Box 2: Principles of species coexistence and exclusion in trophic modules P* rule (apparent competition): The basal (or prey) species capable of sustaining the highest predation pressure dominates the competition and can indirectly exclude its competitor due to higher predation mortality (Holt et al. 1994). R* rule (exploitative competition): Consumer species with the lowest resource requirements is competitively superior (Tilman 1985). This can lead to the exclusion of the inferior competitor or its presence at a lower biomass density. Extinction cascade (trophic chain): A specialist predator cannot persist without its prey. Any species loss within a chain leads to a cascading collapse of all species at higher trophic levels in that chain. Omnivory (intraguild predation): Coexistence in the IGP module relies on two principles, i.e., intraguild prey must be competitively superior to the intraguild predator (R* rule) and must be resilient to predation-induced mortality to avoid its own exclusion (Holt & Polis 1997; Wootton 2017).