Characteristics and Geographical Distribution of the Changes in Scots Pine Needle Surfaces in Finnish Lapland and the Kola Peninsula

Abstract

Effects of air pollution and a variety of other environmental factors on physicochemical characteristics of Scots pine (Pinus sylvestris L.) needle surfaces were studied in an extensive field investigation, comprising 114 sample plots (356 trees) on transect lines extending from the Nikel and Monchegorsk industrial complexes on the Kola Peninsula, Russia, across Finnish Lapland. Preliminary results from some of the investigated physicochemical parameters are presented in this paper. Condition of epicuticular wax structures, occurrence of particle deposition, fungal hyphae and insect damage on needle surfaces were investigated quantitatively under a scanning electron microscope, and needle wettability was measured in terms of contact angles. The investigated parameters showed great variability in terms of pollution, climate and ecology. Both the epicuticular wax erosion rate and needle wettability changed significantly faster during the first year on pines in Kola Peninsula, Russia (transect 1, extending to Monchegorsk) than on pines in Finland (transects 1,2,3,7). Site dependent effects, e. g., variation in ecological conditions of the sample plot, could be diminished by investigating the rate of change in the physicochemical parameter of pine needle surface during the first year, instead of using absolute values from different needle age classes.