(continued)

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published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution.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

Indicators with Full, Partial, and Insufficient Data

Throughout the report, we have classified indicators into four categories:

	Those with all data required for periodic national reporting
	Those with some, but not all, of the data needed for national reporting
	Indicators with insufficient data for national reporting
	Indicators that need further development

Of the 103 indicators included in this report, 58 (56%) are in the first two categories—that is, there are sufficient data to support periodic national-level reporting. Of these, 33 have all the data required and the remaining 25 have some data gaps. These gaps may be regional (i.e., data are available for part but not all of the country) or they may be topical (i.e., data are available on some but not all components of an indicator). An example of the former is the coastal shoreline types indicator, where data are available for the Pacific and southern Atlantic coasts, but not for the middle and northern Atlantic or Gulf Coasts. Several of the at-risk species indicators (see the forest and grasslands indicators) provide examples of the latter. In these cases, we have reported data on the status of native animals, but not plants (such data are available but required additional analysis before they could be used). Table A.1 shows the data availability for all indicators in the report.

Data availability varies by both ecosystem type and indicator category, as shown in Figures A.1 and A.2.

Data are available for more forest indicators than for any other system: there are complete data for about half the forest indictors and some data for another quarter. Full or partial data are available for 50% or fewer of the indicators for farmlands, grasslands and shrublands and urban and suburban areas (although there are more indicators with “full data” for farmlands than for any other system) (see Box A.1). The indicator categories with the highest percentages of data available include those addressing ecosystem extent; contaminants; ecosystem productivity; and food, fiber, and water (i.e., goods provided by ecosystems). Indicator categories with the poorest data availability include those addressing landscape patterns, biological communities, and services provided by ecosystems. No data are included for 45 of the indicators in the report. For 31 of these, the desired indicator is clear, but available data are insufficient for national reporting. For the remaining 14, the indicator itself needs further development. Data gaps and problems with indicator definitions are discussed below.

Box A.1. Three Systems with Large Data Gaps

Farmlands and grasslands and shrublands make up about 60% of the land area of the lower 48 states. Urban and suburban areas, which are quite small in comparison, are home to about three-quarters of all Americans. Yet, for these three ecosystems, full or partial data are available for half or fewer of the indicators.

We can report on the acreage of croplands, the food and fiber they produce, and the nutrients and contaminants that occur in farmland streams. Surprisingly, given how important soil is to farming, we cannot report nationally on soil organic matter, soil salinity, or the microscopic animal communities in cropland soils. Finally, we could not report on any of the indicators describing biological components in farmland areas, either because data were not available or because the indicators need additional development. (Interestingly, for farmlands, where data do exist, they are more complete than for other systems—there are more indicators with all required data than for any other system.)

Data gaps for grasslands and shrublands include information about how these areas are used, the amount of nitrate in groundwater, the amount of carbon stored in plants and soil, the depth to groundwater, the extent of non-native plants, the frequency of fires, and recreation on these lands. We can report fully on the acreage of grasslands and shrublands and the number of cattle that feed on them, on stream and river flows, on population trends for invasive birds and the number of animal species (but not plants) that are at risk of extinction.

We report data for fewer urban and suburban indicators than for any other ecosystem type—only 6 of 15 indicators. We can report on the extent of urban and suburban areas and on the undeveloped lands they contain. We can also report on nutrients and contaminants in stream water (but not on the degree of contamination in soils). All remaining indicators either have inadequate data or require additional development.

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Table of Contents/Downloads

Background & Summary

Data Availability and Gaps

Grasslands & Shrublands

Urban & Suburban Areas