United States Environmental Monitoring and

Environmental Protection Systems Laboratory

Agency Las Vegas, NV 89193-3478

Research and Development EPA/620/SR-94/023 December 1994

E AP Project Summary

The Environmental Monitoring and

Assessment Program’s (EMAP’s)

Agroecosystems Resource Group is developing 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 landscape. 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 information about the location of windbreaks in Nebraska. This information

will be used to draw a probability

sample of windbreaks. NASS enumerators will visit the sample windbreaks

later in the year and collect the data

needed to calculate the Bird Species

Richness Index for windbreaks, including 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. 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 Richness 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 Assessment Program’s (EMAP’s) Agroecosystems Resource Group is developing a

program to monitor and evaluate the ecological 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 farmsteads from the prevailing winds, windbreaks also provide some of the scarce

wooded habitat for birds and other wildlife. For example, less than 2% of Nebraska 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

Environmental Monitoring and

Assessment Program,

Assessing the Suitability of

Windbreaks as Wildlife Habitat—

1994 Pilot Plan

George R. Hess and Jeff M. Bay
2

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

(NASS). During June 1994, NASS enumerators collected information about the

location of windbreaks in Nebraska. This

information will be used to draw a probability sample of windbreaks. NASS enumerators will visit the sample windbreaks

later in the year and collect the data

needed to calculate the Bird Species Richness Index for windbreaks. The index gives

the number of different bird species expected in a windbreak and is based on

four habitat characteristics of the windbreak: 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) estimated extent (number and area) of windbreaks in Nebraska with 95% confidence;

(b) estimated cumulative distribution of the

Bird Species Richness Index of windbreaks

in Nebraska with 90% confidence intervals; and (c) estimated cumulative distribution 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 primarily by the U.S. Environmental Protection

Agency (EPA) through its Office of Research and Development (ORD) under Interagency agreements DW12934170 with

the USDA Agricultural Research Service

(USDA ARS), and DW1293747 with the

USDA National Agricultural Statistics Service (USDA NASS). It was conducted by

our research partners under the management of the Environmental Monitoring Systems Laboratory—Las Vegas in support

of EMAP.

United States

Environmental Protection Agency

Center for Environmental Research Information

Cincinnati, OH 45268

Official Business

Penalty for Private Use

$300

EPA/620/SR-94/023

BULK RATE

POSTAGE & FEES PAID

EPA

PERMIT No. G-35

George R. Hess and Jeff M. 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