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Forestry & Society Silviculture

Forestry & Society Silviculture. HORT/RGSC 302 J.G. Mexal Fall 2008. Allowable Cut Effect Harvesting Clearcut Shelterwood cut Single-tree selection Site Index (SI) Regeneration Stocking Thinning. Fertilization Competition Control Pruning Wood Quality Agroforestry.

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Forestry & Society Silviculture

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  1. Forestry & SocietySilviculture HORT/RGSC 302 J.G. Mexal Fall 2008

  2. Allowable Cut Effect Harvesting Clearcut Shelterwood cut Single-tree selection Site Index (SI) Regeneration Stocking Thinning Fertilization Competition Control Pruning Wood Quality Agroforestry Forestry & SocietySilviculture/Outline

  3. Forestry & SocietyAllowable cut/ Kimmins Allowable Cut = 1/6/decade Function of: site index, silviculture, tree improvement, rotation age

  4. SilvicultureEven-age management: Mixed hardwoods/ Oliver 2008 • Young, even-aged mixed species stand • Striped = shade intolerant dominants • Black = shade intolerant; overtopped and die! • Gray = intermediate shade tolerance • White = extreme shade tolerance A. B. C.

  5. Forestry & SocietySilviculture/Change is Inevitable /Mich. Forest Ecology 1964 Trees/acre B.A. ft2/ac

  6. Forests Change with Time- Pisgah Natl ForLoftis et al. RMRS-P-34, p.235, 2004 Trees/ 2 ac Basal Area (ft2/ac) Stand Age (Years)

  7. Forestry & SocietySilviculture/ Change is Inevitable Forest Ecology, 1964 DBH (in) Pseudotsuga menziesii - NZ D D D D Year

  8. Why do we clearcut? • It’s cheaper • Allows for tree improvement • Favors shade intolerant species (e.g. pine, Doug-fir) Cost ($/CCF) SJAF 18(4):168:’94

  9. Stumpage Value in PNW/Ralston et al. Silva Fenn. 38(1):55:’04 Stumpage Value ($/tree) DBH Class (cm)

  10. Harvest method affects costs in WashingtonW.J. Appl. For. 22(3):204:2007 Harvest Cost ($/mbf) Treatments: Clearcut— take it all~ Patch cut + thin = 20% removal in 1.5-5 ac w/ thinning between openings Two-age = uneven aged w/ ~15 tpa retained Group selection = similar to Patch cut with <1.5 ac openings Conclusions: Harvest costs increase as retention level increases and patch size decreases

  11. Forestry & SocietySilviculture/Harvest Marking Costs / USFS SO-112, 1994 $/100 ft3 Southern Pines/ Ouachita N.F. AR Harvesting Method

  12. Forestry & SocietySilviculture/Harvest Costs / SJAF 18:168-174: $/CCF Southern Pines/ Ouachita N.F. AR Cable Skidder Grapple Skidder Felling Harvesting Method

  13. Forestry & SocietySilviculture/Thinning Method vs Damage/ WJAF 15:27-33:2000 Scar Area (ft2/ac) Pseudotsuga menziesii- OR Residual Stand (tpa)

  14. Forestry & SocietySilviculture/Management Affects Runoff /Erosion in AlabamaGrace, JSoilWaterConsv 59:160:04 Runoff (mm) Rainfall event (mm)

  15. Forestry & SocietySilviculture/Management Affects Runoff /Erosion in Alabama Grace, JSoilWaterConsv 59:160:04 Erosion (t/ha) Erosion Control = 0.07 t/ha/yr (20 mo) Clearcut = 0.8 t/ha/yr (20 mo) Rainfall event (mm)

  16. N leaching beyond 20 cm and 100 cm depth following urea fertilization (224 kg N/ha) to Douglas-fir forest / Flint 2008 Leaching (kg N/ha/yr)

  17. Whole tree harvesting impacts N balancePowers et al.RMRS-P-34, p.235, 2004 Biomass Removed (Mg/ha) Nitrogen Removed (kg/ha) Forest Type

  18. Biofuel from wood residue For. Oper. Rev. 10(1): 21:2008

  19. Forestry & SocietySite Index • Site Index is a measure of site productivity and refers to the height of dominant and codominant trees in even-aged stands at a particular index age, usually 25, 50, or 100 years. • Site Index is a function of environmental factors (soil depth, rainfall, tree species, growing season).

  20. Forestry & SocietySite Index (SI50)/Wenger 1984 Height (ft) Loblolly pine Douglas-fir in WA Years

  21. Forestry & SocietySite Index (SI50)/Wenger 1984 Height (ft) Ponderosa pine in CA SI100 SI50 Years

  22. Forestry & SocietySilviculture/Site Quality/ Schultz 1997 Southern Pines SI25 Southwide Flatwoods (heavy clay) Plantation age (yrs)

  23. Forestry & SocietySilviculture/DBH vs Hgt & Biomass -Shepherd1986 Biomass (kg) DBH (cm) Pinus radiata- NZ-16 yr plantation 24 20 16 12 8 4 Height (m)

  24. Forestry & SocietySilviculture/Site Quality vs Biomass Distribution/Tree Physiol. 3:42:1987 Dry Weight (ton/ac) Age Total Branches Needles 60 70 80 50 Site Index

