THE INFLUENCE OF DIFFERENT TYPES OF PLANT COMMUNITIES ON THE ACIDITY AND HUMUS CONTENT OF SOUTHERN CHERNOZEMS IN THE CITY OF ODESA: THEORETICAL AND PRACTICAL ASPECTS

Abstract

The article presents the results of a study on the impact of various vegetation types (herbaceous, deciduous, and coniferous) on key physicochemical parameters of southern chernozems within the urban ecosystem of Odesa. The relevance of the work is driven by the need to understand the role of the biological factor in the transformation of urban soils under the influence of anthropogenic pressure. The study is based on a comparative analysis of samples collected from the Botanical Garden of Odesa Mechnikov National University and artificial plantations along Shevchenko Avenue. The soil acidity (pH in water) and total humus content were studied. It was established that the type of vegetation cover is a decisive modifier of soil pH and total humus content; however, its influence is localized primarily in the upper soil layer (0–20 cm). The highest pH values (8,01–8,15) and maximum humus content (4,92–4,95%) were recorded under herbaceous vegetation, confirming its exceptional role in organic matter accumulation. Conversely, coniferous plantations contribute to the acidification of the environment (pH 7,40–7,45) and are characterized by the lowest humus content (2,35–3,18%) due to the specific chemical composition of the litterfall. The authors have proved that the influence of vegetation on the properties of southern chernozems has a clearly defined profile differentiation and significantly diminishes at depths exceeding 30 cm. The theoretical significance of the work lies in deepening the knowledge of the biological factor’s role in anthropogenically modified landscapes. The practical value of the results is determined by the possibility of their application in developing strategies for sustainable management of urban ecosystems, the formation of resilient biogeocenoses, and the preservation of urban soil (urbozem) fertility.