A Landscape-Scale Assessment of Holocene Fire Regime Controls in South-Eastern British Columbia, Canada

Multiple vegetation and forest fire history records were established by analyzing Holocene-aged lake sediment stratigraphies collected across a vegetation and elevation gradient in southeast British Columbia, Canada. The stratigraphies were dated using radiometric techniques, lead-210 and radiocarbon dating, and tephrochronology and were examined to understand the spatial controls of forest fires and how those controls varied in importance throughout the Holocene in response to orbital geometry variations, climatic change, forest composition changes, and fuel abundance within the watersheds. Local conditions have been shown to be important controls of fire activity in the region, but can be overridden by other broad-scale factors such as climate. Aspect was shown to be an important spatial control of fire frequencies at mid elevation Engelmann spruce-subalpine fir forests. At subalpine elevations, fuel abundance within the catchment was important in explaining millennial to centennial scale fire frequencies. When investigating past biomass burning, the analysis of macroscopic charcoal morphologies permits a more nuanced analysis of the temporal variability in fuel sources and taphonomic processes in a watershed. This study contributes to our knowledge of the varying spatial controls at the landscape scale of Holocene forest fires in mountainous southeastern British Columbia, to understand the influence of local and broad-scales controls of biomass burning and to the analysis of sediment-charcoal morphologies.