Tri‐trophic interactions: bridging species, communities and ecosystems

Abstract

A vast body of research demonstrates that many ecological and evolutionary processes can only be understood from a tri‐trophic viewpoint, that is, one that moves beyond the pairwise interactions of neighbouring trophic levels to consider the emergent features of interactions among multiple trophic levels. Despite its unifying potential, tri‐trophic research has been fragmented, following two distinct paths. One has focused on the population biology and evolutionary ecology of simple food chains of interacting species. The other has focused on bottom‐up and top‐down controls over the distribution of biomass across trophic levels and other ecosystem‐level variables. Here, we propose pathways to bridge these two long‐standing perspectives. We argue that an expanded theory of tri‐trophic interactions (TTIs) can unify our understanding of biological processes across scales and levels of organisation, ranging from species evolution and pairwise interactions to community structure and ecosystem function. To do so requires addressing how community structure and ecosystem function arise as emergent properties of component TTIs, and, in turn, how species traits and TTIs are shaped by the ecosystem processes and the abiotic environment in which they are embedded. We conclude that novel insights will come from applying tri‐trophic theory systematically across all levels of biological organisation.

Molecular Ecological Network Analyses: An Effective Conservation Tool for the Assessment of Biodiversity, Trophic Interactions, and Community Structure

“…While many of these studies targeted the diet of a single species or a trophic guild, few compared across mammal species and multiple trophic levels, a shortcoming that hinders our full knowledge of complex ecological processes (Eisenhauer et al, 2019). Multitrophic perspectives provide a better understanding of ecological and evolutionary processes than do typical pairwise interactions between trophic levels (Abdala-Roberts et al, 2019). Despite this, our knowledge of ecosystem function in multitrophic communities is limited to date (Eisenhauer et al, 2019).…”

Impact of pathogenic fungi, herbivores and predators on secondary succession of tropical rainforest vegetation

“…However, the presence of higher trophic levels is known to influence plant responses to their natural enemies (Abdala-Roberts et al, 2019). Predators may control abundance of their prey and trigger shifts in herbivore host use.…”

Top predators govern multitrophic diversity effects in tritrophic food webs

“…In this study, we want to advance our understanding of how functional diversity affects ecosystem functioning in model communities by including a diverse third trophic level. While it has often been highlighted how important the effects of the third trophic level on ecosystem functions are (Bruno and O’Connor, 2005; Duffy et al, 2007; Daam et al, 2019; Abdala-Roberts et al, 2019; Ehrlich and Gaedke, 2020), relatively few studies have attempted to explicitly take these effects into account. Ceulemans et al (2019) showed that functional diversity increases the biomass production, temporal stability, and biomass transfer efficiency to higher trophic levels of a tritrophic food web, when diversity is increased simultaneously at all three trophic levels.…”