United States	Environmental Research	November 1994
Environmental Protection Laboratory - Corvallis
<& EPA Wetlands Research Update
Prepared by:
Richard Sumner, Regional Liaison - Wetlands Research Program
Mary E. Kentula, Manager- Wetlands Research Program
The Update is prepared to keep those who are interested in the
U.S. Environmental Protection Agency's Wetlands Research Program (WRP)
abreast of our activities and accomplishments.
Strategic Research Goals		
The WRP is in the third year of implementing
research towards the development of a risk-based
approach to wetlands protection (Leibowitz et al.
1992a). The specific research objectives of WRP are:
(1) determine how wetlands contribute to envi-
ronmental quality, both individually and as
an aggregate within the landscape;
(2)	quantify the effects of stressors and landscape
factors on wetlands function to assess the
risks posed by the associated loss and degra-
dation of wetlands;
(3)	develop risk management options through
the use of site prioritization and performance
criteria for wetlands restoration;
(4)	design and test a monitoring system that can
assess wetlands function and condition, and
the effectiveness of risk reduction activities
(i.e., adaptive management); and
(5)	evaluate relationships between the design and
operation of constructed wetlands and water
quality improvement.
Landscape Function
The implementation of a risk-based approach to
wetlands protection requires information on the
interaction of wetlands with other ecosystems
within broad geographic areas, such as ecoregions
and watersheds. Empirical analysis and overlay
analysis (i.e., Geographic Information System -
GIS) are two approaches being evaluated by
WRP for use in landscape-scale assessments.
For example, the WRP continues its evaluation
of empirical approaches in studies of prairie

Wetlands Research Update  Page Two
pothole wetlands of North Dakota. The study is
being conducted in collaboration with EPA's
Environmental Monitoring and Assessment
Program (EMAP).
Newly proposed study will evaluate envi-
ronmental indicators for describing the
condition of wetlands within the prairie
pothole region of North Dakota.
The WRP has funded an agreement with the
National Biological Survey's Northern
Prairie Laboratory to characterize the condi-
tion and landscape function of prairie pothole
wetlands. The study will employ the use of
a probability-based sampling design to
determine both the wetland and landscape
characteristics that influence the abundance
and distribution of various bird populations
in the prairie pothole region. A major goal of
the study is to substantiate various relation-
ships between land use practices, wetland
condition, and the functional capacity of
wetlands. A principal objective is to evaluate
and compare the advantages and limitations
of remote imagery and field measurements
for producing regional estimates of ecologi-
cal condition. The proposed study will
consist of two years of field work, plus a
third year for analysis and the production of
reports and articles.
Also, WRP will begin reporting in 1995 the results
of a study conducted in Delaware in cooperation
with the U.S. Geological Survey (USGS). The
study examines how a hydrogeomorphic-based
landscape classification system might be used to
differentiate the capacity of wetlands within
different landscape units to perform a water
quality improvement function. Analysis will rely
upon the results from USGS's Delmarva National
Water Quality Assessment (NAWQA) study.
New field data also are being collected to test
hypothesized correlations between landscape,
hydrogeologic and water quality characteristics,
and wetlands function.
Watersheds or other landscape units also can be
prioritized for ecosystem protection and restora-
tion activities through a GIS-based approach.
A clear understanding of the landscape factors
responsible for the formation and maintenance of
wetlands is a prerequisite to this type of analysis.
Preliminary results from a synoptic assess-
ment of the Tensas River Basin are being
used to develop criteria for selecting areas
suitable for wetlands restoration.
