The focus of Pinus sylvestris L. withering in the conditions of Minusinsk tape pine forests

The research objective was to find out the regu-larity of formation of the centers of Pinus sylvestris L. withering, depending on edaphic conditions, cli-mate change, biological efficiency, inner cenosis competition influencing the resistance of pine woods against root rot caused by Heterobasidion annosum (Fr.) Bref s. str. and Armillaria mellea s.l. The objects of the research were forests of Pinus sylvestris L. in various sanitary states on the territo-ry of Minusinsk Tape. 27 circular constant test are-as with mapping from the center through measured corner and distance were put. The cores were tak-en from humid conditioned trees of the pine adjoin-ing the centers of withering. As control of forest stands, those similar in structure, age, having no signs of defeat by root pathogens and other dis-eases were chosen. For the research of influence of edaphic conditions on the development of the disease in the part of Minusinsk tape pine forests, remote from the Yenisei, in 8 centers of withering (experimental) and on the removal from their rec-orded borders 30 soil cuttings were made, 172 samples of the soil for measurement of humidity and the content of physical clay were taken. The main role of root pathogens in curtain withering of pine woods was proved. In the centers of defeat of the pine during drought period the humidity of soil in its root layer made 12.4 % (the maximum value of 25.5 %). In control it was 9.16 and 18.4 % re-spectively. The content of physical clay in the cen-ters of withering of Pinus sylvestris and control planting had essential distinctions (R