The number of species present in a community, measured as the number of species per unit of ground area. This contrasts with diversity, which takes account of the way individuals are apportioned among the different species. Several factors influence species richness, the most important being the resources available and the extent to which species overlap in their exploitation of them. More resources will support more species, and the more that species overlap in their use of resources the more species the habitat will support. Predation also affects richness, by preventing species from reaching their carrying capacity and thereby allowing more species to share the resources.
Subjects: Ecology and Conservation.