Research of the trunk lower part form of the tree-like willow in the north-taiga area and development of transition tables from the stump diameter to the diameter at breast height

The paper considers the results of studying the shape of the lower part of tree-like willow trunks in the north-taiga area of the Arkhangelsk region. As a result of the studies, the diameters of willow trees at the 1.3 m height were calculated depending on the stump-level diameter at various heights from 0 to 1.3 m. This work aims at the development of two versions of tables for receiving trunk diameter at the 1.3 m height basing on stump diameter. Standards development for the transition from the stump diameter (at heights from 0 to 100 cm) to the diameter at the 1.3 m height is essential since the height and diameter at 1.3 m are the input parameters to the tables for determining trunk volumes. A need to determine the volume of felled trees` trunks arises while performing various kinds of examinations, and need to determine the stock of stands arises when addressing issues related to the evaluation of illegal logging. Various input and output data options allow more flexible use of patterns established during research and more rational use of tables in practice. Processing of field materials was carried out by methods generally accepted in forest evaluation practice.