Trait concepts, categories, and databases in soil invertebrate ecology – ordering the mess

Abstract

The trait-based approach is increasingly used for soil invertebrates. Complementary to the taxonomy based approach, the trait-based approach can provide a more mechanistic understanding of the responses of organisms to environmental disturbances and of their effects on soil functioning. However, this approach has several limitations linked to the conceptual development of functional traits. There is a large ambiguity and variability in using the term "functional traits” by zoologists and ecologists working with soil invertebrates. In this study, we used a questionnaire and literature scanning to review the practical use of functional traits concept in soil ecology over the last decade. We clarifed and expanded the functional trait definition as "A functional trait is a measurable characteristic of an individual organism or its colony that has a clear link to the organism's fitness and/or its effect on other organisms and/or the environment”. We also reviewed existing trait databases showing a high amount, but also high heterogeneity and low accessibility of data on the functional traits of soil invertebrates. We suggest synthesising existing trait data and databases, using the functional trait-based approach consistently and reproducibly, and disseminating it to facilitate mechanistic research in soil ecology.

Keywords

• functional traits
• soil fauna
• functional ecology
• community ecology
• terminology