ABUNDANCE AND DIVERSITY OF SMALL MAMMALS IN SUGAR BEET STANDS IN CZECH SILESIA

The community structure and the dynamics of populations of small mammals in the Czech Silesia in the sugar beet growths, and for comparison in winter wheat as the preceding winter crop, were studied. The most numerous species was the striped field mouse (Apodemus agrarius) with relative abundances 8.79 % and 77.97 % dominance. Other recorded species were the yellow-necked mouse (Apodemus flavicollis; D = 14.41 %, rA 1.62 %), the wood mouse (Apodemus sylvaticus; D = 5.93 %, rA 0.67 %) and the house mouse (Mus musculus; D = 1.70 %, rA 0.19 %). Mostly all the recorded species were representatives of the Muridae family which suggests that the representatives of this family are able to maintain a stable and prosperous population in sugar beet growths and this plant thus represents the most suitable habitat for them. From this point of view sugar beet growths serve a non-productive ecosystem function as a source of suitable habitat for Muridae. In terms of potential damage to the sugar beet, the Apodemus species are as consumers of weed seeds and insects rather beneficial. The damage caused by them is only marginal, e.g. consumption of sugar beet seeds shortly after sowing or in seed sugar beet stands. Winter wheat as the preceding crop is significant from germination to harvest for the recorded small mammals. From autumn the vegetative parts of winter wheat provide a food source and habitat particularly to the common vole. From spring to harvest the ratio of Muridae increases in connection with the increasing food range (seeds of wheat and weeds and animal food). After the harvest, the small mammals leave these areas due to the lack of shelter and food and use later harvested crops, poplar plantations or forests.