NO GENERAL EFFECT OF OZONE ON FOLIAR NUTRIENT CONCENTRATIONS IN MATURE SCIONS OF GRAFTED PICEA-ABIES TREES

The effect of ozone (< 10, 200, or 400 mug m-3), on foliar nutrient co ncentrations of Picea abies were determined by fumigating potted graft s from mature trees (> 55 and 125 years), representing six clones, in open-top chambers at two locations in Norway. The concentration of nut rients in needles of grafted plants were significantly affected by clo ne and location. Generally, the concentrations of nutrients were not a ffected by ozone, but a significant increase in the concentrations of potassium and iron in two of the clones were found. These two clones w ere the only ones injured (yellow needles) by the fumigation.