Вплив осушувальної меліорації на кількісний та видовий склад дрібних ссавців

Abstract

The article is devoted to the research on the abundance and species composition of small mammals in the territory of central Ukraine (Cherkasy, Poltava, and Kyiv oblasts) affected by land development by drainage. The drainage areas of the studied region are located mainly in fens, which in most cases are connected with river valleys. The vegetation there used to be represented by reed sets with thickets of reed–mace as well as various sedges and horsetails. The drainage process consists of several stages. It is possible to outline four of them within the studied areas. The aim of the research was to analyse the influence drainage has on the abundance and species composition of small mammals. In total, 4161 rodents and shrews were captured at a sampling effort of 60 890 trap-days. It was found that drainage is a strong anthropogenic factor that shapes the abundance and species composition of small mammals within the drained lands of central Ukraine. It was revealed that the species diversity of small mammals decreases essentially as the area of drainage grows. In general, with drainage, the number of hydrophilous species decreases sharply or they become extinct, whereas the number of species that prefer open habitats increases. At the same time, the general diversity index (H) reaches the greatest value in areas of the second stage of drainage, and, as drainage works expand, the species diversity decreases significantly. The abundance dynamics of small-mammal species both by habitats and drainage stages is presented. The research results make it possible to understand some patterns drainage causes to the fauna of shrews and rodents, and, accordingly, the specifics of adaptation of the latter to those patterns. The obtained data can be used to estimate and foresee the number of small mammals within different regions of Ukraine, to develop measures to control harmful rodents in drainage areas, to predict the real scale of economic damage caused by them, and to elaborate some theoretical issues in biogeography.