Understanding patterns of biodiversity change across time and geographic space is a fundamental goal of ecology and essential for assessing anthropogenic impact on ecosystems. Species diversity is a ubiquitous metric of biodiversity change, providing a relatively simple and transferrable assessment of community structure. However, recent assessments of global trends in species richness show that it is not capturing the kinds of changes happening at a local scale. Functional diversity provides one potentially powerful alternative for assessing changes in community structure by directly measuring the traits mechanistically linked to ecosystem process. Recent efforts to compile functional trait data databases for many different taxa make broad-scale assessment of functional diversity change feasible for the first time. We pair functional trait databases with existing community timeseries to offer a first assessment of functional diversity change through time across over 200 communities spanning geographic and taxonomic space.
Results/Conclusions
We find that functional diversity provides evidence of biodiversity change independent of species richness change, with trends detected in functional diversity timeseries not detected for species diversity alone. These results indicate that a more mechanistic representation of community structure is essential for assessing biodiversity change.