Fire History of Montane Forests of the East Kootenays

RESEARCH TEAM

Dr. Lori Daniels and Jed Cochrane (MSc 2007), Geography, UBC
Robert W. Gray, R.W. Gray Consulting, Ltd.
Rick Kubian and Jed Cochrane, Parks Canada Agency

ABSTRACT

We used tree rings to reconstruct the fire history and quantify the climate conditions associated with historic fires in the montane forests of the southern Rocky Mountain Trench, including Kootenay National Park. Our work focuses on components of the landscape where historically a mixed-severity fire regime was dominant. All study stands included large-diameter western larch, Douglas-fir, or ponderosa pine trees and were in the Montane Spruce biogeoclimatic zone. Each stand was structurally complex with an upper stratum of veteran trees that established prior to 1870. Our goal is to provide baseline data on fire frequency that can be used to guide ecologically-based restoration of the historic fire regime and fuels mitigation.

Of the 30 fire history study sites, 10 sites were subjectively selected to represent old-growth forests and 20 sites were randomly selected to represent southerly, warm-aspect slopes (n = 10) and northerly, cool-aspect slopes (n = 10) in the landscape. Fire records were based on 249 fire scar samples that yielded 567 fire scars between 1509 and 2003. At the old-growth sites, the median fire intervals ranged from 10.3 to 25.6 years, with two to 123 years separating successive fires within sites. At the remaining sites, median fire return intervals ranged from 15.5 to 77.5 years, with 5 to 138 years between fires within sites. Evidently, the old-growth sites represent a subset of the landscape in which historic fire frequency was relatively high.

Our fire scar records included only 6 fires since 1944. Time since last fire has exceeded the maximum interval between historic fires at 16 of 28 (57%) sites. Had fires burned and scarred trees as frequently throughout the 20th century as they did over the entire fire record, we would have expected 20 fire years between 1944 and 2004. The low incidence of fire scars is partly due to climate and largely due to fire suppression. Climate conditions were not conducive to fire from 1946 to 1966, but conditions suitable for fires have dominated since 1981. The low incidence of fire during the past 65 years suggests fire suppression is having a substantial impact on the fire regime of forests in the southern Rocky Mountain Trench.

We have two recommendations for managers:
(1) Management decisions based on fire regime attributes must account for the full range of natural variation. In many montane forests, low to moderate severity fires burned on average every 15 to 75 years (range = 5 to 138 between fires).

(2) Long fire free intervals during the 20th century are the result of climate variation and fire suppression. Where fire suppression has altered the fire regime, fuels likely have accumulated and may result in severe fires. Ongoing research in Kootenay National Park is designed to test for the impacts of fire suppression on forest composition, structure and fuels.

RESEARCH CONTRIBUTIONS

JOURNAL PUBLICATIONS

Cochrane, J. and Daniels, L.D. 2008. Striking a balance: safe sampling of partial stem cross-sections in British Columbia BC Journal of Ecosystems and Management 9:38-46.

RESEARCH REPORTS

Daniels, L.D., J. Cochrane and R.W. Gray. 2007. Mixed-severity fire regimes: Regional analysis of the impacts of climate on fire frequency in the Rocky Mountain Forest District. Report to Tembec Inc., BC Division, Canadian Forest Products Ltd., Radium Hot Springs, and the Forest Investment Account of British Columbia. March 2007. 26p.

Daniels, L.D., J. Cochrane and R.W. Gray. 2006. Refining mixed-severity fire regimes in the Rocky Mountain Forest District. Report to Tembec Inc., BC Division, Canadian Forest Products Ltd., Radium Hot Springs, and the Forest Investment Account of British Columbia. March 2006. 26p.

CONFERENCE PRESENTATIONS AND PUBLIC LECTURES

The Nature of Fire: Stewardship Tips & Lessons from the Field. The Land Conservancy of British Columbia, Public Speaker Series, Cranbrook, BC, August 2008.

