Species diversity components and descriptors studied.

xi (i = 1, …, S) denotes the abundance of the ith species, N ( = ) is the total number of individuals in the sample. pi ( = xi/N) is the proportion of all individuals belonging to species i, Nmax is the number of individuals of the most abundant species, ωij is the “distinctness weight” given to the path length linking species i to the first common node with species j in the hierarchical classification. Double summations are over all pairs of species i and j (note that the distance between 2 individuals of the same species is set to 0). Indices based on presence-absence data are marked by 1. See detailed properties and original references of the indices in Magurran (2004) and in Mérigot et al. (2007b).