Formation of Tree Morphology in Cultivated Pine Stands

Abstract

The aim of this study is to assess the qualitative characteristics of the crowns, stems and growth of Scots pine (Pinus sylvestris L.) trees in cultivated stands of a dry forest on gently sloping hills thinned in a regular-uniform manner, as well as to develop proposals for production based on the data obtained. The stands under study grow in the southwestern part of the ribbon forests of the Altai Territory in the territory of the Klyuchevskoye forestry. The thinning was carried out in 2016 as part of the planned forest maintenance activities. The field stage of the research was completed in 2022. The sample plots laid had a rectangular shape and a square of at least 0.25 ha. The assessment of the qualitative characteristics of the trees has been carried out in accordance with the classification proposed by G.A. Chibisov et al. The significance of differences (or their absence) in the tree distribution by quality categories in the plots has been established using the χ2 test for comparing two distributions. The article presents the taxation characteristics of the main forest element of the stands under study, the quality indices for the assessed tree indicators, and the graphs of tree distribution by diameter and quality classes. It has been found that most of the trees have poor crowns (27–45 %) and growth (14–41 %). Such indicators are a consequence of an excessively high density of the stands and the lack of timely thinning. Regular-uniform thinning of moderate and moderately high intensity has contributed to an increase in the quality class of the trees. The impact of high and very high intensity thinning on the stands has been negative. Based on the conducted research, it is recommended to carry out thinning at an earlier age of the stand, abandon the regular-uniform thinning in favor of selective thinning using the grassroots method (if possible) and carry out thinning along the largest exploitable diameter of 10 cm in the studied forest stands and similar ones. The study can be continued by establishing the optimal exploitable diameter in younger plantations and in other types of forests, as well as determining the intervals of optimal density of pine stands of different ages and different types of forest. The results obtained can be useful in designing economic activities in the study area.