DAMAGE CAUSES OF EUROPEAN ASH IN THE PERMANENT SAMPLING PLOTS IN KHARKIV REGION

Abstract

European (common) ash (Fraxinus excelsior L.) health condition and occurrence of certain damage types were estimated in permanent sampling plots in Kharkiv region. The following eight types of damage were revealed in inspected ash stands: frost cracks, mechanical damage of stems, epicormic shoots, branch dieback, symptoms of the bacterial disease and butt rot, signs of wood destroying fungi and insect feeding. Branch dieback and butt rot dominated with occurrence of 52 and 39 % respectively. In the stands of vegetative origin in fresh fertile forest site conditions, stand age correlation with forest health condition, with an occurrence of bacterial disease, branch dieback, and insect damage was significant. Percentage of trees with butt rots, branch dieback, and epicormic shoots was significantly higher in humid fertile forest site conditions than in fresh fertile forest site conditions. In young stands (20–30 years old) significantly higher occurrence of the bacterial disease of ash, epicormic shoots, butt rot and mechanical damage of stems was registered more often in humid relatively fertile forest site conditions than in fresh relatively fertile forest site conditions.