Anna Maria Jönsson

Concentration of nutrients and balance between nutrients in trees can affect tree vitality, and are dependent on soil conditions and atmospheric deposition. The aim of this investigation was to survey the concentration of nutrients in beech bark and to look for relationships with the frost sensitivity of the bark. Beech trees with bark lesions were compared to undamaged beech trees on five experimental sites with control plots, plots treated with nitrogen, ash or lime. Trees treated with lime had increased Ca/Al ratio and decreased concentrations of Mn and B. Negative influence from N fertilization could be traced in the concentration of nutrients in the bark seven years after treatment, but the absence of new lesions indicated that the vigour of the trees has increased. The frost sensitivity was correlated to the nutrient content. Trees with lesions had higher concentrations of N and Al, indicating influence of soil acidity.