Horrelt, Daniel Ross2024-12-202024-12-202024https://hdl.handle.net/1828/20879Climate change is driving a global increase in wildfire that is disproportionately impacting temperate coniferous forests. These trends are forecast to continue with regional increases in area burned and extreme fire weather; however, the uncertainty associated with modelling the future extent and magnitude of change in complex fire systems remains a challenge for researchers. Examining historical fire regimes through paleoecological reconstructions of climate, vegetation, and fire can offer insights and can help validate models of future fire environments by characterizing potential analogues in the past. This study investigates the susceptibility of northern coastal temperate forests on Vancouver Island, Canada, to both past and future wildfire disturbance. Sediment cores were extracted from three lakes along a regional east-west precipitation gradient within a high-value forested water supply area. Supplemental data from a previously cored fourth lake within the water supply were also analysed. A comparison between warm-dry early- and cool-moist late-Holocene intervals was used to delineate spatio-temporal changes in fire regime. The results indicate that precipitation was lower in the past, with more open forests that were dominated by invaders and resisters – two important fire-related plant functional types. The wettest, western-most site experienced the greatest change and had frequent fires in the early-Holocene. This highlights the extent of fire regime shift and suggests that forests currently less predisposed to fire may become vulnerable in the future, the implications of which concern fire probability simulations and management actions to reduce wildfire risk to water supply.enAvailable to the World Wide WebWildfireClimateHoloceneTemperate forestWaterPaleoecologyThesis