Ábrahám Levente: Biomonitoring a Dráva folyó magyarországi szakasza mentén 2000-2004 - Natura Somogyiensis 7. (Kaposvár, 2005)

Horváth, Gy., Molnár, Dániel - Csonka, Gergely: Population dynamics and spatial pattern of small mammals in protected forest and reforested area - Kisemlősök populációdinamikája és térbeli mintázata védett erdei és újraerdősödő területen

200 NATURA SOMOGYIENSIS Both the homogeneity tests of capture data in the two study plots and the population dynamics of the frequent rodent species indicated that the spatial arrangement of individuals of the various populations is an important factor in creating and changing the spatial and temporal pattern of small mammals moving between the strictly protected closed forest and the regrowing area. By evaluating capture point coordinates in the Biotas program we first analysed the space use and distribution of individuals in the populations of the three frequent rodents. Because of the low capture rates in 2003, in this analysis we used yearly cumulated data in both years (2003, 2004) for performing the graphical analysis of space use and the distribution investigations applying the nearest neighbour method. The use of the closed forest and the regrowing area in the three studied species was different among the two years. The striped field mouse, a generalist species in habitat use, occupied the edge area between Grids A and В in 2003. In 2004, the greater density of its population resulted in an increased space use, thus the striped field mouse populated the regrowing plot as well as the edge areas. Difference in the space use of the yellow-necked wood mouse between the two years was smaller. This species clearly preferred to use the closed alder gallery forest, although even in 2003 it did occur in a certain patch of the regrowing plot that was covered by larger trees and dense vegetation. In the following year, individuals of the population dispersed more intensely in the regrowing forest area. In the comparison of the two years, the most striking difference in space use was found for the bank vole. When it had low densities in 2003, it used mostly the closed forest, with only few individuals captured in the edge zone of the regrowing plot. In the following year it was found that as density grew, individuals started to use the regrowing plot more intensely (Fig. 5.). Fig. 5.: Space use by the three characteristic species in the regrowing forest area (B) and the closed alder gallery forest (A) in 2003 (left) and in 2004 (right)