Mutualism and Dispersal Heterogeneity Shape Stability, Biodiversity, and Structure of Theoretical Plant-Pollinator Meta-Networks.

Mutualistic interactions are crucial to the structure and functioning of ecological communities, playing a vital role in maintaining biodiversity amidst environmental perturbations. In studies of meta-networks, which are groups of local networks connected by dispersal, most research has focused on the effect of dispersal on interaction networks of competition and predation, without much attention given to mutualistic interactions. Consequently, the role of different dispersal rates (between local networks and across species) in stability and network structures is not well understood. We present a competition-mutualism model for meta-networks where mutualistic interactions follow a type II functional response, to investigate stability and species abundance dynamics under varying dispersal scenarios. We specifically assess the impact of mutualism and dispersal heterogeneity, both between local networks and across species, on the structure and stability of meta-networks. We find that mutualistic meta-networks exhibit greater stability, higher total abundance, lower species unevenness, and greater nestedness compared to meta-networks with only competition interactions. Although dispersal heterogeneity across species exerts some influence, dispersal heterogeneity between local networks mainly drives the patterns observed: it reduces total abundance, increases unevenness, and diminishes compositional similarity across the meta-network. These results highlight the pivotal role of both mutualism and spatial dispersal structure in shaping ecological networks. Our work advances understanding of how mutualistic interactions and dispersal dynamics interact to influence biodiversity and stability in complex ecosystems.