Estimating diameter at breast height and stem volume from stump dimensions for six timber species in Galicia (Northwestern Spain)

Abstract

It becomes necessary to use stump dimensions to predict tree volume when a tree has been cut and only the stump remains as an indicator of tree size. Thus, diameter at breast height (dbh) can be predicted from stump measurements and an estimated volume can be obtained by the use of local volume equations, or stem volume can be estimated directly from stump dimensions with a specifically constructed volume equation. Regression equations for predicting dbh and stem volume from tree stump dimensions were adjusted for six of the main timber species in Galicia (Northwestern Spain) (Eucalyptus globulus Labill., Pinus pinaster Ait., Pinus radiata D. Don, Pinus sylvestris L., Quercus robur L. and Betula alba L.), using data collected on 1,450 trees cut in even-aged stands, and fitting linear and multiplicative models transformed by taking natural logarithms. Results show that stump diameter is the most related variable with dbh and stem volume. Stump height did not improve significantly the predictions, except in Betula alba. With this work a simple and important tool is offered to forest sector professionals, private owners and public institutions.