The Historic Fire Return Interval and the Ecological Effects of Fire Suppression on Montane Longleaf Pine Dominated Ecosystems in Northwestern Georgia.

Longleaf pine ecosystems have experienced pronounced declines across the southeastern United States since Euro-American settlement took place in the late 19th century. These declines were primarily caused by federal fire suppression policies implemented in the 1920’s, in combination with resource harvesting and land use conversion. In an absence of fire, tree species composition of frequently burned xeric ecosystems progressively becomes more mesic and fire-intolerant (i.e. mesophication). The change in the species composition and historic fire frequency of a montane longleaf pine ecosystem located in Sheffield Wildlife Management Area (WMA), Paulding County, Georgia was investigated. The change in forest composition was measured using modern vegetation surveys and historic “witness tree” vegetation data obtained from a georeferenced 1832 Georgia Land Lottery Survey map. The historic fire return interval was estimated using remnant longleaf stumps and dendrochronological techniques. Results from chi-squared tests indicated the modern forest is significantly more mesic and fire-intolerant than the historic forest (p \u3c 0.0001), with no statistically significant difference in species composition between north- and south-facing slopes. A chronology for longleaf pine was constructed using 214 cores from extant longleaf pine and 14 relict stumps found in Sheffield WMA. Using fire scars found in seven of the preserved stumps, the historic mean fire return interval was calculated to be 5.5-years with a median return interval of 3.5-years. It was concluded that mesophication has occurred in Sheffield WMA since Euro-American settlement, and that fires were historically present in the forest but likely of low intensity and fragmented across the landscape