Seasonal dynamics of the parameters of ecological structure of Collembola taxocene in the red oak forest in the Yavoriv NNP

The dynamics of Collembola populations in the territory of Yavoriv NNP in different seasons of the year was analysed. As a result of the study, 59 species of Collembola belonging to 42 genera and 13 families were identified in the areas of invasive Red Oak. The main indicators of the taxonomic structure fluctuate significantly throughout the year. The largest number of species and families occurs in summer (39 out of 42 species identified during the study), and the smallest in autumn (28 species). In winter, a high population density of - 3.4 thousand spec./m² was recorded, while the lowest density of 1.2 thousand spec./m² was recorded in spring. The synecological structure determined by non-parametric diversity indices demonstrates the lowest values in autumn, the same results of the Q index calculations. Of all the species identified in Red Oak, 22 belong to mass forms. The eurybiont species Folsomia manolachei is absolutely constant in 3 out of 4 seasons. The analysis of the ecological structure showed that eurybiont species predominate in the studied biotope, on average, their share is 51.8% of the total number of Collembola, 25.5% are hygro-mesophilic species, and the rest (mesophilic, xeroresistant and xero-mesophilic) are classified as random species. In total, representatives of 5 biotope groups were found over the entire period. On average over the 4 seasons, in terms of relative species richness, eutrophic species (54.8%) prevail, followed by forest-meadow (29.9%) and forest species groups (16.1%), while the rest are represented by only a few species in some seasons. In all seasons of the year, a high diversity of species was found in the spectrum of life forms, with the most numerous being litter and soil species (52.9% in spring), upper soil (43.9% in summer) and lower litter (22.5% in summer). Abrupt changes in the main parameters of diversity, dominance structure and composition of mass forms, as well as restructuring of the ecological structure, may be associated with a change in the stand classification in the studied area.