Occurrence of Fire in Southern Appalachian Yellow Pine Forests As Indicated by Macroscopic Charcoal in Soil

ABSTRACT
Federal land managers use prescribed burning to restore degraded yellow pine stands of the southern Appalachian Mountains. When justifying burning decisions, land managers need evidence of past fire occurrences in the selected stands. This research explored using macroscopic charcoal in soils as an indicator of past fire occurrences. Soil cores were extracted in 10-cm increments from seven yellow pine stands. Soil cores were retrieved from erosional (summit, shoulder, backslope) and depositional (footslope and toeslope) slope positions. Each 10-cm soil sample was examined for the presence or absence of charcoal. The mean percentage of soil samples per site containing macroscopic charcoal fragments was 85.0 ± 12.5%. The presence or absence of charcoal did not differ with sampling depth or with slope position. These results demonstrated that macroscopic charcoal is present in soils supporting these yellow pine stands and serves as an indicator of past fire events. It is important to remember that the charcoal in each sample may be from multiple fires. Furthermore, these methods do not answer questions of when the fire occurred or historic fire frequencies.