VEGETATION RECOVERY FOLLOWING HIGH-INTENSITY WILDFIRE AND SILVICULTURAL TREATMENTS IN SAND PINE SCRUB

We hypothesized that clear-cutting mimics natural high-intensity distu rbance 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 commu nity composition and structural characteristics in three replicated di sturbance treatments and in mature sand pine forest (MF). Treatments w ere: (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 wer e significantly lower in MF than in disturbance treatments. Ruderal sp ecies were more abundant in HIBS and RC, but not to the exclusion of t he characteristic suite of native scrub species. Shrub richness and di versity did not differ, but some species responded differently among t reatments. Differences may be due to season of disturbance or rhizome depth [e.g., Serenoa repens (Bartr.) Small vs. Sabal etonia Swingle ex Nash.]. Oak stem density was significantly lower in HIBS and RC. Most structural characteristics were similar in HIBS, RC and BM but differ ed from MF. Results suggest that many scrub species responded similarl y to aboveground biomass removal and the consequent structural and mic roclimatic conditions across these disturbance types. We suggest that plant resiliency traits, which evolved in response to the selective pr essures of high-intensity disturbance and harsh environmental conditio ns, 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.