Allelopathically active substances serving as environmental chemoregulators are therefore an important factor in determining the species composition, cenotic structure, dynamics and productivity of plant communities. The allelochemicals get into soil from different organs, particularly lots are contained in the leaf deposit. Scientists focused on the research of allelopathic activity, mainly invasive species, while chemical interaction of aboriginal species remained disregarded. The paperwork is devoted to the research of allelopathic properties of leaf litter and rhizosphere of species of the genus Acer L. The index was determined by the conventional method of bioassays using water extracts from plants leaf litter and rhizosphere. For the purpose of objective evaluation of allelopathic effect, the impact of extracts in different concentrations (1:10, 1:50, 1: 100) was analyzed. As a biotester Raphanus sativus L. var. radicula Pers. was used. The presence of allelopathic effect of leaf litter of the investigated species is proved, manifested in inhibition (germination of seeds, length of aerial parts of seedlings), as well as stimulating (root length) biotester indices. The descending row of allelopathic activity of leaf litter of the investigated species is as following: A. pseudoplatanus - A. campestre - A. platanoides - A. negundo. It was determined, that the rhizospheric soil layer from under the crown of studied species of the genus Acer L. is characterized by different allelopathic activity, which was manifested both in inhibition (including growth of the aerial part) and stimulation (root growth) of biotester indicators. Our research confirms the information that the effect of allelopathic interaction of plants can be both negative and positive. The studied species of the genus Acer L. have allelopathic property, so they can play an important role in intraspecific and interspecific interactions in plant communities.

Проаналізовано сезонні зміни вмісту розчинного кисню у поверхневих водах р. Малий Сірет. Підкреслено вагомий внесок вітчизняних учених (П. І. Чернеги, Ю. С. Ющенка, В. Г. Явкіна та ін.) у розробку окремих аспектів даного питання. Із метою визначення фонових територій басейну річки Малий Сірет запропоновано та апробовано нову методику виявлення фонових і унікальних територій, які слугують еталоном для моніторингу басейну р. Малий Сірет.