Analyzing Trophic Ecosystem Functions with the Interaction Functional Space.

Trophic ecosystem functions between consumer and resource species have been explored either using functional trait diversity or interaction networks.However, these approaches miss a critical element that has not been addressed yet: traits only impact trophic ecosystem functions when species interact.Understanding the mechanisms shaping trophic ecosystem functions requires the integration of functional and network ecology into a single trait-based framework.Based on previous developments of functional diversity and interactions networks, we present the interaction functional space (IFS) as an integrative framework to analyze how the traits of interacting species build up a combined functional space that underpins trophic ecosystem functions.The IFS can be applied to a broad range of trophic functions to understand how they emerge and change under global change.