Implications of climate change on fire and thinning prescriptions

1. Implications of climate change on fire and thinning prescriptions Jessica Halofsky1, 2 Morris Johnson2 1 University of Washington, School of Forest Resources 2 U. S. Forest Service, Pacific Wildland Fire Sciences Laboratory, Seattle, WA

2. Climate controls ecosystem processes • The hydrologic cycle • Plant establishment, growth, and distribution • Disturbance • Drought • Fire • Flooding • Insect outbreaks

3. Fire Behavior Triangle Weather Topography Fuels

4. Fire Behavior Triangle Weather Topography Fuels

5. Area burned – Western U.S., 1916 - 2007

6. Area burned – Western U.S., 1916 - 2007 Fire Suppression Fire Exclusion Fuel Accumulation

7. Area burned – Western U.S., 1916 - 2007 Fire Suppression Fire Exclusion Fuel Accumulation

8. Area burned – Western U.S., 1916 - 2007 Fire Suppression Fire Exclusion Fuel Accumulation Lots of Fire Much Less Fire Lots of Fire

9. Fire area burned and PDO Cascade Mixed ecoregion Figure courtesy of J. Littell

10. Years with fire area > 200,000 acres

11. Climate Change and Fire • Warmer and drier spring conditions = • early snowmelt • lower summer soil and fuel moisture • longer fire seasons • increased fire frequency and extent • Fire intensity and severity may also increase

12. Trends in Area Burned •Average Area Burned 1970-1979       3,000,000 ac •Average Area Burned 1980-1989       2,900,000 ac •Average Area Burned 1990-1999       3,200,000 ac •Average Area Burned 2000-2007       7,100,000 ac

13. Recent trends also show increased: • Length of fire season • Fire intensity/severity • Number of fires • Invasive species (cheatgrass) • Time needed to suppress average wildfire • Cost of suppression • Number of structures lost • Strain on fire management resources

14. How much will area burned increase with climate change? • Analysis of wildfire data since 1916 for the 11 contiguous Western states shows that for a 4°F increase that annual area burned will be 2-3 times higher. • McKenzie et al. (2004), Conservation Biology 18:890-902 McKenzie et al. (2004)

15. Wildfire area burned in Oregon with 2°C warming McKenzie et al. (2004) • McKenzie et al. (2004), Conservation Biology 18:890-902

16. Wildfire area burned in Washington with 2°C warming McKenzie et al. (2004) • McKenzie et al. (2004), Conservation Biology 18:890-902

17. Projected changes in area burned in the PNW Littell et al. 2010

18. Projected changes in area burned in the PNW 2.0 M Ac 1.1 M Ac 0.8 M Ac 0.5 M Ac Littell et al. 2010

20. Fire Regimes Vary by Environment Warm Cold WetDry Agee 1993

21. Gradients of Fire Regime Controls Mixed Severity High Severity Weather Driven Mixed Severity Low Severity Fuel Driven Adapted from J. Agee

22. Relative influence of climate and fuels on fire regimes in common western US ecosystems PNW-IM = Pacific Northwest and intermountain region of the West SW = American Southwest

23. Relative influence of climate and fuels on fire regimes in common western US ecosystems PNW-IM = Pacific Northwest and intermountain region of the West SW = American Southwest

24. Relative influence of climate and fuels on fire regimes in common western US ecosystems Climate Change PNW-IM = Pacific Northwest and intermountain region of the West SW = American Southwest

25. Some energy (climate) limited forests may become water (fuel) limited forests Littell et al. 2010

26. Variation in Fire Severity within a General Fire Regime Low High Moderate Proportion Low Mixed High Severity Adapted from Agee 1993

27. Initially, with more frequent extreme burning conditions? High Low Proportion Moderate Low Mixed High Severity Adapted from Agee 1993

28. With eventual drought- and fire-induced reductions in fuel in drier forest types? Low High Proportion Moderate Low Mixed High Severity Adapted from Agee 1993

29. Fire Regimes and Landscape Patterns Low-Severity Fire Regime Mixed-Severity Fire Regime High-Severity Fire Regime Agee 1998

30. A2 A1B B1 MIROC3_MEDRES HADCM3 CSIRO_MK3 percent Percent change in biomass consumed by fire 2051-2100 vs. 1951-2000 R. Neilson et al., USFS and OSU MAPSS Team, Corvallis, OR

31. Fire interacts with other disturbances and vegetation/fuel conditions

32. The Disease Spiral Manion 1991

33. McKenzie et al. 2009

34. Adaptation strategies for natural resource management?

35. Adaptation strategy #1 Increase landscape diversity Thin forest stands to create lower density, and diverse stand structures and species assemblages that reduce fire hazard and increase resilience to wildfire.

36. Adaptation strategy #2 Increase resilience at large spatial scales Implement thinning and surface fuel treatments across large portions of landscapes where wildfires may occur Orient the location of treatments to modify fire severity and fire spread Focus the spatial scale of treatments on units of hundreds to thousands of acres

37. Adaptation strategy #3 Maintain biological diversity Modify genetic guidelines Experiment with mixed species, mixed genotypes Assist colonization, establish neo-native species Identify species, populations, and communities that are sensitive to increased disturbance

38. Adaptation strategy #4 Plan for post-disturbance management Treat fire and other ecological disturbance as normal, periodic occurrences Incorporate fire management options directly in general planning process

39. Adaptation strategy #5 Implement early detection / rapid response Eliminate or control exotic species Monitor post-disturbance conditions, reduce fire-enhancing species (e.g., cheatgrass)

40. Adaptation strategy #6 Collaborate with a variety of partners Develop mutual plans for fire and fuels management with adjacent landowners to ensure consistency and effectiveness across large landscapes

41. Adaptation strategy #7 Promote education and awareness about climate change Facilitate discussion among management staff regarding the effects of a warmer climate on fire and interactions among multiple resources Educate local residents about how a warmer climate will increase fire frequency and how fuel reduction can protect property