Long-term Fire History from Sedimentary Charcoal in the Eastern Highland Rim of Tennessee

Lead Presenter(s)

Christian Rees

Abstract or Description

Charcoal in sediment cores from lakes and wetlands can provide information on long-term fire history. Natural lakes are rare in Tennessee, but wetlands are common in some areas. One area in particular with a high concentration of wetlands is the wildlife management area at Arnold Air Force Base (AAFB) in Tullahoma, Tennessee. Here we examined the charcoal stratigraphy of cores from two small wetland ponds located 2 km apart to reconstruct long-term fire history in the Eastern Highland Rim. The cores from Wetland H1 and H2 are both only about 0.6 m long, but reach into the late Pleistocene, to ca. 16,500 and 18,700 cal yr BP, respectively. These core lengths and ages are consistent with results from other wetlands at AAFB and may include hiatuses in sedimentation. We isolated charcoal from core samples by sieving using a 125-micron screen. The pattern of charcoal abundance through the profiles is similar at the two sites, with H1 having an average concentration of 30 particles per cm3 and H2 having an average concentration of 22 particles per cm3. Both show lowest charcoal concentrations in deeper sediments, increasing steeply upcore at Wetland H1 and more gradually at H2. The high concentrations of charcoal correspond to the Holocene, but additional radiocarbon dates are needed to develop age models. Our results suggest fire activity was low during the late Pleistocene and increased during the Holocene at the site, possibly associated with Indigenous American settlement and use of fire.

Mentor

Sally P. Horn