FIRE HISTORY SINCE THE MEDIEVAL WARM PERIOD IN THE STRAIT OF GEORGIA LOWLANDS, SOUTHWESTERN BRITISH COLUMBIA: IMPLICATIONS FOR ECOLOGICAL RESTORATION

Throughout the world, restoring ecosystem processes and understanding disturbance regimes and natural ranges of variability are key components of land-use planning and restoration. This is particularly relevant in western North America where fire suppression has hindered natural ecosystem processes and increased risk of wildfire damage. Although prescribed fire and other fire management activities are increasingly accepted throughout western North America, considerable resistance and limited knowledge present challenges to effective management in the heavily populated and biodiverse region of the Strait of Georgia lowlands in southwest British Columbia.

This project aims to understand natural disturbance regimes (i.e., fire history) for the Strait of Georgia Lowlands, focusing on two lacustrine sites from southeast Vancouver Island (Somenos Lake) and the Fraser Valley (Chadsey Lake). To provide historical data on the natural variability of fire disturbances, we analyze radiometrically dated sediments for macroscopic charcoal over the last 2000 years. Preliminary results reveal 7 charcoal peaks over the last 3500 years at Somenos Lake with a considerable increase in peak magnitude over the Anthropocene. Analysis of these results will potentially allow us to discern ecocultural prescribed burning from natural fire events prior to western colonization, as well as improve our understanding of the natural range of ecosystem variability associated with climatic periods such as the Little Ice Age (1400-1700 AD) and the Medieval Warm Period (950-1250 AD).