A model for species diversity monitoring at community level and its applications.

A simple, handly and powerful tool, called the DIMO model based on the Shannon-Wiener index, has been developed for analysis and evaluation of species diversity at plant community (alpha) level. Three axes, i.e. species richness, species evenness and the Shannon-Wiener index, were plotted in a two-dimensional space. Any change in these parameters and their relationship can be easily analysed and demonstrated by the model. A modified Shannon-Wiener index,Q, based on the DIMO model, was constructed to integrate species richness and evenness. The model and theQ index were tested with the real-life data collected from vegetation monitoring by the Swedish National Environmental Monitoring Program (PMK) during a 12-year period. Because of its dynamic features, the DIMO model is especially suitable for biodiversity monitoring at community level and can be applied to other levels as well if one replaces species taxa by other categories.