The problem of drying up spruce stands and ways to solve it

Abstract

The last decades has been witnessed of the mass spruce stands drying up problem in different countries of the world. The investigation purpose consists in establishing influence of the growth conditions and the bark beetle, on the drying up of spruce forests. Forest stands of the coniferous-broadleaved (mixed) zone forests in Russian Federation served as an object of our researcb. Based on the results of the acts of pathologic inspection, it is established that the share of drying up spruce forests decreases with increasing soil fertility and moisture. The influence of the bark beetle was investigated on the basis of materials of three sample plots in stands of the green-moss spruce type of forest. We did not find traces of vital activities of the bark beetle by the drying spruce trees with a diameter at altitudes of 1.3 m to 14 cm fully, as well as with a diameter of 14 to 22 cm partly. The fact revealed is explained by the fact that these spruce trees have a thin bark which is not enough for the beetle laying inside of it the mother gallery, and the brood bark for subsequent feeding. The bark beetle is not the primary reason of the spruce forests drying in the Permsky Kray. It is necessary to conduct a much deeper study on this problem. © 2019 Published under licence by IOP Publishing Ltd.