1. Alan Tepley and Jane Kertis May 28, 2009 Fire Regimes and Successional Pathways in the Western Cascades of Oregon

2. Fire-regime gradients in the Western Cascades – Gradients of driving factors – Location and severity of recent fires Fire effects and successional trajectories – Warner Creek post-fire stand structure – Age structure in the central western Cascades Topographic influences on fine-scale variability Influence of fire-severity mosaics on subsequent burn patterns – 2008 Rattle Fire reburn of the 1996 Spring Fire Fire Regimes in the Western Cascades as a Context for Restoration

3. Fire Regimes Based on Kuchlers Potential Natural Vegetation Types Stand-Replacement Fires 500+ yrs Stand-Replacement Fires 201–500 yrs Understory Fires 0–34 yrs Mixed-Severity Fires 0–34 yrs Brown et al. 2000 Wildland Fire in Ecosystems: Effects of Fire on Flora

4. Data from NIFMID and ODF, Compiled by Ray Davis Not Modeled High Low Density of Lightning Ignitions (1970–2002) Mean Annual Precipitation (1961–1990) Gradients of Fire Regime Drivers Oregon Climate Service PRISM Project < 70 70-95 95-120 120-150 150-175 175-200 200-230 230-270 270-320 320-390 > 390 Annual Precipitation (cm)

5. Frequency of Large Fires (1,000 acres) (1970-2008) 1 burn 2 burns 3 burns Ray Davis, Unpublished

6. Dry Fire-Prone Provinces Frequency of Large Fires (1,000 acres) (1970-2008) 1 burn 2 burns 3 burns Ray Davis, Unpublished

7. Low Moderate High Fire Severity Severity of Recent Fires in the Western Cascades 012 km Clark 2003 4,905 acres 01.53 km Warner Creek 1991 8,960 acres 01.53 km Spring 1996 15,960 acres 02.55 km Apple 2002 19,139 acres 036 km Boulder 2002 48,505 acres 01.53 km Shady Beach 1988 5,174 acres Clark Warner Creek Shady Beach Spring Apple Boulder 02040 Kilometers 60 N

8. Morrison & Swanson 1990 0.501 km Cook-Quentin Study Area Cumulative Effects of 19 th -Century Fires Low severity (< 30% mortality) High severity (> 70% mortality) Moderate severity (30–70% mortality) Comparison to Historical Fire Severity 03060 Kilometers 90 N Cook- Quentin Clark Warner Creek Shady Beach Spring Apple Boulder

9. Comparison of Two Recent Fires Seral Stage Distribution Pre-Fire Post-Fire (%) (%) Early 5 30 Mid 5 5 Late 90 65 Fire Severity Low 61% Moderate 13% High 25% Kertis 2000 Spring Fire 1996 15,960 acres 036 Kilometers 9 N Kushla and Ripple 1998 Fire Severity Low 48% Moderate 12% High 40% Warner Creek Fire 1991 8,960 acres 024 Kilometers 6 N Seral Stage Distribution Pre-Fire Post-Fire (%) (%) Early Seral/Rock 14 46 Sapling/Pole 9 4 Open Mature/Old 0 18 Closed Mature/Old 77 32

10. Pre-fire Density of Small Trees (5–30 cm dbh) Pre-fire Density of Small & Medium Trees (5–60 cm dbh) Pre-fire Density of Large Trees (> 100 cm dbh) R 2 = 0.010 p = 0.410 R 2 = 0.024 p = 0.197 R 2 = 0.002 p = 0.399 Basal Area Mortality (%) 0100200300400 Density (stems/ha) 0 20 40 60 80 100 Summarized from data of Larson and Franklin (2005) Warner Creek Fire Severity was Weakly Related to Stand Structure at a Plot Scale 0200400600 Density (stems/ha) 0 20 40 60 80 100

11. Low Severity < 30% BA Mortality (n = 31) Density (trees/ha) 0 5 10 15 20 25 20 15 10 5 020406080100120140160 Survival Mortality Shade-Intolerant Shade-Tolerant DBH (cm) 0 10 20 30 20 10 020406080100120140160 Survival Mortality Density (trees/ha) Moderate Severity 30–70% BA Mortality (n = 23) 0 5 10 15 20 Density (trees/ha) 20 15 10 5 020406080100120140160 Survival Mortality Shade-Intolerant DBH (cm) 50 40 30 20 10 Density (trees/ha) 020406080100120140 160 0 10 20 30 40 50 Survival Mortality Shade-Tolerant High Severity > 70% BA Mortality (n = 14) DBH (cm) Survival Mortality Density (trees/ha) 020406080100120140 160 Shade-Tolerant 0 10 20 30 40 50 60 70 10 20 30 40 50 60 70 Density (trees/ha) 020406080100120140 160 Survival Mortality Shade-Intolerant 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70

