Species persistence in spatially regular networks

Over the past decades, numerous studies have provided new insights into the importance of spatial network structure for metapopulation persistence. However, systematic work on how variation in patch degree (i.e., the number of neighbors of a patch) in spatial networks modifies metapopulation dynamics is still lacking. Using both pair approximation (PA) and cellular automaton (CA) models, we investigate how different patch network structures affect species persistence while considering both local and global dispersal. Generally, the PA model displays similar metapopulation patterns compared to the CA simulations. Using both models, we find that an increase of relative extinction rate decreases global patch occupancy (GPO) and thereby increases the extinction risk for local dispersers, while increasing patch degree promotes species persistence through increasing dispersal pathways. Interestingly, patch degree does not affect local species clumping in spatially regular patch networks. Relative to local dispersers, species with global dispersal can maintain the highest GPO, and their metapopulation dynamics are not influenced by spatial network structure, as they can establish in any patch randomly without dispersal limitation. Concerning species conservation, we theoretically demonstrate that increasing patch connectivity (e.g., constructing ecological corridors) in spatial patch networks would be an effective strategy for the survival of species with distance-limited dispersal.