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u S. ^vromw.tal Protection Agency
ni '':: ;H in:Cf>iiation Resource
Cv'/'.r U-Pi-1'^-)
C-il Ci^:;f.at Street
Philadeiphia, PA 19107
PEAT MINING
An Initial Assessment of Wetland Impacts and
Measures to Mitigate Adverse Effects
Final Report
July 28, 1981
Submitted to:
U.S. Environmental Protection Agency
401 M Street, SW
Washington, D.C. 20460
Prepared by:
John M. Carpenter
George T. Farmer
JRB Associates
8400 Westpark Drive
McLean, Virginia 22102
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TABLE OF CONTENTS
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ABSTRACT i
1. INTRODUCTION 1
1.1 Scope of the Report 1
1.2 Definition and Formation of Peat 3
1.3 Definition of Peatland Types 6
1.4 Classification of Peat 6
1.5 Production and Uses of Peat 7
1.6 Basic Peat Mining Techniques 10
1.7 Potential Environmental Impacts of Peat Mining 13
2. POTENTIAL ENVIRONMENTAL IMPACTS OF PEAT MINING 17
2.1 Water Quantity and Quality 17
2.1.1 Hydrological Characterization of Peatlands 17
2.1.2 Identification and Discussion of
Impacts on Water Quantity and Quality 22
2.1.3 Measures to Mitigate
Impacts on Water Resources 24
2.2 Vegetation 26
2.2.1 Characterization of Peatland Vegetation 26
2.2.2 Identification and Discussion
of Impacts on Peatland Vegetation 31
2.2.3 Measures to Mitigate
Impacts on Vegetation 33
2.3 Wildlife Utilization 40
2.3.1 Characterization of Peatland Fauna 41
2.3.2 Identification and Discussion
of Impacts on Peatland Fauna 43
2.3.3 Measures to Mitigate
Impacts on Peatland Fauna. 44
2.4 Air Quality 45
2.4.1 Potential Impacts on Air
Quality and Mitigative Practices 46
2.5 Nonconsumptive Use Values 47
2.5.1 Characterization of
Nonconsumptive Use Values 47
2.5.2 Potential Impacts on Nonconsumptive
Use Values and Mitigative Practices 49
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TABLE OF CONTENTS
(continued)
Page
3. CONCLUSIONS AND RECOMMENDATIONS 50
3.1 Major Findings of Peat Mining Assessment 50
3.2 Best Management Practices
and Administrative Recommendations 63
4. REFERENCES 58
4.1 Literature References 58
4.2 Individuals /Agencies 60
LIST OF TABLES AND FIGURES
Table 1.1 Comparison of the Major
Peat Classification Schemes... 8
1.2 Environmental Effects of Peat Mining 14
2.1 Physical Characteristics of
Fibric, Hemic, and Sapric Peats 18
2.2 A Typical Organic Soil Profile
from a Lake-Filled Perched Bog 19
2.3 Characteristic Peatland Vegetation Found
in Lake Agassiz Peatlands Natural Area, Minnesota 28
2.4 Peatlands Net Primary Productivity Estimates 30
Figure 1.1 Typical Undisturbed Peatland 1
1.2 Typical Mined Peatland 2
1.3 Cross-Section of Paludification
and Lake-Fill Processes 5
1.4 Peat Stockpiled before Processing 9
1.5 First Stage of Peat Mining Clearing Vegetation 10
1.6 Second Stage of Peat Mining Drainage 11
1.7 Small-Scale Mining with Bulldozer 12
1.8 Screening Large Debris from Peat 12
1.9 Elimination of Peatland Vegetation , 15
1.10 Poorly Constructed Drainage Ditch 15
1.11 Alteration of Vegetation due to Drainage 16
1.12 Loss of Peatland Wildlife Habitat 16
2.1 Drainage of Peatlands Affects Water Resources .....18
2.2 Cross-Section of Perched Bog and Ground Water Fen 21
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TABLE OF CONTENTS
(continued)
Page
LIST OF TABLES AND FIGURES (continued)
Figure 2.3 Streamflow from Perched Bog and Ground Water Fen 21
2.4 Abandoned Agricultural Peat Fields 34
2.5 Natural Revegetation of Recently Abandoned Mine 36
2.6 Dry Conditions Prevent
Revegetation by Peatland Species 39
2.7 Saturated Substrate Encourages Peatland Regeneration 39
2.8 Natural Regeneration of Wetland Habitat 44
2.9 Pitcher Plant A Unique Peatland Species 48
3.1 Peat Mining Severely Impacts Peatlands 52
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ABSTRACT
Small-scale dry peat mining operations are having a significant environ-
mental impact on inland bogs and fens in certain regions of the northern
United States. Peat is a valuable nonrenewable resource for horticultural and
agricultural purposes, and the demand for this resource increases each year.
Current dry mining methods can completely destroy the wetland values of small
bogs and fens. In larger peatland complexes small areas may be destroyed, and
widespread alterations in ecosystem structure and function may occur.
This report characterizes the hydrology, water chemistry, vegetation,
wildlife utilization, air quality, and nonconsumptive use values of inland
bogs and fens to better understand the ecological significance and value of
these wetlands. Numerous environmental impacts are associated with the
various stages of peat mining. These potential impacts are identified and
best management practices are recommended for the mitigation of adverse
effects resulting from mining activities. Restoration practices for the
regeneration of an in-kind wetland ecosystem are recommended also. Some
impacts from mining can be controlled or eliminated, and productive wetland
habitats can be created from mined-out peatlands if best management practices
are followed.
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1. INTRODUCTION
1.1 Scope of the Report
The U.S. Environmental Protection Agency (EPA), with the Army Corps of
Engineers (COE) and the Fish and Wildlife Service (FVIS), has a mandate under
Section 404 of the Federal Water Pollution Control Act of 1972 (the Clean
Water Act [CWA] as amended in 1977) to protect the Nation's wetlands which
come under jurisdiction of the CWA by regulating the discharge of dredged or
fill materials. Peat mining activity in wetlands has increased in recent
years to meet the growing demand for peat for horticultural, agricultural, and
alternative energy purposes. EPA Region III recently completed an aerial
photographic inventory of unauthorized wetland activities occurring in
northeastern Pennsylvania. The results of this inventory support the theory
that a large number of peat mining operations are having a significant adverse
effect on the limited bog and fen resources of this region (see Figures 1.1
and 1.2).
Figure 1.1 Vegetation covering a small undisturbed bog in northeastern
Pennsylvania typical of the peatland types being mined for
horticultural peat. Sedges, ericaceous shrubs and stunted trees
are the most conspicuous vegetation types.
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Figure 1.2 Dry peat mining operations in small inland bogs and fens eliminate
most of the peatland vegetation, thus destroying unique plant
species, as well as valuable wildlife habitat.
Similar ecological impact probably is occurring in other selected peat-
producing regions of the United States. For example, the State of Minnesota
has been involved in a peatland research program since 1975. This ongoing
program was initiated in response to a real and anticipated expansion of the
peat industry in the northern regions of the State. Numerous studies have
been conducted which evaluate the environmental, social, and economic
consequences of increased peatland development. Policy recommendations for
peatland management have been developed, and the program is undergoing a
transition from policy development to policy implementation.
The main purpose of this report is to provide the EPA with information on
peat mining practices, the environmental impacts of peat mining, and manage-
ment and restoration practices to mitigate adverse impacts. This information
will aid in developing agency regulatory policy concerning Section 404 permits
in wetlands under jurisdiction of the CWA. The report examines only small-
scale dry peat mining activities in inland bogs and fens of the northern
United States, with examples taken from Minnesota and Pennsylvania. Peat
mining in coastal wetlands is not covered in this report.
Inland mining operations produce peat almost exclusively for horticul-
tural and agricultural purposes. The environmental effects of large-scale
mining of peat for energy production and other industry-intensive uses are not
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examined in this study, although some of the reported baseline environmental
data would apply to other peat program studies. For example, the U.S.
Department of Energy (DOE) is preparing a comprehensive assessment of environ-
mental issues and potential impacts related to various phases of peat energy
development. A great deal of the environmental information summarized in this
report would be applicable to a discussion of the ecological impacts resulting
from mining peat as an energy resource.
This report consists of four major sections with appropriate subsec-
tions. The remainder of Section 1 summarizes important background information
on peat, peat raining methods, and potential environmental impacts of peat
mining. Section 2 contains generic characterizations of the hydrology,
vegetation, wildlife, air quality, and nonconsumptive human use values of
peatlands. Additionally, this section discusses the impacts of horticultural
peat mining on these aspects of peatlands and outlines possible mining,
management, and restoration practices which can be used to mitigate adverse
impacts. The recommendations and conclusions that can be drawn from the
information presented in Section 2 are detailed in Section 3. Finally,
Section 4 contains a complete bibliography of the literature references used
and a listing of the agencies and individuals consulted during the preparation
of this report.
1.2 Definition and Formation of Peat
Peat consists of dead and partially decomposed plant material. It occurs
in wetland ecosystems where there is a net accumulation of plant biomass. The
formation of peat is basically a function of topography, climate, and water
(Minnesota Department of Natural Resources [MDNR] 1979). Geomorphic features
that slow or block water movement, such as glacial lake basins, outwash
plains, ground moraines, or ice block depressions in glaciated regions, are
common templates for peat formation. Peat usually occurs in cool, humid
climates where precipitation exceeds evapotranspiration. Finally, organic
matter decomposition is primarily inhibited in peat producing systems by
anaerobic conditions caused by nearly constant water saturation of the peat
substrate. Also, the nutrient content and acidity of the water determine the
vegetation, and thus, the type of peat that forms.
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In the northern United States, inland peat deposits usually form by the
processes of lake-fill and paludification (or swamping) (MDNR 1979). Lake-
fill refers to the gradual filling in of lakes or ponds by vegetation. This
typical hydroseral succession normally passes from open water, through submer-
gent and emergent vegetation stages, to shrub stages, and finally, to closed
forest (see Figure 1.3B). On relatively flat or gently sloping terrain,
peatland expansion may be caused by a gradual raising of the water table as
peat accumulation impedes drainage. This gradual advance of peatland over
adjacent areas (including upslope and over topographic divides) is referred to
as paludification (see Figure 1.3A). Both processes can be represented on the
same peatland because paludification builds up peat over lake-filled deposits.
It should be emphasized that every peatland does not necessarily pass
through a complete successional sequence. Hydroseral development can start
and terminate at various stages, with some successional stages being omitted
or repeated. Such disturbances in the normal sequence can be caused by
climatic changes, geomorphological changes, natural processes of peatland
development, and the actions of beavers and man (Moore and Bellamy 1974).
Since most peatlands in North America are post-glacial in origin, peat
formation has occurred over the past 10,000 years or less. The rate of peat
accumulation varies considerably between peatlands depending on climatic
conditions, but in all cases it is a slow process. In Minnesota the rate
varies from 2.0 to 5.0 inches/100 years (MDNR 1978). Radiocarbon dating
studies cited by Cameron (1970b) gave accumulation rates of 0.8 to 2.4
inches/100 years for Pennsylvania and New Jersey bogs. For a bog in Manitoba,
Stewart and Reader (1972) determined a peat formation rate of 1.2 inches/100
years, which was less than a reported range of 2.0-2.4 inches/100 years for
other bogs at the same latitude.
The total thickness of a peat deposit is usually greatest in the center
of the bog and at a minimum around the edges. Obviously, peat depth depends
on the history of the bog. Cameron (1970b) reported average depths of 5-15
feet for peat deposits in upland areas and depths of as much as 25 feet for
deposits in lowland areas of southeastern New York. In the Lake Agassiz
peatlands area of northern Minnesota, Heinselman (1970) recorded peat depths
of 10-30 feet. Other bogs in northeastern Minnesota have peat deposits which
average 5-7 feet (Fens Bog - Farnham and Grubich 1970) and 16-20 feet in
thickness (West Central Lakes Bog - Farnham 1964).
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Paludidcation Process (A)
FIBFIIC (sphagnum cMall HEMIC (seogeoea
10 miles
Lakefill Process
SAPRIC LAKE SEGMENTS HEMIC
Figure 1.3 Peatland formed by paludification (A) extends over
large areas and results from a gradual swamping of
gently sloping terrain. Lake-fill (B) occurs in
smaller water-filled depressions which gradually
fill with dead and partially decomposed plant
material.
(Adapted from MDNR 1979)
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1.3 Definition of Peatland Types
In this report two main classes of peatland types are examined bogs
and fens. Peat accumulation is usually much less in marshes and swamps, which
differ markedly from bogs and fens in terms of hydrology, water chemistry, and
vegetation. Distinct differences in these three parameters also characterize
bogs from fens (Bay 1967, Heinselman 1970). Bogs are wetland systems which
receive their water and nutrients primarily from precipitation a condition
referred to as "ombrotrophic." In a true bog there is little or no ground
water input due to the impermeable substrate of the basin or local topography,
or because the rapid growth and accumulation of sphagnum moss has raised the
surface of the bog above the surrounding peatland. Bogs with convex surfaces
and a perched water table are termed "raised bogs." Characteristically, bog
water is highly deficient in mineral nutrients, and has a low pH. The
resulting vegetation is relatively low in species richness. In contrast, fens
receive a large input of water from upslope sources, after it has percolated
through mineral soils, hence the term "minerotrophic." Higher mineral
nutrient status and increased pH of the water favors a more diverse flora.
