diversity index The mathematical expression of the species diversity of a given community or area, which includes due allowance for the relative abundance of different species present. Such indices (e.g. the Shannon–Wiener index) are generally considered an important means for comparisons of community structure and stability. A different and specialized case of a diversity index is the ‘biotic index’ used in water-pollution studies.

diversity index The mathematical expression of the species diversity of a given community or area, which includes due allowance for the relative abundance of different species present. Such indices (e.g. the Shannon-Wiener index) are generally considered an important means for comparison of community structure and stability. A different and specialized case of a diversity index is the ‘biotic index’ used in water-pollution studies.

diversity index A simultaneous mathematical expression of the number of species and number of individuals of each species that are present in a given habitat. Various formulae are used, one of the most common being the Shannon–Wiener index. A different and specialized case of a diversity index is the ‘biotic index’ used in water-pollution studies.