Temporal vegetation dynamics and recolonization mechanisms on different-sized soil disturbances in tallgrass prairie

Assessing the various mechanisms by which plants revegetate disturbances is important for understanding the effects of disturbances on plant populatio n dynamics, plant community structure, community assembly processes, and ec osystem function. We initiated a 2-yr experiment examining temporal vegetat ion dynamics and mechanisms of recolonization on different-sized soil distu rbances created to simulate pocket gopher mounds in North American tallgras s prairie. Treatments were designed to assess potential contributions of th e seed rain, soil seed bank, clonal propagation from the edges of a soil mo und, and regrowth of buried plants. Small mounds were more rapidly recoloni zed than large mounds. Vegetative regrowth strategies were the dominant rec olonization mechanisms, while the seed rain was considerably less important in maintaining the diversity of forbs and annuals than previously believed . All recolonization mechanisms influenced plant succession, but stem densi ties and plant mass on soil mounds remained significantly lower than undist urbed controls after two growing seasons. Because natural pocket gopher mou nds are indistinguishable from undisturbed areas after two seasons, these r esults suggest that multiple modes of recruitment concurrently, albeit diff erentially, contribute to the recolonization of soil disturbances and influ ence tallgrass prairie plant community structure and successional dynamics.