Abstract:

Habitat degradation is one of the leading causes of biodiversity losses, and there is an urgency to understand species responses to human-caused habitat degradation. Habitat degradation includes long-term sustained degradation and instantaneous destruction. Previous studies have focused primarily on the rapid or instantaneous destruction of habitats; therefore, in this paper, we compared species responses to the two different kinds of habitat degradation using an N-species competitive coexistence model. The results showed that both types of habitat degradation altered competitive relationships among strong and weak species. Our results showed that species extinctions were determined by the meta-population structure, which is in contrast to the common holding view that superior species are able to avoid extinction. In the case of instantaneous habitat destruction of a tropical forest, species pass through a phase of adaptation and then a phase of recovery; in contrast, sustained habitat degradation causes species to decay successively without recovery. Sustained habitat degradation is more propitious to species persistence over the long term as compared to instantaneous habitat destruction. Instantaneous habitat destruction of temperate forests cause species to pass through an adaptation phase, a phase of recovery, and then the population oscillates quasi-periodically at an equilibrium level through time; in contrast, sustained habitat degradation leads to species declines without recovery. Our results showed that species respond very differently to the two types of habitat degradation with species abundances declining more in gradual, sustained habitat degradation as compared to the instantaneous destruction of habitats.

Key words: Evolution, Sustained habitat degradation, Instantaneous habitat destruction, Species responses, Extinction