Some fens are characterized by parallel ridges of vegetation separated by less
productive hollows. The ridges of these "patterned fens" are perpendicular to
the downslope direction of water movement. The water resources, water
chemistry, and vegetation of bogs and fens are described in greater detail in
Sections 2.1 and 2.2.
Although these two peatland types exhibit distinctive characteristics,
transitional systems have also been recognized (see Figure 1.3A) where the
peatlands receive a mixture of waters and thus cannot be readily classified as
strictly ombrotrophic or minerotrophic (Heinselman 1970, Hagen and Meyer
1979). A variety of topographic and hydrologic factors that influence sources
and movements of water within large peatlands are responsible for gradual
changes in vegetation types. It is beyond the scope of this report to elabo-
rate on these factors or to discuss the subtle vegetational and chemical
gradations between peatland types.
1.4 Classification of Peat
Peat has been classified for several purposes. Primarily, its commercial
value and various uses have brought about the need to define peat types. In
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general, peat classification has been based on the botanical composition of
the peat, its degree of decomposition, and characteristic physical proper-
ties. Table 1.1 outlines the major peat classification schemes presently in
use. The table was intentionally structured to show the similarities of the
various schemes, even though the specific classification factors differ.
To better understand Table 1.1, several terms should be defined. The
American Society for Testing Materials (ASTM) defines peat as organic matter
of geologic origin, excluding coal, formed from dead plant remains in water
and in the absence of air; it has an ash content not exceeding 25 percent by
dry weight. Fiber is defined as plant material retained on an ASTM No. 100
sieve, i.e., material 0.15 mm (0.006 in) or larger consisting of stems,
leaves, or fragments of bog plants, but containing no particles larger than
12.7 mm (0.5 in). Fragments of other materials, e.g., shells, stones, sand,
and gravel are also excluded. The percentages of fiber are based on an oven-
dry weight at 105°C, not on volume. The fiber content of peat is a direct
measurement of the degree of peat decomposition. Bulk density refers to the
oven-dry weight of a given volume of peat, usually expressed as grams per
cubic centimeter. Finally, water content is the total moisture content of a
peat sample determined by the weight of water per unit weight of oven-dry
peat. The water-holding capacity of peat is related to the degree of decom-
position and the botanical origin of the peat. As peat becomes more decom-
posed, the water content decreases due to a reduction in the pore space.
Similarly, moss peat has a greater water content than herbaceous peat because
of the cellular structure of the moss fibers (MDNR 1979).
1.5 Production and Uses of Peat
The economic importance of peat is indicated by a review of production
statistics (U.S. Bureau of Mines 1980). Peat production increases gradually
each year in response to increased demand. In 1979, 825,000 tons of peat were
produced by 97 active peat mining operations in the United States. Of this
total production, 789,000 tons were sold in bulk form (41%) and in packaged
form (59%) at a total cost of $15,517,000 (see Figure 1.4). Additionally,
381,000 tons of peat were imported (primarily from Canada), which gives a
total apparent consumption of 1,179,000 tons. In contrast, the total world
peat production was 222 million tons, of which 95% was produced in the USSR,
followed by Ireland, Federal Republic of Germany, and Finland.
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*,^S*t atp"^ ' typPM* t
Figure 1.4 Peat is sold in bulk from stockpiles and in packaged form after
having roots and other debris removed during processing. The
demand for horticultural and agricultural peat increases each
year.
Michigan, Florida, Illinois, Indiana, and New York were the top producing
states (in that order of rank), accounting for 77% of production. Ranked by
peat types, reed-sedge peat production was greatest with 59% of total produc-
tion, followed by humus peat (23%), unclassified peat (13%), and sphagnum and
hypnum moss peat (5%).
In the United States, peat is primarily used in horticulture and agricul-
ture. This predominant use is due to the following characteristics of peat:
1) high organic and energy content necessary for growth of soil microbes; 2)
high water-holding capacity; 3) high cation exchange capacity; and 4) benefi-
cial effects on the physical properties of the soil to which it is added.
During 1979 the use of peat for general soil improvement amounted to 49% of
the total production, followed by its utilization in potting soils (26%), in
plant nursery applications (8%), and for packing flowers, plants, and shrubs
for shipment (3%). Additionally, smaller quantities of peat were used (in
order of quantities sold) for the construction of golf courses, for the manu-
facture of mixed fertilizers, as a growing medium for mushrooms, earthworms,
and vegetables, and as a seed inoculant (U.S. Bureau of Mines 1980).
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In other countries peat is used as an energy resource (primarily in the
Soviet Union and Ireland), for the manufacture of decomposable pots for trans-
planting young plants, for the manufacture of compressed insulation boards,
and as a source of industrial chemicals. Reclaimed peatlands are utilized
extensively for agriculture, horticulture, and forestry (Moore and Bellamy
1974).
1.6 Basic Peat Mining Techniques
Small-scale dry peat mining from inland bogs (< 200 acres) generally
consists of three basic operations: 1) clearing the bog surface; 2) draining
the bog to reduce the water content of the peat and facilitate the use of
heavy equipment on the bog; and 3) mining the peat from the bog and processing
it for sale. Clearing the vegetation from the peatland usually takes place
during the winter when bulldozers can operate on the frozen peat. Large
timber may be logged, but generally all shrubs, tree roots, and logs are
pushed to the adjacent uplands and left in piles (see Figure 1.5). Regrading
Figure 1.5 While the bog surface is frozen during the winter the vegetation
is cleared away with bulldozers, exposing the peat deposit
beneath. Generally, clearing is the first stage of peat mining.
of the bog topography may be necessary for proper drainage. Next, drainage
ditches are excavated with either a backhoe or dragline operating during the
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winter or from wide mats placed on the peat surface (see Figure 1.6). Main
ditches and feeder branches are laid out with consideration given to the
natural drainage of the peatland, the depth and type of peat, the extent of
the area to be mined, and the amount of annual rainfall. A range of 2-5 years
usually is required for sufficient peatland drainage to allow mining with
heavy equipment.
Figure 1.6
Ditches are placed at intervals across
the cleared bog to facilitate drainage
of the top several feet of peat.
Usually several years are required for
drainage before mining can begin.
,;^<*L.-..,""',t3^<*<
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After the spring runoff, peat mining begins by harrowing or disking the
bog surface to a depth of several inches to promote drying of the peat. Wide-
tracked bulldozers are used widely for this and subsequent mining opera-
tions. Depending on the weather conditions, one to two weeks are required
before the loosened peat is dry enough to scrape onto stockpiles at the edges
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of the bog (see Figure 1.7). From there it is transported by wagon or truck
to a nearby processing plant. Processing peat for sale usually involves
screening, shredding, weighing, and packaging (see Figure 1.8). Bulk sale of
processed peat is common, and occasionally, unprocessed peat is sold in bulk.
Figure 1.7 Wide-tracked bulldozers are used to scrape the dried surface layer
of peat from the production fields. Next, the peat is transported
to a processing facility by wagon or truck.
Figure 1.8 Large roots and other litter are removed from the peat before it
is shredded, weighed and packaged in the processing plant. Peat
must have a fiber content of greater than 75% to be sold as
"peat."
12
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Large-scale mining operations use more sophisticated equipment which
greatly increases mining efficiency and peat production. Aspinall (1980)
thoroughly reviewed the state-of-the-art of these mining methods, including
both dry and wet techniques. Dry mining methods consisting of "milled" and
"sod" peat are the most common for production of fuel and horticultural peat
both in Europe and the United States. The most economical and efficient use
of dry mining equipment requires a minimum of 1,000-2,000 acres, whereas
hydraulic mining methods usually disturb a smaller area of the peatland.
Equipment such as vacuum collecting machines, excavator/macerators, high
pressure water monitors, and hydraulic dredges are utilized in several
different mining systems.
1.7 Potential Environmental Impacts of Peat Mining
Numerous environmental impacts are associated with peat mining in
wetlands. The majority of these impacts have been documented in the
literature (e.g., MDNR 1981) and are more fully discussed in Section 2. The
impact matrix shown in Table 1.2 summarizes the environmental impacts on the
major components of the peatland ecosystem which are associated with the
different stages of the peat mining process, i.e., clearing, draining, mining,
constructing facilities, processing, and restoration. Construction activities
may include building the processing plant, roads, parking and stockpile areas,
and utility lines. As used in this report, restoration ideally involves
returning the mined-out areas to an in-kind, productive wetland ecosystem.
This work would involve removing structures and solid wastes, regrading the
mined areas, blocking drainage ditches, and promoting revegetation by peatland
species. Figures 1.9-1.12 show the effects of mining on peatland ecosystems.
13
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ENVIRONMENTAL IMPACT
MINING STAGES
PEAT
Removal of nonrenewable resource
Subsidence
Oualitv change
Dessication/Increase fire hazard
WATER OUANTITY AND QUALITY
Increase runoff
Increase water storage
Reduce peak runoff
Reduce interception
Reduce evapotranspiration
1 over water table
* Change t;roundwater flow
Reduce snow accumulation/Accelerate snowmelt
Reduce infiltration of bare peat
Block drainage
Impair water quali tv
'.TCr.TAI ION
Eliminate vegetation
Alter species composition
Change vegetation structure
Alter or eliminate vegetative patterns
WILDLIFT.
eliminate wildlife habitat
Displace wildlife
Create wildlife barriers
* Attract waterfowl
Alter species composition
Change populat ion 1 eve Is
Alter aquatic life
X
AIR OUALI1Y
Increase fimit i ve dust
Increase exhaust emissions
NMN(,t>NSl'MI*'l I VI USK VALLT.S
Alter recreation potential
Alter aesthetic or scenic value
Alter sclentifie/educational value
Alter historical/arch.leolo^ical value
OTHFR IMPACTS
Alter surface landscape
Create noise
Increase tr;iffic
Create solid wastes
Table 1.2 Environmental effects of peat mining.
MDHR 1981)
(Adapted from
14
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Figure 1.9 Many endangered, threatened, and rare species of plants inhabit
peatlands. Clearing has a direct impact on vegetation, while
drainage may cause changes in floristic communities off-site.
Figure 1.10
The water quality of receiving waters
may be imparied by the discharge of
peatland drainage waters. Also,
poorly constructed drainage ditches
could hasten stream bank erosion and
sedimentation of benthic communities.
15
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Figure 1.11
Peatlands that are drained will not support typical wetland
species. Drier soil conditions favor the invasion of upland
plant species, thus altering species composition and diversity.
Figure 1.12 Mined peatlands may revegetate slowly, and then not with peatland
species if water table levels remain low due to continued
drainage. This loss of wildlife habitat will cause the displace-
ment of animals from the area.
16
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2. POTENTIAL ENVIRONMENTAL IMPACTS OF PEAT MINING
2.1 Water Quantity and Quality
Hydrologists generally have concentrated their studies either on areas of
water scarcity or areas of flooding and erosion. The hydrology of saturated
bogs or peatlands largely has been ignored even though in many areas bogs form
the headwaters and recharge areas for major streams.
The most extensive studies of the hydrology of peatlands to date have
been carried out in northern European countries and the USSR, as well as in
the United States in Minnesota and Michigan.
Peatlands are wet environments, so the mining of peat may affect the
quantity and quality of both surface and ground waters. The principal effects
on surface water are impacts on peak flows, the distribution of flow through-
out the year, and total annual flow. Drainage of peatlands prior to mining
may lower the local water table in an area and may, in effect, destroy a
perched water table (see Figure 2.1). The effects of peat mining on water
quality may influence pH, suspended sediment, oxygen, nitrogen, phosphorus,
and metal content. The effects of peat mining on water quantity and quality
will vary with peat type, variety of peatland, the mining method, the location
of the peatland with respect to the watershed, and the climate of the area.
For example, mining a high permeability peat from a fen using drainage ditches
during or shortly after a wet season will have a greater impact on water
quality and quantity in the area than mining a perched bog.
2.1.1 Hydrological Characterization of Peatlands
The organic soils of peatlands develop under wet conditions and, unless
they are artificially drained, they are saturated or nearly saturated at all
times. The three classes of peatland soils as recognized by the SCC (fibric,
sapric, and hemic; see Table 1.1) are well correlated to physical proper-
ties. For example, fibric peat has a total porosity of greater than 90
percent, hemic peat has a total porosity of 84-90 percent, and sapric peat has
a total porosity of less than 84 percent. Their specific yields, hydraulic
conductivities, and bulk densities also vary accordingly (see Table 2.1).
17
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Figure 2.1 The drainage of peatlands has significant effects on surface
runoff, the water table level, and water quality. A primary goal
of peatlands restoration is to maintain a saturated peat substrate
by damming these ditches after mining is completed.
