The structure in diameter and sanitary condition of geographical cultures of Scots pine

Abstract

The study of geographical forest cultures is the scientific basis for forest-seed zoning and selection of tree species. This research identifies the structural features of the diameter of middle-aged stands of different ecotypes of Scots pine (Pinus sylvestris L.) in geographic cultures, as an assessment of its current sanitary state. We studied the stands of 18 forest-steppe and 14 steppe ecotypes. We laid test areas with measuring the diameters of trees with a measuring fork at a height of 1.3 m. Trees with a continuous count were divided into six categories of sanitary status: no signs of weakening, weakened, strongly weakened, shrinking, fresh dead wood and dead wood of past years. Based on the results of continuous recounts, the distribution rows of trees were constructed according to 2- and 4-cm thickness steps. In forest-steppe ecotypes, the distribution of trees along 2-and 4-centimeter-thick steps is single-vertex, but with right asymmetry. The distribution of trees of steppe ecotypes over 2-cm steps of thickness is asymmetric and two-peaked. The distribution of trees of steppe ecotypes by 2-cm thickness steps is asymmetric and two-vertex. The average score of the sanitary state of stands of forest-steppe ecotypes is 1.5 (healthy), in steppe – 1.7 (weakened).