Monday, August 6, 2007

PS 18-176: Responses of Florida oak scrub vegetation to multiple cycles of cutting and burning

Paul A. Schmalzer and Tammy E. Foster. Dynamac Corporation

Oak scrub and oak-saw palmetto scrub in Florida are shrub communities maintained by periodic, high intensity fires. They are habitat for the threatened Florida Scrub-Jay (Aphelocoma coerulescens) and other species of conservation concern. With fire suppression, scrub oaks increase in size, sandy openings decline, and habitat conditions for Scrub-Jays and other species decline. Prescribed burning is required to manage scrub. With burning, cover of saw palmetto (Serenoa repens) > 0.5 m in height returns to preburn levels in 1-2 years. Cover of woody shrubs (oaks, ericads) > 0.5 m is similar to preburn values within 5 years. With long periods of fire suppression, oaks become fire resistant, and mechanical cutting combined with burning is necessary for restoration. We have examined vegetation responses to combinations of cutting and burning using permanent 15 m line-intercept transects on Kennedy Space Center/Merritt Island National Wildlife Refuge since 1992. Nineteen stands with123 transects have been sampled for different lengths of time.  Oaks and ericads resprout after burning and cutting/burning treatments. Saw palmetto cover is reduced by mechanical treatments, and the reduction is persistent (>10 years). Five stands (44 transects) have now been burned a second time after the initial restoration. Saw palmetto cover in sites cut once and burned twice recovers to the level before the second burn promptly. Transects cut twice and burned twice show further reduction of saw palmetto. Saw palmetto is the most flammable component of the system, and its loss may reduce the ability to manage the system with prescribed burning.

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See more of The ESA/SER Joint Meeting (August 5 -- August 10, 2007)