Disturbance is a key ecological process that influences species diversity, community stability, and invasibility at various spatial and temporal scales. However, less clear is whether community responses are contingent on scales of observation, community structure prior to disturbance, or interactions among these factors. We investigated how the vascular plant community responded to a gradient of forest canopy disturbance intensity in Appalachian hardwood forests of Virginia and West Virginia, varying in initial diversity. Five disturbance treatments (from uncut control to clearcut) replicated at seven sites were sampled three times including before disturbance, one year following, and ten years following. Data were used to estimate species diversity, community stability (resistance and resilience in community composition), and invasibility (number of nonnative species introduced) at three spatial scales.
Results/Conclusions
Diversity tended to increase with disturbance intensity and remained high ten years following disturbance. Resistance in species compositional shifts was lowest in the most disturbed treatments, but resilience (i.e., return to pre-disturbance composition) did not differ between treatments. However, resilience was lower in sites with higher pre-disturbance diversity. The latter pattern suggests that higher species diversity allows greater long-term community shifts following disturbance. Invasibility increased with increasing disturbance intensity and tended to be positively correlated with native species diversity. However, nonnative species richness decreased ten years after disturbance. These results suggest that communities are shaped by both the species pools present during disturbance as well as disturbance intensity.