Table 2.1. Physical Characteristics of Fibric, Hemic,
and Sapric Peats
Hydraulic Bulk
Degree of Total porosity Specific yield conductivity density
decomposition (percent volume) (percent volume) (10 cm/sec) (g/cm )
Fibric
Hemic
Sapric
90
84-90
84
45 150 0.09
10-45 1.2-150 0.09-0.20
10 1.2 0.20
Adapted from Verry and Boelter (1978)
13
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As can be seen from Table 2.1, all peats have a porosity in excess of 80
percent. Thus, when saturated, all peats are at least 80 percent water. When
drained, fibric peat will release greater than 45 percent of its water (Verry
and Boelter 1978). Fibric peats have a high horizontal hydraulic conductivity
and sapric peats, because of their small pore openings (greater bulk density),
have a low hydraulic conductivity. The rate of saturated water movement
through fibric peats is much faster than through sapric peats. Fibric peats
generally occur in the upper 30 cm of the soil profile, which is called the
active horizon because it is where most physical and biological processes take
place. A typical organic soil profile is given in Table 2.2, from which it
can be seen that hemic soils underly fibric soils and, in turn, are underlain
by sapric soils.
Table 2.2. A Typical Organic Soil Profile from a
Lake-Filled Perched Bog
Depth
(cm)
0-15
15-30
30-45
Fiber Bulk
Description content (%) density
Fibric peat undecomposed sphagnum
moss and leaves of heath shrubs
Fibric peat relatively undecomposed
sphagnum moss and roots of heath shrubs
Hemic peat moderately to well
90-98
70-80
40-45
0.015-0.028
0.050-0.075
0.08-0.19
decomposed sphagnum moss with wood
inclusions
45-60 Sapric peat well decomposed aggre- 15-30 0.12-0.17
gated peat with no recognizable plant
remains
60-100
100-200
200-225
225+
Hemic peat moderately decomposed 40-55
herbaceous peat from reeds and sedges
Hemic peat moderately decomposed
sedge peat
Sapric peat well decomposed peat
mixed with considerable sand
Lacustrine silt and clay
0.12-0.17
Adapted from Boelter and Verry (1977)
Because fibric peats occur at the surface of most peatlands and have high
porosities, specific yields, and hydraulic conductivities, most water movement
takes place within the zones of fibric peat. Hydraulic conductivity has been
19
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shown to decrease rapidly with depth (Goode et al. 1977), even within the
active zone of fibric peats. Water moves less readily through hemic and
sapric peats. Boelter (1972) cites water table drawdown around open ditches
in two cases in northern Minnesota, one in which the organic soil consisted of
moderately decomposed peat materials and the other of relatively undecomposed
materials. The drawdown as a result of the ditch in the undecomposed material
was much greater than that in the decomposed material over the same interval
of time.
Peatlands either are part of the regional ground water system or are
isolated from it (see Figure 2.2). Those that are not part of the regional
ground water system are either perched above it or sealed off from it by
natural barriers. Peatlands that are connected to the regional system are
called fens; those that are not are usually called bogs. Water entering fens
comes from precipitation, interflow (lateral flow from surrounding soils), and
ground water. The water in perched bogs comes only from precipitation and
interflow. Precipitation and interflow sources are seasonal with greatest
inflows resulting from spring snow melts in higher latitudes and periods of
heavy rainfall. Minerotrophic waters may be diluted by precipitation falling
directly on the peatland. They may also be diluted by ombrotrophic waters
flowing from other peatlands into minerotrophic peatland.
Whether a peatland is fed by ground water or is isolated from the
regional water table substantially affects the peatland water chemistry.
Ground water adds mineral matter to fens, which is not available to bogs, and
provides a more uniform water flow through the peatland (see Figure 2.3). An
example of mineral matter added to fens by ground water is calcium. The
calcium content of ground water commonly exceeds 30 mg/1, while that of preci-
pitation ranges from 0.3 to 2.0 mg/1 and surface and interflow from 2.0 to 10
mg/1 (Verry and Boelter 1978). Calcium reacts with carbonic acid from rain to
form calcium bicarbonate, which buffers most natural waters to yield pH values
of 6 to 8. Peatlands with circumneutral pH values contain more plant
nutrients than more acidic peatlands.
Ombrotrophic and minerotrophic peatlands generally have different water
chemistries. Ombrotrophic peatland waters are characterized by a narrow range
of pH (usually 3 to 4), a specific conductance less than 80 umhos, and a
calcium concentration less than 4 or 5 mg/1. The acidity of bog water results
from a variety of factors such as the presence of humic acids, and the
20
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I
I
I
I
I
I
I
I
I
I
I
I
1
I
I
I
I
I
I
SANDS
REGIONAL WATER TABLE
GROUND WATER FEN
[""I FIBRIC PEAT
gH HEMIC AND SAPRIC PEAT
100
200
METERS
300
14
10 ft
^
20
60
55
50
45
40
35
C 30
i M
a.
O
ANNUAL STHEAMFt
0 Ul O Ul
'ii i< . ,..t,
PERCHED
BOG
_.
)- ]
15
10
5
0
GROUND WATER FEN
-
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEPT
OCT
NOV
DEC
MONTH
Figure 2.2
Peatland isolated from the regional
ground water system (A) and fed by the
regional ground water system (B).
(Frori Boelter and Verry, 1977)
Figure 2.3
Monthly distribution of annual stream-
flow from a perched bog and a ground
vater fen, 1969. (From Boelter and
Verry, 1977)
21
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metabolic activities of bog plants, especially Sphagnum. Minerotrophic
peatland waters have higher pH values (4 to 8), a specific conductance more
than 100 umhos, and calcium concentration of more than 15 mg/1. The ratio of
organic matter to minerals in fen and bog peats has a profound effect on water
chemistry. In less organic soils the metallic cations Ca"1""*", Mg"*"1", Na+, and K+
are common, but as organic content rises, hydrogen ions increase. The
metallic cations dominate in minerotrophic peatlands, whereas hydrogen ions
dominate in ombrotrophic peatlands.
Peatlands tend to reduce the peak rates of streamflow from heavy rain-
falls and snow melts and thereby reduce the potential for flooding. Water
from these sources is stored in peatlands for short periods. However,
peatlands do not release their water to streams gradually during dry periods
and thus do not maintain a uniform source of recharge throughout the year. In
fact, they give off little water to surface drainage during dry seasons
primarily because 1) the rate of evapotranspiration in peatlands is very high
during dry periods of the year, and 2) runoff is progressively reduced as the
water table in a bog or fen falls within the active horizon.
The quantity and chemistry of water in peatlands affect the types of
vegetation found, which in turn affects the quantity and quality of water
present. The vegetation of peatlands Is discussed in detail in Section 2.2.
2.1.2 Identification and Discussion of Impacts on Water Quantity and Quality
Before peat can be mined from a wetland using the most common mining
methods, it is necessary that drainage ditches be dug and the wetland drained
so that the upper few centimeters of peat can be dried. The basic techniques
of peat mining are discussed in Section 1.6.
The major effects of the draining of peatlands are:
o A considerable increase in surface runoff over the long term. Initial
drainage of the active horiEon increases storage capacity, thus
impeding runoff. Removal of the active horizon by mining then
increases surface runoff.
o A decrease in evapotranspiration. There is less water in the peatland
to evaporate and fewer plants for transpiration.
o A considerable increase in humus content of discharged water during
the early phases of drainage, then a decrease in humus content with
time.
22
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o A possible impairment of the water quality of receiving waters,
resulting in adverse effects on downstream biotic communities.
o A possible change in water relationships of mineral soils surrounding
the drained peatland. Water from mineral soils will also be drained
along with peatland water.
o A lowering of the water table and a resulting decrease in ground water
flow into the peatland. The water table may actually be lowered below
the level of the peatland.
Surface water flow in perched bogs is easily determined by measurements
at weirs. Ground water fens are more difficult to measure because stream
gauges record only surface flow. Ground water flow must be measured by more
indirect methods. However, long-term studies of the influence of drained land
on runoff, such as that by Mustonen and Seuna (1971), indicated that artifi-
cial drainage increased annual surface runoff by 43%. Such studies have led
to the conclusion that runoff increases during the first years after drainage,
this increase being particularly marked during low runoff periods. Maximum
runoff usually increases as a result of artificial drainage (Heikurainen
1972).
The increased runoff created by artificial drainage and the concurrent
drying of the surface effectively reduces evapotranspiration in drained peat-
lands. Elimination of the peatland vegetation has the most dramatic influence
on reduction of evapotranspiration and a resultant increase in surface runoff.
A high humus content in water is considered ecologically unfavorable.
Humus carries phosphorus, the most important factor in eutrophication, which
in turn leads to oxygen-consuming biological processes. This can result in
algal "blooms" and oxygen depletion of water. Such conditions can adversely
affect aquatic macroinvertebrates and fish. An extremely high humus content,
on the other hand, can decrease solar penetration of the water which leads to
a concomitant decrease in biological processes. The humus content of runoff
from peatlands is increased dramatically during and for some time after the
installation of drainage ditches. The humus content of drained waters then
lessens gradually with time. Water discharging from old drained areas becomes
relatively "clean."
From a thorough review of the literature and experimentation, Crawford
(1978) reached a number of conclusions concerning the quality of peat bog
water. As previously mentioned, bog waters are often quite acidic. Nitrogen
and phosphorous concentrations are high in bog waters and stimulate algal
23
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growth and photosynthesis. Bog waters have been demonstrated to be toxic to
plants, animals and microorganisms. This toxicity probably results from pH
effects and a variety of aqueous humic substances. It was found that lake
water can receive at least an equal volume of bog water before the pH of the
lake water is reduced. However, this buffering capacity of the receiving
water would be site-specific. Finally, peat has a tremendous capacity to
adsorb metals and metal ions such as copper, lead, nickel, mercury and
uranium. Thus, draining peatland water into streams or lakes may result in
impaired water quality of the receiving waters from increased nutrients,
acidity, humic substances, or heavy metals.
Mineral soils that are saturated with water and surround artificially
drained peatlands may contribute water to the peatland drainage. The amount
of water contributed to peatland drainage is related directly to permeabili-
ties of the mineral soils, e.g., those with high permeabilities contribute
much water and those with low permeabilities contribute little or no water.
Studies using tree growth as an indicator of water balance in mineral soils
surrounding peatlands (Heikurainen 1972) have indicated that artificial
drainage has affected tree growth only along the border of the drained peat-
lands. No widespread effects on tree growth have been reported in mineral
soils surrounding peatlands as a direct result of artificial drainage.
The impact of peatland drainage on ground water is a lowering of the
water table, thus adding less nutrients to peatland water and decreasing
evapotranspiration. Heikurainen (1972) cites several studies which indicate
that this increase in ground water discharge as a result of artificial
drainage is extremely small. These studies indicate that peatland drainage
lowers the water table of peatlands by only 200 to 300 mm and that a lowering
of this magnitude probably has little effect on the ground water runoff. This
lowering of the water table would, however, greatly affect the vegetation in
drained peatlands by removing ground water from the roots of shallow-rooted
plants. In the case of perched bogs, the perched water table essentially can
be destroyed by artificial drainage.
2.1.3 Measures to Mitigate Impacts on Water Resources
The best overall method for mitigating the impacts of peat mining on
water resources is one that makes maximum use of natural processes. Wetlands
in a natural setting represent a very effective water purification system
-------
because the pollutants (mainly nutrients and heavy metals) are removed by non-
food phreatophyte plant species. The use of existing and man-made wetlands is
one possible way to achieve acceptable water quality at a reasonable cost
(Hazen and Beeson 1979).
Hazen and Beeson (1979) recommended the following specific techniques
used in combinations depending on site-specific conditions to achieve accept-
able water quality in drained peatlands:
o Buffer zones
o pH control
o Water flux control
o Artificially established wetlands.
A buffer zone is an area left undisturbed by peat mining. It may be left
around the periphery of and within the mined area. It is used as a natural
filter to remove suspended particulates, heavy metals and nutrients, and to
control the interchange of waters within the mined area and between it and the
surrounding land. This control insures that water will be available after
peat mining to allow the return of vegetation to the mined peatland. A buffer
zone will retain water of original quality.
Both natural and artificial methods are available for control of the pH
of waters impacted by peat mining. In all cases, natural methods, where
applicable, are preferred over artificial ones. Two natural methods of
controlling pH are by upwelling water from near-surface aquifers and by
passing water through calcareous in situ soils. Chemicals may be added to
buffer pH where natural methods are not feasible. Controlling pH is essential
to maintaining the water quality and biotic communities of receiving waters.
Vertical and horizontal movement of waters impacted by peat mining can be
controlled using materials with different permeabilities, such as hemic or
sapric peat and relatively impermeable clays. Artificial methods of
controlling water flux include the construction of cut-off walls, berms, and
dikes, and the routing of surface waters to areas underlain by less permeable
materials. Water flow into the peatland should be returned to its original
state as nearly as possible to establish the proper balance for restoration.
