Vegetation cover and small mammals as the components of biocoenosis in the conditions of the Volga Upland
The study of the nature reserve «oak forest near the village of Pelya-Khovanskaya» ecosystem was done in the region of Nizhny Novgorod. The investigated wood is unique for its complex structure. It is situated in the forest-steppe zone, characterized by a high species diversity of small mammals and vegetation, which indicates the complexity of trophic and spatial connections. Several series of sample plots were described: 41 of 20×20 m and a number of 1×1 m sites, totaling 300. Abundance of species by Brown-Blanke scale and the number of specimens of adolescence were specified for each 1 sq. m. plot. Mammals were trapped with the help of trapping grooves and transects method. Vegetation cover is characterized by the presence of a clear intra-differentiation as well as the existence of two basic ecologo-coenotic groups/cores - the nemoral (with Pulmonaria obscura Dum. as the center species of the core) and the meadow-fringe. The most distinct group is formed by forest-shoot species. It can be explained by more forest-steppe rather than nemoral nature of vegetation. Small mammals are represented by the following species: common and small shrews, small forest mouse, yellow-throated and field mice and harvest mouse, vole-housekeeper, common, plowed and red voles, European mole. Two species among them - vole-housekeeper and mouse-baby - are listed in the Red Book of the Nizhny Novgorod Region. Matching burrows of mouse-like rodents with soil richness with nitrogen and humidity, two well-defined peaks are observed. The greatest number of burrows is found in places where the soil is high in nitrogen. Moles were found in areas with a large projective coating of Primula veris: coefficient Spearman rank 0,50. There was a negative correlation of the number of moles and vegetation covering of Pyrethrum corymbosum (-0,46), which is the marker of the driest parts in the forest. In general, the nature reserve «oak forest near the village of Pelya-Khovanskaya» is of considerable interest, both from botanical and from zoological point of view. Long-term studies of biocoenosis will allow to monitor the facility and to correct the proposed protective measures.