Analysis of the secondary vegetation of the tamaulipan thornscrub, Mexico

Abstract

Productive activities, such as agriculture and animal husbandry, undergone by the Tamaulipan thornscrub have been the cause of a decreasing vegetal cover and changes in vegetation structure. The main goal of this research was to quantify the changes in species composition of vascular plants (beta diversity) and their abundance in 5 sampling areas exposed to different agroforestry systems (intensive and extensive livestock farming, agriculture, clear-cutting and forest plantation). Four plots (20 in totals) were established in these sampling sites to evaluate vascular plant regeneration. We registered 30 species belonging to 26 genera and 15 families. The Fabaceae family has the highest number of species (9 species). Low similarity indexes between the 5 sampling areas were detected by the Bray-Curtis model (beta diversity). The similarity index was less than 28.6\%, except for the forest plantation and the clear cutting area that showed an index of 60.6\%. In accordance with the rarefaction curve, the sampling effort needed to reach the expected species richness in the extensive livestock farming and clear-cutting area was higher than that in the others. However, the five areas needed 60 individuals to achieve the theoretical maximum species richness. This study contributes to the knowledge of tamaulipan thornscrub species regeneration under different agroforestry systems.