Wildfire History and Its Relationship With Top-down and Bottom-up Controls
Updated: Sep 15, 2021
Eric Da Silva, M.Sc. Thesis (2009)
Department of Geography, University of Guelph, Ontario
This study identifies patterns of historic fire activity that characterize the Joseph
and Gold Creek watersheds near Cranbrook, British Columbia as a mixed-severity regime and provide evidence that both bottom-up and top-down controls significantly regulate fire activity. Fire scar chronologies from 33 plots in the watersheds demonstrate that the relative importance of bottom-up controls vary over very short distances. Fire frequency was significantly higher in plots found on a steep southwest-facing sloping compared with the rest of the landscape, an area characterized by xeric conditions.
Species distribution was strongly driven by elevation related microclimate and transitioned from fire-resistant to sub-alpine species along elevation gradients, likely reflecting a transition in fire activity – although this could not be substantiated by the fire scar record because of a lack of fire history information. Historic fire activity in this area showed a strong relationship with drought, which may be associated with the warm phase of the Pacific Decadal Oscillation.
Similar results were found when analyses were completed using regionally significant fire years. The effects of fire exclusion in the past half century are evident in this fire history reconstruction. The low incidence of fire in the hundred years following a large event in the early 20th century has served to homogenize the landscape and increase fire hazard in the wildland-urban interface.
Daniels, L.D., Z. Gedalof, M.F.J. Pisaric, C.J. Courtney Mustaphi, E. Da Silva, H. Marcoux, V. Mather, J. Nesbitt, E. Paul-Limoges, J. Perrault, C.L. Steele. 2011. Historic climate-fire-vegetation interactions of the West versus East Kootenays: Implications of climate change and fire suppression. Final Report to NSERC-Strategic Research Partners. June 2011.
Gedalof, Z., E. Da Silva, and L.D. Daniels. 2010. Fire History of the Joseph Gold Creek Watersheds, Kootenay Mountains, BC, Canada. Annual Meeting of the Association of American Geographers, April 2010, Washington DC, USA
Da Silva, E., Z. Gedalof and L.D. Daniels. 2009. Fire History Reconstruction of a Mixed-Severity System in the Southern Interior British Columbia. (Poster) Annual Meeting of the Association of American Geographers, Las Vegas, NV, March 2009.
Eric Da Silva is continuing his education in medicine.
For further information, contact Dr. Lori Daniels, Department of Forest Sciences, University of British Columbia, email@example.com or Dr. Ze’ev Gedalof, Department of Geography, University of Guelph, firstname.lastname@example.org