The Impact of Anthropogenic Disturbance on Assembly Patterns of Termite Communities

Abstract

AbstractIntensification of land‐use threatens biodiversity, especially in tropical ecosystems that harbor the planet's highest species richness. This negative impact of anthropogenic disturbance on species numbers is well established, but the mechanisms underlying the community assembly processes are less well understood. Termites are of fundamental importance in tropical ecosystems where they are critical for nutrient recycling and species diversity. We tested the impact of anthropogenic disturbance on termite species diversity and assembly processes in a West African savanna applying the newest techniques of phylogenetic community analyses. Species richness dropped in areas of intensive land‐use and compositional similarity between intensive land‐use areas was high. This contrasted with a protected National Park where communities were characterized by high species richness and intermediate species turnover between sites. Slightly disturbed areas in the buffer zone surrounding the park were intermediate, they still had high species richness but similarity between sites increased. Strikingly, the assembly pattern also changed with disturbance from more phylogenetic overdispersion to more clustering (coexisting species became phylogenetically more similar), but only when the fungus‐growing termite Macrotermes bellicosus was absent. Our data suggest that the major forces structuring termite communities depend: (1) on the presence of this dominant mound‐building termite; and (2) that they change to more environmental filtering with disturbance. Anthropogenic disturbance seems to function as a filter that allows only a specific subset of species to occur. Such an effect might be widespread in ecology but it is difficult to document quantitatively. Phylogenetic community analyses can help to contribute such evidence.