On the Correlations between Certain Diversity Indices

Positive correlations are expected between a number of widely used diversity indices. The correlations arise from definitions of the indices, and make it difficult to interpret calculated correlation coefficients between them. The value of these expected correlations depends on the probability distributions assumed to describe the distributions of values of the several indices over samples from different communities. The only indication, in published data, of a biological phenomenon that may possibly influence values these indices take is a decrease in variance of species evenness as species richness increases.