Mixedwood management for the late 21 st century what might the future hold?

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1 Mixedwood management for the late 21 st century what might the future hold? Phil Comeau University of Alberta, Edmonton, Canada

2 Boreal Mixedwood Stands in 2062 Heterogeneity spatial (horizontal) and vertical (structural) Still exists in a large portion of the forest. TRIAD intensively managed mixtures and monocultures (Sizeable area in monocultures); extensively managed aspen and mixtures; reserves Mixewoods provide a range of ecological values (habitat, productivity, recreation, aesthetic) now and in the future

3 Bergeron and Harvey 1997 Natural forest dynamics following fire on mesic sites involve a gradual replacement of stands of broadleaf species by mixedwood then softwood stands. (Kenkel indicates that deciduous and mixedwood stand types may persist for a long time) Natural dynamics indicate that a silvicultural approach favouring species replacement while, at the landscape level preserving a representative proportion of hardwood, mixedwood and softwood stands would be more appropriate (than current practices which attempt to replace existing stands with the same stand) ECOSYSTEM BASED MANAGEMENT

4 Ecological and Social issues 2062 (likely stronger than in 2012) Boreal forests important contributors to global C and H2O cycling Natural Wilderness Sustainable (ECOSYSTEM BASED) management that conserves natural characteristics and diversity (ie. keeping the mix in mixedwoods) Continuous cover (uneven-aged or 2- aged management) Close to Nature - creating and maintaining irregular structure and composition that meets public expectations for natural Employment, rural communities,..

5 Climate Change From Gray and Hamann 2011 From Johnston et al. 2009

6 Using Aspen as a nurse crop for young white spruce: Aspen reduces frost injury and grass competition, aspen litter beneficial to longterm productivity but aspen DOES compete with spruce! Competition (intra or inter specific) may improve spruce wood quality Height (m) Root collar diameter (cm) Spruce height (m) age 19/20 (WESBOGY LTS - 4 Installations) Spruce rcd (cm) age 19/20 (WESBOGY LTS - 4 Installations) Aspen density (sph) Aspen density (sph) Hare browsing damage is worse under aspen cover than in the open (faster growth = less risk)

7 Spruce and aspen grow well in monocultures

8 Volume (m 3 /ha) MGM2005a simulation: Underplant at 40, harvest aspen at 60, clearcut at Mixtures can be more productive than monocultures (up to 20%?? (MacPherson et al. 2001) but this will only be observed at full stocking and at certain ages Optimal management (with proper timing of thinnings) could give more total yield than spruce monoculture Age Spruce Aspen

9 Successional considerations and mixedwood stand structure Codominant mixtures of spruce and aspen occur in a mid-successional window So how do we maintain these mid and late succesional stages in a managed forest? Repeated rotations of spruce could reduce productivity crop rotation desirable Fire control may make fire less common as the major stand initiating disturbance (replaced by harvesting??) But climate change will increase fire risk and increase need to manage forests to reduce fire risk Policies must continue to evolve to enable mixedwood management general move towards objective/goal oriented approaches

10 Technological advances Remote sensing LiDAR, satellites (accurate spatial data) GPS Harvesters (processing and sorting technology) Site prep equipment Tending equipment Cost reductions? Improve information available to publics.

11 Regenerating and maintaining mixedwood stands Will need knowledgable and skilled foresters and forest workers Need to have a variety of options in use to enable creation of wide range of stands. Methods will evolve from current and new knowledge (some approaches I feel are promising follow):

12 Can substantially reduce aspen regeneration postharvest Preharvest aspen control Preharvest treatments Aerial herbicide (glyphosate) Stem injection Girdling Cutting

13 Natural regeneration of white spruce Natural regeneration is possible today but variable Cutblocks must be smaller, seed trees <200 m apart, in retention patches to reduce windthrow, Need to be patient!! (allow time, longer rotation) 50 years from now we will know better how to make this work

14 Striping, banding Plant and treat to create bands or patches Banded and patchy treatments- show good spruce growth response Aerial herbicide treatments potentially very costeffective (<$300/ha in 2012$) GPS and spatial data will enable planning of planting to match treated ground.

15 Pulse spray treatments applied July 26, 2007 (2009 photo)

16 12m x 12m Alternating Pulse

17 Pulse spray - Spruce size 3 years after pulse herbicide treatment (split plot treated vs untreated) Variable Treated Untreated Overall mean p Height 2010 (m) <0.01 D5_2010 (cm) <0.01 Leader2010 (cm) <0.01 Height Increment (cm/ 2y) <0.01 Diameter increment (cm/ 2y) <0.01

18 Plant spruce and precommercial Reducing amount of aspen can improve spruce growth thin aspen (age >4) Retaining overstory provides protection of spruce from frost and winter injury Thinning is expensive ($600/ha+) and sites must be accessible

