Age differences of pine stands as a factor of harmonization of the system of forest management activities in ribbon forests of the Altai Krai

The ratio of the same- and uneven-aged pine forests in various types of ribbon forests in Altai Krai, as well as the patterns of forming natural pine plantations, is determined. This issue is important for the harmonization of the entire set of forest management activities in the study area. The research is based on the analysis of an electronic database that contains information on the forest fund of 11 forest districts in Altai Krai (more than 268 thousand stratums with a total area of 1014 thousand ha). With the help of queries using filters and summary tables, a sample of natural plantations with a predominance of Scotch pine (Pinus sylvestris L.) was obtained. For each plantation in the sample, the number of age generations and the distributions of the area of the same- and uneven-aged pine forests by forest districts, forest types, and quality classes were determined. Statistical data processing included cluster analysis and chi-squared test. Pine forests of natural origin in the study area consist mainly of 2-3 pine generations. The share of uneven-aged forest stands accounts for 79.6% of the area. Same-aged pine forests occupy 20.4% of the area. During the transition from damp to very dry growing conditions, the proportion of uneven-aged pine forests increases. In the future it is planned to improve the existing systems of improvement thinning in mature, declining stands of forest-steppes and ribbon forests in the Altai-Novosibirsk forest growing district considering the ratio of the same- and uneven-aged pine forests. The improvement of the system of forest management activities should be performed on a forest-typological basis in combination with the division of plantings into high- and low-quality.