PHYTODIVERSITY OF THE RESEARCH TERRITORY OF THE EDUCATIONAL AND SCIENTIFIC STATIONARY OF THE ODESA I. I. MECHNIKOV NATIONAL UNIVERSITY

Abstract

Problem Statement and Purpose. Biological and landscape diversity is considered as the fundamental property of natural complexes, which ensures their stability and manifests itself at different levels of their hierarchy. One of the types of biodiversity is phytodiversity which is the variety of plants. The stability of geosystems directly depends on the number of species of living organisms that form a complex relationship within the supply chain and struggle for survival. The more species is the higher stability of the system. This means that in the case of loss of one species, there is a high probability that another species will assume its functions. If species are not enough the ecosystem will lose one link, resulting in an imbalance. Finally, the geosystem can be completely destroyed.The purpose of the study is the estimation of the phytodiversity of the area, which for a long time (more than 15 years) is not involved in human activity, as well as the determination of changes in the conditionally natural system in a three-year interval. The main tasks are quantitative and qualitative estimation of the species diversity of grassy plants of the geosystem, analysis of weather conditions, analysis of individual geocomponents.Data & Methods. The investigations were carried out within the area which is located on the left slope of the Labushna Valley of the southwestern exposition. The slope has a complicated profile. Its length is about 400 m, average slope is 8 °. The area is surrounded by fields of crop rotation. It is situated on the territory of the Educational and Scientific Stationary of the Odessa I. I. Mechnikov National University.The study of biodiversity of grassy plants was carried out along the 5 m transect (strips), laid from top to bottom of the slope. On transect, plant groups were distinguished by external signs. Within each group, a standard geobotanical research was carried out, during which species of plants, the abundance of each species (in %), dominant species, composition and height of plantations, projective coverage (in %) were determined. Such studies were conducted in 2015 and 2018.The time of observation is the third decade of June. Two rows of data are obtained for calculations and estimation of phytogenic diversity.Also, in the study floristic germination and index of adventitious species are calculated on the basis of the species composition. Abundance of dominant species in two years of research was estimated on the Drude scale.Results. The Stationary was organized in 1980 for to study the conditions of the forest-steppe landscapes, and the regime of excessively moist soils (wetlands, mochars), as well as their melioration. The vegetation of the territory is represented by the diversity of grasses, grass, cereal, leguminous grass and legume-cereal dry meadows, overgrown areas with a predominance of cane and various species of ascension and broadleaf elderberry-ash-oak, maple-ash-oak and birch leaf-cherryoak forests.The total cultivation of the Baltic Stationary is 55.4%. Forest areas, including peat and sloping anti-erosion plantings, occupy 21.6% of the area. The total area of conventionally natural areas which are not used for arable land and not occupied by forests and settlements is 17.49 sq. km, or 13.4% of the area.The investigated area is characterized by a high diversity of plant species. The alternation of plant groups is subject to a certain spatial pattern associated with external factors (human impact, groundwater level, weather conditions) and internal features of the area (shape and exposition of the slope, soil cover). The value of the Sierressen floristic germination (58 %) indicates a high similarity of species during the years of study, from which it can be concluded that the geosystem of the area is sustainable enough. According to the values of the index of adventitious species, the plant groups contain a significant proportion of the adventitious species (18 % in 2015 and 27 % in 2018).