  25. Improvements in Southern Pine SilvicultureJ.For. 105(7):337:2007 Total Yield (ft3/acre)

  26. Artificial vs Natural Regeneration- Subalpine Forests CanadaW.J. Appl. For. 23(1):46:2008 Seedlings/ha Stocking = 9,360 t/ha Planted 1,500 t/ha Regeneration Clearcut Why plant when natural regeneration yields over 9,000 tree/ha? Sufficient seed rain occurs only within 70m of forest edge. Keep clearcuts <140 m wide! What species do you want? This is what they planted on 6 clearcuts

  27. Natural regeneration after fire in OregonJ. For. 105(3):139:2007 Seedlings/ha Seedlings/ha Why do these 2 species react differently to cover? Upper boundary? Distance from seed source (m) Broad leaved vegetation (% cover)

  28. Allowable Cut Effect Site Index (SI) Regeneration Stocking Thinning Fertilization Competition Control Pruning Wood Quality Agroforestry Forestry & SocietySilviculture/Outline

  29. 10,000 1,000 100 10 10 25 50 100 SilvicultureYou can have either a bunch of little trees, or a few big trees. Not both!! Stocking (trees/ha) Reineke’s -3/2 slope Scot’s pine Norway spruce DBH (cm) quadratic For.Sci. 50(6)848:’05

  30. Forestry & SocietySilviculture/Natural Regeneration Volume Growth (m3/ha/yr) No./ha 20 2,000,000 15 200,000 20,000 10 2,000 5 200 Time

  31. Forestry & SocietySilviculture/Artificial Regeneration Volume Growth (m3/ha/yr) No./ha 20 2,000,000 15 200,000 20,000 10 2,000 5 200 Time

  32. Forestry & SocietySilviculture/Clearcut does not eliminate species (necessarily)/ Bettis, 9th So.Silv.Res.Conf. Stems/acre Oak Ridge, TN Planted 600 tpa Pine

  33. Forestry & SocietySilviculture/Clearcut does not eliminate species (necessarily)/J.For. 24(1)37-44:2000 Stems/acre Coastal Plain, AL Planted 300 tpa * *

  34. Forestry & SocietyOld Orchard Plantation (NC)/Pinus strobus March1899 April 1999 thinned BA (ft2/ac) SI 75 SI 56 SI 71 thinned Years J. For. 98:18-23:2000

  35. Forestry & SocietyOld Orchard Plantation (NC)/Pinus strobus 1% = % standing volume (gross volume less removals and mortality)

  36. Forestry & SocietyConversion from Even-Aged to Uneven-Aged/ GTR SO 118, 1996 Southern Pine - 50 yrs old Reproduction Removed 2,114 b.f. Before After DBH (in) DBH (in)

  37. Forestry & SocietyConversion from Even-Aged to Uneven-Aged/ GTR SO 118, 1996 Southern Pine - 50 yrs old Reproduction Reproduction

  38. Forestry & SocietySilviculture/Changing Harvest Strategies/ USFS SO-112, 1994 Ouachita Nat’l For. Harvested Acres Clearcut

  39. Management Regime Even-aged Unthinned Thinned Shelterwood Uneven-aged Low diameter limit Current diameter distribution Heavy BDq selection Productivity (m3/ha/yr) 10.3 10.9 6.2 11.8 10.0 8.3 Annual productivity in PNW under different scenarios Ralston et al. Silva Fenn. 38(1):55:’04

  40. Allowable Cut Effect Site Index (SI) Regeneration Stocking Thinning Fertilization Competition Control Pruning Wood Quality Agroforestry Forestry & SocietySilviculture/Outline

  41. 10,000 1,000 100 10 10 25 50 100 SilvicultureYou can have either a bunch of little trees, or a few big trees. Not both!! Stocking (trees/ha) Reineke’s -3/2 slope Scot’s pine Norway spruce DBH (cm) quadratic For.Sci. 50(6)848:’05

  42. Forestry & SocietySilviculture/ Stocking affects Growth/ Shepherd 1986 DBH (cm) or BA (m2/ha) Basal Area DBH Stocking (trees/ha)

  43. Forestry & SocietySilviculture/ Stocking affects Growth/ USDA Hndbk 713, 1997 DBH (cm) Pinus taeda Trees/ha

  44. Forestry & SocietySilviculture/ Stocking affects Biomass Distribution/ Shepherd 1986 Pinus resinosa- (27 yrs) k 190 171 127 (tons/ha) 92

  45. Forestry & SocietySilviculture/ Stocking affects Biomass Distribution/ Shepherd 1986 Pinus resinosa- (27 yrs) Biomass 170 kg 120 kg 80 kg 40 kg crown diameter 2.4m 1.7m 1.2m 1.0m 550 1070 2220 4330 Trees/ha

  46. Forestry & SocietySilviculture/ Stocking affects Volume Growth/ Shepherd 1986 Volume growth (m3/ha) Pinus radiata- NZ Basal Area (m2/ha)

  47. Forestry & SocietySilviculture/ Stocking Lincoln National Forest Sue Nichols

  48. Allowable Cut Effect Site Index (SI) Regeneration Stocking Thinning Fertilization Competition Control Pruning Wood Quality Agroforestry Forestry & SocietySilviculture/Outline

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