Carabid fauna of 16 sampling sites located in the Bereg-plain and in the Carpathians were studied using pitfall samples. During the two-year-study we trapped 5849 individuals of 51 carabid species. We determined the occurrence of Carabus glabratus, Abax schueppeli and Leistus piceus in the Bereg-plain. We demonstrated additional localities of Carabus arcensis carpathus, Carabus intricatus, Carabus hampei and Cychrus caraboides. Considering the above results as well as our earlier data, we showed that the studied sampling sites can be classified into four groups based on their carabid fauna by cluster analysis: (1) forest stands of the Carpathians, (2) island-like hills of the Bereg-plain, (3) lowland forests maintaining several carabid species characteristic of hills and mountains, and (4) lowland forests containing mainly widely distributed and lowland species. We pointed out that the carabid fauna of the forests of the Bereg-plain is related to the fauna of the Carpathians, in addition, that the Bereg-plain can be regarded as the fluctuation zone of the forest-inhabiting mountainous carabid species. Based on our results it is proved that some forests of the Bereg-plain can be regarded as refuges and potential dispersal centres for the forest-inhabiting mountainous carabid species.
Sampling effort in pitfall trapping sessions is routinely calculated as a product of trap numbers and time period, expressed in units of trap-days or trap-weeks. This assumes that these two components contribute equally to the catch, so that the catch from 2n traps run for z days should be equivalent to the catch of n traps run for 2z days. We tested this equivalence relationship by comparing two pitfall trapping sessions, representing an identical trapping effort, performed in the same habitat (an apple orchard in Hungary), using the same pitfall trapping arrangement. The Time Series session had 20 traps operating for 20 weeks (400 trap-weeks), while the Spatial Series session had 100 traps operating for 4 weeks (400 trap-weeks). The Time Series session caught 1265 individuals of 44 species, while the Spatial Series session had fewer (757) individuals but 52 species. The virtual structure of the two carabid assemblages was different, although the major species were the same. Rarefaction curves clearly show that the Spatial Series indicated the presence of a significantly more species-rich ground beetle assemblage than the Time Series. The “common currency” for trapping effort needs to be re-examined because its two components, number of traps and length of operation do not contribute to the final catch in the same way. This has an important consequence for the design of biodiversity monitoring: trapping effort allocation for monitoring may be better when the number of traps is at the possible maximum and the time of sampling shortened rather than the other way around.
Effects of forestry management were studied in the Szatmár-Bereg Landscape Protection Area (NE-Hungary). Carabid assemblages of forest stands managed by different management techniques (stand put under acorn after clearing the herbaceous and shrub layer, the other prepared for seedlings by grubbing and deep loosening) have been compared with that of a non-managed control stand using pitfall traps. The number of carabid individuals and species has been found to be the highest in the non-managed stand, followed by that of the stand which was put under acorn after clearing the herbaceous and shrub layer. The fewest individuals and species were observed in the stand managed by grubbing and deep loosening. There was no significant difference between the species richness of the control stand and the stand managed by clearing the herbs and shrubs and put under acorn, while both values were found to be significantly higher than that of the stand managed by grubbing and loosening. The composition of the carabid assemblage of the non-managed stand and that of the stand cleared and put under acorn were similar to each other, while the carabid assemblage of the stand managed by grubbing and deep loosening was considerably different from the assemblages of the two above stands. The results suggest that the grubbing and deep loosening management practice completely changes the structure and composition of the carabid assemblage, thus it is not recommended to use in protected areas. Clearing the herbaceous and shrub layer followed by putting under acorn, does not substantially change the structure and composition of the carabid assemblage, so it can be used on protected areas for forestry management.
Several managed native forest stands have been reforested with conifer trees in Europe during recent centuries. These habitat alterations have influenced ground-dwelling invertebrates. We studied carabid beetle assemblages from a native beech forest (70-y-old), and a recently established (5-y-old), a young (15-y-old), a middle-aged (30-y-old) and a mature (50-y-old) Norway spruce plantation by pitfall trapping to explore the effect of reforestation on carabid beetles. The total number of carabid species, and the forest species were highest in the beech forest. The number of open-habitat species was highest in the youngest, relatively open monoculture. Ordination also confirmed changes in carabid composition with change in the studied habitats. Newly proposed forest affinity indices, based on species specificity, fidelity, and on a combination of specificity and fidelity were significantly higher in beech forest than in spruce plantations. We found these affinity indices especially useful in revealing the ecological character of the studied carabid assemblages. Regression analyses showed that leaf litter cover, herbs, shrubs, canopy closure and prey abundance were related to the structure of carabid-beetle assemblages.
The abundance of terrestrial isopods (Isopoda: Oniscidea) was evaluated along an urban-suburban-rural gradient. We tested two hypotheses regarding the response of species: (i) habitat specialist hypothesis, according to which the abundance of the forest specialists would increase, while the abundance of the urban environment specialist isopods would decrease along the urban-rural gradient, and (ii) opportunistic species hypothesis (abundance of the generalist species would increase by increasing level of urbanization). The abundance of the forest specialist isopod
increased significantly along the studied gradient. An opposite tendency was observed for the abundance of the urban environment specialist isopod
, as it was significantly higher in the urban area than in the suburban and rural sites. One generalist species (
gained dominance in the urban area, while other two generalists (
) showed no significant changes in abundance along the gradient.