SEASONAL DYNAMICS OF THE CONTENT OF PHOTOSYNTHETIC PIGMENTS IN CONIFEROUS PLANTS UNDER THE CONDITIONS OF THE URBAN ENVIRONMENT

Background. The main share in the landscaping of the city of Yoshkar-Ola is made up of such deciduous woody and shrub plantings such as Betula pendula Roth., Tilia cordata Mill., Syringa vulgaris L., Acer negundo L., Populus pyramidalis Salisb., etc. Coniferous plants are not so usually used as often as deciduous plants in landscaping urban areas. However, most of them belong to the group of evergreens and play the role of green spaces all year round. In score of the high sensitivity to gaseous pollutants in cities, the problem arises using of it in urban landscaping. But such species of introduced conifers as Picea pungens Engelm., Thuja occidentalis L., Juniperus sabina L. are notable for their significant resistance to technogenic pollution. Materials and methods. The studies were conducted during 2018 in three different zones of Yoshkar-Ola which differ with degrees of anthropogenic load (recreational, residential, industrial). The objects of the study were Picea pungens Engelm., Thuja occidentalis L., Juniperus sabina L. The content of photosynthetic pigments (chlorophyll a and b, carotenoids) was studied in the needles of the second year of life in seasonal dynamics (May, July, October, December). Results. The study found that with an increasing of anthropogenic load, the quantitative content of photosynthetic pigments decreased in the needles of introduced plant species. Needle Picea pungens Engelm. was characterized by the highest content of the studied types of pigments. Conclusions. The obtained data expand the idea of the pigment composition of conifers growing in urban environment. The quantitative content of photosynthetic pigments depends on the species, season of the year and place were, it grows.