Interactive effects of disturbance and dispersal on community assembly

The traditional debate on alternative community states has been over whether or not they exist. Studies of community assembly have examined the role of assembly history in driving community divergence, but the context in which assembly history becomes important is a continued topic of interest. In this study, we created communities of bacterivorous ciliated protists in laboratory microcosms and manipulated assembly history, disturbance frequency, and the presence of dispersal among local communities to investigate the mechanisms behind community divergence. Specifically, we sought to understand how the role of assembly history changed in response to disturbance, dispersal, and the combination of the two. Assembly history influenced the identity of the dominant species through priority effects, and dispersal and disturbance showed interactive effects on both alpha and beta diversity. Dispersal substantially increased alpha diversity, but only in the absence of disturbance, and it reduced...