Above- and Below-stump Relationships for Picea Abies: Estimating Root System Biomass from Breast-height Diameters
Estimates of below-ground biomass are important in understanding the dynamics of forest ecosystems. With this aim in view, allometric relationships between above- and below-stump parameters for 15 40-yr-old Norway spruce (Picea abies L. Karst.) from a pure stand in Lower Saxony, Germany, were developed. Using a small sample of trees enabled allometric relationships for estimating biomass and diameter distributions to be tested between above- and below - stump tree components [biomass and cross - sectional area of roots with diameter > 0.5 cm, diameter at breast height (DBH), sapwood and transversal area at breast height and needle biomass]. Root biomass ranged from 8.1 to 31.7 kg, DBH from 14.7 to 22.8 cm and needle biomass from 5.0 to 24.7 kg. All root parameters were positively correlated with above-stump parameters. The regression model proposed in this study provides a reasonable prediction of structural root biomass given the DBH for Norway spruce.