THE INFLUENCE OF AIR-POLLUTANTS ON NEEDLES AND STEMS OF SCOTS PINE (PINUS-SYLVESTRIS L.) TREES

The influence of air pollution on the chemical composition of needles and stem anatomy (cambium, phloem, and xylem) of Scot spines (Pinus sy lvestris L.) was examined in polluted and control forest sires near Wa rsaw, Poland. Foliar chemical composition was determined as an indicat or of contamination of the trees examined anatomically. Anatomical ana lysis was carried out on samples including phloem, cambium, and curren t-year xylem collected at the breast height and from the tree top of t he leader during one growing season. At the control site in current-ye ar foliage, concentrations were N 1.53%, P 0.18%, K 0.5%, Ca 0.17%, Mg 910 ppm, Na 45 ppm, and S 0.145%, while at the polluted site concentr ations were N 1.73%, P 0.18%, K 0.66%, Ca 0.35%, Mg 1509 ppm, Na 105 p pm and S 0.201%. Concentrations Of heavy metals were significantly hig her at the polluted sire; only Mn was found in lower concentration. In trees from the polluted site, anatomical analysis revealed a decrease d number of cambial cells at the beginning of growing season, phloem c ells (at the tr ee top average number in a radial file was 21 and 14 i n control and polluted sites, respectively), and formation of false ri ngs with tracheids, similar to those in compression wood. Anatomical c hanges observed in trees from polluted sites are most likely caused by toxic effects of pollutants. (C) 1997 Elsevier Science Ltd. All right s reserved.