Effects of moisture conditions on the small mammal communities of floodplain forests in south Moravia (Czech Republic)

Abstract

Changes of the moisture regime and its influence on the dominance of selected species of small mammal communities were studied in floodplain forests in southern Moravia (river Dyje). In period of typical floodplain regime characterized by groundwater table fluctuation (1968–1972, with high groundwater table level or floods in spring) dominance of Apodemus flavicollis (Mel.) was 42%, Myodes glareolus (Schreb.) 33% and Sorex araneus L. 15% of the total small mammal communities. In period 1982–1987 after cessation of floods by river regulation, rapid groundwater drop and changes in the herb layer, the dominance of Apodemus flavicollis and Myodes glareolus increased. Also the dominance of Apodemus sylvaticus (L.) increased, but that of Sorex araneus collapsed. Further revitalization measures were applied by systems of channels supplying the water to root system of forest trees but not to the herb layer. In 2002–2006 decreasing moisture condition further influenced the dominance of Apodemus flavicollis reaching mean dominance 62%, Myodes glareolus dominance decreased to 20% and that of Sorex araneus remain to be low. All estimated changes were correlated with moisture regime changes and were significant. Thus the changes in the forest moisture regime significantly affect the community of small terrestrial mammals.