How will trees grow in a warmer climate?

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2 How will trees grow in a warmer climate? Subalpine forests Mid eleva3on forests Low eleva3on forests Olympic Forests Western Cascades Forests Eastern Cascades Forests Graphic by J. LI/ell

3 How will trees grow in a warmer climate? Subalpine forests Mid eleva3on forests Low eleva3on forests Olympic Forests Western Cascades Forests Eastern Cascades Forests Subalpine forests: less snowpack, longer growing season growth increase

4 How will trees grow in a warmer climate? Subalpine forests Mid eleva3on forests Low eleva3on forests Olympic Forests Western Cascades Forests Eastern Cascades Forests Subalpine forests: less snowpack, longer growing season growth increase Mid eleva3on forests: warmer summer, less snow pack depends on precip.

5 How will trees grow in a warmer climate? Subalpine forests Mid eleva3on forests Low eleva3on forests Olympic Forests Western Cascades Forests Eastern Cascades Forests Subalpine forests: less snowpack, longer growing season growth increase Mid eleva3on forests: warmer summer, less snow pack depends on precip. Low eleva3on forests: warmer summer, less snow pack growth decrease

6 How will climate change affect tree regenera<on?! Effects of a warmer climate will be site specific: In high- snow forests, regenerabon will increase In dry forests, regenerabon will decrease

7 The effects of altered disturbance will overwhelm gradual changes in forest ecosystems

8 Lessons from geomorphology The geomorphic development of landscapes and soil is not a uniform process it s steady by jerks. -- Ray Daniels, NC State Univ.

9 Lessons from geomorphology The geomorphic development of landscapes and soil is not a uniform process it s steady by jerks. -- Ray Daniels, NC State Univ.

10 Lessons from geomorphology The geomorphic development of landscapes and soil is not a uniform process it s steady by jerks. -- Ray Daniels, NC State Univ.

11 Steady by Jerks Ecosystem Change in a Greenhouse World David L. Peterson U.S. Forest Service Pacific Northwest Research Station Metcalf Institute seminar September 7, 2013

12 Anyone remember 2012? The US experienced a drought that was unprecedented for its overall magni-tude, spatial extent, and persistence. The warmest year since 1895, the beginning of formal measurements. More area burned in the western US than any other year on record (since 1916).

13 Extremes ma>er Frequency, extent, and severity of disturbances may be affected by climate change, altering the mean and variability of disturbance properties. A shift of 1 standard deviation changes a 1 in 40 yr event to a 1 in 6 yr event Standard deviation 1 in 40 yr high range A shift in distribution of fire properties has a larger relative effect at the extremes than near the mean.

14 Thresholds matter Critical Threshold Temperature Increase Climate Climatic Variability Time

15 October 2002 Pinyon pine - juniper Jemez Mountains, NM

16 May 2004 Pinyon pine dead Jemez Mountains, NM

17 Climate change affects insects Mountain pine beetle Warmer temperature has favored MPB by: Increasing its reproductive rate Allowing an expanded geographic range

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19 Trees killed by beetles, Okanogan-Wenatchee NF 3,500,000 3,000,000 2,500,000 Trees Killed 2,000,000 1,500,000 1,000, , Year

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22 How does climate affect wildfire?

23 Has anyone heard this statement? Wildfires are becoming larger, more frequent, and more severe.

24 Has anyone heard this statement? Climate change is causing wildfires to become larger, more frequent, and more severe.

25 Unfortunately Many scienbfic statements become fact for no be/er reason than they are repeated frequently at meebngs.

26 Pacific Decadal Oscilla<on

27 Area burned in 11 Western states, Warm PDO Cool PDO Warm PDO Period of postsettlement fire Period of active fire suppression and fuel accumulation Period of fire increase From J. Littell

28 Wildfire area burned, 2050 From J. Littell

29 Wildfire area burned, 2050 gg Annual area burned will be 2-3 times higher in most of the western U.S. From J. Littell

30 The Disease Spiral Stress complexes, mediated by climate, lead to forest mortality and other changes. From Manion (1991)

31 Mixed conifer (Sierra Nevada, southern California) Ozone pollubon Fire exclusion high stand densibes Extended drought insects Ponderosa pine, Jeffrey pine, white fir die Fuels accumulate severe fires Non- nabve plants increase where fires occur

32 Global warming Sierra Nevada mixed conifer Higher temperatures & more severe and extended droughts Fire exclusion Ozone Bark beetles and defoliators High stand densibes Fuel accumulabon Tree mortality Large severe fires McKenzie et al. (2009) Changes in species composibon (including exobcs)

33 Global warming Sierra Nevada mixed conifer Higher temperatures & more severe and extended droughts Fire exclusion Ozone Bark beetles and defoliators High stand densibes Fuel accumulabon Tree mortality Large severe fires Changes in species composibon (including exobcs)

34 Global warming Sierra Nevada mixed conifer Higher temperatures & more severe and extended droughts Fire exclusion Ozone Bark beetles and defoliators High stand densibes Fuel accumulabon Tree mortality Large severe fires Changes in species composibon (including exobcs)

35 Global warming Sierra Nevada mixed conifer Higher temperatures & more severe and extended droughts Fire exclusion Ozone Bark beetles and defoliators High stand densibes Fuel accumulabon Tree mortality Large severe fires Changes in species composibon (including exobcs)

36 Global warming Sierra Nevada mixed conifer Higher temperatures & more severe and extended droughts Fire exclusion Ozone Bark beetles and defoliators High stand densibes Fuel accumulabon Tree mortality Large severe fires Changes in species composibon (including exobcs)

37 How do we manage for resilient systems in a warmer climate? Tripod Fire 2006 Okanogan Wenatchee NF Tripod Fire, ,000 acres

38 From this

39 From this To this?

40 Evidence from the Tripod Fire No pre-fire treatment Pre-fire treatment - Thinning - Prescribed fire

41 Tripod Fire, 2006

42 Is forest harvest a tool for building resilience?

43 The challenge: Managing large landscapes to increase resilience

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45 Adaptation option 1 Increase landscape diversity Thin stands to create lower density, diverse stand structures and diverse species assemblages. Increase resilience to wildfire and increase tree vigor by reducing competition.

46 Adaptation option 2 Increase biological diversity Plant nursery stock from warmer locations than specified by genetic guidelines. Plant mixed species and genotypes, with emphasis on fire resistant species.

47 Adaptation option 3 Increase resilience at large spatial scales Implement thinning and fuel treatments across large landscapes. Orient the location of treatments in large blocks to modify fire severity and spread.

48 Adaptation option 4 Treat large disturbance as an opportunity Develop plans for management objectives and activities following large fires, including long-term experimentation.

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50 THANK YOU!