State of dark coniferous plantations in the southern part of the Yenisei Siberia: the role of biotic factors

Abstract

The article assumes that, the areas of dark coniferous forests with disturbed and lost stability are catastrophically expanding in Siberian regions in the modern period. This fully applies to the plantations with a prevalence of Abies sibirica Ledeb., located in the southern part of the Yenisei Siberia (territory of the Krasnoyarsk Region). The research was carried out in the spruce and fir plantations of the Biryusinsky district forestry of the KGU “Emelyanovskoye lesnichestvo” in order to clarify the role of the main biotic factors of the sanitary state violation and drying out of dark coniferous plantations. The method of research is route and detailed forest pathological inspection with the subsequent integral evaluation of the sanitary and forest pathological state of forest plantations. On the basis of all indicators of the state and tree falling parameters, a slight disturbance of the stability of the forest plantations Picea obovata Ledeb. was established; weak-strong disturbance until the loss of stability of A. sibirica plantation with their progressive drying out. The main biotic factors in the accumulation of pathological tree fallings and degradation of fir stands are the root pathogen Armillaria mellea s. l. and the invasive xylophage Polygraphus proximus Blandford in association with the micromycete Grosmannia aoshimae, that have a concomitant negative effect on trees. Additional factors of weakening, less often drying of fir trees are necrotic rust diseases; they are bacterial dropsy (pathogen is an association of phytopathogenic bacteria) and blister rust (pathogen is Melampsorella caryophyllacearum G. Schrot.), genus Monochamus.