Abstract

HUERTA-MARTINEZ, Francisco Martín  and  GARCIA-MOYA, Edmundo. Diversidad de especies perennes y su relación con el ambiente en un área semiárida del centro de México: Implicaciones para la conservación. INCI [online]. 2004, vol.29, n.8, pp.435-441. ISSN 0378-1844.

Vegetation-environment relationships as well as richness, a and b diversity were studied at El Huizache, San Luis Potosi state, which is a priority region for biological conservation in Mexico. A Bray-Curtis ordination revealed that landscape features play an important role on plant communities organization; such variables explained 80% of the total variation. Geology, soil depth and slope inclination were the most important variables, because of their correlation coefficient with the first axis. These variables influence species distribution and abundance by the existence of geological refuges, at the same time that they influence other variables indirectly, which increases habitat heterogeneity at the scale of the study. Three vegetation types were clearly recognized; that with more richness was the rosetofilous desert shrubland and the poorest was the microphylous desert shrubland. Cluster analysis recognized a group of sites representing ecotones between different vegetation types. Total b diversity was 5.14sd, which means great changes in composition at the study region. The highest b diversity value was at the ecotone (3.39sd). This means that there is a great compositional heterogeneity within it, a reflection from landscape heterogeneity.

Keywords : Diversidad; Ordenación de Bray-Curtis; Relación Vegetación-Ambiente.