Island Biogeography of Dry Forest Relict of the Cauca River Geographical Valley (Colombia)

Abstract

This study analyzed the relationships between species-area richness and phylogenetic diversity-Area in the relict flora of the tropical dry forest in the Cauca River valley in Colombia, using a species list from 38 relict sites. The results showed that plant richness followed the species-Area relationship (SAR) model, albeit with steeper slopes than expected for habitat islands, and that species dispersion affected the SAR model. Additionally, plant communities showed a nested pattern. Climate did not influence plant richness, but it did affect species composition. Phylogenetic diversity was not related to area, but phylogenetic clustering increased with it. As a conclusion, dispersion limitation is the factor that structures plant richness in tropical dry forest relicts.