Estimating Biomass Yield for Sub-Merchantable Ponderosa Pine of Northcentral Colorado


  • Kurt H. Mackes
  • Debra A. Lozinski


Biomass yield, ponderosa pine, sub-merchantable


Volume, mass, and moisture content data were collected for 28 sub-merchantable ponderosa pine trees harvested in northcentral Colorado. The average green bulk density of these trees was 280 kg/m3. The average oven-dry bulk density was 169 kg/m3. Average green moisture content (oven-dry mass basis) was 91%. A multiple regression analysis was conducted using diameter at breast height (DBH), tree height, and crown vigor class to identify which of these variables could be used to predict biomass yield (oven-dry tree mass). Based on an analysis of variance at α = 0.05 level-of-significance, only DBH was a significant predictor of oven-dry tree mass. Therefore, oven-dry mass estimates were calculated based on a regression line fitted to ln(oven-dry mass) vs ln(DBH) data. The R-square value for the regression line was 0.897. Although differences between actual and predicted oven-dry tree mass ranged up to 57.8%, the average difference was 2.9%.


Gholz HL, Grier CC, Campbell AG, Brown AT (1979) Equations for estimating biomass and leaf area of plants in the Pacific Northwest. Oregon State Univ For Res Lab Res Paper 41.nLynch DL (2005) Foresters field handbook. Cooperative Extension, Colorado State University, Fort Collins, CO. 302 pp.nLynch DL, Mackes KH (2002) Opportunities for making wood products from small diameter trees in Colorado. USDA For Serv Rocky Mountain Research Station, Res Paper RMRS-RP-32.nLynch DL, Mackes KH (2003) Cost for reducing fuels in Colorado forest restoration projects. Proc Fire, Fuel Treatments, and Ecological Restoration Conference. USDA For Serv Proc RMRS-P-29: 167-175.nVan Hooser DD, Chojnacky DC (1983) Whole tree volume estimates for the Rocky Mountain States. USDA For Serv Res Bull INT-29, Intermountain Forest and Range Experiment Station, Ogden, UT.n






Research Contributions