EFFECTS OF EMISSIONS FROM COPPER-NICKEL SMELTERS ON THE FROST HARDINESS OF PINUS-SYLVESTRIS NEEDLES IN THE SUB-ARCTIC REGION

It has been proposed that freezing injuries play an important role in the forest decline phenomenon. In this study, the effect of emissions from the copper-nickel smelters in Monchegorsk and Nikel-Zapolyarnyi i n the Kola Peninsula, south-west Russia, on seasonal changes in the fr ost hardiness of Pinus sylvestris L. needles were studied. The frost h ardiness of current-pear needles during autumn, winter, spring and ear ly summer in 1991-1993 was estimated by the electrolyte leakage method and by visual estimation of the proportion of damaged needles at nine sites in Finnish Lapland, at five sites in the vicinity of Monchegors k and at two sites in Norway, in the vicinity of Nikel. The foliar S, Cu, and Ni concentrations also analysed. There were no significant dif ferences at any time of the year between the frost hardiness of pine n eedles at the sites in Norway and Finnish Lapland. However, in the win ter, the degree of visual damage at -45 degrees C, the temperature clo se to the lowest recorded temperature in this area, was slightly highe r at the sites near to Nikel than at the sites in Finnish Lapland. In the Kola Peninsula the frost hardiness was consistently lower at the s ites located 10 km to the south and 36 km to the south-west of Moncheg orsk than at the other sites (48-110 km to the south-west). The differ ences were greatest in early June, 1991, when frost hardiness was -2 d egrees C and -8 degrees C at the sites closest to Monchegorsk. At the same time, the frost hardiness at the other sites was c. -20 degrees C . There were slight differences between years, but the trends were the same. A clearly increasing gradient in the S, Cu and Ni concentration s was observed on moving towards the emission point source at Monchego rsk. Highly elevated concentrations were found within 40 km of the sme lter. The results suggest that air pollutants from the copper-nickel s melter have predisposed the pines to freezing injuries, thus contribut ing to forest decline in the Kola Peninsula.