Artificially established wetlands such as open lakes, natural bog areas,
and man-made marshes may serve as settling ponds for suspended sediment,
25
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filtering areas for water discharged from the mined area, and attenuators of
peak flows from the mined area.
In mined areas that are to be restored to the natural state, it is essen-
tial that water quantity and quality be returned to its original state.
Damming or otherwise closing the drainage ditches around the mined area is an
important first step in the restoration process.
2.2 Vegetation
The inland peatlands of the northern United States support a variety of
plants adapted to relatively poor growing conditions, such as low nutrient
availability, a waterlogged and anaerobic substrate, and often high acidity.
In Minnesota, over 700 plant species have been recorded in peatland communi-
ties, the actual number depending on the location in the state (MDNR 1981).
Many species are unique to the peatland environment, and some have been given
special status as rare, threatened, and endangered species. In all peatlands
there is an inseparable relationship between the peatland hydrology, the water
chemistry, and the types of vegetation which develop.
The effects of clearing and draining on peatland vegetation are rela-
tively straightforward. All vegetation covering the peat deposit is destroyed
by clearing, while off-site effects may result from increased drainage and
other construction activities. Due to the close relationship between water
resources and peatland vegetation, any restoration activities aimed at
returning the mined land to a wetland ecosystem must focus primarily on
restriction of continued drainage. Other mitigative actions include careful
selection of the mine site to avoid especially unique and sensitive areas, and
protection of off-site vegetation by not interfering with the regional
drainage patterns.
2.2.1 Characterization of Peatland Vegetation
Inland peatlands typically are covered by scattered, stunted trees, a
dense layer of low ericaceous shrubs, and a ground cover of herbs, grasses,
sedges, and mosses. As previously noted, fens support a richer, more produc-
tive plant community than bogs. The peatlands of concern in this report
contain many of the same plant species, so that descriptions of dominant
vegetation from Minnesota to Pennsylvania to Maine are usually similar.
Several studies from an extensive literature base on peatland vegetation
26
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illustrate these generalizations.
Heinselman (1970) thoroughly described the vegetation and land forms of
the Lake Agassiz Peatlands Natural Area, a 70-square-raile peatland complex in
north central Minnesota. The vegetation was classified into seven types: 1)
rich swamp forest, 2) poor swamp forest, 3) cedar string bog and fen, 4) larch
string bog and fen, 5) black spruce-feathermoss forest, 6) Sphagnum - black
spruce-leatherleaf bog forest, and 7) Sphagnum - leatherleaf - Kalmia - spruce
heath. Vegetation types 1-4 were characteristic of fens, while types 5-7
generally occurred in bogs. Table 2.3 presents Heinselman's data on these
species associations in a simplified and condensed form. Only the more common
and abundant species are listed, and the significant variability between types
is not shown. However, the species richness values indicate the greater
diversity of plants found in minerotrophic peatlands. The fens contained a
total of approximately 95 species in contrast to only approximately 25 species
in the bogs. In general, the shrubs and mosses were more ubiquitous, whereas
a majority of the herbs, grasses, and sedges were confined to the fens.
Similar differences in the floristics of a perched bog and a bog
influenced by the regional ground water system in northern Minnesota were
reported by Bay (1967). The ground water bog (or fen as defined in this
report) had a greater variety and abundance of vegetation and contained some
plants found only on fertile sites. Additionally, a comparison of the black
spruce stands on both sites indicated that the fen was a good site for black
spruce production, whereas the perched bog was of poor to medium quality.
These studies reiterate the important relationships between the peatland
water chemistry, hydrotopography, vegetation types, productivity, and peat
accumulation and decay. As discussed in Section 2.1, the differences in water
chemistry between bogs and fens depends on the water sources. Also, in large
peatland complexes, the topography controls the directions and rates of water-
flow, and thus indirectly influences the sources of water. Thus, water move-
ment and water chemistry are the primary factors controlling peat accumulation
and decay, and the types of vegetative communities that develop. Heinselman
(1970) correlated the differences in fen and bog vegetation with the pH and
calcium and magnesium concentrations of the peatland water. Similarly, Vitt
and Slack (1975), using direct gradient analysis, determined that bog
community types followed gradients of pH, calcium and magnesium concentra-
tions, and light.
27
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Table 2.3. Characteristic Peatlands Vegetation Found in
Lake Agassiz Peatlands Natural Area, Minnesota
Species presence
FENS (# Species) BOGS (# Species)
Species (Veg. types 1-4)
Tree layer
Black ash (Fraxinus nigra )
White birch (Betula papyrifera)
Balsam fir (Abies balsamea)
N. white cedar (Thuja occidentalis)
Tamarack (Larix laricina)
Black spruce (Picea mariana)
Shrub layer
Willows (Salix spp. )
Swamp birch (Betula pumila)
Bog rosemary (Andromeda glaucophylla)
Velvetleaf blueberry (Vaccinium myrtilloides)
Late low blueberry (Vaccinium angustif olium)
Small cranberry (Vaccinium oxycoccus)
N. mountain cranberry (Vaccinium vitis-idaea)
Labrador tea (Ledum groenlandicum)
Leatherleaf (Chamaedaphne calyculata)
Pale laurel (Kalmia polifolia)
Field layer
Herbs
Marsh cinquefoil (Potentilla palustris)
Buckbean (Menyanthes trif oliata)
Bladderworts (Utricularia spp.)
Round-leaved sundew (Drosera rotundif olia)
Three-leaved false Solomon's seal (Smilancina trifolia)
Pitcher plant (Sarracenia purpurea)
Grasses, Sedges
Giant reed grass (Phragmites communis)
Manna grass (Glyceria sp. )
Reed grass (Calamagrostis sp.)
Common cattail (Typha latif olia)
Sedges (Car ex spp.)
Bulrush (Scirpus sp.)
Beak-rush (Rhyrichpspora sp.)
Cotton grasses (Eriophorum spp.)
Ferns, Horsetails
Marsh fern (Thelypteris palustris)
Swamp horsetail (Equisetum fluviatile)
Ground layer
Mosses, Lichens, Clubmosses
Sphagnums (Sphagnum spp.)
Hair caps (Polytrichum spp.)
Feathermoss (Pleurozium sp.)
Reindeer moss (Cladonia spp.)
(6)
X
X
X
X
X
X
(20)
X
X
X
X
X
X
X
X
X
X
(37)
X
X
X
X
X
X
(17)
X
X
X
X
X
X
X
X
(4)
X
X
(11)
X
X
X
(Veg. types 5-7)
(2)
X
X
(9)
X
X
X
X
X
X
X
X
(2)
X
X
(2)
X
X
(0)
(10)
X
X
X
X
Adapted from Heinselman (1970)
23
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The genera and species of vegetation listed in Table 2.3 are characteris-
tic of inland bogs and fens of the northern United States. Similar floristic
descriptions have been published for bogs in Michigan (Schwintzer and Williams
1974, Vitt and Slack 1975), Pennsylvania (Cameron 1970a), and Maine (Cameron
1975). In northeastern Pennsylvania red maple (Acer rubrum). hemlock (Tsupa
canadensis), white pine (Pinus strobus), rhododendron (Rhododendron maximum),
and viburnum (Viburnum sp.) are other common trees and shrubs found on peat
deposits (Cameron 1970a). This author also noted that the boundaries of peat
bogs in this area could be recognized by the habitat preference of several
species of blueberries (Vaccinium spp.). The low-bush blueberries grow on the
upland slopes, whereas the high-bush blueberries are common to the peat
deposits.
In addition to the more common plant species adapted for growth in peat-
lands, a number of less common species are known to inhabit these wetlands.
Through extensive field work conducted for the Minnesota Peat Program, plant
species seldom or never recorded in the state were discovered, and other
supposedly rare species were found to be in greater abundance. A total of
five endangered species, five threatened species, and 20 rare species of
herbs, grasses, and sedges were found in the northern peatlands of
Minnesota. Two other herb species were given an "undetermined" status, and
species of the orchid family were slated for "special concern" (MDNR 1981).
At least 18 more plant species occurring in southern Minnesota peatlands have
been given special status, also. Thus, peatlands provide valuable habitat for
the maintenance of floristic genetic diversity.
Comparison of productivity values for a variety of fresh water wetlands
indicates that bogs and fens exhibit relatively low productivity. A review of
net primary productivity (NPP) estimates (totals of above- and below-ground
NPP) showed that cattail, reed, fresh water tidal, and Carex marshes had mean
NPP values greater than the mean NPP value for bogs, fens, and muskegs
(Richardson 1978). However, the mean NPP of bogs, fens, and muskegs was
greater than that for grasslands in the United States. Table 2.4 gives NPP
values for several peatland types in the United States and Canada. Unfortu-
nately, productivity data are lacking for different peatland types, so that
direct comparison of NPP values in Table 2.4 is not warranted. Also, esti-
mates of below-ground productivity are difficult to obtain and often variable,
and losses due to leaf mortality and herbivory are seldom measured.
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Table 2.4. Peatlands Net Primary Productivity Estimates
Peatland type and
dominant species
Bog, leatherleaf
Marginal fen, leatherleaf
Muskeg, Labrador tea
Fen, leatherleaf and
swamp birch
Latitude
50°N
50°N
50°N
44°N
Location
Manitoba
Manitoba
Manitoba
Michigan
NPP (m.t.
Above-ground
3.7
10.2
3.4
3.4
ha'1 yr'1)
Below-ground
14.6
5.1
5.9
1.0
Total
18.3
15.3
9.3
4.4
Adapted from Richardson (1978)
Several factors probably are responsible for the relatively low produc-
tivity of inland peatlands, including: 1) the northern latitude of the peat-
land types, 2) low nutrient availability, and 3) waterlogging (Reader 1978).
The northern location of the bogs examined in this report results in a short
growing season and possibly a reduced soil temperature which could limit
organic matter decomposition and microbial nutrient recycling. Nitrogen,
phosphorus, and potassium are considered the primary limiting nutrients, but
the relative importance of these elements to bog vegetation may differ between
sites. Also, the availability of mineral nutrients is pH-dependent. This may
be an important factor considering the pH range found among peatland types.
Lastly, poor root aeration caused by waterlogging influences nutrient availa-
bility by impairing the ability of roots to absorb nutrients and by restric-
ting root growth to the upper peat horizons.
Peatland vegetation exhibits a number of adaptations for growing in
waterlogged, low-nutrient environments (Moore and Bellamy 1974). Some plants
have developed lacunae and large intercellular spaces to aid in the transfer
of oxygen to the rhizomes and roots. The diffusion of oxygen from the roots
into the surrounding medium, thus creating a locally aerobic root environment,
has been documented. Metabolic adaptations for the tolerance of waterlogged
conditions have been shown in which flood-tolerant species prevent the toxic
buildup of ethanol that can result from incomplete glycolysis under anaerobic
conditions.
Moore and Bellamy (1974) outlined three adaptive mechanisms regarding
nutrient deficiency in peatland species: 1) nutrient accumulation and conser-
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I
I
I
I
I
I
I
1
I
I
I
I
1
I
I
I
I
I
I
vation, 2) nitrogen fixation, and 3) a carnivorous habit. Bryophyte species,
especially Sphagnum spp.. have high cation exchange capacities, and thus have
the ability to readily absorb available mineral nutrients. Other bog plants
are capable of concentrating essential nutrients, mobilizing these reserves at
times of increased need, and then returning these nutrients to a perennating
organ for storage. Another alternative for overcoming nitrogen deficiency is
through symbiotic nitrogen fixation. This process occurs in the root nodules
of peatland species such as sweetgale (Myrica gale) and alders (Alnus spp.).
Additionally, certain plants have evolved specialized trapping mechanisms to
capture animals as a nutrient source. The pitcher plant (Sarracenia purpurea)
and sundews (Drosera spp.) are examples of carnivorous plants found in
northern inland bogs.
Finally, Small (1972) postulated that the high occurrence of evergreen-
leaved plants in nutrient-poor environments, such as peat bogs, may exhibit a
decreased need for nitrogen and phosphorus. This hypothesis was based on the
finding that certain evergreen bog species apparently manufacture more photo-
synthate per acquired unit of nitrogen or phosphorus than do deciduous-leaved
bog plants primarily because of the increased longevity of evergreen leaves.
2.2.2 Identification and Discussion of Impacts on Peatland Vegetation
The most apparent impact on peatland vegetation occurs during the early
stages of the peat mining process. Clearing and draining of peat bogs and
fens have dramatic and long-lasting effects on the peatland vegetation, which
primarily include:
o Elimination of vegetation
o Alteration of species composition
o Alteration of vegetation structure
o Alteration or elimination of vegetation patterns.
Obviously, the clearing operation destroys all of the vegetation as
bulldozers scrape the bog surface clean. Usually the ground layer of mosses
and herbs as well as the first few inches of peat are removed, thus elimi-
nating most of the plant root systems. Many rare and endangered species would
be eliminated along with unique vegetation patterns (e.g., raised bog,
patterned fen) which occur only in peatlands. Because of their small size,
isolated bogs, like those in northeastern Pennsylvania, would be especially
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susceptible to the complete elimination of vegetation that is distinctly
different from the vegetation of the adjacent uplands.
