Home – Home – Jornals – Contemporary Problems of Ecology 2010 number 2

Effect of strong (75 %) and complete (100 %) artificial defoliation of Betula pendula Roth on the dynamics of soluble sugars and phenols - flavonols, catechins and tannins - in the leaves of damaged plants was investigated. Within the first 15 days after strong defoliation of birch, no changes in flavonol, catechin and tannin content were revealed in the leaves. The amount of sugars increased at first, but returned to the normal level on the 10th day after defoliation. One year after strong defoliation, the amount of catechins and tannins in the leaves of damaged trees increased, while the amount of flavonols and sugars did not exhibit any differences from the leaves of reference trees. Within two years after strong damage, increased tannin content is conserved in the leaves, while the level of catechins and sugars remains at the reference level. One year after complete (100 %) artificial defoliation, the amount of flavonols and sugars in the leaves of damaged plants did not differ from that in the reference plants, while the concentrations of catechins and tannins exceeded those in reference plants. Two years after complete damage, the leaves contained increased amount of tannins, while the level of catechins, flavоnols and sugars did not differ from the reference.