The USDA Soil Conservation Service (SCS),
in cooperation with WRP, is, completing an
assessment of the Tensas River Basin of
Louisiana using a synoptic approach to
cumulative impact assessment (Leibowitz
et al. 1992b). One aspect of the study is the
development of a conceptual model for
combining indices of landscape attributes
pertinent to wetlands restoration. Mappable
landscape indicators are identified for each
index. Using GIS overlay analysis each
index acts as a filter layer that collectively
focuses on areas with higher potentials
for wetlands restoration, where the pre-
determined goal is water quality improvement
and floodwater storage. The actual concep-
tual model being evaluated for the Tensas
Basin depicts wetlands restoration potential
as a product of:
(1)	land use conversion,
(2)	wetland soils,
(3)	landscape morphology,
(4)	hydrologic transport systems (e.g.,
ditches), and
(5)	geographic areas that significantly
contribute to nonpoint source pollution.
A final project report is anticipated in the fall
of 1994.
Results from the Tensas Project have encouraged
the WRP to initiate a new study within the State
of Arkansas also using the "Synoptic Approach."
The project will take place in the White River
Basin. We will continue to evaluate the Synoptic
Approach as a method for identifying areas
ecologically suitable for wetlands restoration.

Wetlands Research Update  Page Three
Restoration Project		
The WRP has commissioned several studies
designed to demonstrate and refine WRP's
"An Approach to Improving Decision Making in
Wetlands Restoration and Creation" (Kentula
et al. 1992). The work will culminate in a series
of new publications discussing methods for:
(1)	characterizing populations of wetlands to
establish their reference condition,
(2)	analyzing the information gathered to pro-
duce monitoring protocols for establishing
wetlands protection goals (e.g., state water
quality standards) and/or performance goals
for wetlands restoration projects, and
(3)	prioritizing areas ecologically suitable for
riparian restoration.
For example, the WRP is continuing its work on
the Oregon Wetland Study (OWS). The study
entails the characterization and comparative
analysis of a sample of approximately 100 natural,
created, and restored freshwater wetlands located
in the Portland Metropolitan Area of Oregon
(Magee et al. 1993).
Preliminary findings suggest soil organic
matter accumulates slowly in freshwater
wetlands mitigation projects.
The amount of soil organic matter in wetland
soils plays a critical role in the wetland
functions of nutrient cycling and pollutant
detoxification, provides substrate for essen-
tial microbes, and influences the development
of wetlands vegetation. During 1993, over
2000 soil samples were collected from 48
naturally-occurring wetlands and 49 mitiga-
tion projects within the Portland Metropolitan
Area. Preliminary data analyses show that
. soils from mitigation projects have signifi-
cantly lower soil organic matter content than
soils from natural wetlands, in both surface
(0-5 cm) and subsurface (15-20 cm) horizons.
A subset (n=10) of the projects had been
sampled in 1987 as part of a pilot study.
A comparison of 1987 and 1993 data shows
that soil organic matter content in the surface
soil increased very slowly (ca. 0.2% a year)
during the 6-year period, and did not
increase at all at some locations.
Study results suggest that it may take dec-
ades for soil organic matter to accumulate in
mitigation projects to levels comparable with
those in similar, naturally-occurring wetlands.
Additional studies are needed to evaluate
(1) how soils low in organic matter affect
wetland function and (2) whether the
amount of organic matter at project sites can
be increased through properly timed soils
augmentation and nutrient applications.
Further analysis of data from the OWS soil
studies, and associated hydrological monitoring,
likely will provide important new information for
the development of site selection and design
guidelines for wetland projects.
The WRP intends to use its research findings from
Oregon to begin the preparation of a wetlands
monitoring manual. The manual, as currently
envisioned, will serve as a template for multiple
applications, including the establishment of
wetlands protection criteria and performance
criteria for restoration projects. The manual will
reflect OWS results as well as information gath-
ered from several other WRP-supported projects
being completed around the country. One such
study is located within the Puget Sound Area of
Washington. Researchers from the University of
Washington are examining how information
gathered at reference wetland sites within the
Puget Sound area can be used to advance the
design and monitoring of wetland mitigation
banks. Somewhat similar work also is being
implemented by the University of Massachusetts
at Amherst for selected watersheds within the
Connecticut River Basin. Their study examines
the relationship between the amount of impervi-
ous surfaces within urban areas and its effect
upon the aquatic life associated with wetlands.