The direct impact on vegetation has secondary impacts on wildlife, water
resources, and air quality. The clearing procedure may eliminate wildlife
habitat, thus displacing the various wildlife species dependent on them (see
Section 2.3.2). Generally, runoff is increased by clearing because intercep-
tion of precipitation and transpiration are reduced. This runoff may increase
the potential for flooding downstream, increase peatland erosion, and affect
the water quality of receiving waterbodies (see Section 2.1.2). Air quality
may be affected by fugitive dust from the exposed peat and emissions from
equipment (see Section 2.4.2).
More subtle impacts on vegetation result from drainage activities.
Drainage upsets the balance between both on-site and off-site water resources
and peatland vegetation. Numerous studies have documented the effects of
increased or blocked drainage on peatland vegetation. In northern Minnesota
extensive ditching was undertaken in the early 1900's in an attempt to reclaim
the peatlands for agricultural use. This effort was largely unsuccessful
because of poor planning and design; however, the effects of this drainage are
still evident. Also, the impacts of fire and the damming effects of roadways
are visible on aerial photographs (Hagen and Meyer 1979).
The large minerotrophie fens have been affected most downslope from the
ditches. The drier conditions downslope caused by the ground water flow
interruption have resulted in a significant invasion by shrubs and exotic
species not usually characteristic of peatland vegetation. The vegetation of
ombrotrophic bogs has not been as noticeably impacted by drainage ditches and
roadways (MDNR 1981). The species composition has not been altered as
severely, and smaller areas have been affected.
Since true bogs are not influenced by the regional ground water system,
less impact would be expected from distrubed ground water flow. However, bog
vegetation that was not destroyed during the clearing process would be greatly
affected by a reduced water table level because of their dependence on a
saturated substrate. Thus, vegetation growing on peat deposits of insuffi-
cient depth to mine, nevertheless may be severely impacted by increased
drainage of the mined portion of the bog. Peatland species would be replaced
by upland plant species more tolerant of drier soil conditions.
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Boelter and Close (1974) discussed the impact of blocked drainage on
timber species. Large natural gas and petroleum pipelines that cross forested
wetlands often impede the natural water flow thereby causing upslope
flooding. This flooding eventually may reduce tree growth or even kill the
trees. However, such damage can be prevented by constructing cross ditches
under the pipelines to permit normal drainage. Similarly, Jeglum (1975)
described the considerable vegetation changes caused by the damming effect of
a roadway across a peatland valley. Over a 30-year period the species compo-
sition and vegetation structure were altered significantly in the upslope
peatland. Downslope from the road little change occurred in the forested bog,
except that tree growth probably increased because of the drier conditions.
On the upslope side the water level gradually increased, the trees died, and
the treed bog was replaced by an open bog wih a floating Sphagnum mat, low
shrubs, and sedges.
2.2.3 Measures to Mitigate Impacts on Vegetation
As outlined above, peat mining activities can produce significant and
immediate impacts on the natural vegetation of peatlands. After completion of
the mining activities, the long-term effects on off-site communities may
persist. Likewise, the mined-out area may remain severely impacted. A
variety of reclamation alternatives are practiced on mined-out peat bogs.
Depending on a variety of factors, such as the thickness of the peat left
unmined, the type of mineral soil underlying the bog, the nutrient status of
the soil, and the climate of the area, abandoned mine sites are commonly used
for silviculture and agriculture. Timber species (e.g., black spruce and
lowland hardwoods), vegetable and grain crops (e.g., celery, carrots,
potatoes, wild rice), cranberries, blueberries, and various sod grasses are
grown on peat fields. Additionally, energy crops such as cattails, reeds,
sedges, alders, and willows, can be raised for conversion into gas or liquid
fuels. To obtain the most productive results, all of these reclamation
options require some degree of management primarily water level control and
fertilization.
In view of the many values attributed to wetland ecosystems, a particu-
larly attractive option is restoration of the mined-out area to a productive
in-kind wetland ecosystem. However, many factors must be considered prior to,
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during, and after the mining operation. Natural succession will not neces-
sarily result in a vegetative community typical to inland peatlands. Drier
soil conditions caused by continued drainage of a peatland will favor the
establishment of upland plant species (see Figure 2.4). Also, simply allowing
water to collect in the mined-out area may not be the most effective method
for wetland restoration, although the maintenance of sufficient water is
always of primary concern. Thus, a variety of measures to mitigate adverse
impacts on vegetation must be undertaken throughout the entire mining process.
Figure 2.4 These abandoned agricultural fields in northern Minnesota show
little resemblance to the original peatland. Drainage and
fertilization has encouraged the establishment of quack grass over
many acres.
First, the proper selection of a potential peat mining site is essen-
tial. A thorough scientific survey should be made of the peat deposit and
adjacent community types. This survey should inventory the peat resource
(e.g., areal extent, peat type and quality, peat thickness, geological sub-
strata); determine drainage patterns and water sources; and document the flora
and fauna, especially rare and specialized species. Small peatlands which
contain rare, threatened, and/or endangered species of plants and animals
should not be exploited further. In larger peatland complexes, highly sensi-
tive areas containing unique species must be avoided and protected from both
the direct and indirect impacts of clearing, draining, and filling. Such a
survey will provide a rational basis for all aspects of mining and restoration
activities.
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Second, several practices should be followed during the mining phases.
Generally, the mining should be restricted to the core area of the bog or fen,
i.e., only that portion where the peat is uniformly thick. This implies that
drainage systems should be constructed so that only the core area will be
affected to the greatest degree. In large peatlands initial drainage should
be restricted to the downslope portion of the watershed. As discussed in
Section 2.2.2, blocking or diverting the near-surface ground water flow with
drainage ditches or roadways affects peatland vegetation both upslope and
downslope. Such widespread impacts could be minimized by beginning the mining
activities in the downslope portion of the watershed. If development
continues further into the peatland, then the drainage water from upslope may
be contained within the mined portion of the peatland to initiate wetland
regeneration. In all cases the water level must be maintained in those areas
not intended to be mined. The genetic diversity of the peatland must be
preserved by leaving undisturbed areas of natural vegetation around the
margins and throughout the actively mined area. The vegetation cleared from
the site should not be burned but should be stockpiled for later use.
Processing buildings, roads, stockpile areas, and other facilities should be
constructed on the adjacent uplands whenever possible. Construction of roads
or utility lines that traverse wetland areas should contain provisions for
adequate cross-drainage to avoid affecting the water balance of the wetlands
downslope.
Finally, the post-mining restoration involves several critical activities
to insure that a wetland ecosystem is regenerated as rapidly as possible.
Theoretically, two types of wetland systems can be restored a peatland (bog
or fen) with a minimum of open water, or a shallow lake surrounded by wet-
lands. For both of these options the most important restoration activities
are 1) controlling the water level in the mined area, and 2) maintaining
revegetative stock by leaving some of the original vegetation undistrubed and
selectively planting certain species. In reality, a combination of these
wetland types probably would be the easiest to accomplish, depending on
factors such as the degree of ground water inflow, size and topography of the
mined area, and the type of substrate underlying the peatland. These restora-
tion schemes will be outlined, and supported by findings reported in the
literature and observations made by JRB personnel during site investigations
in Pennsylvania and Minnesota.
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The basins left by mining very small lake-fill bogs and fens could be
allowed to fill with water after the drainage system has been dammed or
completely filled in. Similar deep depressions may occur in larger peatlands
where only the thickest peat deposits are rained, and these could be flooded to
form lakes. In either case, shallow water margins should be established to
encourage emergent vegetation by regrading the sides of the basins before the
drainage ditches have been closed (see Figure 2.5). It is likely that such
lakes would support fish and other aquatic life, and attract waterfowl and
furbearers. Factors controlling the water quality in these lakes would be
site-specific and should be determined prior to restoration.
Figure 2.5 This recently abandoned peat mine site in northern Minnesota has
revegetated naturally with emergent wetland species. Habitat
diversification should be established in such areas by creating
scattered islands and an uneven topography throughout the area to
be flooded.
Several investigations of small lakes created from mined peatlands have
been conducted in Minnesota as part of the state's Peat Program (MDNR 1981).
In 1978, at the Wilderness Valley Farms (WVF) Peat Research Station, two one-
acre ponds were excavated in peat fields formerly used for vegetable crops.
Both ponds were perfectly square with steep banks that dropped abruptly into
the water. One pond was excavated to the underlying mineral soil (6 feet
deep), whereas a foot of peat was left on the bottom of the other pond.
Although the peat fields were drained, the ponds naturally filled with
water. The water quality, hydrologic budget, and plant and animal communities
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were monitored. Two other ponds near Floodwood, Minnesota that had resulted
from a peat mining operation during the 1950's, were investigated for the same
information.
Similar results were obtained at both sites. The water quality in both
excavated ponds was found to be good (pH generally greater than 7, and
dissolved oxygen concentrations adequate for fish life). Very little emergent
aquatic vegetation has colonized the WVF ponds, except for a small patch of
sedges growing on a portion of the bank that slumped into the pond. More
emergent growth (cattails and sedges) was found at the Floodwood ponds, but
most of the shoreline lacks aquatic vegetation (observations by JRB
personnel). At both sites the steep vertical walls apparently have prevented
typical shoreline revegetation. This finding supports the recommendation to
create shallow water margins around mined-out areas for optimal revegeta-
tion. The construction of irregular shorelines that provide cover and nesting
sites for waterfowl is recommended also.
Wetlands restoration can lead to a more diversified habitat especially in
large mined areas. A layer of peat (1-2 feet thick) should be left covering
the mineral subsoil to act as a substrate for plant growth. The relatively
flat topography created by dry mining methods should be graded to re-establish
an uneven peat surface. The discarded vegetation from the clearing operation
and the screenings from the peat processing plant (mostly roots and chunks of
peat) should be redistributed as small islands throughout the area to be
flooded. These measures will increase the spatial diversity of an otherwise
flat topography and provide a variety of habitats for animals and vegeta-
tion. Then, the drainage ditches should be plugged and the remaining peat
substrate allowed to become saturated, as in the pre-mined peatlands. As
previously mentioned, low-lying areas (either naturally occurring or excavated
basins) will form shallow lakes interspersed with artifical islands. The
higher, but saturated peat substrate will provide the proper environmental
conditions for natural revegetation by peatland species.
To create a totally diversified wetland ecosystem, it may be necessary to
plant perennial species rather than to rely solely on the natural invasion of
pioneer annual species. Shallow water areas would enhance the establishment
of emergent aquatic vegetation, while submergent plants would colonize the
deeper areas. Lofton (1979) suggested introducing locally adapted submergent
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aquatics such as water-weed (Elodea). tapegrass (Vallisneria). water nymph
(Najas). and pondweed (Potamogeton) to supply oxygen, food, and cover for
aquatic animals. The author also recommended that the scattered islands be
planted with a variety of locally adapted grasses if drainage permits, e.g.,
redtop (Agrostis). bluejoint grass (Calamagrostis), reed grass (Phragmites),
manna grass (Glyceria), canary grass (Phalaris). wild oats (Danthonia), and
wild rice (Zizania). Shrubs such as alder (Alnus), willow (Salix). and autumn
olive (Eleaegnus umbellata) could be planted in rows between stands of taller
trees to increase the diversity of the area and to supply food and cover.
Mined-over peatlands have been found to revegetate naturally with varying
degrees of success. Rogers and Bellamy (1972) reported that a large peatland
in England, which has been disturbed over 95% of its surface area by peat
mining operations, contains areas where revegetation has occurred naturally.
Local naturalists studying the mined areas reported the existence of a rich
flora including many of the same species that originally inhabited the peat-
land. According to Cameron (1975) peat exploitation for the past 75 years has
had little impact on the vegetation of several raised bogs in eastern Maine.
Since only the sphagnum moss peat of raised domes was removed and shallow
ditching did not change the regional ground water table, the remaining bog
vegetation regenerated new peat.
Another abandoned mine site near Cromwell, Minnesota also has revegetated
naturally to different degrees of cover. Twenty-five years after the mining,
three of the fields are conspicuously void of vegetation (less than 50% cover)
(see Figure 2.6), whereas the fourth field has revegetated to 100% cover (see
Figure 2.7) (MDNR 1981). This successful area contains typical bog vegetation
(e.g., Sphagnum, low shrubs, sedges) and a small body of open water. As part
of revegetation experiments with several grass species on the bare fields, a
Minnesota Peat Program study measured several physical properties (surface
temperature, water level, water content, redox potential, pH, bulk density,
and peat depth and type) in an attempt to explain the differences between the
vegetated and unvegetated fields. Of these factors, it was determined that a
lack of water was limiting revegetation. Thus, these results indicate the
importance of maintaining saturated soil conditions to promote revegetation by
peatland species.
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Figure 2.6 Tests were conducted on this sparsely revegetated (50% ground
cover) abandoned mine site to determine the factors controlling
revegetation. A lack of water is apparently limiting the invasion
of peatland species.
