterization - the final component of a traditional risk assessment, involving the
integration of the information (and uncertainties) resulting from the three steps of hazard
identification, stressor/response relationships, and exposure assessment, to estimate the
probability of occurrence of specific events, such as the loss or degradation of an important
ecosystem/landscape attribute.
Risk management - the development and implementation of a specific environmental
management strategy to control the most serious environmental problems, thereby reducing risks.
Risk reduction - a policy goal or process to focus environmental protection activities on those
problems or areas where the greatest decrease can be achieved in the potential for adverse
environmental effects.
Sediment accretion - the net accumulation of particulate material deposited within a wetland or
other ecosystem.
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Sediment trapping - the reduction in the quantity of particulate material carried by surface or
groundwater as it passes through a wetland.
Sedimentation - the process by which particulate material settles to the bottom of the water
column of a wetland, lake, stream, or other water body.
Stressor - any material or process (physical, chemical, or biological) caused by man that can
adversely affect a wetland (or other ecosystem) and thus degrade wetland (or other ecological)
functlon(s). Stressors include the addition of harmful agents, such as pollutants, and the
removal of beneficial factors (e.g., stream diversions).
Stressor/response relationship - the quantitative association between the level of some
stressor to which an organism, biological population, or ecosystem is exposed and the magnitude
of response or probability of an adverse effect on one or more important attributes of the
ecosystem(s) or landscape.
Synoptic landscape assessment - the ranking and mapping, at large scales (e.g., ecoregions
or states) of Indicators of wetland function, wetland value, functional loss, orVepiacement
potential.
Technical Information transfer - a program strategy to ensure that the technical information
collected and methods developed in a research program, such as the Wetlands Research
Program, are relevant to policy and regulatory needs and that the innovations developed through
research will be adopted and widely used by environmental managers at regional and state levels.
Toxic contaminant - impurities that enter wetlands or other ecosystems as a result of human
activities (either point or nonpoint source pollution), potentially causing an increase in mortality
or sublethal adverse effects on organisms exposed to these materials.
Value - the benefits of a wetland or other ecosystem that are realized or recognized by society.
Water quality criteria - as defined by the U.S. Environmental Protection Agency, the
recommended levels of various water quality parameters (including biocriteria) that should not
be exceeded (or in some cases, minimum recommended levels) to protect aquatic life and human
health.
Water quality standards - a law or regulation that consists of the beneficial designated use or
uses for a waterbody, the water quality criteria (including biocriteria) that are necessary to
protect the use or uses of that particular waterbody, and an antidegradation statement.
Watershed - the geographic area from which all of the surface water that drains into a particular
wetland or other aquatic ecosystem is derived.
Wetland - a type of ecosystem that occurs at the interface between terrestrial and aquatic
systems. In the Clean Water Act, wetlands are defined as "those areas inundated or saturated
by surface or groundwater at a frequency and duration sufficient to support, and that under
normal conditions do support, a prevalence of vegetation typically adapted for life in saturated soil
conditions. Wetlands generally include swamps, marshes, bogs, and similar areas."
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Wetland creation - see created wetland.
Wetland function - the benefits derived from or role served by an individual wetland (cf.
landscape function). Wetland functions are generally grouped into three categories: (1) habitat
(providing the factors and conditions necessary to support wetland-dependent species); (2) water
quality (improving the quality of "downstream" surface and groundwaters through the uptake of
contaminants, sediment retention, nutrient retention or supply, etc.); and (3) hydrology
(moderating surface and groundwater flows, including flood attenuation, maintenance of base
flow, etc.).
Wetland mosaic - the complex or group of often interconnected wetlands, often of different types
and/or sizes, within a given geographic area.
Wetland restoration - see restored wetland. '
Wetland type - a group of wetlands with common qualities and characteristics that distinguish
them as an identifiable class. Several formal wetland classification schemes have been
developed. The term wetland type is used in this document, however, in a general sense and
does not refer to any of these formal or standard wetland classifications. The wetland types
discussed include freshwater emergent wetlands, bottomland hardwood forests, and wetlands
within western riparian systems.
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