Clustering of dispersal corridors in metapopulations leads to higher rates of recovery following subpopulation extinction

Understanding how spatially divided populations are affected by the physical characteristics of the landscapes they occupy is critical to their conservation. While some metapopulations have dispersal corridors spread relatively evenly through space in a homogeneous arrangement such that most subpopulations are connected to a few neighbors, others may have corridors clustered in a heterogeneous arrangement, creating a few highly connected subpopulations and leaving most subpopulations with only one or two neighbors. Graph theory and empirical data from other biological and non-biological networks suggest that heterogeneous metapopulations should be the most robust to subpopulation extinction. Here, I used Pseudomonas syringae pv. syringae B728a in metapopulation microcosms to compare the recovery of metapopulations with homogeneous and heterogeneous corridor arrangements following small, medium, and large subpopulation extinction events. I found that while metapopulations with heterogeneous corridor arrangements had the fastest rates of recovery following extinction events of all sizes and had the shortest absolute time to recovery following medium-sized extinction events, metapopulations with homogeneous corridor arrangements had the shortest time to recovery following the smallest extinction events.