Effects of habitat fragmentation on the mammalian assemblage at the Iztaccíhuatl and Popocatépetl Volcanoes, Mexico

Abstract

Rapid habitat transformation calls for efficient methods to lead conservation efforts. For this reason, landscape analysis is becoming a major issue in biodiversity conservation. In Mexico, as in many parts of the world, management strategies are scarce so that biodiversity depletion processes continue. This is the case on the Iztaccihuatl and Popocatépetl volcanoes, which harbour over 10% of the total Mexican mammalian species within ca. 0.02% of the surface of Mexico. The present paper aims at assessing the effect of landscape dynamics on mammalian assemblages through a RS/GIS modelling approach. A database including all mammalian species recorded in the region from 1839 up to 1997 was compiled. The records, at genus level, were linked to land cover classes obtained from Landsat satellite images taken in 1986 and 1997. Land cover and habitat changes were analysed through a statistical analysis by crossing land cover maps of 1986 and 1997, which were transformed, into habitat richness types. Major changes from high to medium and medium to low habitat richness classes prevail in the area. This reduces the resilience of the natural landscapes and increases the threats for most mammalian species. From a landscape ecological perspective, the present chapter demonstrates the importance of the area as a unique mosaic of mammalian assemblages.