Intracenotic patterns in damage of Abies sibirica Ledeb.-dominated stands by infectious diseases in the south of Central Siberia

Abstract

Abies sibirica Ledeb.-dominated stands degradation is of special concern. Nevertheless, insufficient attention is paid to the role of pathogens in this process. The aim of the present study is to assess the coenotic role of infectious diseases in fir-dominated stands in the south of Central Siberia. The research was based on a forest pathological examination conducted in A. sibirica-dominated forest stands in the Krasnoyarsk Krai. The cenotic role of the identified diseases is unequal. Stem decay and fir broom rust are typical diseases that weaken trees and induce rotten windsnap accumulation. Fir broom rust randomly affects trees of different age and size. The prevalence of fir broom rust in the studied fir stands reached 10% or more. The most hazard diseases in the studied stands are bacterial soft rot and root rot. Bacterial soft rot damages up to 20% of trees and causes their gradual dieback. The main cause of tree mortality in fir-dominated stands is root rot. The root rot-causing fungi lead to rapid dieback of trees of different cenotic status. In synergy with other factors, root rot acts as a significant endogenous factor in the current reorganization of coniferous forest ecosystems in the south of Central Siberia.