GAP ANALYSIS OF MEXICAN PROTECTED AREAS
AND REMAINING PRIMARY TERRESTRIAL VEGETATION The Nature Conservancy (Bezaury-Creel et al.,2000)
Gap analysis is a method used to determine the protection status of biodiversity within a given region. Using this technique, conservation targets which are not well-protected by the current system of protection (called "gaps") can be pinpointed. A gap analysis can be performed at many scales, and is dependent on the quantity and quality of spatial data that is available for the region in question. Our goal for this analysis was to apply this technique at a nationwide level to perform a preliminary conservation assessment of Mexico's vegetation types, creating a data base that can be used to further refine the analysis to the ecoregional level. Arcview and Arcinfo software were used to carry out the GIS overlay analysis.
The current system of protected areas in Mexico was overlaid with the vegetation map to determine the amount of vegetation (remaining primary vegetation INEGI, 1996 1:1,000,000) contained within the current protected area system. The results of this process can then be analyzed in any number of ways. The graphs, maps and table included show examples of how these data can be used. For the analysis 10% was selected as a baseline goal for the desired amount of protection for each vegetation type. We then proposed that vegetation types of which little primary vegetation remained should have a higher percentage within protected areas in order to be considered 'well-protected'. The criteria we used for this analysis was:
Less than .5 %
From .5 to 1 %
From 1 to 2 %
More than 2%
Since the vegetation classification at a country level is at a rather coarse scale, it is desirable to analyze these vegetation types at the ecoregional level. Many of these types span across several ecoregions, so the variation within these vegetation types that occur in more that one ecoregion is not well represented by a country-wide analysis.