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published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution.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.

Trends and Other Context Information

This report does not make normative judgments about whether particular ecosystem conditions are “good” or “bad.” Rather, we aim to present the available data in as neutral a form as possible—a “just the facts” approach. However, we also seek to provide information that places current ecosystem conditions in context, to assist the reader in understanding and making his or her own judgments about those conditions.

View Data for Figure A.1	View Data for Figure A.2

An obvious and (importantly) neutral way to place current conditions into context is to report the value of the indicator over time. Trends provide information both on the direction of change (is the value increasing or decreasing?), but also on the rate of change, which may be useful in determining whether there is reason for concern. In addition, providing information on the geographic distribution of conditions can be useful. So, for example, for some indicators we report whether one region of the country or one ecosystem type (forest, farmlands, etc.) had higher or lower values than other regions or types. A third method for placing information in context is through comparisons to relatively undisturbed “reference” conditions, and a final method is to compare current conditions to broadly accepted reference points, primarily federal limits for the allowable concentration of certain chemicals in the air or water.

As noted above, this report presents full or partial data on 58 indicators (56% of the total). Trends are presented for about half of these (31 indicators). For another 11 indicators, we have provided comparisons against widely accepted standards or against undisturbed or other reference conditions. For the remaining 16, we have information for only one point in time, without useful reference information.

The availability of trends and other reference and comparative information differs according to ecosystem type and indicator category, as shown in Figures A.3 and A.4. For example, as noted above, there are trends for 31 indicators (30%). For urban systems, trends are available for only 7%, while trends are available for about half of the forest indicators.

The situation is even more varied when one considers the availability of trends by indicator category. Trend data are available for more than 80% of indicators describing production and use of food, fiber, and water, and for about 40% of indicators of ecosystem extent. These strong showings are largely a result of the long-standing and well-supported monitoring and reporting programs devoted to accounting for goods of economic interest and the lands used in their production. For indicators of nutrients and related chemicals, contaminants, plant and animal species, and biological communities, trends are considerably less common—20% or less in all four cases. For contaminants and nutrients, however, regulatory standards and nonregulatory guidance levels provide a substantial increase in the amount of context information provided for these indicators.