Traits Without Borders: Integrating Functional Diversity Across Scales

• Published in: Trends in ecology & evolution (Amsterdam) Vol. 31; no. 5; pp. 382 - 394
• Main Authors: Carmona, Carlos P., de Bello, Francesco, Mason, Norman W.H., Lepš, Jan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2016
• Subjects: Ecology; Ecosystem; functional diversity; Models, Biological; Phenotype; Probability; probability distribution; uncertainty
• ISSN: 0169-5347; 1872-8383; 1872-8383
• DOI: 10.1016/j.tree.2016.02.003

Owing to the conceptual complexity of functional diversity (FD), a multitude of different methods are available for measuring it, with most being operational at only a small range of spatial scales. This causes uncertainty in ecological interpretations and limits the potential to generalize findings across studies or compare patterns across scales. We solve this problem by providing a unified framework expanding on and integrating existing approaches. The framework, based on trait probability density (TPD), is the first to fully implement the Hutchinsonian concept of the niche as a probabilistic hypervolume in estimating FD. This novel approach could revolutionize FD-based research by allowing quantification of the various FD components from organismal to macroecological scales, and allowing seamless transitions between scales. Functional trait diversity, in other words the variation of traits between organisms, can be used to address a great number of pressing ecological questions. Consequently, trait-based approaches are increasingly being used by ecologists. However, functional diversity comprises several components that can be evaluated at different spatial scales. Because of this conceptual complexity, there is an overabundance of disparate approaches for estimating it, which leads to confusion among users and hampers the comparability of different studies. A single mathematical framework encompassing different approaches while providing a seamless continuity between spatial scales is needed. Reconciling the approaches based on the concept of the niche as a hypervolume and those that consider traits in probabilistic terms is the first step towards the foundation of a unified framework.