Análisis comparativo de Ia estructura, diversidad y composición de comunidades arbóreas de un paisaje agropecuario en Tabasco, México

Abstract

In order to evaluate the effect of management on diversity, structure and composition of native arboreal flora in a mountainous Neotropical landscape, we studied 2 ecomosaics: montane rain forest, and the surrounding agricultural matrix. We inventoried 96 plots, registering 172 species. As a result of management, the ecomosaics differed in species richness and abundance as well as in vegetation structure, with forest remnants and pastures as the 2 extremes. Mature secondary vegetation had the most tree species (92), and pastures the fewest. Two thirds of forest tree species were also represented in the surrounding matrix, especially in fallows. Twenty-seven species were characteristic of particular landscape units. Most of these were zoochores associated with mature forest. The actual landscape management maintains a certain proportion of conserved habitats and dispersed forest remnants which enrich the agricultural matrix. However the tendency toward less fallow area and more pasture indicates a transition toward a more homogeneous agricultural matrix, less forest regrowth and greater contrast between forest and agricultural ecomosaics. This will increase the contrast between the ecomosaics and threaten the regeneration of mature forest and its associated species.