Feasibility studies also have been recently initi-
ated for the monitoring of vernal pool wetlands in
California and riparian wetlands in the Southeast-
em Plains of North Carolina and South Carolina.

Wetlands Research Update  Page Four
The projects are being conducted by Chico State
University and Eastern Carolina University,
respectively. Finally, a companion study is being
funded in Ohio by EPA's Regional Office in
Chicago. It will examine the use of various
vegetation indices as tools for establishing wet-
lands reference condition.
Four more WRP-sponsored studies designed to
help restoration planning are either finished or
will be completed within the next year. The
overall objective of the studies is the development
of methods for prioritizing the environmental
suitability of sites (i.e. stream reaches) for riparian
The selection of stream reaches environ-
mentally suitable for riparian wetlands
restoration can proceed under a hierarchical
format using an established set of environ-
mental indicators.
The University of California, Berkeley and
the Kansas Biological Survey recently sub-
mitted reports to WRP describing the results
of their studies within the San Luis Rey
Watershed of California, and the Upper
Delaware Watershed of Kansas, respectively.
Field results from the San Luis Rey water-
shed study were used to generate a set of
decision variables or indicators for screening
stream reaches as sites environmentally
suitable for restoration. In successive order
of importance, from greatest to least, the
indicators are: geomorphic setting, propor-
tion of natural vegetation, proportion of land
use in the area, upland land use bordering
the floodplain and degree of fragmentation
in natural vegetation.
Landscape-level and site specific factors that
affect the success of riparian restoration
projects were examined in the Upper Dela-
ware Watershed. Techniques using GIS were
applied to spatially match areas of aquatic
pollution with existing and potential riparian
sites. The process leads to a prioritization of
restoration areas based upon the opportunity
for risk reduction as well as potential for
project success. Specific factors that might be
used to predict the performance of restora-
tion projects are:
(1)	type of land use change within historic
riparian ecosystems (e.g., 30 meters
lateral to stream channel),
(2)	low to moderate soil permeability,
(3)	moderate to high groundwater conditions,
(4)	soils with high organic content, and
(5)	broader-scale land use history.
Companion studies aire being conducted by Utah
State University within the Upper Arkansas Basin
of Colorado and also within the San Luis Rey
River Watershed of California. These studies are
exploring different field and remote imagery
approaches for identifying stream reaches suitable
for riparian wetlands restoration. Publications
from these research efforts are scheduled for 1995.
Wetlands Function Project...
Information on relationships between stressors
and the degradation of wetland functions is
needed for a risk-based approach to wetlands
protection. New research sponsored by the
Project is finding appropriate environmental
indicators for characterizing the condition and
function of wetlands along a gradient of environ-
mental disturbance. Study results should prove
useful to states interested in developing wetlands
management strategies and the biological criteria
needed to protect the aquatic life use of wetlands
(Detenbeck, In press). One major study currently
underway explores the role of environmental
buffers surrounding prairie pothole wetlands.
Preliminary results from research reveal
that climatic variability, and associated
water level fluctuation, should be considered
when designing environmental buffers to
protect prairie pothole wetlands from

Wetlands Research Update  Page Five
Twenty seasonal wetlands with a range of
upland agricultural practices are being mon-
itored within the Missouri Coteau Ecoregion
of North Dakota. Five of the wetlands
represent the control setting of native prairie.
Fifteen additional wetlands are influenced by
a range of different farm practices (i.e., five
wetlands enrolled in USDA's Conservation
Reserve Program, five wetlands with five
meter buffers, and five wetlands with tillage
to the wetlands edge). Sedimentation rates
are being monitored in each wetland, along
with measures of water quality, primary
productivity, macro-invertebrate popula-
tions, and waterfowl use. Field observations
already have revealed that some wetland
buffers are under-designed and may not
effectively reduce ecological risks associated
with sedimentation. The buffers were
designated during a time of drought, and
provide reduced filtration capacity (i.e, less
buffer width) during the current period of
normal rainfall.
