Food web energy fluxes and their relation to ecosystem services across ecosystems – From Barnes et al. (2018) TREE

Research efforts have long focused on how biodiversity influences ecosystem function, with recent attention turning toward multitrophic biodiversity and the provisioning of multiple ecosystem functions. What still remains poorly understood is how interactions among trophic groups are linked to specific functions as well as ecosystem multifunctionality, especially in real-world ecosystems.

We have been addressing this challenge by investigating energy fluxes among trophic groups in food webs, as these fluxes characterise ecosystem functions carried out by respective consumers. While the concept of energy flux in ecological networks is not new, its application in understanding the relationship between multitrophic community structure and ecosystem functioning has gone relatively unexplored.

In a recent review paper, we formalise this concept within a framework for assessing ecosystem functioning in multitrophic systems (above). We have also developed a method for quantifying energy flux in networks that is particularly useful for biodiversity studies in both experimental and real-world systems (below). We have applied this to investigate the impacts of land-use change on litter invertebrate community structure and multitrophic functioning in Indonesia, as well as to disentangle the factors that modulate spatial turnover in multitrophic functioning of invertebrate communities across temperate and tropical forest landscapes.

A forest soil food web from central Germany with weighted arrows to represent energy fluxes – From Gauzens et al. (2019)
Estimated rates of ecosystem functioning based on energy fluxes in the German soil food web – From Gauzens et al. (2019).