The influence of root sponge on the pine wood products in the focus of disease
Root sponge Heterobasidion annosum (Fr.) Bref. is one of the most malicious and most spread fungi in the world and affects many conifers and deciduous tree species, but deciduous trees suffer from the root fungus less than conifers. Spruce, pine, fir and larch are especially often damaged by root fungus. Therefore, the study of biological and ecological peculiarities of the influence of root fungus on the productivity of coniferous plantations is very relevant. The purpose of this work is to investigate the nature of differentiation of trees according to categories of the state and dynamics of wood products in the focus of the root fungus in pine stands of Ulyanovsk region. Research of influence of root fungus on differentiation of the trees in the lesions were held in Kuzovatovsky forestry of Ulyanovsk region in the pine stands of artificial origin in different degrees of development of the centers of the root fungus. Generally accepted phytopathological and silviculture methods were used. In the focus of root fungus, the degree of differentiation of the trees according to the state depends on the type of the focus. If in emerging focus of root fungus the average for all forest types of distribution of trees slightly differs from the similar distribution of trees in the control variant, in current and especially in the fading focus there is the gradual redistribution of trees in the category of severely weakened, drying out and dried. Comparing the trees of average volume the following can be stated. In the control group, the average volume of a tree is slightly more than the similar indicator in all investigated focuses of the disease. With the strengthening of the development of the focus from emerging to fading the average volume of wood decreases in all examined types of forest. The average stand in the focuses gradually decreases with the development from the arising to the fading focus. This trend is typical for all the studied forest types.