Provision of essential resources as a higher-order interaction that ensures persistence in food webs
Higher-order interactions are increasingly recognized as important building bricks when assembling small food web modules to ultimately capture natural food web dynamics. A prominent representative of such food web modules is apparent competition of two prey types mediated by a shared predator. In this presentation, I will present how the provision of essential resources by one prey species within an apparent competition module creates a higher-order interaction that prevents extinction of that prey type. I cover both the provision of essential resources for the competitor, as well as for the shared predator and show that this ensures persistence for trait combinations that would otherwise exclude the focal prey. Motivated by realistic, but also assumption-rich model formulations based on rotifer-algae-bacteria systems, I generalize the food web model and show that the underlying mechanism is robust and requires only few specific assumptions. Therefore, I postulate that this higher-order interaction constitutes a so far unrecognized coexistence mechanism that likely occurs in aquatic food webs.
Host: Luc De Meester