Analysis of solid waste landfills vegetation cover of Kharkiv region

Abstract
Background. Determination of plant species diversity in the areas of solid waste landfills (hereinafter “landfills”) was carried out in order to identify patterns of vegetation cover and give an ecological assessment of the technocenosis. Plant species diversity was definedon the territories of Derhachiv and Rohan landfills in the city of Kharkiv. Materials and Methods. The method of linear routes and trial areas was used to determine the number of species. The degree of coverage was measured by the Drude method. The degree of similarity was determined by calculating the Jacquard coefficient. Plants were systematized by species, life forms, life expectancy, types of cenomorphs. Results and Discussion. 117 species have been recorded at Kharkiv landfills in total. At Rohan landfill and in the adjacent territories the vegetation cover is represented by 92 species, at Derhachiv landfill – by 93 species. Because of the uneven distribution of vegetation in the territories, areas of landfills were identified according to the specifics of vegetation cover (4 for Derhachiv and 3 for Rohan landfills). The most pronounced species diversity of plants at Derhachiv landfill is in the zone of natural landscape (44.0 %), at Rohan landfill – in the zone of ruderal landscape (38.4 %). The obtained data were classified by plant species composition and the conditions of their existence. Herbaceous plants of Derhachiv and Rohan llandfills are dominant in terms of life forms – 83.8% and 85.8%, respectively. Perennial plants predominate in terms of life expectancy – 53.8 % and 52.2 %, respectively. By their practical use, landfill plants include medicinal (18.6 %), food (11.1 %), and honey (10.8 %) ones; phytomeliorant plants constitute the smallest part – 2.2 %. The Drude method was used to determine the degree of coverage. The dominant families at both landfills are Asteraceae (24.6 %) and Poaceae (13 %). Jacquard similarity coefficients ranged from 0.18 in the least similar zones to 0.75 in similar zones. Cj calculated for two landfills equals 0.11. The plants were systematized by cenomorphic affiliation. The leading type of cenomorph for the flora of landfills is ruderal species (Ru); a significant share is occupied by forest plants (Sil), meadow (Pr) and steppe (St) plant species. Conclusions. Solid waste landfill sites are characterized by a high degree of transformation, which is clearly manifested in the vegetation formation patterns. The significant difference between the vegetation cover of landfill areas (Сj = 0.11) indicates a low degree of similarity of species diversity due to the specifics of technogenesis of the studied ecosystems, historical landscape and preconditions for the formation of vegetation. Natural grass cover on the landfills is replaced by ruderal and shrub cover, which indicates harsh living conditions for cultivated plants and succession processes. There are three main patterns of the formarion of vegetation cover in the landfills: as a result of severe disturbances, indigenous plants are replaced by ruderants in the process of succession, while uncharacteristic species are introduced by biotic and abiotic factors. Keywords: vegetation cover, Derhachiv landfill, Rohan landfill, transformed landscapes, cenomorphic affiliation