Наукові горизонти (Mar 2020)
FORMATION OF CANOPY WITH PINE AND BIRCH IN FOCUS OF MOTTLED BUTT ROT IN THE CONDITIONS OF ZHYTOMIR POLISSYA
Abstract
Due to the lack of up-to-date information for the region on the age structure, composition, origin of pine stands in the focuses of mottled butt rot, it is difficult to estimate the success of forestry in these areas. In addition to analyzing the formation of the composition of pine trees growing in the focuses of mottled butt rot in the most common site conditions, the aim was to investigate the patterns of joint growth of pine and birch. For this purpose, a comparative analysis of the mean height and diameter of these species in the disease focuses and in healthy stands was performed. The forest management database was used as the source. To carry out the analysis, a general set of pine sites located in the disease focuses was analyzed. It has been determined that silver birch is the most common concomitant pine species in all types of site conditions considered. With increasing fertility and soil moisture, there is an increase in the proportion of pine trees with the presence of birch and oak. In the formation of the composition in the pines in the focuses of mottled butt rot, there is insufficient involvement of minor species. In young plantations the participation of birch in the composition is the largest: in fresh poor site conditions – 36%, in fairly poor – 27–31%, in fresh fairly rich – 20 %. In the older pine stands in the focuses of the disease, the formation of a low proportion of birch in the composition – 11–19 %. In fresh site conditions birch in the composition of pine forests mainly artificial origin (in fresh poor site conditions – 71 %, in fresh fairly poor – 50 %, in fresh fairly rich – 76 %), in moist fairly poor conditions artificial birch is the least common (only 20 %). Natural birch is almost vegetative origin in almost half of all areas. According to the dynamics of the mean diameter and height of pine and birch, the largest difference between plantations in the focuses of mottled butt rot and healthy stands is observed in the fresh poor site conditions. In the investigated types of site conditions, the common in the dynamics of growth is the dominance of birch over pine in young plants both within and outside the disease. It is noted that in the focuses of mottled butt rot, unlike healthy plantings, birch for a longer time (in fresh poor and moist fairly poor site conditions up to 20 years) dominates the pine tree in mean diameter and height. In the future, it is of particular interest to determine the conditions of pine stands, depending on the proportion of related species and age.
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