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ECOLOGICAL FOREST MANAGEMENT Northwest Natural Resources Group Rolf Gersonde, 6/11/2016 [email protected] Ecological Forestry in 60 Seconds – The Element of Ecological Forestry • Using site Adapted Species • Based on Natural Processes • Improve Soil Productivity • Enhance Habitat and Biodiversity • Improve Natural Capital • Economic and Ecological Resilience 2 Ecological Forestry in 90 Minutes – Outline of the Presentation • Forest Stand Dynamics • Forest Ecology • Silviculture and Multi-aged Management • Group Selection Example • Single Tree Selection Example • Tools for Assessment and Management • Operations 3 Forest Stand Dynamics Stand Development Stages following a major disturbance • S 0 70 150 Age 250 500 750 Stand Initiation Franklin and Van Pelt 2004 Stem Exclusion Understory Re-Initiation Diversification –Vertical - Horizontal 4 Seedling/Sapling – Stand Initiation Early Seral Vegetation 5 Canopy Closure in Young Forests 6 Competitive Exclusion Phase – Crown Differentiation and Self-thinning 7 Crown Differentiation – The development of crown classes during early stand development D – Dominant C – Co-dominant I – Intermediate O – Overtopped 8 Biomass Production – Trees versus Stands Stand Volume Growth Volume Tree Stand Density 9 Tree Diameter Growth – The effect of stand density on diameter growth 665 TPA 75 TPA 333 TPA 110 TPA 166 TPA 10 Tree Vigor and Stability - Live crown ratio and height to diameter ratio as indicators 11 Tree Height Growth – Height growth changes with age a differs between species 12 Understory Establishment – following overstory disturbance and gap creation 13 Competition versus Agent Based Motality 14 Natural Regeneration - Understory Establishment Stage • Seed Source • Species, Seed Year, Predation • Environment • Temp, Water, Light • Seed bed • Soil, Competition, Mycorrhiza 15 Understory Light and Canopy Gap – Progressively more light in gap and shading of the gap edge 35 90 80 30 70 60 50 40 25 30 20 20 20 20 20 15 10 30 30 Canopy Height (m) Height Canopy 50 40 40 60 5 40 40 10 40 30 20 60 50 70 90 110 North - South Distance (m) 16 Identify Shade Tolerance by Branch Morphology – Shade and Light Adapted Conifers Grand fir Grand Douglas - fir Western hemlock Western Western white pine Western 17 Shade Tolerance – Ranking of Western Tree Species (Daniel et al. 1979) Western hemlock Pacific yew Very tolerant Pacific silver fir Vine maple Western redcedar Tolerant Grand fir Sitka spruce Big-leaf maple Intermediate Douglas-fir Western white pine Ponderosa pine Intolerant Lodgepole pine Red alder Cottonwoods Very intolerant Larch 18 Understory Growth – Morphological Plasticity Pacific silver fir •Sun and shade foliage Noble fir •Terminal vs. lateral growth •Apical dominance 19 Western hemlock Soil Nutrients Site and Tree Species Soil Water Soil 20 Tree species and Ecological Amplitude Soil Nutrients Poor Rich Very Poor Medium Very Rich Douglas-fir Very Dry Dry Max Productivity Crop Reliability Slightly Dry Silvicultural Fresh Feasibility Soil Water Soil Moist Very Moist Modified from: Klinka, Worrall, Skoda and Varga (2000): The Distribution and Synopsis of Ecological and Silvical Wet Characteristics of Tree Species of British Columbia www.for.gov.bc.ca/hfp/silviculture/compendium 21 Understory Species as Indicators of Site Conditions Modified from: 22 www.for.gov.bc.ca/hfp/silviculture/compendium Red Alder Redcedar P Silver Fir Sitka SpruceHemlock B CottonwoodGrant Fir Yew BL Maple WW Pine B Cherry Douglas-fir Ponderosa PWhite Oak Madrone VERY DRY Dry Slightly Dry FRESH Moist Tree Species and Soil Moisture Very Moist WET Maximum Sustainable Productivity Crop Reliability (Silvicultural Feasibility) Modified from: www.for.gov.bc.ca/hfp/silviculture/compendium 23 Soil Moisture and Topographic Position Ridge Dry Thin soil Upper Slope Fresh Thin soil (Colluvium) Lower Slope Moist Thicker soil Valley Wet – Deep rich soil (Alluvium) 24 Mixed-species Forests 25 Percent hardwood mixture in conifer forests affects song bird density From Ellis and Betts, 2010, Western Forester 55(2) 26 Benefits of Mixed-species Stands Hardwood plant litter with high decomposition rates improves soil development and is forage for many species 27 Mixed-Species Stands Species specific Growing space Height growth Shade tolerance Senescence Disease & Pests 28 Mixed-Species Stands Symbiosis Nutrient enrichment Resilience Mycorhiza Frankia alni bacteria 29 Root Disease Indicators Photos: www.forestryimages.org and www.fs.fed.us 30 Armillaria root disease • Widespread • Most tree species Manage for Tree Vigor Phellinus or Laminated Root Rot • Localized • Species specific Manage for Species Conversion Ecological Forestry manages for Species Diversity 31 Bark Beetle Indicators 32 Positive Feedback Cycle in Disturbance