Recovery of disturbed ecosystems as monitored by ant and vegetation diversity in forests and surrounding Savannas of Venezuela

The recovery of tropical ecosystems after disturbance is of interest for fu ture programs of sustainable development. The dynamics of such processes wa s evaluated at 26 sites in Venezuela. Ant and plant diversity were compared between disturbed forests and surrounding savannas, different stages of re covery and nearby plots with primary vegetation. We estimated the species c omposition for ants, the number of species and equitability for ants and pl ants, and the plant coverage at each site. Of these indices, percentage of plant cover showed the most rapid return to pre-disturbance values. In a fe w cases, full return occurred after around 25 years in both savanna and for est. A multiple factorial analysis of ant composition showed that species s tructure in old recovered sites converged sometimes, but not always, to tha t in surrounding natural habitats. Therefore, ant diversity may be used to monitor ecosystem recovery. However, even small scale human intervention ma y have irreversible effects on tropical habitats. The estimated time consta nt for forest recovery could serve to calculate human carrying capacity of forest sites for eventual sustainable use of these ecosystems in the Neotro pics.