Anna Maria Jönsson

Bark lesions on beech are mostly caused by frost damage and/or insect and fungal infections. Liming, treatment with wood ash and N-fertilization were hypothesised to affect this type of damage. The frost sensitivity was measured as an index of injury, calculated from electrolytic leakage of bark samples. Samples were taken from the same trees in August and November at five sites. Two sites had been limed, one treated with wood ash and two had been fertilized with nitrogen, one of them with an additional phosphorous fertilization. Trees fertilized with nitrogen had significantly more lesions than trees from other treatments. The bark was more damaged at -20 degrees C than at -10 degrees C in both August and November at experimental conditions. No clear pattern in temperature sensitivity was detectable among sites or treatments approximately seven years after soil treatment. Trees with bark lesions seemed to be less able to withstand low temperatures. (C) 2000 Elsevier Science B.V. All rights reserved.