Local and Spatial Processes Shape the Collapse and Recovery of Mutualistic Networks

Abstract

Ecosystems can undergo abrupt critical transitions even when environmental change is gradual, resulting in hysteresis, where recovery requires conditions far more favorable than those that triggered collapse. While previous research has mainly focused on local network dynamics, the role of spatial heterogeneity and dispersal in mutualistic ecosystem resilience remains less explored. This study examines how spatial structures--grid, random, small-world, and scale-free networks--interact with dispersal rates to influence ecosystem recovery and mutualistic network persistence. We find that with low dispersal, restoration cost is similar across spatial structures, but at intermediate dispersal rates, scale-free networks show faster recovery and smaller restoration costs. At high dispersal rates, increased connectivity initially reduces restoration cost; however, over time, homogenization weakens spatial heterogeneity, causing restoration cost to increase. Importantly, increasing nestedness can delay collapse but also extends the recovery distance, making ecosystems harder to restore. By adjusting dispersal rates and transitioning from homogeneous to heterogeneous spatial structures, we can decrease restoration cost and improve ecosystem stability, offering key insights for ecological management strategies.