The global concern with reduction in biodiversity has generated responses in the United States, such as the Endangered Species Act (ESA). Although the ESA has had some effect, the species-by-species approach presents a problem because it does not consider the broad ecological principles of biodiversity including the need for balance between different species and their combined influence on a given habitat. There is an implicit assumption that national parks, wildlife sanctuaries, and other protected areas provide for conservation needs. However, these areas have not necessarily been delineated on the basis of animal habitat zones or ecologically significant units. Gap Analysis is an evaluation method providing a systematic approach for assessing the protection afforded biodiversity in a given area. It uses geographic information systems to identify "gaps" in biodiversity protection that may be filled by the establishment of new preserves or changes in land-use practices. Gap Analysis has three primary layers: (1) distribution of vegetation types delineated from satellite imagery, (2) land ownership, and (3) distribution of vegetation types delineated from satellite imagery, habitat preference models. Vegetation classification procedures using satellite image or aerial photograph analysis are linked to wildlife/ habitat databases. Gap analysis includes seral as well as climax vegetation, and classes must be compatible with those used in neighboring states. The examples of these procedures for the Utah Gap Analysis are given with some reference to Gap Analysis in other states. The overall approach provides a logical base for evaluating and protecting national biological diversity.
Edwards, Thomas C. Jr.; Scott, J. Michael; Homer, Collin G.; and Ramsey, R. Douglas
"Gap analysis: a geographic approach for assessing national biological diversity,"
Natural Resources and Environmental Issues: Vol. 2
, Article 11.
Available at: http://digitalcommons.usu.edu/nrei/vol2/iss1/11