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published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution.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

What Is This Indicator, and Why Is It Important? This indicator will report on the degree to which “original” plants and animals are either absent entirely or are at risk of being lost from metropolitan areas. Original species are those that, before European settlement, inhabited the lands now occupied by metropolitan areas. Specifically, the indicator will report on the fraction of metropolitan areas where 25% or more, 50% or more, and 75% or more of original species are at risk of being displaced or are absent.

Species differ in their ability to cope with urban/suburban development, and cities and suburbs differ in their capacity to accommodate those species common in the area before European settlement. How thoroughly an area is developed, and whether there are areas and corridors maintained for wildlife, has an influence on whether some species—those less tolerant of people and development—become reduced in population or displaced from the local area. Some of these species may have healthy populations outside cities and their suburbs, but in other cases the loss of habitat in urban and suburban areas can contribute to the overall decline of a species’ population. Efforts to improve or restore habitat within urban/suburban areas can increase the likelihood that original species will re-inhabit these areas.

Why Can't This Indicator Be Reported at This Time? The historical data necessary to establish lists of original species are incomplete, and current information on their status, especially within cities and their suburbs, is not systematically collected and reported. When available, the amount, quality, and format of such data are extremely variable.

Discussion Note that it is difficult to distinguish between at-risk and absent in this context, so both are included. In addition, presettlement is used as a benchmark simply as a way to track changes, not because the full suite of original species would necessarily be desirable in any given metropolitan area.

This indicator would not be calculated for all urban and suburban areas, as defined in this report (see Area of Urban and Suburban Lands), as it is likely that information, expertise, and financial resources will be available only for larger metropolitan areas. Thus, it might be appropriate to base reporting for this indicator on data from a suite of cities (and their suburbs) whose population exceeds 100,000 or that cover at least 50 square miles, for example.