A framework to assess the effects of changes in species composition on processes derived from trophic interactions

Abstract

Functional diversity uses response and effect traits to understand how communities are affected by changes in the environment and the consequences of modifications on communities composition to the ecosystem functioning. However, most studies focus on a single taxonomic or functional group, ignoring that many processes result from interspecific interactions. Here we established a multi-trophic trait-based framework to evaluate the consequences of community change for ecological processes. Specifically, we estimate each species’ potential effect taking in account the consumers and resource communities involved on the trophic interaction. Both communities’ functional spaces are incorporated into a single analysis by using resource traits to estimate consumers’ functional space. The framework includes a parameter that allows giving different weights to unique interactions when estimating a species potential effect. We present two modifications for application using abundance and species richness data and two modifications to allow incorporating absent species into the analysis. Our framework can be used to investigate consequences of community changes in different situations, such as species extinctions, invasions and refaunation. To demonstrate the insights derived from our framework we use an exemplary study case of refaunation of an impacted tropical forest. This framework informs on a species contribution to an ecological process according to the uniqueness or redundancy of its interactions and the magnitude of its effect, indicated by the frequency of the resource’s community trait values with which it interacts. Thus, it helps to increase the understanding of the effects of changes in community composition on ecological processes resulting from trophic interactions. It assists practitioners and researches with predictions and evaluations on potential loss and reestablishment of ecological functions resulted from changes in community functional composition.

The contribution of mutualistic interactions to functional and phylogenetic diversity

“…This approach facilitates comparisons of functional roles in ecological processes (Fig. 1c) and has led to new insights into species' contributions to ecological processes [44][45][46] and spatio-temporal variation in species' functional roles [41,47,48].…”