Trophic complementarity drives the biodiversity–ecosystem functioning relationship in food webs

Abstract

The biodiversity-ecosystem functioning (BEF) relationship is central in community ecology. Its drivers in competitive systems (sampling effect and functional complementarity) are intuitive and elegant, but we lack an integrative understanding of these drivers in complex ecosystems. Because networks encompass two key components of the BEF relationship (species richness and biomass flow), they provide a key to identify these drivers, assuming that we have a meaningful measure of functional complementarity. In a network, diversity can be defined by species richness, the number of trophic levels, but perhaps more importantly, the diversity of interactions. In this paper, we define the concept of trophic complementarity (TC), which emerges through exploitative and apparent competition processes, and study its contribution to ecosystem functioning. Using a model of trophic community dynamics, we show that TC predicts various measures of ecosystem functioning, and generate a range of testable predictions. We find that, in addition to the number of species, the structure of their interactions needs to be accounted for to predict ecosystem productivity.

A Generalist Protist Predator Enables Coexistence in Multitrophic Predator-Prey Systems Containing a Phage and the Bacterial Predator Bdellovibrio

“…Due to the predators' partially distinct prey range and a potential trophic complementarity, we expected the greatest prey removal in the presence of all three predators (Poisot et al, 2013). However, we did not find the number of different predators to be a trigger for increased prey removal, but rather the prey range of a predator.…”

Biodiversity and ecosystem functioning in evolving food webs

“…Alternative definitions of functional diversities can be found in [41]. A measure of link overlap that additionally includes the overlap in predator links and that is applicable to discrete trophic layers was introduced by Poisot et al [26]. We analyse the relationship between FD and five measures of ecosystem functioning:…”

“…These are the metabolic loss of the predator community, the total biomasses of the basal and the predator community, and the consumption rates on the basal community and within the predator community. Theoretical [24][25][26] and empirical [27] food web studies suggest a large variety of different BEF relations, owing to bottom-up or top-down effects. Other studies suggest a saturation of BEF relations owing to the dampening of trophic cascades in complex and diverse communities [28][29][30][31][32][33].…”

Uses of Innovative Modeling Tools within the Implementation of the Marine Strategy Framework Directive

“…The fragmentation of habitats is a threat to the maintenance of biological diversity, thus dispersal traits of species and the connectivity within and between population and communities are important attributes of species distributional patterns (Chust et al, 2016). As multiple species traits are likely to influence trophic interactions and functioning, approaches which seek to integrate trait-based methods with the food webs framework are also emerging with many recent advances stemming from modeling work (e.g., Thompson et al, 2012;Eklöf et al, 2013;Poisot et al, 2013;Nordström et al, 2015). These have shown to be successful at predicting network structure (Eklöf et al, 2013), in determining the strength of individual trophic links (Klecka and Boukal, 2013), highlighting that multiple traits are needed for more complete descriptions of interactions (Eklöf et al, 2013) and that functional and trophic attributes should be assessed in an integrated manner to provide accurate assessments in a changing environment (Boukal, 2014).…”