Weikard et al. (Diversity and Distributions, 12, 215-217) show that the taxonomic diversity measure proposed by Ricotta (2004) violates 'weak species monotonicity'. This condition requires that the addition of a species to a given species set should always increase diversity if abundances change only marginally. They further propose a new taxonomic diversity index that overcomes this drawback. In this paper, some statistical properties of this new diversity index are briefly analysed.
Strong requirements for weak diversities / Ricotta, Carlo. - STAMPA. - 12:2(2006), pp. 218-219. [10.1111/j.1366-9516.2005.00233.x]