Bark constitutes significant part of the trees volume for some species, being also one of the main residues and by-products of the mechanized tree harvest. Therefore, in order to conduct effective forest management, it is essential to estimate the possible amount of that product which can be obtained during the harvest process. Our objective was to develop a model to estimate two basic parameters of bark: its volume and its share in the total volume of a tree. For the study we choose larch (Larix sp.) that is a rare but valuable forest raw material in Poland.

The research material was collected in northern (2 sites), central (1 site), and southern (2 sites) Poland. In total, we obtained data from 700 trees. We used geographical location and site type as well as tree’s age, breast height diameter, height and volume as an independent variables.

Bark volume increased, while share of bark in total volume of a tree decreased along with increasing breast height diameter, height or tree volume. The previous parameter was strongly related to tree’s age and site type, while in case of the latter one these relationships were significant for age and not that evident for site type. As geographical location turned to significantly influence investigated bark parameters (p < 0.01 in both cases), we developed models separately for each region. Obtained formulae might be applied in harvest planning or in software utilised during the process of felling and assortments production.