Spatial and Temporal Variations in Fire Hazard Associated with Forest Management Practices

1. Spatial and Temporal Variations in Fire Hazard Associated with Forest Management Practices ENVIRONMENT K. Hirsch, V. Kafka, C. Tymstra Introduction Researchers at the Canadian Forest Service are working in collaboration with Millar Western Forest Products (MWFP) Ltd., Alberta Land and Forest Service, and The Forestry Corp. in order to develop procedures and techniques for integrating fire and forest management. Although forest managers understand the ecological importance of fire, in Canada’s industrial forest minimizing area burned by unwanted wildfires is necessary to maintain an adequate wood supply. This study was conducted to determine the effect of different forest management practices on forest-level wildfire potential. The study provides a general understanding of the spatial and temporal changes in fire hazard associated with the practices based on an assessment of the Canadian Forest Fire Behavior Prediction (FBP) System fuel types found in the MWFP Forest Management Agreement (FMA) area. Methods A program was developed to convert vegetation characteristics to FBP System fuel types in order to produce fuel type maps for each of the four round 1 scenarios at 50-year intervals over a 200-year rotation period. General observations of fuel type continuity and spatial arrangement were used to qualitatively assess the fire behavior potential. Maps presented here are the initial landbase in 1998, the Business As Usual scenario at 50-year intervals and three different forest management approaches at the end of the rotation period. Fuel types (and flammability) Spruce-lichen woodland (moderate) Boreal spruce (high) Mature jack or lodgepole pine (moderate) Immature jack or lodgepole pine (high) Aspen (very low) Boreal mixedwood (30% D:70% C) (moderate) Boreal mixedwood (50% D:50% C) (low-moderate) No data or fuel Grass (moderate) Ponderosa pine-Douglas-fir (low-moderate) Landbase: 1998 Business As Usual: 2048 Business As Usual: 2148 Business As Usual: 2198 Business As Usual: 2098 kilometers 20 0 20 40 • Results • All scenarios continue to have a large component of fuels that are very prone to crown fire (spruce and immature pine) and there is a general reduction in less flammable fuels (aspen and mixedwood) • None of the approaches create fuel changes of a sufficient size to stop large fires • All scenarios maintain a high proportion of grass, a very flammable fuel in the spring • The Business As Usual and Intensive 2-Pass scenarios create small blocks of different stand ages that would not influence the spread of large fires but could minimize the impact of a large fire on timber supply because the fire’s impact would be spread across a range of age classes • The Adjusted Spatial Pattern and Enhanced Timber Supply scenarios create large areas of continuous highly flammable fuels which are conducive to the development of large fires Adjusted Spatial Pattern: 2198 Intensive 2-Pass: 2198 Enhanced Timber Production: 2198 Current Status This study has indicated that none of the proposed forestry practices reduce the flammability of the FMA area. In fact, some scenarios make the FMA area more susceptible to very large fires during the 200-year rotation. Therefore, a new strategy (i.e., a “Fire Smart” forest management scenario) was developed to reduce the potential for large fires while attempting to maintain timber production goals. This scenario advocates compartmentalization of the FMA area through the use of strategically located treatments including fuel conversion, reduction, and isolation. • Next Steps • Assess the effectiveness of the Fire Smart scenario • Evaluate the impact of the Fire Smart scenario on timber supply • Incorporate fire principles and concepts into future forest management and operations Collaborators Contact Information: Natural Resources Canada Canadian Forest Service Northern Forestry Centre 5320 - 122 Street Edmonton, AB T6H 3S5 780-435-7319