Estimating Large-Root Biomass from Breast-Height Diameters for Ponderosa Pine in Northern New Mexico

Abstract An important component of forest ecosystems in the southern Rocky Mountains is the belowground biomass associated with mature stands of ponderosa pine (Pinus ponderosa). Information on root biomass is fundamental to understanding the dynamics of ecological systems and designing studies of those systems. Ponderosa pine trees from a stand in northern New Mexico were cut and their root systems excavated. Biomass of all roots > 0.6 cm in diameter and the belowground portion of the stump was determined on a dry-weight basis. A regression model was constructed using data on breast-height diameter and belowground stump and coarse-root biomass from 42 trees in the stand. Diameter at breast height ranged from 18.3 to 67.6 cm, and belowground biomass ranged from 3 to 576 kg. West. J. Appl. For. 16(1):18–21.