Сибирский лесной журнал (Jun 2020)
Fire hazard of young pine stands on unused agricultural lands
Abstract
At present the problem of abandoned agricultural land overgrown with trees and shrubs is relevant in Russia. At the same time, there is a problem of fire hazard of coniferous young forest, formed on these lands. The paper considers the fire hazard of pine young forest on unused agricultural lands with different duration of the period of termination of land cultivation. On the basis of spatial distribution of young pine trees on overgrown fields it is revealed that overgrowth occurs gradually and it begins from the bordering forest. The main amount of self-seeding and undergrowth occurs at a distance of up to 125 m from the bordering forest in the amount of 4 to 7 thousand trees per ha, and as you move away from the bordering forest, the number of trees gradually decreases. On the studied fields different-aged pine young growth is formed, the vital condition of which is estimated as satisfactory. Proportion of healthy self-seeding and undergrowth is more than 70 %, unreliable to 20 % and dry up to 10 %. The number of seedlings in the fields is insignificant, there are no tree shoots in the fields, which is due to the overgrowth of the fields with grassy vegetation from 53 to 80 % of their area. Duff on sites for this period is not formed. The stock of ground fuels consisting of litter and moss does not exceed 180 g/m2 and does not form a continuous layer, in connection with which the spread of fire is impossible. It is revealed, that the ignition is possible in places where young growth grows in small groups or singly in the presence of a loose layer of dry grass consisting of cereals. Young pine stands are most flammable in spring.
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