Community Structure of Litter Invertebrates of Forest Belt Ecosystems in the Ukrainian Steppe Zone

Specific features of the structure of the ground litter invertebrate community in forest belt ecosystems in the Ukrainian steppe zone have been considered. For 14 years invertebrate fauna of the litter of 176 forest belt sites with different composition has been studied with the aid of soil traps. The main characteristics of litter invertebrate communities (total population, a number of species, Shannon-Wiener and Pielou indices of diversity) are not significantly different in various types of forest belt. The maximum number of saprophages is typical for Robinia pseudoacacia L., Fraxinus excelsior L. and Betula pubescens Ehrh stands. Zoophages and polyphages are dominant (20 and 50%, respectively, by numbers) in all forest belts of the steppe zone. There are more zoophages and fewer polyphages in Acer tataricum L. forest belts than in other types of forest belt. The most leveled size structure of the litter invertebrate community can be observed in the forest belts composed of Gleditsia triacanthos L., A. tataricum L., R. pseudoacacia L. and F. excelsior L. The average number of species with a body length less than 4 mm exceeds 20% of the litter invertebrate community composition only in F. excelsior L. and R. pseudoacacia L. forest belts indicating the presence of relatively stable temperature and moisture conditions throughout the season in these types of habitat. Compared with the natural forest types in the steppe zone of Ukraine, the same families of litter invertebrates dominate in forests belt but the numbers of Julidae, Isopoda, Silphidae and Staphylinidae are lower.