Natural resumption of pine trees on the cuttings of the Middle Priangarya due to the peculiarities of forest soil

Abstract

Studies of the subsequent resumption were carried out on the cuttings of 5-15-year-olds in the Northern Forestry of The Ust-Ilim district of Irkutsk region. The focus was on the growth of the pine tree as the most common and most exploited coniferous breed. The soil excavations measured the thickness of the A1 humus horizon and the forest litter A0, as well as the granulometric composition of the upper mineral horizons of the soils. The absence of a significant correlation between the density of the pine grower with the ratio of the thickness of A1/A0 of the osolode-made red-brown longseason-permafrost soils of the region, formed in conditions of sharp continentality of the climate, the predominance of evaporation over precipitation, the wealth of the mother breed exchange calcium, magnesium and sodium. There is a high inverse correlation of the number of the growth of pine with the "weighting" of the granulometric composition of soils from the sandy loam to the average loam. The largest number of teenagers (3-5 thousand ex./ha) was found in the original pines with the soils of the supine, less often – lightly coglinish mechanical composition. On the soils of light- and medium-sougling pines are much smaller, in the teenage part of the birch and aspen dominate. The growth of pine is practically absent on relatively rich loamy soils in the original firs, spruce trees, larch. The A1/A0 ratio, due to the peculiarities of soil formation in the research area, does not play a decisive role in the success of the subsequent resumption of pine cuttings.