Revised and updated periodically, "The State of the Nation's Ecosystems" is widely recognized as America's most comprehensive report on the condition of our lands, waters, and living resources. Like the acclaimed first edition, this second edition provides nonpartisan, scientifically reliable information for policymakers, scientists, journalists, and anyone who is interested in the state of America's environment."The State of the Nation's Ecosystems" provides a way to "take the pulse" of America's environment. It is organized around the nation's primary ecosystems: farmlands, forests, fresh waters, coasts and oceans, grasslands and shrublands, urban and suburban areas, and the nation as a whole. For each, it identifies what should be measured, counted, and reported so that decision makers and others can understand the changes that are occurring, set priorities for action, and measure whether we are achieving our environmental goals. Conditions are tracked using approximately 100 indicators, agreed upon by hundreds of experts from universities, government agencies, corporations, and environmental organizations. The new report refines the set of indicators and supplies data.Until its publication, there was no environmental equivalent to the kind of "key economic indicators" that help to gauge the economic health of the nation, like gross domestic product. "The State of the Nation's Ecosystems" provides our first set of "key environmental indicators." It won't eliminate differences of opinion about environmental policy, but it will provide a common set of data to inform the debate as well as a common yardstick for measuring the effectiveness of our actions. Most importantly, it will provide much-needed assistance in setting our future agenda.