Additivity in tree biomass components of Pyrenean oak (Quercus pyrenaica Willd.)

In tree biomass estimations, it is important to consider the property of additivity,.i.e., the total tree biomass should equal the sum of the components. This work presents functions that allow estimation of the stem and crown dry weight components of Pyrenean oak (Quercus pyrenaica Willd.) trees. A procedure that considers additivity of tree biomass components is presented, and applied to a particular case. The application of a simultaneous equations system estimation procedure that used parameter restrictions and considered residual contemporaneous correlations allowed more efficient estimates and consistent prediction intervals. (C) 2002 Elsevier Science B.V. All rights reserved.