Biochemical peculiarities of common oak old forest and 55-year old culture trees in connection with their suitability to an herbivorous insects

Abstract

Aims. Decline of common oak plantations in last 40–50 decades is a serious problem in many countries. In eastern part of Ukraine there were observed two neighboring common oak plantations: 200–300-year old health trees and 55-year old culture with 15–16 % of decaying trees. Methods. Biochemical peculiarities of these plantations were studied for several leaf traits: common protein content (Pt), condensed tannins (CT) and hydrolysable ones (HT). The degree of herbivore insects’ activity was studied also. Results. It was found the much more intensive damage in 55-year old culture by two dominance species of herbivores – Altica quercetorum and Erranis sp. The specialist (A. quercetorum) prefer trees with high content of Pt in leaves and low content of HT. The generalist (E. sp.) prefer opposite proportion of these groups of compounds in leaves. The most stable trees were found in 200–300-year old plantation. Conclusions. The most special peculiarity concerned the content of CT. Their content in leaves of old plantation trees was 200–250 % higher compared to 55-year old culture.

Key words: old forest, Quercus robur L., biochemical peculiarities, herbivorous insects.