The assessment of biological diversity on the basis of occurrence

The relation between parameters of various types of rank distributions and parameters of the species number-area empirical relationships is deduced fr om the thermostatic model of biological diversity. A rank distribution is c onstructed based on parameters calculated for actually existing relationshi ps. Another type of rank distribution for the same original data is obtaine d by converting the frequency of species into relative parameters of their abundance, based on Poisson distribution. The resulting rank distributions are used for assessing diversity on the basis of entropy. This approach is illustrated by the example of measuring the biological diversity of higher plants in middle taiga communities. The method is sufficiently universal to be used for measuring the diversity of any organisms, their communities, a nd ecosystems.