19 Aspen density effects on growth after clearcutting and precommercial thinning at year WESBOGY Long Term Study Aspen DBH 9/10 years (11 LTS installations) 19/20 years (4 LTS installations) Treatment Density (sph) DBH (cm) Tukey's DBH (cm) Tukey's A A A AB A BC A C Natural (unthinned) 5.26 B 9.39 D White Spruce 9/10 years (11 LTS installations) 19/20 years (4 LTS installations) Treatment Density (sph) HT (m) Tukey's HT (m) Tukey's A 4.14 AB AB 4.23 A A 4.35 A A 4.18 AB A 3.75 B Natural (unthinned) 1.31 B 2.98 C Treatment Density (sph) RCD (cm) Tukey's RCD (cm) Tukey's A 9.57 A AB 8.88 AB BC 8.50 B CD 7.31 C D 5.75 D Natural (unthinned) 1.95 E 4.51 E

20 Merch volume (age 90) (m3/ha) Aspen density effects on yield after clearcutting and precommercial thinning MGM 2007a simulations of effects of aspen density on yield of a stand planted with 1000 spruce (Sw SI50=18, Ht12=1.9m ; At SI50=20, Ht12=6.3m ) Aspen density at age 12 (sph) Sw volume Aw volume

21 Performance survey Sw density (s Future Stand composition predicted based on densities at age 14 (based on model projections from MGM2008) %Conifer (by volume) at Age 90 AwSI=20 SwSI=18 (size data from WESBOGY DMI) note scales are categorical C: red, CD: green, DC: blue, D: lt blue %-100% 80%-90% 70%-80% 60%-70% 50%-60% 40%-50% 30%-40% 20%-30% 10%-20% 0%-10% Perform ance survey Aw density (sph)

22 Spot treatments for mixedwood stands Plant and spot tend 1-2 m around low to moderate density of planted spruce (chemical site prep, herbicide or manual/motor manual) Retain aspen surrounding each spruce Provides frost protection, good stem form Cost? >$300/ha for 400 spots (backpack), >$400/ha for motormanual Technological developments in spot treatment technologies may make this approach more cost effective. See Pitt et al. 2010

23 Volume (m 3 /ha) Understory Protection (careful logging around advance growth) Remove overstory aspen at ages 60 to 80 while leaving advance regeneration of white spruce let spruce grow to merch sizes MGM2005a simulation: Underplant at 40, harvest aspen at 60, clearcut at Age Spruce Aspen Underplant stands at age 40 to provide advance regeneration where needed Advantage: height of advance spruce regeneration provides it with a growth advantage; no need for site preparation or vegetation control (Comeau et al. 2010)

24 Understory protection When spruce is taller than 7 m, aspen is retained in strips to provide wind protection and reduce windthrow (leaving 15-20% of aspen volume behind in strips). (MacIsaac et al 1999; MacIsaac and Krygier 2009)

25 Silviculture Cost (2012) of recreating/maintaining mixedwood Mounding -$250 terrateck; $400 ripper plow; $1000 excavator) Planting - $600/ha + Herbicide backpack - $400/ha Herbicide aerial - $250/ha Herbicide basal bark - $600/ha Motor-manual brushing - $700/ha PCT/spacing (aspen) - $600/ha stands Cost in 2062??? Will competition with the Oil and Gas sector have resolved itself in the next 50 years? What impacts on cost and availability of labour?

26 Yield and financial implications of 6 selected crop plans Crop Plan Cost ($ CDN) MAI Spruce (m3/ha/y) MAI Aspen (m3/ha/y) MAI total (m3/ha/y) NPV CC, aspen natural (70 yr rotation) CC, plant Sw, herbicide (90 y rotation) CC, plant Sw, thin aspen to 1500 sph (90 y rotation) Spot treatment 400 spruce/ha (90 y) CC, plant Sw, spray patches (60%) (90 y) CC, underplant Sw at 40, harvest aspen at 70, spruce at Based on MGM 2008 simulations Phil s guess (cannott be simulated directly) NPV 5% discount rate, $50/m3 aspen, $75/m3 spruce

27 Wood Quality Think Value not just volume (Value Chain Optimization) Main drivers of wood quality Stand-level: Species composition Stand Density Tree-level: DBH, Height, Crown Length/LCR, Slenderness Knot size and abundance Specific Gravity, MFA, Fibre Length, Coarseness Products: Lumber, chips, pulp, bioenergy, extractives Efficient and organized end uses (sorting, transport,..) Enhanced Inventory, technological support, decision support System SylviLAB FORVALUENET, FPINNOVATIONS, CWFC Need for data and for tools to enable its use.

28 Summary Increased pressure for conservation and sustainable management We will have advanced spatial tools using advanced GPS, remote sensing and computer technology better planning and improved efficiency In 2062 we will be better at creating and maintaining heterogeneity at all scales using Ecosystem Based Management TRIAD approach with longer rotations (>150 years) on extensively managed landbase, plus intensive management for fibre and lumber production. We will be practicing a mixed bag of silviculture More use of natural regeneration Spot, strip/band, patch treatments still using herbicides due to their cost effectiveness Assisted succession (ct, understory protection) Growing for value - and diverse range of products High value conifer (j grade, peelers) Other uses for aspen (in addition to chips and pulp) Bioenergy Extractives We will need a highly skilled and trained workforce Still lots to learn and to do between 2012 and 2062

29 A journey of a thousand miles begins with a single step. Lao-tzu, Chinese philosopher (604 BC BC). lets keep moving! (but don t forget to call home once in a while)!

30 Thank-you Your thoughts?