PARENT SESSION
Oral Session #59: Conservation Ecology: Terrestrial Biodiversity. Presiding: K. Schulz.
Thursday, August 9, 2001. 8:00 AM to 12:15 PM. Madison Ballroom D.
Rare vascular flora of the longleaf pine-wiregrass ecosystem: temporal responses to fire frequency.
Shipley, Janet1,2, Wentworth, Thomas2, Brownie, Cavell2, 1 2
ABSTRACT- We examined factors likely to be important in the management of rare flora occurring in the longleaf pine-wiregrass ecosystem on Fort Bragg and Camp Mackall Military Reservations in North Carolina. Thirty-six rare plant taxa, comprising 1,268 records, were documented during the course of two inventories of rare flora conducted during the periods 1991-93 and 1998-99. There were 891 (70.3%) records of persistence, 258 (20.3%) records of extinction, and 119 (9.4%) records of colonization; extinctions exceeded colonizations by 139 records. We used analyses of contingency tables and logit regressions to test hypotheses about temporal responses of local populations of rare flora. We found statistically significant effects of fire frequency on the persistence, colonization, and extinction of rare flora; extinctions declined and colonizations increased with increasing fire frequency. We also found statistically significant effects of both area occupied and stem number on the persistence and extinction of rare flora; extinctions declined and persistences increased with increasing area occupied and stem number. Our analyses indicate the importance of fire for the conservation of rare flora in this landscape. Local populations occupying larger areas or having greater numbers of stems are more likely to persist.
KEY WORDS: rare flora, fire frequency, longleaf pine-wiregrass ecosystem, conservation biology