Vegetation cover and microtine rodents spatial distribution under conditions of Nizhny Novgorod oakwood

Abstract

This paper deals with the problem of the connection between small mammals spatial distribution and the vegetation cover. The study was carried out during the summer period of 2018 and 2019 in the landscape protected area Oakwood of the NNSU Botanical Garden in the province of Nizhny Novgorod. Three relevs were set up in various plant associations: Ulmetum pulmonarioso-asaroso-aegopodiosum, Acereto-Tilietum pulmonarioso-impatienosum (noli-tangerae), Querceto-Acereto-Tilietum asareto-aegopodiosum. A standard geobotanical description was carried out according to the generally accepted method using a series of Raunkier sites registration. Microtine rodents were trapped by standart traps and live traps. The caught animals turned out to belong to 2 genera and 3 species: the bank vole Myodes glareolus Schreber, the pygmy wood mouse Apodemus uralensis Pallas, and the field mouse Apodemus agrarius Pallas. The low population size of animals, as well as the fact that Apodemus agrarius is a co-dominant, may indirectly indicate the anthropogenic pressure in the investigated oak groves. Ecological plasticity of the species Myodes glareolus has been confirmed. Bank voles inhabit micro-habitats with the average data of illumination as well as shaded ones. In general, the vegetation projective cover and the presence of Norway maple undergrowth are crucial for the microtine rodents spatial distribution. Small mammals choose sites with a minimum number of Acer platanoides undergrowth, and gravitate to places where the projective cover of grass has moderate rates (from 35 to 50%). The Principal Component Analysis (PCA) using a vegetation cover species spectrum showed the presence of a significant factor for microtine rodents, which is associated with nitrophilous species (common nettle and touch-me-not balsam). The presence of those plants may indicate a significant anthropogenic pressure on the vegetation cover. In addition, it is important that plants belong to a particular eco-coenotic group. The species Myodes glareolus and Apodemus agrarius differ on the nemoral factor, and their ecological niches do not overlap.