Quantifying and comparing variation in fire regimes in mixed-conifer montane forests of the southern Rocky Mountain Trench, British Columbia. Presented by J. Cochrane. Co-Author: L.D. Daniels. Presented at the Annual Meeting of the Association of American Geographers, Boston, MA, April 2008.

Fire History of the Southern Rocky Mountain Trench. Co-Authors: J. Cochrane and R.W. Gray. Timber Growth and Value Conference, Smithers, BC, February 2008.

Hot Topics in Biogeography: The Impacts of Climate and People on Fire Regimes in British Columbia, Canada. Colloquium, Department of Geography, Texas A&M University, College Station, TX, January 2008.

Mixed severity fire regimes in the montane forests of the Southern Rocky Mountain Trench. Co-Authors: J. Cochrane and R.W. Gray. Ecological Restoration Best Practices in Protected Natural Areas & Canadian Council on Ecological Areas Meeting, Waterton Lakes, AB, October 2007.

Historical Fire Regime of the East Kootenays: 1540 to 2005. Co-Authors: J. Cochrane and R.W. Gray. Presented at the Columbia Mountains Institute and Society for Ecological Restoration Meeting, Cranbrook, BC, October 2007.

Forest Fires: Human Impacts and Climate Change. Changing Climate, Changing Basin panel, Columbia Basin Trust, 2007 Symposium on Environmental Change and Sustainability, Castlegar, BC, October 2007.

Quantifying spatial variation in fire regimes in MSdk Stands of the southern rocky mountain trench: southern versus northern aspects. Presented by J. Cochrane. Co-Author: L.D. Daniels. Presented at the 6th North American Forest Ecology Workshop, Vancouver, BC, June 2007.

Forest Fires and Climate Change in the Kootenays. Climate Change: Exploring Regional Solutions. West Kootenay Eco Society, Nelson, BC, April 2007.

Temporal Variation in Fire History of the Southern Rocky Mountain Trench. Co-Presenters: J. Cochrane and L.D. Daniels. Fire Public Advisory Group to Canfor, Radium Hot Springs, BC, March, 2007.

Quantifying spatial variation in fire regimes of the southern Rocky Mountain Trench: Northern versus Southern Aspects. Presented by J. Cochrane. Co-Author: L.D. Daniels. Presented at Northwest Scientific Association Meeting, Victoria, BC, February 2007.

Temporal variation in fire history of the Southern Rocky Mountain Trench: 1700-2000. Co-Authors: J. Cochrane and R.W. Gray. Presented at Northwest Scientific Association Meeting, Victoria, BC, February 2007.

Hot Topics in Forest Ecology: Fire and Climate Change. Botany Section of the Vancouver Natural History Society, Vancouver, BC, September 2006.

Mixed-Severity Fire Regimes of the Rocky Mountain Trench. Co-Presenters: L.D. Daniels and J. Cochrane. August, 2006. Fire History Workshop and Field Tour, Cranbrook, BC, August, 2006.

WORKSHOPS AND CONFERENCE FIELD TRIPS

Mixed Severity Fire Regimes in Montane Forests of the East Kootenays. Co-Presenters: L.D Daniels, J. Cochrane, and R.W. Gray. Workshop and field tour with Tembec Industries Ltd. and BC Ministry of Forests and Range, Cranbrook, BC, August 2008.

The Nature of Fire: Stewardship Tips & Lessons from the Field. Co-Presenters: J. Cochrane, L.D Daniels and R.W. Gray. Field trip with The Land Conservancy of British Columbia, Cranbrook, BC, August 2008.

Fire Regimes and Wildfire Restoration. Co-Presenters: J. Cochrane, L.D Daniels and R.W. Gray. Field trip at the Columbia Mountains Institute and Society for Ecological Restoration Meeting, Cranbrook, BC, October 2007.

FURTHER INFORMATION

Contact Dr. Lori Daniels, Department of Geography,
University of British Columbia, daniels@geog.ubc.ca