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Date: Nov. 19, 1999
Contacts: Molly Galvin, Media Relations Officer
David Schneier, Media Relations Assistant
(202) 334-2138; e-mail <>


Publication Announcement

National Ecological Indicators Needed To Assess the Environment

Policy-makers often must rely on incomplete, complicated information about environmental conditions or trends when making decisions that affect the environment. For decades, researchers have been trying to improve public understanding of this information by developing scientific measures known as indicators. Just as indicators of inflation and employment rates describe the state of the nation's economy, similar measures are needed to assess the nation's ecological status. For example, indicators such as mean temperature and carbon dioxide concentrations in the atmosphere already are in place to track global climate change. But few national measures exist to track how land is being used, the status of wildlife, and other natural resources.

Such indicators on a national scale could help to form sound environmental policies, says Ecological Indicators for the Nation, a new report by a committee of the National Academies' National Research Council. These measures would identify potential environmental problems and evaluate the effectiveness of protective regulations and policies.

The committee recommended specific indicators in the following three categories that could provide meaningful information.

The status of the nation's ecosystems. The types and extent of the nation's land cover -- such as wetlands, forests, and deserts – should be documented. Data should be reported every five years to determine how conditions are changing. Since several other indicators will depend on this information, implementing this indicator should be a top priority.

Ecological capital. The capacity of an ecosystem to sustain itself is determined by ecological capital. This can be measured by the indicators of total species as well as native species diversity, nutrient runoff, and soil quality. For example, soil that is lacking essential nutrients will not be able to support plant life. Nutrients such as nitrogen and phosphorus can filter into nearby rivers, lakes, and coastal areas, causing harmful algal blooms and reducing water clarity. And because human activities can reduce native plants and animals, native species diversity is an important indicator of how people are affecting the land.

Ecosystem productivity. Ecosystems must be able to produce oxygen, and capture and store energy to support life. Ecological indicators in this area include production capacity, carbon storage, and oxygen content in rivers, streams, and coastal areas. Tracking the amount of chlorophyll in a specific area, for example, will indicate how much energy plants are able to produce. To evaluate water-based ecosystems in rivers or coastal areas, oxygen content is an important clue to environmental conditions.

Some of the indicators identified by the committee will require further development and testing before they can be implemented. Collecting information from all parts of the country and applying it to national indicators will be a difficult process. However, many of the needed data already are being collected regionally by federal and state agencies and could provide a solid base for a national effort.

National indicators should be credible, understandable, quantifiable, and broadly applicable, the committee said. Data that support them need to be clear and interpreted objectively to gain public confidence. Before indicators are used on a national basis, several criteria should be used to evaluate them, such as the significance of ecological changes they measure, the ecological understanding they are based on, their reliability, the quality of the data, and their costs and benefits.

Read the full text of Ecological Indicators for the Nation for free on the Web, as well as more than 1,800 other publications from the National Academies. Printed copies are available for purchase from the National Academy Press Web site or at the mailing address in the letterhead; tel. (202) 334-3313 or 1-800-624-6242. Reporters may obtain a pre-publication copy from the Office of News and Public Information at the letterhead address (contacts listed above).

Commission on Geosciences, Environment, and Resources
Board on Environmental Studies and Toxicology
Water Science and Technology Board

Committee to Evaluate Indicators for Monitoring Aquatic and Terrestrial Environments

Gordon H. Orians * (chair)
Professor Emeritus of Zoology
University of Washington

Martin Alexander
Liberty Hyde Bailey Professor of Soil Science
Cornell University
Ithaca, N.Y.

Patrick L. Brezonik
Professor of Environmental Engineering, and Director, Water Resources Research Center
University of Minnesota
St. Paul

Grace Brush
Department of Geography and Environmental Engineering
Johns Hopkins University

Eville Gorham *
Regents' Professor Emeritus of Ecology and Botany
University of Minnesota

Anthony Janetos
Senior Vice President for Program
World Resources Institute
Washington, D.C.

Arthur H. Johnson
Professor of Geology
Department of Geology
University of Pennsylvania

Daniel V. Markowitz
Senior Scientist
Malcolm Pirnie
Akron, Ohio

Stephen W. Pacala
Department of Ecology and Evolutionary Biology
Princeton University
Princeton, N.J.

John Pastor
Professor of Biology, and
Senior Research Associate, Natural Resources Research Institute
University of Minnesota

Gary W. Petersen
Professor of Soil and Land Resources
Department of Agronomy
College of Agricultural Sciences
Pennsylvania State University
University Park

James R. Pratt
Professor of Environmental Science
Environmental Studies Program
Portland State University
Portland, Ore.

Terry Root
Associate Professor of Natural Resources
School of Natural Resources and Environment
University of Michigan
Ann Arbor

Michael L. Rosenzweig
Professor of Ecology and Evolutionary Biology
Department of Ecology and Evolutionary Biology
University of Arizona

Milton Russell
Senior Fellow
Joint Institute for Energy and Environment
University of Tennessee

Susan Stafford
Forest Biometrician
College of Natural Resources
Colorado State University
Fort Collins


David J. Policansky
Project Director

* Member, National Academy of Sciences