ESTIMATION OF ECOLOGICAL PARAMETERS OF SMALL MAMMAL COMMUNITIES BY A NEW METHOD OF SAMPLING

In 1989 communities of small terrestrial mammals were studied in two d ifferent habitats, a grassy slope and a deciduous forest stand. Small mammal communities were sampled with Y-shaped arrays of pitfalls and d rift fences ( K i r k l a n d et al. 1990, Z u k a l & G a i s l e r 1 992), which were used in Europe for the first time in this study. Each habitat was sampled five times between March and November 1989. Altho ugh each sampling period was 10 days, only data from the first five da ys were used in determining small mammal community characteristics. Th ree hundred and sixty-two specimens were collected, representing two o rders (Insectivora and Rodentia) and eight species - Sorex araneus, S. minutus, Microtus arvalis, Clethrionomys glareolus, Apodemus sylvatic us, A. flavicollis, Micromys minutus and Muscardinus avellanarius. Ana lysis of variance revealed no difference among four methods of estimat ing the effective sampling area of the arrays. In the forest the relat ive abundance of small mammals 2.7%, the mean annual density 10.4 ind. /ha, and the biomass 196.5 g/ha. On the grassy slope and in adjacent f ields there was a high population of Microtus arvalis, which influence d all ecological parameters of the small mammal community. The relativ e abundance of small terrestrial mammals on the grassy slope was 37.2% , the mean annual hectare density 380.4 ind./ha, and the biomass 7893. 5 g/ha. The value of 1029.1 ind./ha from the June trapping represented one of the highest small mammal densities ever found in the CSFR.