United States
Environmental Protection
Agency
Environmental Monitoring and
Systems Laboratory
Las Vegas, NV 89193-3478
Research and Development
EPA/620/SR-94/023 December 1994
EPA Project Summary
Environmental Monitoring and
Assessment Program,
Assessing the Suitability of
Windbreaks as Wildlife Habitat-
1994 Pilot Plan
George R. Hess and Jeff M. Bay
The Environmental Monitoring and
Assessment Program's (EMAP's)
Agroecosystems Resource Group is de-
veloping a program to monitor and
evaluate the ecological condition of U.S.
agricultural lands. Windbreaks are an
important non-crop element in the Great
Plains, an extensive agricultural land-
scape. Although planted to protect
fields, crops, livestock, and farmsteads
from the prevailing winds, windbreaks
also provide some of the scarce wooded
habitat for birds and other wildlife. This
document describes the plan for a pilot
study that focuses on the potential
biodiversity value of windbreaks in the
Great Plains and is designed to test the
feasibility of applying the U.S. Fish and
Wildlife's Bird Species Richness Index
for windbreaks on a regional basis.
The pilot study will be conducted in
cooperation with the U.S. Department
of Agriculture's National Agricultural
Statistics Service (NASS). During June
1994, NASS enumerators collected in-
formation about the location of wind-
breaks in Nebraska. This information
will be used to draw a probability
sample of windbreaks. NASS enumera-
tors will visit the sample windbreaks
later in the year and collect the data
needed to calculate the Bird Species
Richness Index for windbreaks, includ-
ing windbreak area, average height of
the tallest row of trees in the wind-
break, foliage height diversity, and snag
density. An associated Wildlife Habitat
Suitability Index can also be calculated
from these data. A follow-up visit to the
sample windbreaks is planned for the
spring of 1995 to survey the birds
present and test the Bird Species Rich-
ness Index.
This Project Summary was developed
by EPA's Environmental Monitoring and
Systems Laboratory, Las Vegas, NV, to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The Environmental Monitoring and As-
sessment Program's (EMAP's) Agroeco-
systems Resource Group is developing a
program to monitor and evaluate the eco-
logical condition of U.S. agricultural lands.
We are evaluating agricultural lands from
several perspectives: productivity; quality
of air, water, and soil; and biodiversity.
This pilot focuses on the potential
biodiversity value of windbreaks in the
Great Plains and is designed to test the
feasibility of applying the U.S. Fish and
Wildlife's Bird Species Richness Index for
windbreaks on a regional basis.
Windbreaks are an important non-crop
element in the Great Plains, an extensive
agricultural landscape. Although planted
to protect fields, crops, livestock, and farm-
steads from the prevailing winds, wind-
breaks also provide some of the scarce
wooded habitat for birds and other wild-
life. For example, less than 2% of Ne-
braska is covered by trees, and
approximately 25% of that wooded cover
is provided by windbreaks. Windbreaks
may have a negative impact on wildlife
species that require large, uninterrupted
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areas of grassland habitat; this issue is
not addressed by this research.
We are working in cooperation with the
U.S. Department of Agriculture's (USDA's)
National Agricultural Statistics Service
(MASS). During June 1994, MASS enu-
merators collected information about the
location of windbreaks in Nebraska. This
information will be used to draw a prob-
ability sample of windbreaks. MASS enu-
merators will visit the sample windbreaks
later in the year and collect the data
needed to calculate the Bird Species Rich-
ness Index for windbreaks. The index gives
the number of different bird species ex-
pected in a windbreak and is based on
four habitat characteristics of the wind-
break: windbreak area, average height of
the tallest row of trees in the windbreak,
foliage height diversity, and snag density.
An associated Wildlife Habitat Suitability
Index can also be calculated from these
data; this index reflects a windbreak's value
as habitat for birds and small mammals
but has been subjected to less extensive
testing.
We will produce a report documenting
the results of this study, including (a) esti-
mated extent (number and area) of wind-
breaks in Nebraska with 95% confidence;
(b) estimated cumulative distribution of the
Bird Species Richness Index of windbreaks
in Nebraska with 90% confidence inter-
vals; and (c) estimated cumulative distri-
bution of windbreak area in Nebraska with
90% confidence.
We are also planning a follow-up visit to
the sample windbreaks during the spring
of 1995 to survey the birds present and
test the Bird Species Richness Index. As
part of that study, we will also collect
multi-scale remote sensing data for the
study sites in an attempt to determine the
spatial scales of habitat to which the bird
community composition is most closely
correlated. Details of these future efforts
are not covered in this plan.
This research has been funded prima-
rily by the U.S. Environmental Protection
Agency (EPA) through its Office of Re-
search and Development (ORD) under In-
teragency agreements DW12934170 with
the USDA Agricultural Research Service
(USDA ARS), and DW1293747 with the
USDA National Agricultural Statistics Ser-
vice (USDA NASS). It was conducted by
our research partners under the manage-
ment of the Environmental Monitoring Sys-
tems Laboratory—Las Vegas in support
of EMAP.
George R. Hess and JeffM. Bay are with North Carolina State University, Raleigh,
NC 27606.
Susan E. Franson is the EPA Project Officer (see below).
The complete report, entitled "Environmental Monitoring and Assessment Program,
Assessing the Suitability of Windbreaks as Wildlife Habitat—1994 Pilot Plan,"
(Order No. PB95-129136; Cost: $17.50, subject to change) will be available only
from
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at
Environmental Monitoring and Systems Laboratory
U.S. Environmental Protection Agency
Las Vegas, NV 89193-3478
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/620/SR-94/023
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