Dispersal underpins mismatches between persistence and occupancy
By exploring (mis)matches between occupancy and persistence across the productivity gradient, we found that the role of dispersal is contingent upon environmental conditions (Fig. 4, Table S6). In unproductive environments, populations were most likely to be well-matched to conditions they were found in regardless of whether neighbors were present or absent–species sorting was observed in 65% of species [51-81] with neighbors, compared to 0.64 [0.51, 0.78] without neighbors (Fig. 4; gray). By contrast, in productive environments, sink populations were common, especially in the presence of neighbors, suggesting that dispersal tended to be excessive, causing populations in locations that could not maintain a positive growth rate (Table S6). Growth rates and proportion of sink populations were not dependent on intraspecific density dependence (Figs. S7, S8). Generally, dispersal limitation was uncommon regardless of species interactions. Similar qualitative trends in species sorting, dispersal limitation, and dispersal excess occurred with neighbors and without neighbors (Table S6).