Poster Session # 11: Disturbance Ecology.

Tuesday, August 5 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Fire history of a Florida barrier island slash pine savanna.

Huffman, Jean*,1, Platt, William1, Grissino Mayer, Henri2, Boyce, Carla3, 1 Louisiana State University, Baton Rouge, LA2 University of Tennessee, Knoxville, TN3 Apalachicola National Estuarine Research Reserve, Eastpoint, FL

ABSTRACT- Fire regimes of pine savannas on barrier islands along the coast of the Gulf of Mexico are unknown. We determined the years and seasons of fires and turpentine operations using dendrochronological techniques to precisely date scars from 54 slash pines (Pinus elliottii var. elliottii ) on Little St. George Island, an undeveloped barrier island. We also mapped the spatial distribution of past fires. Five separate periods with different fire frequencies were found. Fires were frequent between 1866 and 1904 (mean fire-return interval of 4 years). No scars were found from 1905-1923, years during which turpentine operations (1912-1918) protected trees from fires. Frequent fires were again recorded from 1924-1945, (mean fire return interval of 4 years). During the period from 1945-1962, turpentine operations (1949-1956) protected trees from fires and no fire scars were found. The most recent period, 1963 to the present, had a mean fire-return interval of 9 years with active, although not entirely effective, fire suppression. Most historic fires occurred during the lightning season. Although the trees used in this study were not old enough to determine pre-settlement fire frequencies, the data does reveal much about fire regimes on this barrier island during the past 145 years, showing that historic fire regimes of this barrier island slash pine savanna consisted of predominately growing-season fires with short fire return intervals.

Key words: barrier island, Pinus elliottii var. elliottii, fire history, fire frequency and season