Data from: Functional identity and diversity of animals predict ecosystem functioning better than species-based indices

Drastic biodiversity declines have raised concerns about the deterioration
of ecosystem functions and have motivated much recent research on the
relationship between species diversity and ecosystem functioning. A
functional trait framework has been proposed to improve the mechanistic
understanding of this relationship, but this has rarely been tested for
organisms other than plants. We analysed eight datasets, including five
animal groups, to examine how well a trait-based approach, compared with a
more traditional taxonomic approach, predicts seven ecosystem functions
below- and above-ground. Trait-based indices consistently provided greater
explanatory power than species richness or abundance. The frequency
distributions of single or multiple traits in the community were the best
predictors of ecosystem functioning. This implies that the ecosystem
functions we investigated were underpinned by the combination of trait
identities (i.e. single-trait indices) and trait complementarity (i.e.
multi-trait indices) in the communities. Our study provides new insights
into the general mechanisms that link biodiversity to ecosystem
functioning in natural animal communities and suggests that the observed
responses were due to the identity and dominance patterns of the trait
composition rather than the number or abundance of species per se.