Species richness is the number of species in a habitat. The more species present, the richer the habitat. This can be measured using the methods of Simpsons index of diversity. Simpsons index of diversity takes into both species richness and species eveness. By using the the formula. Therefore Simpsons index of diversity is always a valve between 0 and 1. A high valve indicates a diverse habitat. The habitat that tends to be stable and able to withstand change. A low valve indicates a habitat dominted by a few species. A small change could damage or detroy the whole habitat.