The long-term role of fire in the southern Appalachians and its interplay with southern yellow pines is a theme that has generated speculation, but little hard evidence. Indigenous and Euro-American societies have left unique signatures of land use in the southern Appalachian region, but to what extent has each subsequent group of inhabitants created changes in forest composition and fire occurrence?
Doctoral student Christopher Underwood, under the supervision of Dr. Sally Horn at the University of Tennesse seeks to document forest and fire history in modern yellow pine and mixed hardwood-pine forests of Great Smoky Mountains National Park, Tennessee, through the recovery, identification, and dating of soil charcoal. The over-arching idea to be tested is whether prehistoric fires set by indigenous occupants or lightning caused sufficient disturbance to maintain yellow pine communities on sites other than rocky slopes and ridge tops. Forty-eight soil cores for charcoal analysis have been recovered from eight sites in the western portion of the park. In a companion study, other researchers have quantified modern forest composition and tree age structures at the eight sites, and have reconstructed fires over the past several centuries based on analyses of fire-scarred trees. The identification and dating of macroscopic charcoal fragments will extend the dendrochronological record of fire, and provide evidence of past local fires and forest composition that cannot be obtained through any other method. While charcoal assemblages in surface soils reflect forest composition at the time of historic fires, charcoal assemblages at depth include significantly older particles that provide evidence of local forest composition before the period of Euro-American settlement. Comparing surface charcoal assemblages to recent forest composition as documented by vegetation surveys provides a basis for calibrating the taxonomic signal provided by this deep charcoal.
This research will be the first to specifically address the spatio-temporal patterns of forest composition and fire history in the southern Appalachians using taxonomically-identified soil charcoal as the primary proxy. Information on forest composition and fire history in the early historic and prehistoric periods is needed to help place indigenous and Euro-American human impacts on forest composition and fire history in context. This research design can also be applied in other regions to facilitate similar studies. Data and conclusions will assist forest and park managers in making conservation and management decisions regarding forest and fire management. Information about past forest fires and the departure of current fire occurrences from past conditions is important for guiding and justifying forest management practices such as the use of prescribed burns for ecosystem restoration. A better understanding of long-term fire-vegetation dynamics is important not only to the health and conservation of the forest communities of the southern Appalachians, but also to the protection of human life and property along the expanding forest-urban interface of Great Smoky Mountains National Park.