12. Data from Jane Kertis, Prepared by Stuart Johnston Plot Burned at Low Severity

13. Data from Jane Kertis, Prepared by Stuart Johnston Plot Burned at Moderate Severity

14. Data from Jane Kertis, Prepared by Stuart Johnston Plot Burned at High Severity

15. Elevation (m) High: 3,196 Low: 45 Transect Location Willamette National Forest Study Area N 0103050 Kilometers 2040 Oregon Eugene Bend Fall Creek Blue River Crest of the Cascades Warner Creek Fire

16. DBH (cm) Density (trees/ha) 040 80120160 Survival Mortality 20 40 60 0 20 40 60 Low Severity < 30% BA Mortality Density (trees/ha) 0 5 10 15 20 25 20 15 10 5 04080120160 Survival Mortality DBH (cm) Moderate Severity 30–70% BA Mortality Density (trees/ha) 0 5 10 15 20 15 10 5 04080120 160 Survival Mortality DBH (cm) High Severity > 70% BA Mortality 0 50 100 150 200 250 300 Density (trees/ha) No Evidence of Fire (n = 18) Low Severity (n = 19) Moderate Severity (n = 33) High Severity (n = 15) Before 1800 After 1800 Establishment Date 62 43 7 0 4 108 210 Using the Past to Infer Successional Trajectories Comparing Warner Creek to Sites Burned in the 19 th Century Warner Creek post-fire data (shade-intolerant only) Sites burned in the 19 th Century (shade-intolerant only)

17. Low Severity < 30% BA Mortality Density (trees/ha) 0 5 10 15 20 25 20 15 10 5 020406080100120140160 Survival Mortality Shade-Intolerant Shade-Tolerant DBH (cm) 0 10 20 30 20 10 020406080100120140160 Survival Mortality Density (trees/ha) Succession Following Low-Severity Fire % of Sampled Trees 0 4 0 4 8 12 150016001700180019002000 Shade Tolerants (n = 340 trees) Shade Intolerants (n = 103 trees) Composite for 19 Sites 2 Representative Transects 0 10 20 30 150016001700180019002000 0 10 20 30 150016001700180019002000 Establishment Date % of Sampled Trees Shade-TolerantShade-Intolerant with charred barkHardwood

18. % of Sampled Trees 0 4 0 150016001700180019002000 4 8 12 Shade Tolerants (n = 304 trees) Shade Intolerants (n = 106 trees) Establishment Date No Evidence of 19 th -Century Fire (composite of 18 transects) 0 4 0 % of Sampled Trees 150016001700180019002000 4 8 12 Shade Tolerants (n = 340 trees) Shade Intolerants (n = 103 trees) Establishment Date 19 th -Century Low-Severity Fire (composite of 19 transects) Effects of Low-Severity Fire Shade- Tolerant Shade Intolerant Shade- Intolerant with charred bark

19. Moderate Severity 30–70% BA Mortality (n = 23) 0 5 10 15 20 Density (trees/ha) 20 15 10 5 020406080100120140160 Survival Mortality Shade-Intolerant DBH (cm) 50 40 30 20 10 Density (trees/ha) 020406080100120140 160 0 10 20 30 40 50 Survival Mortality Shade-Tolerant Succession Following Moderate-Severity Fire 0 5 10 15 20 25 150016001700180019002000 0 10 20 30 40 50 150016001700180019002000 Establishment Date % of Sampled Trees 2 Representative Transects % of Sampled Trees 0 4 8 12 0 4 150016001700180019002000 Shade Tolerants (n = 528 trees) Shade Intolerants (n = 350 trees) Composite of 33 Transects Shade-TolerantShade-Intolerant with charred barkHardwood

20. High Severity > 70% BA Mortality (n = 14) DBH (cm) Survival Mortality Density (trees/ha) 020406080100120140 160 Shade-Tolerant 0 10 20 30 40 50 60 70 10 20 30 40 50 60 70 Density (trees/ha) 020406080100120140 160 Survival Mortality Shade-Intolerant 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 Shade-TolerantShade-Intolerant with charred barkHardwood 0 10 20 30 150016001700180019002000 0 10 20 30 40 150016001700180019002000 Establishment Date % of Sampled Trees 2 Representative Transects Succession Following High-Severity Fire