The information being gathered through
wetlands monitoring in North Dakota will be
used to develop and confirm relationships
between wetland buffers and wetland condi-
tion. Sedimentation and food chain models
also are being developed as a means to
extrapolate study results across the Ecoregion.
Ancillary work is being conducted to exam-
ine the exposure and effects of pesticide use
on wetlands within the Ecoregion.
The Wetlands Function Project also is supporting
research that looks at the effects of urbanization on
wetlands. Specific studies have been commissioned
to explore how stormwater affects the function and
condition of wetlands within urban landscapes.
Water level fluctuation provides a good
indication of wetlands condition within
urbanizing areas.
Scientists from the University of Washington
recently completed studies evaluating how
the effects of urbanization influence wetland
amphibians and vegetation. With respect to
amphibians, they found decreased species
richness at wetlands located within heavily
urbanized watersheds. The association
could be due to a variety of factors, including
water level fluctuation, which is highly
correlated to urbanization. Conversely, low
velocity flows and low fluctuation are corre-
lated with high species richness. Wetland
size, number of vegetation classes, and
seasonal persistence of water were unrelated
to species richness.
Greenhouse experiments with vegetation
revealed that certain species of sedges are
resilient to cycles of flooding and drying, but
that resilience decreases (e.g., decreased
biomass) when exposed to sediment deposits
and high water levels. Observations in the
field also have shown that episodic flooding
and sediment transport generated in urban
landscapes will kill mature trees within
wetlands. To protect plant communities, the
tolerance limits of individual species should
not be exceeded at the most sensitive time in
their life cycles.
In addition, the WRP has initiated several new
studies designed specifically to support the
development by the states of biological criteria for
wetlands. One study is being conducted in
conjunction with the National Biological Survey
to evaluate the condition of Great Lakes coastal
wetlands. Researchers already have characterized
a population of minimally disturbed "reference
wetlands" along the south shore of Lake Superior.
Information gathered at the reference sites
currently is being used to evaluate the condition
of other wetlands sites in Lake Superior and
comparable sites in die other Great Lakes.
Finally, the WRP has funded new research to
develop indices of biotic integrity (IBI) for South-
eastern bottomland hardwood forests. The
project was proposed by Louisiana State Univer-
sity in conjunction with Gemson University.
Researchers hope to compile and analyze data
collected over the past 20 years from wetlands
sites in Louisiana and South Carolina. Results
from the analysis are expected to produce IBIs
that are initially based upon a broad spectrum of
ecosystem functional attributes, and later simpli-
fied for ease of application.

Wetlands Research Update  Page Six
Constructed Wetlands Project
The Project continues work on evaluating the per-
formance of constructed wetlands built primarily
for the purpose of treating domestic wastewater.
Work is progressing in four areas.
A wetlands treatment database has been completed
using-dBase IV software. The database is a
collection of existing information from all wet-
lands in North America known to be treating
wastewater, except for agricultural and acid mine
drainage systems. The database offers a reference
to engineers interested in estimating the perform-
ance of wetland treatment systems. The title of
the software is "North American Wetlands for
Water Quality Treatment Database." Copies can
be obtained by calling Dr. Don Brown, of EPA's
Risk Reduction Engineering Laboratory, at
A study of pilot scale subsurface flow wetlands
is being completed at Tennessee Technological
University. Results from the study were pre-
sented by Dr. Dennis B. George at the October
1994 Water Environmental Federation meetings in
Chicago. Preliminary results confirm that sub-
surface flow wetlands effectively reduce BOD and
suspended solids from waste streams. However,
the systems can be less effective at nutrient re-
moval, depending upon design. Improper design
and flow rates also can lead to the plugging of
rock media pores.
A study to evaluate the performance of on-site
(individual home) subsurface flow wetlands is
underway by the Arkansas Environmental
Academy. The study will monitor seven on-site
systems for a variety of water quality parameters.
