Tuesday, August 7, 2007 - 8:40 AMOOS 13-3: A multi-scale, multi-taxon analysis of landscape quality and its impact on biodiversity in coffee farms in Central Veracruz, Mexico
Robert H. Manson, Fabiola López Barrera, and Vinicio Sosa Fernández. Instituto de Ecología, A.C.
Numerous studies have documented changes in the biodiversity of different taxonomic groups along management intensity gradients in shade coffee farms and highlighted the potential importance of these agroecosystems in the conservation of tropical montane biodiversity. Nevertheless, traditional shade coffee that conserves most forest biodiversity is increasingly threatened by global cycles of overproduction and low prices that force coffee farmers to abandon their farms or convert them to other, more intensive, land uses. The conservation value of shade coffee farms may depend on variation both within and between these agroecosystems, however few studies have evaluated the impact of landscape-scale variation on the distribution and abundance of the species they harbor. Here we describe the results from a multi-taxonomic (12 groups of plants and animals) and multi-scale (500, 1000 and 2000 m buffer areas) study designed to evaluate the importance of such variation in explaining changes in biodiversity among 15 coffee farms and 2 forest control sites spanning the range of coffee management intensity typical for central Veracruz, Mexico. We used an estimate derived from the Normalized Difference Vegetation Index (NDVI) to evaluate landscape quality around permanent vegetation and diversity sampling points located in each site. We found few effects of changes in landscape-scale variation on total diversity. However, more taxon-specific patterns were detected once generalist species were removed from the analysis. Furthermore, our results highlight the importance of considering internal management intensity and external landscape quality as independent factors in the evaluation of the conservation value of these agroecosystems.