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Discuss silvicultural principles related to restoration/fuels treatments Compare conditions from the 1900 Cheesman Lake reconstruction to current project work. ◦ Comments apply to the Stand/Treatment level for 1 treatment entry. ◦ Recommended metrics apply to PSI treatments. 2 Regeneration (Reproduction) Method: A cutting method by which a new age class is created. Stand Improvement: A term comprising all intermediate cuttings made to improve the composition, structure, condition, health, and growth of even- or uneven-aged stands. 3 Stand Density Index (SDI): A relative measure of stand density that provides a relationship between stand basal area, trees per unit area, average stand diameter, and stocking of a forested stand (Reineke 1933). The index is not influenced by age or site quality. 4 25% RD 35% RD 60% RD Source: Oliver and Larson, 1990 5 Gringrich stocking curves for ponderosa pine in the Forest Service’s Rocky Mountain Region (R2) (Forest Service Manual, R2 Supplement 2409.17-92-2 1992) 6 Long term study of ponderosa pine seedfall, natural regeneration, and seedling growth, 1981-2001, Manitou Experimental Forest Results: ◦ Good seed crops produced every 4-6 years. ◦ Predation by animals resulted in on 14% of total seedfall available for germination. ◦ Shelterwood Overstories between 25-60 BA over scarified seedbeds provided optimal conditions for natural seedling establishment. Shepperd et al. 2006 7 Black Hills Rocky Mts & Southwest USDA Forest Service General Technical Report RMRS-GTR-97. 2002 8 Density, structure, and species composition is highly variable by aspect. Reconstructed stocking levels may be low due to: ◦ Many of these plots burned severely in 1851. ◦ Mortality of pre 1900 trees was not factored in. 9 Riparian plot, 77 trees/ac, 57 BA 10 South plot, 65 trees/ac, 1 BA 11 Ridgetop plot, 32 trees/ac, 19 BA 12 West plot, 20 trees/ac, 5 BA 13 North plot, 166 trees/ac, 36 BA 14 Average Residual Basal Area = 60 sq. ft. COVER TYPE RESIDUAL BA % PROJECT AREA Aspen 20 5 Ponderosa Pine 50 40-50 Mixed Conifer 70 30-40 Douglas-fir 90 10-15 No Treatment <1% Spruce 15 16 Ponderosa pine stand, 46 trees/ac, 50 BA 17 Mixed conifer stand, 73 trees/ac, 70 BA 18 Ponderosa Pine Stands METRIC LOW HIGH TPA (> 1.0 " dbh) 30 80 BA (sq. ft.) 40 60 % PP - Overstory (BA) 90 100 % DF - Overstory (BA) 0 10 15 25 0.015 0.035 25 35 CC (%) CBD (kg/m¯³) CBH (feet) Age Classes Existing Understory Species %: TPA-seedlings Existing Understory Species %: Shrubs, Forbs, Grasses Existing Noxious Weeds/Exotics Presence of 19 Mixed Conifer: Ponderosa Pine/Douglas-fir METRIC LOW HIGH TPA (> 1.0 " dbh) 50 160 BA (sq. ft.) 60 80 % PP - Overstory (BA) 65 100 % DF - Overstory (BA) 0 35 15 25 0.035 0.05 15 30 CC (%) CBD (kg/m¯³) CBH (feet) Age Classes Existing Understory Species %: TPA-seedlings Existing Understory Species %: Shrubs, Forbs, Grasses Existing Noxious Weeds/Exotics Presence of 20 Cheesman Basal Area (1900) 12 Frequency 10 Projected BA Distribution 8 6 4 2 0 0 10 20 30 40 50 60 70 80 90 Basal area (ft2/acre) 21 Canopy base height (circa 1900) 40 Projected CBH = 20-36 30 feet 20 10 0 0 1 2 X Data 22 Canopy bulk density (circa 1900) 0.035 Projected CBD = 0.019-0.046 0.030 kg m -3 0.025 0.020 0.015 0.010 0.005 0.000 0 1 2 X Data 23 Treatments will result in a high level of variability for residual stand conditions within treatment areas. (density, structure, species composition, size classes) Natural regeneration will occur at lower stand densities Restoration ecology research should identify the target trend and range but may not be appropriate to assess precise post treatment conditions. Target ranges must be wide enough to capture variation of major cover types in treatment areas: ◦ For example: 40-80 sq. ft. of BA. 24