Agent Complex: Forest – Wind –Insects - Drought – Pathogens Forest Wind Pathogens Insects Drought Daniel Miller, USDA Forest Service, Bugwood.org Kenneth E. Gibson, USDA Forest Service, Bugwood.org 33 Landscape level effect of tree species diversity on disturbance propagation Disturbance Propagation Species Diversity 34 Silvicultural System – System of coordinated regeneration, tending, control, and harvest treatments Even-aged System Clear Cut Seed Tree Shelterwood Thinning Two-aged System Variable Retention Coppice with Reserves Uneven-aged system Group Selection Thinning Single Tree Selection 35 Stand Volume and Rotation in Even-aged System Stand Volume Stand Stand Age Rotation Age 36 Seed-Tree and Shelterwood Regeneration Methods 37 Continuum of Silvicultural Approaches – A- individual tree selection, B-group selection, C- mixture of individual tree and group selection 38 What is Uneven-aged Management? Even-aged “age-class” Forestry Uneven-aged Management System 39 Origins of Uneven-aged forest management: Henry Biolley (France) Alfred Möller (Germany) “Dauerwald” “Continuous Cover Forestry” 40 Ecological Basis - Small-scale disturbance regime and species composition lead to characteristic diameter distribution of natural stands Meyer 1952 Tree Count Tree Tree Diameter 41 History of Uneven-aged Management in the Pacific Northwest Kirkland and Brandstrom 1936 Leo Isaac 1956 42 Managing Multi-aged Stands 43 Managing Uneven-aged Stands Manage stand density to: 1. Sustain growth of all stand components 2. Maintain stand structure 3. Replace tree mortality and harvest through regeneration Transformation of even-aged to multi-aged stands 44 Cutting Cycle – cutting cycle length depends on cutting intensity and growth rates Cutting Cycle Length - Density Density - Growth Rate Volume Volume Removed Growing Space Growing Timber Volume Stand Stand Stand Age 45 Cutting Cycle 2. Age 60 180 TPA BA 180 1. Age 40 4. Age 80/20 200 TPA 200 TPA Volume BA 120 BA 160 Stand Stand 3. Age 60 90 TPA BA 120 Stand Age 46 Single Tree Selection – Age classes are mixed at fine scale, growth and regeneration are regulated by removal of individual trees 47 While individual trees are removed, the stand structure remains the same 48 Single Tree Selection – developing a guide curve from tree count and diameter Tree Tally by 2 inch Diameter Class Number of Trees of Number 2 4 6 8 10 12 14 16 18 20 22 24 Tree Diameter 49 Single Tree Selection Guide Curve: Total basal area Maximum Diameter “slope” Target Number At each cutting cycle Actual Number we thin trees in classes that exceed the guide curve. 50 Group Selection System - A Systematic Approach to Diverse Forests 51 Group Selection System – Age classes are mixed at group scale (1/2 – 2 acres), growth and regeneration are regulated by removing groups of trees AND thinning individual trees The group selection system allows for mixture of shade and intolerant species in the same stand. 52 Group Selection System - Age-class mixture and management activities Regeneration PCT Activities: Group-Selection Harvest Thinned Natural Regeneration Matrix Planting Pre-comm. Thinning Commercial Thinning Understory Thinning Un-thinned Large Tree Scheduling Group Selection Treatments Area Control Method – Stand is divided into even areas, these areas are treated during the cutting cycle (e.g. 20% regenerated in one-acre group selection cuts, 40% commercial thinning, 20% pre-commercial thinning of regeneration in previous group selection cuts). Cutting Cycle 1 2 3 4 5 6 Stand Area Group Commercial Commercial Group 20% PCT PCT Selection Thin Thin Selection Commercial Group Commercial Commercial Group 20% PCT Thin Selection Thin Thin Selection Commercial Commercial Group Commercial Commercial 20% PCT Thin Thin Selection Thin Thin Commercial Commercial Group Commercial 20% PCT Thin Thin Selection Thin Commercial Commercial Group 20% PCT Thin Thin Selection 40 60 80 100 120 140 Stand Age The Silviculture Toolbox – Commercial and Ecological Forestry use the same tools. The difference is in when and how they are applied. Protect Redistribute Regenerate Select 55 Pure Hardwood Stands - Alder Hardwood Silviculture Cooperative http://www.cof.orst.edu/coops/hsc/ Planted 1200 TPA Age 9 Thinned to 230 TPA Age 12 Planted 230 TPA, Age 13 56 Naturally Regenerated Hardwood Stands Red alder, Darrington, WA, Hardwood Silviculture Cooperative, Unthinned Thinned to 250 TPA 57 Hardwood Thinning Regime • Planting 500-600 TPA • PCT to 200-250 TPA (age 12) • Pruning to retain 60% of crown • Life branch pruning only • 25-30 year harvest age • 16 foot logs, 12 inch diameter • High price of knot-free lumber • Snow and ice damage From John Belton 2004, Northwest Woodlands Photo: Hardwood Silviculture Cooperative 58 Assessing
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