SPECIFIC FEATURES OF THE GROWTH OF FEW-ROW FOREST BELTS ON CHESTNUT SOILS
The results of the study of pure tree stands growth within 33-36-year-old 2-4-row forest belts in the south of Western siberia are presented. the response of the current increase in height and diameter of Ulmus laevisPALL., Betula pendulaROtH, and PinussilvestrisL. model trees to the fluctuations in the amount of atmospheric precipitation for a hydrological year, cold and warm seasons were analyzed, as well as the density and age of tree stands. It was found that the growth and longevity of trees in sparse forest belts is highly dependent on the regime of atmospheric moisture and other factors that determine their moisture supply. solid precipitations are of great importance for their water supply which increases with the density and age of the stands. snowy winters delay the beginning of the growing season, slow down the growth of deciduous trees, and, on the contrary, accelerate the pine growth. Forest belts with proximate rows and higher number of the rows impairs their growth and makes them more dependent on the state of soil cover within the adjacent fields. By contrast, the fringe rows of shrubs increase the volume of trapped snow and spring reserves of soil moisture, and reduce the effect of weather conditions during the growing season, the adjacent fields and the age of tree stands.two-threerow belts with row spacing about 3 m wide and density of 1-2 thousand of middleaged trees per 1 ha have relatively stable growth, and are, therefore, more durable on the chestnut soils of Western siberia. Pure planting of Pinus silvestrisL. and Ulmus laevisPALL. and forest belts with edge rows of low shrubs should be used more widely in fieldprotective afforestation in the south of the region. Agrotechnical reclamation should be applied during their creating, and timely thinning should be carried out in young and middleaged stands.