NUTRIENT CONTENT AND IONIC PATTERN IN BEECH (FAGUS-SYLVATICA L) FROM NATURAL STANDS IN EASTERN AUSTRIA AND ECOLOGICAL IMPLICATIONS

Macro and Micro cation content, concentration of water soluble cations and anions, as well as nitrogen content in beech leaves from a variety of forest stands in the eastern part of Austria have been determined. Special attention has been focused on the highly air polluted Vienna Woods. A broad natural variability in total content of minerals, as well as in nitrogen content could be observed. In general, cation nourishment has been found to be adequate on all stands. The pattern of water soluble i.e. physiologically active cations, especially with regard to divalent cations, varies broadly among beeches from different provenances: Mg/Mn ratios differ within three orders of magnitude between dolomite and highly acidic, nutrient poor stands over silicate rock. The term 'mineral deficiency limit' should, therefore, be used very carefully with respect to single nutrients. Organic anions (quinate, malate, citrate) clearly dominate over inorganic anions. The relative amount of the latter increased from NO3, Cl, inorganic phosphate to SO4. A concentration of SO4 is markedly in leaves within the direct reach Of SO2 sources, its level, however, remaining well below the organic anions. Slight evidence of an antagonistic behavior between SO4 and organic acids could be found. Total nitrogen as well as the ratio insoluble:soluble nitrogen were tendencially higher in Vienna Wood beeches, indicating an additional use of the airborne nitrogen. The high flexibility of beech with respect to mineral content and ionic balance is discussed with regard to the ecological distribution of beech and the susceptibility to air pollution.