Functional richness, functional evenness and functional divergence: the primary components of functional diversity

TLDR

Functional diversity is hypothesized to enhance ecosystem functions such as productivity and resistance to invasion, yet a precise definition and quantification framework remain elusive. The study proposes a definition of functional diversity by analogizing species diversity components—richness, evenness, and divergence. The authors apply these concepts to functional traits, defining functional richness, functional evenness, and functional divergence, and demonstrate how to calculate each component. They anticipate that this definition and its components will aid in elucidating the mechanisms linking diversity to ecosystem function.

Abstract

Functional diversity is hypothesised as being beneficial for ecosystem functions, such as productivity and resistance to invasion. However, a precise definition of functional diversity, and hence a framework for its quantification, have proved elusive. We present a definition based on the analogy of the components of species diversity – richness, evenness and divergence. These concepts are applied to functional characters to give three components of functional diversity – functional richness, functional evenness and functional divergence. We demonstrate how each of these components may be calculated. It is hoped that our definition of functional diversity and its components will aid in elucidation of the mechanisms behind diversity/ecosystem‐function relationships.