Vegetation Recovery Following High-intensity Wildfire and Silvicultural Treatments in Sand Pine Scrub
We hypothesized that clear-cutting mimics natural high-intensity disturbance by wildfire followed by salvage logging in sand pine scrub, and tested whether vegetation adapted to recovery from fire would respond similarly to another type of biomass removal. We measured plant community composition and structural characteristics in three replicated disturbance treatments and in mature sand pine forest (MF). Treatments were: (1) high-intensity burn, salvage logged and naturally regenerated (HIBS); (2) clear-cut, roller-chopped, and broadcast-seeded (RC); and (3) clear-cut and bracke-seeded (BK). All treatments were sampled 5-7 yr postdisturbance. Nonwoody plant species richness and diversity were significantly lower in MF than in disturbance treatments. Ruderal species were more abundant in HIBS and RC, but not to the exclusion of the characteristic suite of native scrub species. Shrub richness and diversity did not differ, but some species responded differently among treatments. Differences may be due to season of disturbance or rhizome depth [e.g., Serenoa repens (Bartr.) Small vs. Sabal etonia Swingle ex Nash.]. Oakstem density was significantly lower in HIBS and RC. Most suuctural characteristics were similar in HIBS, RC and BK but differed from MF. Results suggest that many scrub species responded similarly to aboveground biomass removal and the consequent structural and microclimatic conditions across these disturbance types. We suggest that plant resiliency traits, which evolved in response to the selective pressures of high-intensity disturbance and harsh environmental conditions, confer resiliency to human-caused disturbance as well. Mechanical biomass removal may be a suitable ecosystem management practice where burning is impractical. Due to the absence of a "virgin" (unsalvaged) burn treatment or pretreatment data and the short-term scope of this study, interpretation of results should be made with caution.