Larger Islands House More Bacterial Taxa.

ECOLOGY education; BACTERIA; ENVIRONMENTAL sciences; BIODIVERSITY; HABITATS; BIOLOGY

This article reports that the relationship between species richness and area size is one of the few generalizations in ecology, but recent studies show that the slope of the relationship differs for microbes. Several mechanisms explain how the number of taxa can increase with the size of the area. The number of taxa in a particular area results from the balance between the colonization of new taxa and the extinction of extant taxa. The size of the area influences the rate of colonization and extinction and so indirectly influences biodiversity. Alternatively, if taxa are adapted to a particular habitat, then larger areas likely contain more habitats and therefore more species. Finally, a taxa-area relationship will appear if more effort is devoted to sampling larger areas, because the number of taxa discovered increases with sampling effort. Many microbial taxa appear to be ubiquitous, so increasing the area of a survey results in only a marginal increase in the species richness of the sample.