Ábrahám Levente (szerk.): Válogatott tanulmányok VI. - Natura Somogyiensis 19. (Kaposvár, 2010)

HORVÁTH GY., HERCZEG R., TAMÁSI K. & SALI N.: Nestedness of small mammal assemblages and role of indicator species in isolated marshland habitats

292 NATURA SOMOGYIENSIS Table 3: Table of the indicator values of the species, based on the hierarchy level of the habitat patches in 2005, where the first value is the number of caught individuals by single habitat patch and the second value is the number of those trap points where the species occurred in the given patch Macrohabitat/ Sampling plot IndVal (%) Keleti 4« rek Halász-rét Ingói-berek Komlósi-berek Balatoni-berek Rózsa-berek Species KE_1 KE_2 H_1 I_1 KO_l B_3 R_1 S. araneus 77.59 66/10 38/11 22/9 11/4 7/5 11/4 4/2 S. minutus 50.91" 10/7 4/4 1/1 0/0 0/0 0/0 0/0 C. suaveolens 27.27* 0/0 3/3 0/0 0/0 0/0 0/0 0/0 N. anomalus 11.89 0/0 1/1 2/2 2/1 0/0 0/0 0/0 N. fodiens 32.59* 0/0 0/0 1/1 2/2 0/0 0/0 0/0 M. glareolus 51.31** 0/0 3/2 0/0 8/2 0/0 0/0 9/5 M. agrestis 82.76 68/11 41/10 16/6 18/4 30/8 7/4 33/5 M. oeconomus 18.18* 0/0 0/0 3/2 0/0 0/0 0/0 0/0 M. arvalis 63.64** 18/7 0/0 0/0 0/0 0/0 0/0 0/0 A. terrestris 45.45** 0/0 0/0 6/5 0/0 0/0 0/0 0/0 R. rati us 20* 0/0 0/0 0/0 1/1 0/0 0/0 0/0 A. agrarius 82.76 23/11 26/10 34/9 39/4 8/5 20/5 11/4 A. flavi collis 43.14** 19/8 4/4 3/3 8/1 0/0 0/0 1/1 A. syhaticus 69.26** 10/8 1/1 0/0 0/0 0/0 0/0 0/0 M. spicilegus 9.09 0/0 1/1 0/0 0/0 0/0 0/0 0/0 M. minutus 69.82** 32/11 27/7 33/10 7/2 0/0 8/4 0/0 Total 243/73 149/54 121/48 96/21 45/18 46/17 58/17 **: P < 0.01; *: P <0.05 of quantitative values we separated three smaller clusters (one incorporated 3 habitats, two of them contained 2) in the 2005 analysis. In the first cluster the habitat patches of Keleti-berek (KE 1, KE_2) and the Halász-rét (H I) were joined on the basis of their similarities. In the second cluster the Ingói-berek (11) and the Balatoni-berek (B_l) were joined at the same dissimilarity value range like the previous ones. This fact is caused by the high frequency of striped field mouse (A. agrarius) in case of the latter two habitats (Table 3). In the south-western part of KBWPS-II the examined sedgy habitat patches of the Komlósi-berek (KO_l) and Rózsa-berek (R_l) were joint with the lowest distance value, which showed the highest similarity of the small mammal assemblages of these two habitats (Fig. 3). Every species that was characterized with lower IndVal values than 55 % were typical only in the given habitat patch, where they can be considered as asymmetrical indicator species. In the sampling plot of Halász-rét (H I) laying by River Zala the root vole showed up with low IndVal values as an asymmetrical indicator species. The european water vole (A. terrestris) appeared in the same patch as a significant species, however its character values were higher than those of the root vole and thus we can state that both of these vole species appear as indicators of the reedy-sedgy habitat patches characterized by higher water level close to River Zala. Regarding the two vole species the significant character value - typified locally for every habitat patch - indicates such optimal habitat quality that provides suitable environmental conditions for root vole settling (colonisation). In case of the Keleti-berek (K_2) the lesser white-toothed shrew (C. suaveolens) was an asymmetrical indicator species characterized by significant IndVal values revealing one habitat type, while in the area of Ingó-berek (I_l) water shrew (N.