Effect of Industrial Environmental Pollution on Winter Dormancy in Scotch Pine

Abstract

Many complexes of adaptive responses to environmental factors that have been formed in the course of evolution change under the effect of technogenic pollution. Disturbance of the natural dynamics of transition to winter dormancy in woody plants is among the possible manifestations of this effect. We may presume that, as a result, some of the plants growing in regions with a high level of air pollution do not complete their transition to dormancy, remain unprepared for severe conditions in winter, and may be damaged. Apparently, this is actually the case, as the composition of sugars in plant leaves changes under the effect of air pollution, and the increase in their contents in autumn and winter is less pronounced and occurs later than under normal conditions (Huttunen et al. , 1981b). Seasonal dynamics of transpiration rate is also altered in plants growing in polluted areas (Huttunen et al. , 1981a). To resolve this issue, it is necessary to study in detail the seasonal dynamics of the state of plants, including their transition to winter dormancy, using adequate methods for monitoring their physiological condition. Measurement of chlorophyll fluorescence is one such approach. It allows the researcher to estimate structural and functional changes in the photoassimilatory system of plants (Matorin et al. , 1985; Veselovskii and Veselova, 1990; Gaevskii and Morgun, 1993; Grigor’ev and Buchel’nikov, 1999). The purpose of this study was to analyze the seasonal dynamics of chlorophyll fluorescence in the needles and the depth of winter dormancy in Scotch pine trees ( Pinus sylvestris L.) growing in areas with different levels of air pollution.