Current_Status_Of_Biodiversity_Indicators_Using_GIS Page 1 of 9 file://C:\mwp\school\Geog 4405\Current_Status_Of_Biodiversity_Indicators_Using_GIS.htm 1/30/2001 Blair Csuti, Patrick Kennelly, S. Mark Meyers, and K. Sahr Current status of biodiversity indicators using GIS Abstract Described as a crisis, the loss of biodiversity cannot be quantified nor spatial solutions proposed without GIS analysis of spatial biological resource data sets. The National Gap Analysis Program (GAP), Biological Resources Division, U.S. Geological Survey, develops and disseminates information on the distribution of biodiversity elements mapped at the landscape scale. Analyses of these data layers may contribute to private and public agency understanding of and planning for future changes in the status of elements of biodiversity resulting from human modification of the environment. GIS coverages of current land cover, based on LANDSAT imagery, and predicted distribution of terrestrial vertebrate species, based on known occurrences and relationships to land cover types, are analyzed relative to the location of existing natural areas to describe their current representation in these areas. Land management strategies promoting future maintenance of these elements of biodiversity are developed through several types of spatial analyses of these data. The status of individual and collective elements of biodiversity, the location of optimal natural area networks, the effects of scale on results of these analyses, and cross-level effects of protection strategies for different major classes of biodiversity are all under investigation. These multi-disciplinary studies involve a variety of software applications including a variety of image processing software packages (often SPECRTUM or ERDAS), GIS software (ARC/INFO), IBM Integer Programming software, C++ programming language, and Advanced Revelation information system software. Introduction Gap analysis has consistently been promoted as a proactive complement to efforts to recover endangered species (Scott et al. 1987, 1993, 1996; Scott and Csuti 1997). Given the inevitable loss of habitat that will accompany continuing growth in the human population, the status of many species not currently at risk of extinction will deteriorate (Scott et al. 1987, Margules 1989). The best way to avoid the costs and controversy of rescuing endangered species is to manage natural areas in such a way as to prevent more species from becoming endangered in the future. Many species and ecosystems will remain viable in landscapes subject to a sustainable level of resource exploitation (Scott et al. 1990). However, some ecosystem types and the species associated with them have virtually disappeared in the face of expanding human activities (Noss et al. 1995). Gap analysis provides a way to assess how well species and ecosystem types are represented in the current network of areas managed for the long-term maintenance of biodiversity. Beyond identifying and mapping the distribution of unprotected species and ecosystem types, gap analysis can locate sets of areas that, if managed primarily for biodiversity, would most efficiently insure that most species and ecosystems were secure from future threats of extinction. This is important, since there is a practical limit to the percent of a nation's total area will be managed primarily for biodiversity (Pressey 1990). Gap analysis is based on the comparison of maps of land cover and selected animal species with current patterns of land ownership and management activities. In practice, there have been no preexisting sources for these three spatial data layers at scales compatible with regional land use planning. Of necessity, the state