TRANSNATIONAL GAP ANALYSIS OF THE RIO-BRAVO RIO-GRANDE REGION

Cap analysis is a CIS approach to biodiversity currently employed thro ughout the continental United States to determine how well native biod iversity is represented in the network of conservation lands. Here, re describe an effort to apply gap analysis to the Rio Bravo/Lower Rio G rande region of Mexico and the United States. Implementation of the st udy was preceded by establishment of an agreement between the Mexican National Commission for the Knowledge and Use of Biodiversity (CONABIO ) and the U.S. Geological Survey. The study will generate land-cover h abitat and vertebrate distribution maps for an area that straddles the Rio Bravo/Lower Rio Grande basin extending from Ciudad Juarez, Chihua hua/ EI Paso, Texas to the Gulf of Mexico. Vertebrate modeling, based on habitat associations, will identify habitats potentially important to vertebrate life cycles and areas of high biodiversity. A map of lan d management practices relevant to biodiversity conservation will prec ede a ''gap analysis,'' which will identify potential areas for the re gion's reserve network. We also describe the project's use of a nor el software program (Spectrum) to analyze Landsat Thematic Mapper imager y. Conducting the gap analysis in Mexico and relating it to the gap an alysis for Texas will reveal how well biodiversity of the Rio Grande B order region is actually protected by the current reserve network.