Press release 14.12.2005
Finnish Forest Research Institute (Metla), together with collaborating organizations, has produced a review article on biomass and stem volume equations for tree species in Europe. The equations are used, for example, for mapping forest resources and for calculating forest carbon balance as required by the UN Framework Convention on Climate Change (UN FCCC).
The study group collected biomass and stem volume equations calculated at tree level for European tree species using breast-height diameter and/or tree height as the independent variable. This review is the first of its kind in Europe. Biomass equations, 607 altogether, are presented for 39 different tree species. The majority of them are intended for predicting above-ground biomass components of trees, particularly branches and leaves. The review contains a total of 230 equations applicable to predicting stem volume for 55 different tree species. The review indicates that significantly more stem volume equations are available for coniferous trees than for broad-leaved trees.
Calculating biomass and stem volume is essential for, for example, mapping forest resources and studying energy and nutrition flows in ecosystems. Stand biomass assessment methods are also needed as tools to calculate the forest carbon stock balance as required by the UN FCCC. The tree-level biomass and stem volume equations can be directly applied to tree-level inventory calculations or they can be used to develop and test biomass expansion factors.
The compilation of these extensive biomass and stem volume equations for European tree species was a more demanding task than compiling sets for North-American and Australian species, which was done earlier. This is mainly due to the fact that so many countries were involved, each having their own traditions of forest research and forest inventories. The stem volume equations have applicational challenges to meet: for example, different countries use their own definitions for stem volume. In some countries stem volume was defined to include stem up to a certain top diameter.
The majority of biomass equations have been developed in northern and central Europe; only 82 equations are derived from southern Europe. New research into predicting biomass will be needed especially from southern Europe and for below ground tree components.