Flammability characteristics of surface fuels in a longleaf pine (Pinus palustris mill.) woodland

Abstract

To investigate fuel flammability, we quantified burning characteristics of 21 fuel categories in a longleaf pine (Pinus palustris Mill.) woodland in central Alabama, USA. Litter was burned under controlled laboratory conditions. Flammability characteristics, including resistance to ignition, flaming duration, smoldering duration, maximum flame height, and percent consumption, were measured. The fuels were hierarchically clustered into five groups of similar flammability characteristics that explained 89% of the variance. Percent consumption and maximum flame height values ranged from 7% ± 1 standard errors (SE) and 12 cm ± 1 SE for the low flammability group (bark and charcoal), to 86% ± 1 SE and 62 cm ± 3 SE for the high flammability group (bracken fern (Pteridium latiusculum (Desv.) Hieron. ex R.E.Fr. = {syn: P. aquilinum}), grass, and fire-facilitating oak (Quercus spp.) leaves). Results support observed flammability differences between fuel types such as oak and pine (Pinus spp.) litter, and duff, and provide a previously unquantified comparison of surface fuels comprehensive of a longleaf pine community. Further, clustering analysis indicated that plant species that become abundant post-disturbance may help maintain fire-vegetation feedbacks in the absence of pine litter. Understanding flammability characteristics of surface fuels may further inform prescribed fire application in stands where fuels have been altered.