Taking species abundance distributions beyond individuals

The species abundance distribution is one of the few “universal” patterns in ecology. Research on this fundamental distribution has been focused to the study of numerical counts, irrespective of the traits of individuals. Here we show that considering a set of Generalized Species Abundance Distributions (GSADs) that encompass several abundance measures, specifically numerical abundance, biomass and resource use can provide novel insights into organizational forces at play in ecological communities. We first leverage a comprehensive dataset to investigate the similarity and difference between GSADs. We then use classical probability theory and allometric scaling laws to explore theoretical linkages among GSADs and between GSADs and other common macroecological distributions. Finally, we show how examining different GSADs in natural systems can help with assessing determinants of community structure. Broadening species abundance distributions to encompass multiple abundance measures opens fresh perspectives in biodiversity research.