The effect of bark phenols upon mountain hare barking of winter-dormant Scots pine

Due to high numbers of mountain hares in recent winters in northern Finland the barking of winter dormant Scots pines was widespread. The hares fed selectively upon upper crown bark of grafted pines, nitrogen fertilized trees and trees in poor condition. Bark of preferred upper crown branches and physiologically mature scions contained less total phenols than lower parts. However, there were no differences between total phenols concentrations of graft bark preferred by hares and nearby unbarked juvenile phase Scots pine. Neither decrease in resistance after nitrogen fertilization n- or stress was correlated with bark total phenolic concentration. Thus, total phenolic concentration is not a reliable predictor of the susceptibility of Scots pine to winter barking by the mountain hare.