Monitoring began in August 1994 and will con-
tinue into 1995.
The fourth project, recommended by WRP for
funding in 1994, will look at the performance of
subsurface flow wetlands systems in cold climate
regions. The study is being proposed by the
Friends of Fort George, a nonprofit group located
in Niagara-on-the-Lake, Ontario, Canada. The
group intends to study the effectiveness of the
wetlands systems for removing nutrients from the
discharge of existing treatment lagoons. The
wetland systems were built as an alternative to
the construction of a larger treatment facility that
would have encroached upon a valued historic
and environmentally sensitive area.
Technical Information Transfer Activities
Over the last year, the WRP contributed resources
and expertise to the following activities per-
formed in collaboration with the EPA Regional
Offices and several of the states.
	Distributed a Permit Tracking System
(Holland and Kentula 1991) to states inter-
ested in compiling wetland restoration
information from permit/project files.
Results generated from the "PTS" can be used
to set geographic priorities and goals for
future projects.
	Contributed to the development of the
Oregon Freshwater Wetlands Assessment
Methodology (Roth et al. 1994). The Oregon
Division of State Lands based the Oregon
Method, in part, on information gleaned from
the "Method for the Comparative Evaluation
of Nontidal Wetlands in New Hampshire"
(Ammann and Stone, 1991). The Oregon
Method also borrows from the ecological
principles associated with WRP's risk-based
approach to wetlands protection and a
hydrogeomorphic classification for wetlands
(Brinson, 1993).
Initiation of a new project designed to
promote broader geographical use of the
"Avian Richness Evaluation Method -
'AREM'" (Adamus 1993). AREM consists of

Wetlands Research Update  Page Seven
a series of wildlife habitat relationship models
covering a number of bird species. The pro-
cedure estimates the number of species likely
to occur regularly in a particular wetland, and
uses this information to assign importance to
the site. AREM was originally developed for
use with riparian and wetland ecosystems of
western Colorado. The new project will be
conducted in the Willamette Valley of Oregon.
Our objective is to develop a procedure that
allows resource managers to "regionalize"
AREM for their area of the country.
 Initiation of a study on the development of
environmental indicators for wetlands
evaluation. The University of Massachusetts
at Amherst is conducting the study in coop-
eration with EPA Region 1 (Boston). Expected
outputs from the study are:
(1)	an "example" state wetland assessment
methodology that can be used as a
template by states wanting to develop
their own standard methodology, and
(2)	a list of indicators of wetland function
within urban landscapes that can be
integrated into state wetland assessment
methodologies. Products are scheduled
for completion during 1994.
Personnel Notes		
The WRP program welcomes Mr. Gerald
Schuytema and Dr. Alan Nebeker. Both Jerry and
A1 join the wetlands program after serving with
EPA's Wildlife Toxicology Research Program.
They bring to the Wetlands Program considerable
expertise in risk assessment, particularly dealing
with the effects of anthropogenic stress on macro-
invertebrates and amphibians. They will be
working specifically on WRP's urban wetlands
projects (e.g., the effects of urbanization on wet-
lands condition).
	Evaluation of the Synoptic Approach as a
tool for prioritizing wetlands restoration
activities in northeastern Illinois. The U.S.
Fish and Wildlife Service, which conducted
the evaluation for WRP, concluded that the
approach has greatest applicability for ad-
vance planning actions (ADID) and in the site
selection of mitigation banks or other off-site
compensatory mitigation sites. They saw little
applicability for its use in decision-making at
the site specific level. The WRP will use this
valuable critique to explore new approaches
to link synoptic assessment methods with site
specific assessment procedures (e.g., the "New
Hampshire" and "Oregon" methods).
	Provided oversight for two extramural study
efforts in the Sandhills region of Nebraska.
Both projects will be completed by the Uni-
versity of Nebraska. They are entitled, "The
influence of landscape scale on avian abundance
and richness in Sandhills Wetlands" and "The
dynamics of Sandhills wetlands and die hydrau-
lic connection with the High Plains Aquifer."
