Lawn covers of Dnipropetrovsk region as a global phenomenon of urban green space in conditions of hostilities

Abstract

In order to facilitate the creation of lawns and maintain the regime of caring for lawn covers in difficult wartime, in which Ukraine and Dnipropetrovsk region is located, suffering from shelling and man-made disturbances of habitats, it is important to conduct observations and studies of the behavior of lawn plants in comparison with natural conditions in order to be able to preserve existing and restore damaged herbaceous groups with the least cost. We hypothesize that these solutions can be found in suburban natural ecosystems and various plant communities that are rich in species, able to withstand harsh climatic and microclimatic living conditions, severe trampling and droughts. Realizing that stable artificial plant groupings can exist only when using the laws of their existence in natural conditions, trial areas of urban agglomerations and out-of-town influence were investigated. 75 lawn covers and grass stands of the lawn type of the Dnipropetrovsk region with a size of 100 m2 in Dnipro, Kamenskoye, Andreevka village were described using the method of route trial areas. The dominant families are defined in the creation of lawn grass stands by their occurrence, projective coating, phytocenotic activity, number of species. It is established that, among other families, the Fabaceae family was in third place with participation in the projective cover among phytocenoses of Dnipro and Andreevka, in fifth ‒ in Kamianske. Phytocenotic activity, used as a criterion for the effect of plants on herbal grouping, was high in Fabaceae plant family (up to k = 19,5), Asteraceae (up to k = 18,7), Plantaginaceae (up to k = 15,4) on lawn grass stands in Andreevka village, which indicates the future trend of their displacement of cereals. Among the grasses plant family Plantaginaceae has significant phytocenotic activity (k = 10.1), which competes even with the main sod-forming plants of the Poaceae plant family (k = 10.7) in Dnipro. This trend is also observed in Kamenskoye (here in Plantaginaceae k = 10.0). This city has a high rating of industrial influence among other territories of the region and those that we have studied so far. In all studied phytocenoses, mutual influence between plants families Poaceae and Fabaceae is established. So, with a larger percentage of projective coverage of the Poaceae plant family, the percentage of the Fabaceae plant family is reduced, and vice versa. In dynamics, these fluctuations can vary in favor of each other, taking into account the further saturation of the upper horizon of the soil with nitrogen by the Fabaceae plant family, or the use of this trace element by representatives of the Poaceae plant family and the displacement of legumes. Such fluctuations will be constant. At the same time, lawn covers will not lose their aesthetics as a green carpet, because the projective coating will be occupied by plants and will not have gaps of free soil. This interdependence of lawn covers should be taken into account when creating high-quality long-term green lawns of cities where the soils are depleted, and constant fertilization is not always possible. Due to environmental conditions, the botanical diversity of the studied herbivores is expanded by adventive plant species from plants families Brassicaceae (up to 5 species in Dnipro), Lamiaceae (up to 7 species in v. Andreevka), Rosaceae (up to 6 species in Dnipro), Scrophulariaceae (up to 4 species in v. Andreevka), which, under favorable conditions, will occupy free ecological niches with grass. The spectrum of the first largest percentage of the occurrence of families reproduces the composition of the regional flora, which corresponds to cereal-grass groups of the structure of meadow lawns and ordinary urban grass stands with the expansion of ruderal representatives. 29% of the trial areas in the Dnieper city indicate the presence in the species composition of seedlings of woody and shrub life forms, the seeds of which are stored in the soil of adjacent territories, and their entry into lawn groups is a consequence of anemochoria and ornithochoria. Currently, given the current state of the country, lawn care is reduced to a minimum or it is absent at all. As a result, seedlings freely begin to take possession of the territory of lawn grass stands along with ruderal representatives of the local flora. This trend is also evidenced by the ratio of monocotyledonous and dicotyledonous plants as a criterion for decorativeness and phytocenotic constancy of lawns. It was ‒ 1:4 in Kamenskoye; 1:6 ‒ in Dnipro and Andreevka village. These are the conclusions that for the existing military period can be used to maintain the stability and aesthetic condition of lawn covers and grass beds of the lawn type of the Dnipropetrovsk region.