Note that the data published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution. For the most recent data, purchase the 2008 Report from Island Press.

Defining Ecosystems

At the heart of this report are a set of six ecosystem types (coasts and oceans, forests, farmlands, fresh waters, grasslands and shrublands, and urban and suburban areas) and the indicators that, taken together, describe the state of these ecosystems and of the nation as a whole. It is reasonable to think about—and to seek indicators for characterizing—the ecosystem of a small watershed, or of the planet as a whole, or of places at any scale in between. However, like the recent National Research Council study on Ecological Indicators for the Nation, this report focuses on indicators that can support policy debate and decision making at the national scale.⁶

The word “ecosystem” is used in a number of ways, and there are two common organizational approaches we might have taken—land cover and geographic. The land cover approach defines ecosystem types based on their dominant vegetation or other physical characteristics. Thus, one would speak of a “forest ecosystem,” a “cropland ecosystem,” or a “freshwater ecosystem.” The geographic approach considers all living and nonliving things in a region to be an ecosystem⁷ regardless of vegetation type. In this approach, boundaries can be defined in many ways: watersheds and ecoregions⁸ are common examples.

We have chosen the land cover approach and we use the terms “land cover types,” “ecosystems,” and “ecosystem types” more or less interchangeably. However, we also use a more geographic approach in some cases, such as when we define a farmland landscape that includes both croplands and interspersed natural areas.

We have chosen the land cover approach in large part because many natural resource management decisions are differentiated by land type. Forests, grasslands and shrublands, farmlands, and so on produce different products, respond to different management approaches, are owned for different reasons, and are, in plain terms, different. Significant government and private activities are aligned with these land cover distinctions, and we believed that a report reflecting this structure would be most useful at this time.

Nevertheless, a growing number of “place-based” efforts are working to implement management strategies that consider all of the interactions within a watershed, ecosystem, or region. These efforts are supported by monitoring and information systems that help decision makers and the public see their region as an integrated whole, rather than as distinct elements to be managed separately.⁹ We strongly support the development of such reporting and information systems, and we have had preliminary discussions on the application of the reporting framework presented in this report to smaller geographic regions.¹⁰