Fluctuating Asymmetry of Leaves of Betula pubescens Ehrh. for Assessment of Pollution of the Urban Environment of the Kola North

Abstract

The results of determining the fluctuating asymmetry (FA) index of Betula pubescens leaves as well as the state of birches in general, as an aboriginal species in the Murmansk region to assess the pollution of urban ecosystems of the Kola North (Murmansk, Apatity, Olenegorsk, Polyarnye Zori, Kandalaksha) in the zone of influence of railway transport have been presented in the article. It has been shown that the most weakened birches grow in Kandalaksha and Olenegorsk, while in Kandalaksha area, there are more than 10% of dead trees. It has been revealed that the highest FA index which characterizes the critical state of plants and the high level of environmental pollution is observed in Olenegorsk. The increased level of FA has also been in Kandalaksha and Polyarnye Zori. The comparative analysis of the state of plants and FA index showed existence of functional interrelation only in Kandalaksha and Olenegorsk when with a significant proportion of weakened trees the indicator of FA is the highest. Due to the fact that the increase in the level of FA is influenced by stress factors caused not only by pollution, the method of assessing the quality of the environment by the fluctuating asymmetry should be used in complex with other studies.