NUTRITIONAL STATUS OF POLLEN AND NEEDLES OF DIVERSE PINUS SYLVESTRIS POPULATIONS GROWN AT SITES WITH CONTRASTING POLLUTION J. OLEKSYN 1,2∗ , P. B. REICH 2 , P. KAROLEWSKI 1 , M. G. TJOELKER 2 and W. CHALUPKA 1 1 Polish Academy of Sciences, Institute of Dendrology, Parkowa 5, PL-62-035 Kórnik, Poland 2 University of Minnesota, Department of Forest Resources, 115 Green Hall, 1530 N. Cleveland Avenue, St. Paul, MN 55108-6112, U.S.A. E-mail: oleks001@gold.tc.umn.edu (Received 15 September 1997; accepted 22 February 1998) Abstract. Pollen may serve as a biological indicator for air pollution stress in plants. However, knowledge of pollen mineral composition and its relationship to environmental and genetic factors is very limited. We studied the concentrations of macro- and micronutrients in pollen and needles for seven European Scots pine (Pinus sylvestris L.) populations grown in two 15-yr-old provenance plantations with contrasting pollution levels. One site was located near a phosphate fertilizer fac- tory, and the other in an area free of acute air pollution. We also tested the relationship between tree age and pollen nutrient composition by sampling 60-yr-old trees of local origin in both sites. No population differences were found in nutrient concentrations in pollen. However, there were significant differences among populations in needle concentrations of K, Mg and Zn, as well as significant site x population interaction for Mn concentration. In pollen, populations at the polluted site had significantly higher concentrations of S, Mn, Al, Na, Cu, Ni and Cd, and lower Zn. Average concentrations of S, P, Mn and Cd was lower in pollen of 60-yr-old than 15-yr-old Scots pine trees. Pollen concentrations of P, K, Ca, Mg, Fe and B were similar between sites and not related to the concentration of these elements in needles. Therefore, by analyzing the chemical composition of pollen it is not possible to detect any nutritional disorders for P, K, Ca and Mg in plants, and it seems unlikely that nutrient analyses of pollen have an advantage over analyses of foliage as a bioindicator of pollution. However, enhanced accumulation by pollen of such elements as Al, S, Mn, Cu, Ni and Cd at the polluted site may adversely affect pollen function. Keywords: environmental pollution, nutrients, pollen, provenance, reproduction 1. Introduction There are numerous reports on the adverse effects of polluted environments on the sexual reproduction of higher plants, including reduced flower and cone initia- tion, pollen production, distribution, germination and growth, fruit abscission and decline of seed germination (for review see Wolters and Martens, 1987; Smith, 1990; Cox, 1992). A large research effort was made to examine the effect of pollu- ∗ Author for all correspondence: J. OLEKSYN, University of Minnesota, Department of Forest Resources, 115 Green Hall, 1530 N. Cleveland Avenue, St. Paul, MN 55108-6112, U.S.A. Water, Air, and Soil Pollution 110: 195–212, 1999. © 1999 Kluwer Academic Publishers. Printed in the Netherlands.