MEASURING DOMINANCE AND DIVERSITY IN ECOLOGICAL COMMUNITIES - CHOOSING THE RIGHT VARIABLES

Although there are many studies in searching for the most useful commu nity diversity index, the importance of choosing an appropriate parame ter has been neglected. Here, we examined dominance and diversity in e arly postfire chaparral communities using different variables, i.e. pl ant density, cover and biomass. Significant different results were pro duced by applying different parameters and the difference may be cause d by the inconsistency in density, cover, and biomass allocated in eac h life form. Among the three parameters, biomass was most successful i n detecting differences among communities because the apportionment of biomass among species was more variable than that of density. Althoug h the three species variables represent different aspects of community properties and their relative performance may vary among communities, we recommend the use of biomass or productivity data as the most appr opriate variable because it can best represent per capita resource use and resource partitioning among organisms in competitive situations.