Species diversity refers to the measure of diversity in an ecological community. Species diversity takes into consideration species richness, which is the total number of different species in a community. It also takes into account evenness, which is the variation of abundance in individuals per species in a community.
Communities with more species are considered more diverse than those with fewer. A community with less variation in the relative abundance of individuals per species is considered more even than one with more variation. Communities that are more even are also said to be more diverse. Several mathematical equations exist that incorporate evenness and abundance to measure species diversity.