Figure 2.7 Where a saturated peat substrate is maintained a peatland
community can be re-established. Complete ground cover occurred
naturally in this abandoned mine site over the past 25 years.
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2.3 Wildlife Utilization
Wildlife utilization of northern inland peatlands varies considerably.
Of the small to moderate number of species of mammals, birds, reptiles, and
amphibians that use peatlands as sources of food, cover, and breeding habitat,
only a few species are restricted to peatlands for their existence. Many
other species utilize uplands and other types of lowland communities more
extensively than peatlands. However, in view of the lack of extensive
research on peatland habitat utilization by wildlife, the importance of peat-
land ecosystems to a variety of species should not be underestimated.
The Minnesota Peat Program funded a series of studies to provide baseline
data on wildlife utilization of northern Minnesota peatlands. The major
conclusions that were derived from this research are listed below (MDNR
1981). In general, these findings may be applied to other peatlands in the
northern United States.
o Peatlands that are located in areas that are under intensive land use
pressure become especially significant to wildlife.
o Peatland habitats play crucial roles in the survival of certain wild-
life species that are specially adapted to the peatland environment
and are restricted to these habitats.
o Certain peatland habitats may not be used much of the time but provide
crucial habitat to certain wildlife species during certain time
periods.
o Many species with relatively flexible habitat requirements may be
minimally affected by the elimination of specific peatland sites.
However, the continued elimination of these habitats could lead to a
significant reduction or extirpation of local populations.
Peat mining activities primarily affect wildlife through the elimination
and alteration of their habitats, thereby causing the displacement of wild-
life. Restoration to a wetland ecosystem would provide a renewed habitat, but
the species composition of the area could be considerably different than that
of the original peatland fauna. For example, the creation of a shallow lake
where none had previously existed would attract waterfowl, beavers, and other
animals characteristic of this habitat type.
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2.3.1 Characterization of Peatland Fauna
Peatlands of the northern United States are characterized by a relatively
poor herpetofauna. Karns and Regal (1979) found only twelve species of amphi-
bians and reptiles in several Minnesota peatlands five frog species, one
toad species, and two species each of snakes and turtles. However, a large
number of individuals of each species was reported. These species were mainly
generalists, i.e., not restricted to peatlands and found in a wide range of
habitats. The wood frog (Rana sylvatica) and the American toad (Bufo
americanus) were the dominant species.
Although a decrease in the diversity of herpetofauna is expected at
higher latitudes, the peatlands studied appeared to contain especially low
numbers of animals. Most of the species avoided the sphagnum-dominated semi-
raised to raised bog sites. Several factors were suggested as limiting condi-
tions to the herpetofauna, including inequitable water distribution,
differences in food resources, high overwintering mortality in water-saturated
substrates, and bog water toxicity to embryos and larvae.
Streams and lakes in peatlands support a variety of aquatic macroinverte-
brates such as flatworms, leeches, oligochaetes, fingernail clams, snails,
daphnia, mayflies, caddisflies, riffle beetles, and chironomid midges. Fish
species such as yellow perch, northern pike, walleye, bass, and black bullhead
are commonly found in northern peatland lakes.
The avian fauna tend to be relatively diverse depending on the peatland
type. Lofton (1979) listed over 90 species of birds that utilize peatland
habitats for cover, nesting, and sources of food. Songbirds, loons, grebes,
shorebirds, waterfowl, gamebirds, owls, and hawks are among the major bird
groups represented in peatlands. Research for the Minnesota Peat Program by
Warner and Wells (MDNR 1981) determined that 72 bird species occupied four
generalized peatland habitat types during the breeding season. The least
number of species (4) was found in the open bog, whereas 32 species were found
in the cedar-spruce swamp. The species richness and population density was
generally lower in peatland habitats than in adjacent uplands. However,
little overlap in species composition occurred between bird communities in
peatlands and upland forests.
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The Minnesota research revealed several significant associations between
peatlands and birds (MDNR 1981). First, peatlands supply food for many bird
species during two periods of very high energy demand: 1) the molting period,
and 2) the period of fat deposition prior to fall migration. Second, peat-
lands provide a critical habitat for some rare and threatened species. In
Minnesota these species include the greater sandhill crane, short-eared owl,
great gray owl, yellow rail, and sharp-tailed sparrow. Lastly, some bird
species reach their maximum population densities in peatlands.
Numerous large and small mammals utilize peatlands to various degrees.
Twenty species of small mammals (e.g., mice, shrews, squirrels, lemmings) were
found in ten peatland habitats in Minnesota (MDNR 1981). Generally, these
small mammals have broad habitat requirements, and most are not dependent on
peatland habitats (with the exception of the northern bog lemming).
Typical large mammal species utilizing Minnesota peatlands include the
moose, white-tailed deer, coyote, timber wolf, cougar, Canada lynx, fisher,
beaver, muskrat, mink, otter, raccoon, snowshoe hare, and striped skunk. Many
of these species, along with the black bear, are found in peatlands in the
northeastern United States also. The majority of these large mammals utilize
both upland and wetland habitats and thus are not restricted to peatlands.
However, wildlife research in Minnesota and Pennsylvania has revealed some
important relationships between certain species and peatland habitat utiliza-
tion.
Pietz and Tester (1979) used radiotelemetry to study habitat use and
selection by snowshoe hare and white-tailed deer in Minnesota. The hares were
found to avoid open habitats at all times and to prefer dense tall shrub cover
(>1 m). Thus, most of the tagged individuals utilized conifer bogs, alder
fens, or jack pine-alder edge. Other researchers have noted that all forested
and bushy habitat types are utilized when hares are abundant, but that peat-
land habitat types provide essential refuges for hares during periods of low
population densities. While the white-tailed deer generally utilized upland
habitats, they selected alder fen, black spruce bog, and edge habitats in
peatlands. In their review of the literature, Pietz and Tester (1979) found
evidence that small, scattered wetlands are more valuable than large wetland
complexes for does with fawns. Cedar swamps, or cedar with balsam fir, black
spruce, or tamarack are used as overwintering yards by deer which depend on
the protection and high food quality of white cedar browse (MDNR 1981).
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In Pennsylvania, black bears show a strong preference for swamp and bog
habitats (Gary Alt, Pennsylvania Game Commission, personal communication).
Alt has found that although swamps and bogs comprise only 7% of the land area
in Pennsylvania, approximately 70% of his radiolocations of black bears are
found in these wetland habitats. The swamps and bogs provide food, cover, and
den sites. Alt also noted that snowshoe hares are found only in the peat bogs
of northeastern Pennsylvania.
2.3.2 Identification and Discussion of Impacts on Peatland Fauna
Peatlands provide certain wildlife species with food, cover, protection
from inclement weather, and reproductive habitat. Few animals are restricted
solely to the use of peatland habitats, but the important part these wetlands
play in ecosystem stability is clearly evident. The main aspects of peat
mining that affect vegetation most significantly (i.e., clearing and draining)
obviously produce the greatest impact on wildlife. The following impacts on
wildlife from peat mining can be anticipated:
o Loss of habitat leading to the displacement of wildlife species
o Elimination of relatively slow-moving species
o Creation of barriers to some species
o Changes in species composition and population levels.
The effects of peat mining on wildlife species include both apparent,
relatively immediate impacts, as well as long-term, subtle changes not readily
apparent to the casual observer. The elimination of bog vegetation obviously
has an immediate effect on any species which may have inhabited the peat-
land. Habitat destruction will force those animals to move into other wetland
or upland habitats. Animals such as the snowshoe hare that prefer dense shrub
cover and avoid all open spaces would be especially affected. Species depen-
dent on the peatland habitat could suffer local extirpation due to habitat
loss. The clearing operation also could destroy relatively slow-moving
animals such as reptiles, amphibians, and small mammals. Drainage ditches and
roadways may act as barriers to the movement of certain species.
Wildlife in the vicinity of cleared bogs may be affected in subtle ways
by the overall increase in human activity associated with peat mining. The
loss of isolation brought about by peatland development could create changes
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in the reproductive patterns of nesting, mating, or rearing young. Similarly,
predator-prey relations could be adversely impacted because of habitat altera-
tion or the removal of selective species. Gradual off-site changes in wild-
life community structure could result from the alteration of vegetation by
disturbed drainage patterns in large peatland complexes. Drainage ditches or
the creation of shallow lakes from mined-out bogs will attract waterfowl,
beavers, and other animals closely associated with open water areas. Thus,
species composition and diversity and population levels eventually could
become quite different from the original peatland fauna.
2.3.3 Measures to Mitigate Impacts on Peatland Fauna
Many of the mitigative practices suggested for vegetation (see Section
2.2.3) would indirectly benefit wildlife and need not be repeated here (see
Figure 2.8). It is difficult to predict exactly what effects the restoration
Figure 2.8 Mined-out peatlands should be restored to diverse wetland habitats
to enhance the development of diverse wildlife associations. A
maximum amount of edge should be created by establishing irregular
shorelines and shallow water margins for the growth of emergent
vegetation.
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of a wetland system will have on wildlife species. Regarding rare and
specialized animals with very specific habitat needs, it may be impractical or
impossible to establish conditions for their reintroduction. Otherwise,
control of water levels, natural revegetation and selected planting, and
habitat diversification should enhance the development of variegated wildlife
associations.
The positive correlation between spatial heterogeneity and species rich-
ness has been demonstrated for wetland birds. Weller (1978) reviewed several
research studies that showed the importance of habitat interspersion (i.e.,
cover-water edge) and structural complexity. Bird species richness was found
to increase with the number of water openings to an optimal level of 50 to 60
percent open water in stands of emergent vegetation, and increased layers of
vegetation (e.g., trees at the edge of wetlands) appearred to increase the
number of bird species in a community. These findings support the suggestion
of creating scattered islands throughout a shallow lake left by peat removal,
thereby promoting a high diversity of emergent vegetation, shrubs, and trees.
As with vegetation, rare and endangered wildlife species, which could be
identified in a pre-mining survey of the peatland, should be protected. Bog
development should not be allowed in sites that provide habitat for these
unique species. Similarly, in areas where other land use pressures are
increasing, e.g., for agricultural development, peatlands may provide valuable
escape cover for wildlife. These refuge sites should be preserved to enhance
the spatial diversity of highly developed areas.
2.4 Air Quality
It is difficult to assess the potential for significant impacts on air
quality from small-scale horticultural mining operations. The geographic
location of the peatland will be a primary factor in determining what Federal
and State air quality standards must be met. Other factors such as the
regional climatology of the area, the areal extent of the mining operation,
the physical characteristics of the peat dust, and the mining techniques used
will determine the magnitude of air quality impacts.
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2.4.1 Potential Impacts on Air Quality and Mitigative Practices
The primary environmental impacts on air quality from horticultural peat
mining include the production of fugitive dust and exhaust gas emissions from
machinery. Once the peat surface has been loosened and dried during the first
stages of mining, disturbance by the wind or the movement of machinery will
create peat dust. Strong winds may carry suspended peat particles for many
miles downwind. Peat dust also is generated at processing plants where the
peat is shredded, screened, and bagged. This dust is usually confined within
the plant. Uncovered stockpiles of raw or processed peat also could be
subject to wind erosion.
Heavy equipment is used during all phases of the mining process to clear
the bog of vegetation, dig drainage ditches, and mine and transport the
peat. The construction of processing and storage facilities requires the use
of heavy equipment and increases vehicular traffic. Restoration activities
also will use heavy machinery to contour the land, fill ditches, and construct
dams and islands. Exhaust emissions from machinery and other vehicles will be
the only other source of air pollutants from horticultural peat mining.
Several practices can be followed to reduce wind erosion of the peat
surface. Conklin (1978) recommended roughening the land surface and estab-
lishing wind barriers at intervals to reduce field widths along the prevailing
wind direction. Increasing the surface roughness of the peat field by 2 to 5
inches (e.g., by using a large disk harrow) sufficiently lowers the wind
energy to reduce peat entrainment. Windbreaks placed broadside to the pre-
vailing wind decrease the surface-wind shear stress and trap moving
particles. A porous windbreak (e.g., several rows of trees) is more effective
over a larger area than a solid windbreak of the same height (e.g., snow
fencing or chicken wire covred with vines) (Conklin 1978). Strips of
undisturbed bog vegetation between production fields probably would serve as
effective windbreaks. In very small bogs surrounded by forested uplands, such
as those in northeastern Pennsylvania, wind erosion probably is not of major
concern.
Wet mining methods using dredges or draglines would keep fugitive dust
emissions at a minimum during mining. However, stockpiling and processing
still may create dust. Stockpiles could be compacted and covered with sheets
of polyethylene film to control erosion.
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The restoration of a mined area to a wetland ecosystem would minimize
long-term wind erosion problems. Raising the water level and resaturating the
remaining peat would produce minimal wind erosion. Drier areas should be
roughened and revegetated as soon as possible.