In Closing
If this Update was mailed to you, you're
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to be added to our mailing list, please
contact the Wetlands Research Program
EPA Environmental Research Laboratory,
200 SW 35th Street, Corvallis, OR 97333.
Inquiries about specific research projects
can be directed to Richard Sumner at the
above address. He will direct the inquiry
to the appropriate principal investigator.

Wetlands Research Update  Page Eight
Recent Program Publications
The following publications may be obtained through a
library. Inquires about EPA publications may be
directed to EPA's Center for Environmental Research
Information (CERI), 26 West Martin Luther King
Boulevard, Cincinnati, OH 45268 - Telephone
Ammann, A.P. and A. Lindley Stone. 1991. Method for
the Comparative Evaluation of Nontidal Wetlands in
New Hampshire. NHDES-WRD-1991-3. New Hampshire
Department of Environmental Services, Concord, NH.
Brinson, M.M. 1993. A Hydrogeomorphic Classifica-
tion for Wetlands. Technical Report WRP-DE-4,
US. Army Engineer Waterways Experiment Station,
Vicksburg, MS.
Detenbeck, N.E. In Press. Prevention, minimization,
and monitoring of the impacts of physical disturbance
to wetlands. Proceedings of the National Transporta-
tion Board's Fourth National Conference for Small and
Medium-sized Communities.
Holland, C.C. and M.E. Kentula. 1991. The Permit
Tracking System (PTS): A User's Manual. EPA/600/
8-91/054. U.S. Environmental Protection Agency,
Environmental Research Laboratory, Corvallis, OR.
Kentula, M.E., R.E. Brooks, S.E. Gwin, C.C. Holland,
A.D. Sherman, and J.C. Sifneos. 1992. An Approach to
Improving Decision Making in Wetland Restoration
and Creation. Island Press; Washington D.C.
 4 Mm9
Knight, R.L, R.W. Ruble, R.H. Kadlec, R.H., and S. Reed.
1993. Wetlands for wastewater treatment: Performance
database. In: Constructed Wetlands for Water Quality
Improvement, G.A. Moshiri, ed. Lewis Publishers,
CRC Press, Boca Raton, FL.
Knight, R.L., R.H. Kadlec, and S.C. Reed. 1992. Wet-
lands Treatment Data Base. In: Proceedings of the
65th Annual Conference of the Water Environment
Federation, New Orleans, September 1992, Volume IX,
"General Topics," WEF Order No. C2009.
Leibowitz, S.G., E.M. Preston, L.Y. Arnaut, N.E.
Detenbeck, C.A. Hagley, M.E. Kentula, R.K. Olson,
W.D. Sanville, and R.R. Sumner. 1992(a). Wetlands
Research Plan FY92-96: An Integrated Risk-Based
Approach. Edited by Joan P. Baker. EPA/600/R-92/060.
US. Environmental Protection Agency, Environmental
Research Laboratory, Corvallis, OR.
Leibowitz, S.G., B. Abbruzzese, PR Adamus, LE. Hughes,
and J.T. Irish. 1992(b). A Synoptic Approach to Cumu-
lative Impact Assessment: A Proposed Methodology.
Edited by S.G. McCannell and A. J. Hairston. EPA/
600/R-92/167. U.S. Environmental Protection Agency,
Environmental Research Laboratory, Corvallis, OR.
Magee, T.K., S.E. Gwin, R.G. Gibson, C.C. Holland, J.E.
Honea, P.W. Shaffer, J.C. Sifneos, and M.E. Kentula. 1993.
Research Plan and Methods Manual for the Oregon Wet-
land Study. Document production by K. Miller. EPA/
600/R-93/072. U.S. Environmental Protection Agency,
Environmental Research Laboratory, Corvallis, OR.
United States Environmental Protection Agency
Corvallis Environmental Research Laboratory
200 Southwest 35th Street
Corvallis, Oregon 97333