Interactions between combined exposure to SO2 and NO2 and nutrient status of trees: effects on nutrient content and uptake, growth, needle ultrastructure and pigments.

Rantanen, L. and Palomäki, V. and Harrison, A. F. and Lucas, P. W. and Mansfield, T. A. (1994) Interactions between combined exposure to SO2 and NO2 and nutrient status of trees: effects on nutrient content and uptake, growth, needle ultrastructure and pigments. New Phytologist, 128 (4). pp. 689-701. ISSN 1469-8137

Abstract

Two-year-old seedlings of Norway spruce were exposed for 110 or 158 d in outdoor chambers to a combination of 30 nl 1−1 sulphur dioxide and 30 nl 1−1 nitrogen dioxide, and limited availability of K, Ca or Mg. Growth, nutrient content and changes in needle ultrastructure and pigments were determined, and nutrient demand for P, K and N was examined using root uptake methods. Exposure to pollutants did not clearly enhance any nutrient deficiencies. However, distinct ultrastructural effects of fumigation and Me and K deficiency stress, especially when applied together, were observed. Slight changes in total carotenoid concentration and the ratio of chlorophyll a/chlorophyll b contents were detected at 110 d but these disappeared as the experiment proceeded. Delayed growth of fumigated seedlings at 110 d was observed. The demand for P and N was almost unaffected by the treatments, but the demand for K increased in seedlings receiving both K deficient nutrient solution and exposure to pollutants. The results suggest that effects of simultaneous exposure to air pollutants and limited availability of nutrients were injuring cell ultrastructure and delaying growth, bur root responses and overall nutrient demand were unaffected by 158 d.