21. High-Severity Fire Low- Severity Fire Moderate- Severity Fire Stand Development Douglas-fir (> 200 yrs old) Western hemlock Western redcedar Douglas-fir (< 200 yrs old) Successional in Douglas-fir Forests

22. 1-4 Decades Since Fire 100–200 Years Since Fire 300–500 Years Since Fire Stand Development Underburn Low-severity fire Moderate-severity fire Douglas-fir (> 200 yrs old) Western hemlock Western redcedar Douglas-fir (< 200 yrs old) Successional Pathways in Douglas-fir Forests

23. % of Sampled Trees 0 4 0 4 8 12 150016001700180019002000 Shade Tolerants (n = 104 trees) Shade Intolerants (n = 202 trees) Composite of 13 Transects Shade-TolerantShade-Intolerant with charred barkHardwood 0 10 20 30 150016001700180019002000 Establishment Date 0 10 20 30 150016001700180019002000 2 Representative Transects % of Sampled Trees Age Structure of Fire-Prone Stands with at least 3 Douglas-fir Cohorts

24. % of Sampled Trees 0 4 0 150016001700180019002000 4 8 12 Shade Tolerants (n = 304 trees) Shade Intolerants (n = 106 trees) Establishment Date No evidence of fire for > 350 yrs (composite of 18 transects) % of Sampled Trees Establishment Date 0 4 0 150016001700180019002000 4 8 12 Shade Tolerants (n = 104 trees) Shade Intolerants (n = 202 trees) At least 3 fires in the last 400 yrs (composite of 13 transects) Shade- Tolerant Shade Intolerant Shade- Intolerant with charred bark Comparison of Stand and Age Structure in the Most and Least Fire-Prone Sites

25. 1,600 1,500 1,400 1,300 1,200 1,100 1,000 900 800 700 Ridgetop Elevation (m) Terrain Shape Probability of Occurrence 0306090120150180 210 0.0 0.1 0.2 0.3 0.4 0.5 ConcaveConvex Topographic Context for Stands with no Evidence of Fire for at Least 350 yrs Shade-Tolerant Shade-Intolerant

26. Probability of Occurrence for the Least Fire-Prone Stands < 0.05 0.05–0.10 0.10–0.15 0.15–0.20 0.20– 0.25 0.25–0.30 0.30–0.35 0.35–0.40 0.40–0.45 0.45–0.50 Probability of Occurrence Present All Other Transects Transect Location 20151050 Kilometers N Blue River Fall Creek 12 9630 Kilometers N 129630 Kilometers N

27. 335038204290476052305700 Insolation 0.0 0.1 0.2 0.3 0.4 Probability of Occurrence 66 60 54 48 42 36 30 24 18 12 Slope Gradient (%) 335038204290476052305700 Insolation 0.0 0.1 0.2 0.3 0.4 0.5 Probability of Occurrence 1,600 1,500 1,400 1,300 1,200 1,100 1,000 900 800 700 Ridgetop Elevation (m) Topographic Context for the Most Fire- Prone Stands

28. Probability of Occurrence < 0.05 0.05–0.10 0.10–0.15 0.15–0.20 0.20–0.25 0.25–0.30 0.30–0.35 0.35–0.40 0.40–0.45 0.45–0.60 Present All Other Transects Transect Location Probability of Occurrence for the most Fire-Prone Stands 20151050 Kilometers N Blue River Fall Creek 129630 Kilometers N 129630 Kilometers N

29. Clearcut High Severity Low Severity Moderate Severity Natural Opening Road Spring Fire Severity Spring Fire 1996 15,960 acres

30. Rattle Fire 2008 19,771 acres Clearcut High Severity Low Severity Moderate Severity Natural Opening Road Spring Fire Severity Rattle Fire Perimeter

31. September 14 September 15 2,202 acres burned September 16 4,182 acres burned September 17 3,069 acres burned The Biggest Fire Days 48% of the Rattle Fire (9,453 acres) burned from 9/14 to 9/17 Clearcut High Severity Low Severity Moderate Severity Natural Opening Road Spring Fire Severity

32. Increasing annual precipitation mean fire intervals proportion of fire covered by large high-severity patches influence of fuel moisture on fire extent and severity Increasing proportion of landscape covered by multi-cohort stands average number of cohorts per stand proportion of fire covered by large low-severity patches influence of fuel amount and continuity on fire extent and severity Summary and Conclusions An understanding of fire-regime gradients is useful in guiding restoration

33. Questions?