Plants are composed of modules, such as shoots and leaves. However, modules have been overlooked as potential abundance measures in describing plant communities. We sampled 8 communities, to examine whether module counts gave different conclusions from biomass on community structure, and better discriminated between communities. Different abundance measures – number of leaves, number of shoots and photosynthetic biomass – gave different results for between-site comparisons of evenness and rank consistency. Since evenness is intended to represent a feature of the whole community, it should vary more between communities than within; module-based abundance achieved this better than biomass. It is speculated that the restrictions on species co-occurrences when plant communities assemble may sometimes be based on the number of modules rather than on biomass.
Abbreviation: PSU = Photosynthetic unit.