2.5 Nonconsumptive Use Values
Peatlands are valuable not only for the peat resources they contain, but
also because of their particular nonconsumptive human use values. Numerous
specific nonconsumptive uses of peatlands could be listed, but in general,
they include aesthetic, recreational, and scientific uses not involving the
extraction and consumption of peat. For the most part, these uses necessitate
intact preservation of the peatland ecosystem. However, regulated mining
followed by certain restoration activities would have a minimal impact on some
of these uses.
2.5.1 Characterization of Nonconsumptive Use Values
The ecological uniqueness of peatlands forms the basis for much of their
nonconsumptive value. As described in this report, inland peatlands form
under a peculiar geological, climatological, and hydrological regime. Several
thousand years were required to develop our current peat resources. Although
geologically young, peat is considered a nonrenewable resource when viewed
anthropocentrically. A bog that has been cleared and drained will no longer
produce peat nor support the same types of vegetation and animal communities.
In comparison with other wetland ecosystems, peatlands may not be as
valuable in several respects. First, primary productivity is relatively low,
mainly because of poor nutrient availability and a short growing season.
Second, only a small number of animal species are restricted to the peatland
environment, and habitat utilization by wildlife is generally limited.
Finally, the hydrological values often ascribed to wetlands (i.e., ground
water recharge, flood control, and water purification) have minimal applica-
bility to certain types of peatlands.
In other respects, peatlands offer many special nonconsumptive values.
The scenic beauty and uniqueness of bogs and fens is aesthetically pleasing to
the appreciative observer. Recreational activities such as hunting, trapping,
photography, hiking, and observation of nature are important, but they may be
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limited by the inaccessibility of some peatlands. Peatlands provide natural
laboratories for teaching ecological principles and natural history. Many
specialized plants and some animals (including rare, threatened, and
endangered species) have adapted in various ways to life in this rather harsh
environment. These specialized organisms contribute significantly to the
genetic pool (see Figure 2.9). Scientific research opportunities abound for
enhanced understanding of peatland evolution, the delicate balance between
hydrology and vegetation, nutrient cycling dynamics, and organismal adapta-
tions, to mention but a few. Peatlands serve as vegetational history books
for the biogeographer by preserving the pollen records over thousands of
Figure 2.9
A large variety of specialized plant species have adapted to
growth under rather harsh conditions in peatlands. Pitcher plant
(Sarracenia purpurea) is a characteristic carnivorous plant of
bogs and fens.
years. Additionally, peatlands have potential archaeological and historical
value. Well-preserved remains of early man have been discovered at several
sites in Europe and the United States.
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2.5.2 Potential Impacts on Nonconsumptive Use Values and Mitlgative Practices
Peat mining inevitably will have adverse impacts on most nonconsumptive
uses. Clearing, draining, and mining operations destroy vegetation, displace
wildlife, disrupt peat profiles, and usually result in a community with
entirely different plant and animal associations (see Sections 2.1 - 2.3).
Even after careful restoration to an in-kind wetland ecosystem, it would take
hundreds of years for a completely destroyed bog to regenerate into something
resembling the original peatland.
Some nonconsumptive uses may be compromised, but not destroyed, by peat
mining. For example, the recreational potential of a restored wetland eco-
system possibly could be greater than for the original peatland (i.e.,
hunting, fishing, trapping, canoeing, and nature observation could improve).
Likewise, opportunities for peatlands research still could exist (e.g., inves-
tigation of factors controlling revegetation). However, it is difficult to
make predictions about the success of revegetation/restoration efforts (see
Section 2.2.3).
Preservation of unique peatlands is the ultimate mitigative action. As
part of the Minnesota Peat Program, a Task Force on Peatlands of Special
Interest was established to evaluate and make recommendations concerning the
ecologically significant peatlands in the State. The Task Force recommended
22 peatlands for special protection because of significant wildlife habitat
and the occurrence of rare plant species and unique peatland types (MDNR
1981). Additionally, two types of management zones were recommended: the
Watershed Protection Zone (WPZ) and the Core Protection Zone (CPZ). The WPZ
acts as a buffer to insure the ecological integrity of the core zone. Various
protective measures are taken within each zone (e.g., prohibitions against
ditching or excavating). This type of management plan possibly could be
applied to smaller inland peatlands throughout the northern United States.
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3. CONCLUSIONS AND RECOMMENDATIONS
This report summarizes many aspects of peat and peat mining based on the
scientific literature, interviews with key persons knowledgeable of peat
mining activities, and personal observations of active and abandoned peat
mines. The hydrology, water chemistry, vegetation, wildlife, air quality, and
nonconsumptive use values of peatlands are characterized in order to better
understand the ecological significance and value of inland bogs and fens. The
variety of environmental impacts associated with peat mining are identified,
along with some important practices for mitigation during mining and for
restoration of mined-out peatlands. From an evaluation of this pertinent
information several major conclusions concerning the environmental signifi-
cance of horticultural peat mining operations are emphasized in this
section. Also, a number of recommendations are given which outline best
management practices (BMPs) for the mitigation of potential adverse effects of
peat mining and peatlands restoration.
3.1 Major Findings of Peat Mining Assessment
o Peat mining from inland bogs and fens can be expected to increase for
some years to come, thus increasing the pressure for development of
these wetland ecosystems.
Peat is a valuable natural resource for horticultural and agricultural
purposes, and the demand for this resource increases each year. Other uses of
peat, e.g., as an alternative energy source and for the extraction of indus-
trial chemicals, are in the development stages in the United States, but pose
an increased demand on U.S. peat reserves. Reclamation of mined peatlands for
agriculture and forestry puts additional pressure on these valuable wetland
habitats.
o Peat is a nonrenewable resource.
Once the peat has been removed from a bog or fen, hundreds or even
thousands of years may be required for a similar deposit to form, provided
that environmental conditions remain conducive to the regeneration of peatland
vegetation. Mined peat gradually loses its integrity when utilized in horti-
culture and agriculture as drier and aerobic soil conditions hasten peat
decomposition. The drainage of peatlands induces peat decomposition, and if
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mining is not conducted within several years the peat quality may be so
reduced as to render mining uneconomical for horticultural and agricultural
purposes.
o Peatlands are unique and valuable wetland habitats.
As characterized in this report, peatlands have evolved under special
environmental conditions and exhibit unique relationships between hydrology,
water chemistry, and vegetation. The following major values are ascribed to
peatlands in general:
- Attenuate peak flows, and thus reduce the potential for flooding
because of flat topography and limited water storage capacity.
- Purify water by filtration of suspended sediments and absorption
of nutrients and heavy metals.
- Critical to the survival of numerous plant and certain animals
species restricted to peatland habitats.
- Some large peatland complexes in the United States contain geo-
morphic features (landforms) found nowhere else in the world.
- Provide habitat diversity in upland areas where other land uses
preclude wildlife utilization.
- Provide crucial wildlife habitat during certain seasons and
certain time periods in the life cycle.
- Small, scattered wetlands more valuable than large wetland
complexes for some wildlife species (e.g., deer and bear).
- Numerous nonconsumptive values, such as aesthetic, recreational,
educational, and scientific uses not involving the extraction and
consumption of peat.
o Current dry peat mining methods for the production of horticultural
and agricultural peat severely impact peatland ecosystems.
In the broadest sense, the wetland values of small inland bogs and fens
(e.g., those found in northeastern Pennsylvania) can be completely destroyed
by peat mining (see Figure 3.1). Large peatland complexes (as in northern
Minnesota) may have small sections destroyed, as well as significant wide-
spread alterations in ecosystem structure. More specifically, the adverse
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Figure 3.1 All wetland vegetation may be destroyed when inland peatlands are
mined. Buffer zones of undisturbed vegetation should be left
around the margins of small bogs and fens as a source of seeds and
revegetative stock.
effects of peat mining are identified in Section 2; but the major impacts
should be reiterated:
- Reduction in evapotranspiration and interception of
precipitation.
- Increase in surface runoff, thus increasing the potential for
flooding downstream.
- Reduction in water table level, or destruction of perched water
table.
Decrease in ground water flow into adjacent peatlands, thus
limiting the water supply to shallow rooted plants.
- Impair water quality by increasing suspended sediments (decreases
light penetration), color, hydrogen ion concentration (lower pH),
nutrients (nitrogen and phosphorous), and heavy metals.
- Eliminate vegetation (including endangered, threatened, and rare
species).
- Alter species composition and vegetative patterns in adjacent
peatlands.
- Eliminate wildlife habitat, thus displacing animals.
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- Alter animal density, species composition, and diversity.
- Impair air quality by emissions of fugitive dust and equipment
exhaust.
- Alter or eliminate recreational, aesthetic, scientific, and
educational values.
- Beneficial impacts: recreational and biological benefits of
properly restored peatland may be greater than the original
peatland (i.e., Increased habitat diversity may support greater
fish and wildlife populations).
o Certain BMPs can be followed during the mining activities to mitigate
adverse impacts on the peatland ecosystem.
Although the ultimate mitigative action is complete preservation of
especially unique peatlands, a number of mitigative techniques can be used in
peatlands where mining is permitted. Certain impacts are unavoidable with dry
peat mining methods (e.g., destruction of vegetation and lowering of the water
table). However, proper management during each phase of raining can reduce
adverse effects and aid in the restoration process. A variety of BMPs are
recommended in Section 3.2.
o Mined-out peatlands can be restored to productive wetland ecosystems
if particular BMPs are followed.
It has been found that some mined peatlands have naturally revegetated
with typical peatland species, whereas others have been invaded by upland
plant species or even lack complete ground cover after many years. For
successful wetlands restoration the water level must be controlled to achieve
a saturated or inundated substrate, and a seed or vegetative stock of wetland
species must be maintained on site. These essential conditions can be
attained through a variety of BMPs as listed in Section 3.2.
3.2 Best Management Practices and Administrative Recommendations
The following best management practices are recommended during the mining
and restoration activities:
o Proper site selection:
Conduct pre-mining survey of peatland being considered for
mining. In general, determine areal extent and depth of
deposit, type and quality of peat, hydrological characteristics
of peatland, water quality, flora and fauna (especially
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endangered, threatened, or rare species), adjacent land uses,
proximity to other wetlands, and percent of total system to be
mined.
- Avoid biologically sensitive areas; peatlands that support
endangered, threatened, and/or rare species of fauna and flora
should be preserved.
- Avoid areas where other land use pressures are increasing;
peatlands that provide critical wildlife habitat (as in highly
developed agricultural areas) should be preserved.
Peatland complexes that contain unique geomorphic features and
representative peatland types should be kept in an unaltered
condition.
o Limited mining is acceptable in some peatlands, provided that the
factors outlined above are evaluated on a site-specific basis.
o In general, mining in preselected portions of large peatlands is
environmentally preferable to the total mining-out of small systems.
For example, if wetland values are comparable between two different
sized peatlands, restricted mining in the larger system would not have
as great an impact as complete destruction of the smaller system,
provided that restoration culminates in a diversified wetland habitat.
o Restrict drainage to portion of peatland to be mined. In large peat-
land complexes mining should be restricted to downslope portions of
the watershed to avoid widespread drainage impacts.
o Restrict mining to core areas of peatlands where peat deposits are
uniformly thick.
o Construct buildings, roads, stockpile areas, and utility lines on
adjacent uplands whenever possible.
- Roads and utility lines across peatlands should have adequate
cross-drainage provisions.
o Stockpile cleared vegetation for use as wildlife cover and seed source
when redistributed as small islands throughout the rained-out area.
o Prohibit the discharge of poor quality (e.g., low pH, high turbidity)
drainage water into receiving streams or lakes, unless properly
treated by the following methods:
- Buffer zones of undisturbed peat should be left to act as natural
filters to remove suspended particulates and dissolved nutrients.
- Artificially established wetlands could be used to remove
suspended particulates and nutrients.
- pH should be controlled by mixing drainage water with minero-
trophic upwelling water from near surface aquifers; by passing
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drainage water through calcareous in situ soils; or by treatment
with chemicals.
- Water flux should be controlled with dikes of impermeable peat or
clay and by selectively routing surface runoff to areas underlain
by impermeable substrate.
o Leave strips of undisturbed vegetation within the mined area and
around the periphery of the bog or fen. These strips serve several
purposes:
- buffer zones for water quality control,
- source of seed and vegetative stock for revegetation,
- wind barriers to prevent erosion, and
- cover for movement of wildlife across mined areas.
o Restoration should encourage regeneration of wetland ecosystems by
maintaining appropriate water levels. For example, re-establish
saturated peat substrate or create shallow lake for growth of wetland
vegetation. The following activities are recommended:
- Leave a surface layer of peat (1-2 feet thick) as a substrate for
revegetation.
- Regrade surface to uneven contours to increase spatial diversity
of mined area.
- Construct scattered islands throughout area from the cleared
vegetation and the screenings from the processing plant to
increase habitat diversity.
- Create shallow water margins around mined area to encourage
growth of emergent vegetation.
- Selective planting of locally adapted wetland species may be
beneficial as opposed to natural revegetation. This is site- or
case-specific.
- Block drainage ditches to maintain a saturated peat substrate;
create lakes by flooding depressions.
- Restore water circulation patterns in fens.
o Monitor environmental factors during mining and restoration activities
to assure adherence to BMPs and other specified permit conditions.
