The role of dormant propagule banks in shaping eco-evolutionary dynamics of community assembly

Abstract

The metacommunity framework provides a theoretical framework for understanding how dispersal alters species distribution patterns at different spatial scales. Dormancy is a strategy that decreases the extinction risk and can be viewed as dispersal over time, shaping the assembly dynamics of populations and communities. However, dormancy has only recently been recognized as a potentially important mediator of metacommunity-level processes. Here, we extend an individual-based model of metacommunity dynamics by adding propagule banks that store dormant propagules that can hatch in subsequent growing seasons. By systematically varying the propagule bank size in the model, we investigated how dormant propagule bank size influenced the eco-evolutionary dynamics of community assembly in populations of both asexual and sexual species at three dispersal levels (isolated communities and weakly and strongly connected communities). Our simulations show that as the propagule bank size increases, 1) the rate of evolution decreases in asexual species, whereas the rate of evolution increases in sexual species; 2) species sorting becomes less important while evolution-mediated zpriority effects (monopolization) make a more significant contribution; and 3) -diversity decreases and {beta}-diversity increases. We also found that patches with well-established propagule banks contributed more to the regional species pool than patches with less well-developed propagule banks. Dispersal asymmetries also emerge as patches with a well-established bank tend to reduce the invasion success of new arrivals while also providing more emigrants with diverse genetic variation to the other patches, fostering regional monopolization. To this end, we regard the banks in a metacommunity as a hidden state of a local community, a potential gene pool, and a latent part of a regional species pool.