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Background. The study of the total content of phenolic compounds in the vegetative organs of lawn plants growing in areas with different levels of environmental pollution makes it possible to detect shifts in physiological and biochemical processes during plant ontogenesis in a changing environment, to establish the mechanisms of their ecological stability and to reveal the possibilities of regulating the conditions for creating high-quality lawn coverings. Materials and methods. Lawn plants (Trifolium repens L. and Poa pratensis L.) were studied in three age states: virginal (v), middle-aged generative (g2), and subsenile (ss). Samples taken in clean, moderately polluted and polluted areas of the city of Yoshkar-Ola of the Republic of Mari El were analyzed. The total content of phenolic compounds in plant objects was determined by the photocolorimetric method using the Folin – Denisov reagent. Results. In the vegetative organs of lawn plants (Trifolium repens, Poa pratensis) growing in areas with different levels of environmental pollution, the total content of phenolic compounds was determined. The increase in environmental pollution caused an increase in the content of phenolic compounds in the leaves and roots of lawn plants. In the leaves of T. repens and P. pratensis, this parameter increased from virginal to generative state, followed by a decrease in the subsenile state in all study zones. In the roots of lawn plants growing in areas with different anthropogenic load, a different picture was observed, that is, there was a gradual increase in the content of phenolic compounds from virginal to subsenial plants. In general, a higher content of phenols in vegetative organs was characteristic of individuals of creeping clover in comparison with individuals of meadow bluegrass. Conclusions. The total content of phenolic compounds in the vegetative organs of lawn plants is influenced by species characteristics, ontogenetic state, as well as the state of environmental conditions. An increased content of phenols was observed in the leaves of virginal and generative individuals of the studied lawn plants in all habitats, while in subsenile individuals of creeping clover and meadow bluegrass, on the contrary, indicators in the roots were higher than in the leaves. As the pollution of the environment increased, an increase in the content of phenolic compounds in the vegetative organs of lawn plants was observed, which, in turn, contributes to an increase in the resistance of the species under unfavorable and stressful environmental conditions. Since phenols, being components of the antioxidant system, play an important role as protective barriers against negative environmental factors.

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.

Background. The study of phosphorus metabolism of lawn plants growing in areas with different degrees of anthropogenic load allows to identify changes in the basic physiological and biochemical processes in plants at different stages of ontogenesis, to reveal the mechanisms of environmental sustainability and the possibility of correcting the conditions for creating high-quality turf coatings in cities. Materials and methods. The objects of study were lawn plants (Dactylis glomerata L. and Poa pratensis L.) of three age States: virginal (v), middle-aged generative (g2) and subsenile (ss). The research was carried out in the territory of the city of Yoshkar-Ola of the Mari El Republic. Samples were taken for analysis in conditionally clean, medium-polluted and polluted zones. The content of total phosphorus was determined by photocolorimetric method on the “blue” phosphor-molybdenum complex. To characterize the processes of phosphorus movement, the coefficient of motion (Kp) was used. Data processing was carried out by statistical method. Results. In the urban environment in the vegetative organs of lawn plants (D. glomerata, P. pratensis) determined the content of total phosphorus. As pollution increased, the total phosphorus content in the leaves and roots of lawn plants decreased. During ontogenesis from the virginal state to the generative state, this index increased followed by a fall in the subsenile state in all zones of the study. In this case, the basipetal distribution of phosphorus in the vegetative organs of lawn plants was clearly manifested. In general, a higher content of total phosphorus in the vegetative organs was characteristic of individuals of D. glomerata compared to individuals of P. pratensis. Conclusions. The content of total phosphorus in the vegetative organs of lawn plants depends on the species and biological age of lawn plants, as well as environmental conditions. Phosphorus leaves aging cells with age and its concentration in old tissues is usually lower than in young ones. An increase in the negative anthropogenic environmental impact on lawn plants causes a decrease in the total phosphorus content in their vegetative organs.

In annual ornamental plants in the urban environment, were built phenological spectrum. The studies were conducted in the city of Yoshkar-Ola in areas of different anthropogenic load: conditionally clean area, an area with a low level of pollution, the area with the average level of pollution. As objects of research were studied annual ornamental plants commonly used in landscaping the urban environment. To construct phenological spectrums we have identified the following phases: the vegetation, budding, flowering and fruiting. As a result of researches it was shown that the studied species of ornamental plants growing in various on anthropogenous loading districts of the city, differ features of passing and duration separate phenophases. For marigold (stable species) growing in the residential and industrial areas of the city of Yoshkar-Ola, a longer growing season characterized, slow development, the later and less long blooming. China aster (unstable form) is characterized by a more rapid passage of all phases of development, in the early transition and longer generative stage (flowering). Thus, the studied species of ornamental plants have a high sensitivity to the environment protection and development, depending on weather conditions and anthropogenic pressure, varied in a wide range.