Loading of stream wood following the 2016 Chimney Tops 2 Wildfire: Great Smoky Mountains National Park, Tennessee, USA

Large wood drives physical and ecological processes in river systems, but the relative roles of continuous individual tree mortality versus episodes of mass mortality in wood recruitment are not well understood. Here, the 2016 Chimney Tops 2 wildfire, a rare severe wildfire in the eastern United States, was used as a case study for examining the role of mass tree mortality in wood loads of streams in Great Smoky Mountains National Park (GSMNP), Tennessee. Wood surveys were conducted on four reaches in two drainage systems affected by the fire to ascertain the total frequency and volume of burned and unburned wood pieces and jams. Relative to unburned wood, the Chimney Tops 2 fire resulted in a major influx of burned wood to the study reaches, with large percentages of individual pieces (average of 47% by frequency, 48% by volume) and jams (average of 72% by frequency, 93% by volume) exhibiting burn marks. Burned wood pieces had a larger diameter than unburned pieces (p = .065). Results suggest that rare mass-mortality events like the Chimney Tops 2 wildfire could play a major role in wood dynamics of mountain streams in humid forested regions.