The importance of species traits in biodiversity-ecosystem functioning research

Biodiversity‐ecosystem functioning research is a major field in ecology. Currently research on biodiversity and ecosystem functioning is shifting from focusing on species diversity to focus on functional diversity. From this point of views species traits play a central role, because it is the traits that determine how a species reacts to environmental change, and how this reaction influences ecosystem functions. In this essay, I present an overview over the nature and measurement of traits, and highlight examples of trait based approaches from different ecosystems. Despite that there is an increasing numbers of studies dealing with this topic, there is still confusion about the terminology of traits and functional groups. A new concept, dividing species traits into response‐ and effect traits seems to be a promising step forward. So far, focus has been placed on plants, because these are the most studied organisms in this field. Some key plant traits, such as leaf dry matter content (LDMC) and specific leaf area (SLA), are identified to be important factors determining species responses to environmental change, and seem to affect ecosystem functioning. Although decomposition is an ecosystem function of fundamental importance, the knowledge about soil communities is still limited. Despite that they are known to have considerable effects on decomposition rates, soil animal traits are rarely considered in decomposition studies. A change may, however be on its way, as the interest of the role of soil animal traits recently seem to be increasing.