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Ecophysiological features of Larix sibirica in urban ecosystems of the Kola north in the railway influence zone

For the first time, a study of the ecophysiological features of the introduced Larix sibirica (middle-aged plantations old 40-50 years) was carried out at a tree nursery and railway stations in four cities in the Kola Subarctic. Content of photosynthetic pigments (per fresh weight) ranged 1185 – 1894 μg·g-1 (chlorophyll a), 377 – 666 μg·g-1 (chlorophyll b), and 256 – 387 μg·g-1 (carotenoids). Exception was found for the specimens from Murmansk (significantly higher) and Olenegorsk (significantly lower values). High content of Fe was found in needles (1865 – 4278 mg·kg-1), however, it did not lead to any damage or abnormalities in the development of Larix sibirica. A close positive correlation was shown between the Fe and Mn contents (r = 0.91). Ni and Cu content in needles increased in all cities from 3 to 8 times in comparison with the background, Pb content increased only in the cities of Apatity and Olenegorsk (2–4 times). The amount of Cd and Zn was found within the optimal range. This study revealed the negative effects of the main pollutants (Ni, Cu, and Pb from the mining industry) on chlorophyll a (r = -0.81) and carotenoids (r = -0.70).