For example, examine water quality, water table level, ground water
flow, wildlife utilization, impacts on vegetation and air quality.
Administrative recommendations for the CWA Section 404 permit program for
peat mining operations are as follows:
o Notify all peat mine operators whose activities require individual
Section 404 permits to apply for permits for all existing and any
proposed mining operations.
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Provide all known and prospective peat mine operators with either a
copy of this report, or an appropriate non-technical summary of the
findings contained in this report.
Evaluate each permit application carefully to assure that mining in
sensitive areas is avoided and that 404(b)(l) criteria are met.
At existing operations, permits should be evaluated to assure impacts
on adjacent sensitive areas are limited by applying best management
practices.
All permits issued at existing operations should be evaluated on a
case-by-case basis to assure BMPs for mining and a site-specific
restoration plan are specified as a condition of permit issuance.
Evaluation should determine the extent to which expansion of work at
the site is feasible.
On-site meetings between peat mine operators requiring permits and the
permit/review agency officials should be held. These meetings will
maximize the understanding of any site-specific considerations and
constraints, and will provide an opportunity for face-to-face
discussion and clarification of BMPs and restoration requirements.
This approach will serve to promote understanding and better working
relationships among the governmental officials and the peat mine
operators alike.
In communications with peat mine operators requiring permits, EPA
should stress the importance of avoiding sensitive systems in any
future mining operations. EPA, the Fish and Wildlife Service (FWS),
and the Corps of Engineers (COE) should offer assistance to mine
operators in the early identification of sensitive systems to avoid,
and also help the operators to locate areas where mining may be
acceptable. Also, assistance should be provided to miners early in
the planning process to help develop environmentally acceptable peat
mining plans.
Establish a demonstration project(s) for intensive environmental
monitoring during mining and restoration. Examine utility of BMPs,
nature of environmental impacts, and factors controlling revegetation.
Limit any large-scale peatland alteration until certain data gaps have
been filled more completely. Additional site-specific and general
information needs include:
- Extent of wildlife utilization of small inland bogs and fens.
- Hydrological characteristics of large peatland complexes.
- Complete lists of endangered, threatened, and rare plants and
animals supported by inland bogs and fens.
- Factors controlling primary productivity and wildlife utiliza-
tion.
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- Extent to which bogs and fens accumulate heavy metals.
- Extent to which peatland drainage waters (with low pH and high
levels of humic substances, nitrogen, and phosphorous) affect
receiving water quality and downstream biota.
o Representatives of the COE, EPA, FWS, and State should meet to discuss
the peat mining issue and agree upon regulatory direction.
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4. REFERENCES
4.1 Literature References
Aspinall, F. 1980. Peat harvesting state of the art. Presented at
Peat as an Energy Alternative Symposium, (IGT), Arlington, VA,
December 1-3, 1980.
Bay, R.R. 1967. Ground water and vegetation in two peat bogs in
northern Minnesota. Ecology 48(2):308-310.
Boelter, D.H. 1972. Water table drawdown around and open ditch in
organic soils. J. Hydrology 15:329-340.
Boelter, D.H. and G.E. Close. 1974. Pipelines in forested wetlands:
Cross drainage needed to prevent timber damage. J. Forestry
72:561-563.
Boelter, D.H. and E.S. Verry. 1977. Peatland and Water in the Northern
Lake States. USDA Forest Service, General Technical Report NC-31.
Cameron, C. 1970a. Peat Deposits of Northeastern Pennsylvania. U.S.
Geological Survey Bulletin 1317-A, Washington, D.C.
Cameron, C. 1970b. Peat Deposits of Southeastern New York. U.S.
Geological Survey Bulletin 1317-B, Washington, D.C.
Cameron, C. 1975. Some Peat Deposits in Washington and Southeastern
Aroostook Counties, Maine. U.S. Geological Survey Bulletin 1317-C,
Washington, D.C.
Conlkin, M.H. 1978. The Potential Air Quality Impacts of Harvesting
Peat in Northern Minnesota. Environmental Research and Technology,
Inc. Document P-4107. Prepared for the Minnesota Department of
Natural Resources.
Crawford, R.L. 1978. Effects of Peat Utilization on Water Quality in
Minnesota. Minnesota Department of Natural Resources. 18pp.
Farnham, R. 1964. Peat Resources of Minnesota, Report of Inventory
No. 1, West Central Lakes Bog, St. Louis Co., Minnesota. Iron Range
Resources and Rehabilitation Commission, State of Minnesota. 20 pp.
Farnham R. and D. Grubich. 1970. Peat Resources of Minnesota,
Potentiality Report, Fens Bog Area, St. Louis Co., Minnesota. Iron
Range Resources and Rehabilitation Commission, State of Minnesota.
17 pp.
Goode, D., A. Marsan and J.-R. Michaud. 1977. Water Resources. In:
N.W. Radforth and C.O. Bawner (eds.). Muskeg and the Northern
Environment in Canada. Univ. Toronto Press, Toronto, Canada.
pp. 299-231.
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Hagen, R. and M. Meyer. 1979. Vegetation Analysis of the Red Lake
Peatlands by Remote Sensing Methods, Final Report. Minnesota
Department of Natural Resources. 56 pp.
Hazen, C. and R. Beeson. 1979. Techniques for the assessment of bog
hydrology Harvesting and mitigation of water quality impacts
resulting from peat harvesting. Presented at Conference on
Management Assessment of Peat as an Energy Resource, Arlington, VA,
July 22-24, 1979.
Heikurainen, L. 1972. Hydrological changes caused by forest drainage.
Hydrology of Marsh-Ridden Areas. Int'l. Assoc. of Hydrol. Sci.,
Study Report, pp. 493-499.
Heinselman, M. 1970. Landscape evolution, peatland types, and the
environment in the Lake Agassiz Peatlands Natural Area, Minnesota.
Ecological Monographs 40:235-261.
Jeglum, J. 1975. Vegetation-habitat changes caused by damming a
peatland drainage way in northern Ontario. Canadian Field-
Naturalist 89(4):400-412.
Karns, D. and P. Regal. 1979. The Relationship of Amphibians and
Reptiles to Peatland Habitats in Minnesota. Minn. Dept. Nat. Res.
84 pp.
Lofton, M. 1979. Peat: Ecologically sound resource development.
Presented at Conference on Management Assessment of Peat as an
Energy Resource, Arlington, VA, July 22-24, 1979.
Minnesota Department of Natural Resources (MDNR). 1978. Minnesota Peat
Program Peat Information Flyer and Minnesota Peatlands Map.
MDNR, St. Paul, Minnesota.
Minnesota Department of Natural Resources (MDNR). 1979. Sphagnum Moss
Peat Deposits in Minnesota. MDNR Peat Inventory Project, Hibbing,
MN. 44 pp.
Minnesota Department of Natural Resources (MDNR). 1981. Minnesota Peat
Program Draft Final Report. MDNR Division of Minerals. 237 pp.
Moore, P. and D. Bellamy. 1974. Peatlands. Springer-Verlag New York,
Inc., New York. 221 pp.
Mustonen, S and P. Seuna. 1972. Influence of forest drainage on the
hydrology of an open bog in Finland. Hydrology of Marsh-Ridden
Areas. Int'l. Assoc. of Hydrol. Sci., Study Report, pp. 519-530.
Pietz, P. and J. Tester. 1979. Utilization of Minnesota Peatland
Habitats by Snowshoe Hare, White-tailed Deer, Spruce Grouse, and
Ruffed Grouse. Minnesota Department of Natural Resources. 80 pp.
Reader, R. 1978. Primary production in northern bog marshes. In: R.E.
Good, D.G. Whigham and R.L. Simpson (eds.). Freshwater Wetlands:
Ecological Processes and Management Potential, pp. 53-62.
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Richardson, C. 1978. Primary productivity values in freshwater
wetlands. In: P.E. Greeson, J.R. Clark and J.E. Clark (eds.).
Wetland Functions and Values: The State of Our Understanding.
Proceedings of the National Symposium on Wetlands, Lake Buena Vista,
Florida, Nov. 7-10, 1978. American Water Resources Association.
pp. 131-145.
Rogers, S. and D. Bellamy. 1972. Peat exploitation and conservation
a case history. Fourth International Peat Congress 3:219-232.
Schwintzer, C. and G. Williams. 1974. Vegetation changes in a small
Michigan bog from 1917 to 1972. American Midland Naturalist
92(2):447-459.
Small, E. 1972. Ecological significance of four critical elements in
plants of raised sphagnum peat bogs. Ecology 53(3):498-503.
Stewart, J. and R. Reader. 1972. Some considerations of production:
Accumulation dynamics in organic terrain. Fourth International Peat
Congress 3:247-258.
U.S. Bureau of Mines. 1980. Minerals Yearbook 1978-79, Vol. I, Metals
and Minerals. Washington, D.C.
Verry, E. and D. Boelter. 1978. Peatland hydrology. In: P.E. Greeson,
J.R. Clark and J.E. Clark (eds.). Wetland Functions and Values:
The State of Our Understanding. Proceedings of the National
Symposium on Wetlands, Lake Buena Vista, Florida, Nov. 7-10, 1978.
American Water Resources Association, pp. 389-402.
Vitt, D. and N. Slack. 1975. An analysis of the vegetation of Sphagnum-
dominated kettle-hole bogs in relation to environmental gradients.
Canadian J. Botany 53:332-359.
Waller, M. 1978. Wetland habitats. In: P.E. Greeson, J.R. Clark and
J.E. Clark (eds.). Wetland Functions and Values: The State of Our
Understanding. Proceedings of the National Symposium on Wetlands,
Lake Buena Vista, Florida, Nov. 7-10, 1978. American Water
Resources Association, pp. 210-234.
4.2 Individuals/Agencies
o Gary Alt
Wildlife Biologist
Pennsylvania Game Commission
(717) 842-6333
o Dennis Asmussen
Manager, Minnesota Peat Program
Minnesota Department of Natural Resources
Centennial Office Building
St. Paul, Minnesota 55155
(612) 296-4807
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John Clausen,
Hydrologist, College of Forestry
University of Minnesota
110 Green Hall
St. Paul, Minnesota 55108
(612) 373-0825
Altay Ertugral
Director, Environmental Services
Williams Brothers Engineering Company
Tulsa, Oklahoma 74177
(918) 496-5020
Rouse Farnham
Professor of Soil Science
University of Minnesota
St. Paul, Minnesota 55105
(612) 373-1447
Ed Garbisch
Environmental Concern
P. 0. Box P
St. Michaels, Maryland 21663
(301) 745-9620
Don Grubich
Research Supervisor
IRRRB
P. 0. Box 678
Eveleth, Minnesota 55734
(218) 744-2993
Bill Hudak
Dravo Engineers and Constructors
Pittsburgh, Pennsylvania 15222
(412) 566-3000
Elon Verry
USDA Peatland Hydrology Project Officer
North Central Forest Experiment Station
St. Paul, Minnesota
(218) 326-8571
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
Contract Report - Not numberled
3. RECIPIENT'S ACCESSION"NO.
4. TITLE AND SUBTITLE
PEAT MINING - An Initial Assessment of Wetland
Impacts and Measures to Mitigate Adverse Effects
5. REPORT DATE
July 28. 1981-Date of Issue
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
John M. Carpenter
George T. Farmer
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
JRB Associates
8400 Westpark Dr.
McLean, Virginia 22102
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-6087
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
401 M St., SW
Washington, DC 20460
13. TYPE OF REPORT AND PERIOD COVERED
Initial Report~2/81 thru 7/81
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Sponsored in cooperation with EPA Region III, Philadelphia, PA - contact John Pomponio
16. ABSTRACT
Small-scale dry peat mining operations are having a significant environmental impact
on inland bogs and fens in certain regions of the northern United States. Peat is a
valuable nonrenewable resource for horticultural and agricultural purposes, and the
demand for this resource increases each year. Current dry mining methods can destroy
the wetland values of small bogs and fens. In larger peatland complexes small areas
may be destroyed, and widespread alterations in ecosystem structure and function may
occur.
This report characterizes the hydrology, water chemistry, vegetation, wildlife utili-
zation, air quality, and nonconsumptive use values of inland bogs and fens to better
understand the ecological significance and value of these wetlands. Numerous environ-
mental impacts are associated with the various stages of peat mining. These potential
impacts are identified and best management practices are recommended for the mitiga-
tion of adverse effects resulting from mining activities. Restoration practices for t
regeneration of an in-kind wetland ecosystem are recommended also. Some impacts from
mining can be controlled or eliminated, and productive wetland habitats can be created
from mined-out peatlands if best management practices are followed.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
-Peat
-Mining
-Peat Dining
-Wetlands
-Best Management Practices
13. DISTRIBUTION STATEMENT
Release unlimited
Available to public at request
19. SECURITY CLASS (This Report)
21. NO. OF PAGES
82
20. SECURITY CLASS (This page)
22. PRICE
EPA Form 2220-1 (9-73)
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EPA Form 2220-1 (9-73) (Reverse)
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