Proportion of Birch Leaves Damaged by Insects along the Pollution Gradient of the Middle Ural Copper Smelter

The proportion of leaves of downy birch (Betula pubescens Ehrh.) damaged by insects at ten sites of coniferous forest along the pollution gradient of the Middle Ural copper smelter was analyzed. The study was conducted during periods of moderate (2009) and low (2019) emissions in early and late summer. The proportion of damaged leaves was higher in 2019 and increased towards the end of the growing season but was not associated with distance to the smelter and lead concentration in leaves.