S. Mahunka szerk.: Folia Entomologica Hungarica 60. (Budapest, 1999)

(part of Matricum), comprising volcanic, mainly andesitic rock, brown forest soil. Its highest point reaches 700 m, yearly average precipitation is between 600 and 800 mm. The principal forest type is hornbeam-oak (Horánszky 1964). The area is about 21,000 ha. Fifteen various sites were sampled throughout PBR in 1982-1984. These sites were topographically different units, selected to cover a wide range of vegetation type (plant association). Sampling period of each site was visited only through one year. Ground beetles were sampled by using pitfall trapping. Five plastic cups (diameter 7 cm, depth 13 cm), partly filled with ethylene glycol and water, spaced in each vegetation types of the given site(s). Traps were emptied three times per year (1-12 sites) or monthly (intervals) (13-15 sites). The data were analysed by hierarchical classification, clustering methods: UPGMA (Manhattan distance), and Principal Component Analysis (PCA) (Podani 1997). For the evaluation of data the Statistica program package (StatSoft 1994) was used. Catches were pooled for each site and the relative frequency of each species was expressed as the percentage of the total catch at the site. Mean relative frequency was calculated to select the most and moderately common carabid species (mean rel. freq. > 1%). RESULTS AND DISCUSSION A total of 12,188 individuals belonging to 66 species were caught in 15 sites (Table 1). The relative high number of species may indicate that the sites are heterogeneous. De Felici and Vigna Taglianti (1991), in 21 sites (16 new stands) of the Central Apennine, showed 58 species, Korbel ( 1973) in 10 localities of the Carpathian beech forests captured 46 species, Baguette (1993) in 68 deciduous woodlands in Belgium registered 98 species, Heijerman and Turin (1989) recorded 88 species in 48 sites in different types of forest located various geographic parts of the Netherlands, and Terrel-Nield (1990) caught 68 species in 18 mixed deciduous English woodland sites. Mean numbers of species and individuals were per site 23.1 (range: 8-33) and 812.5 (range: 56-3,260), respectively. 19 species were registered in only one site, there were two species (Pterostichus melas and Abax parallelepipedus) in all units, and several occurred at least in 10 sites. Information on distribution, mean relative frequency, and total number of individual of more frequent 18 species is also given in Table 1. Mostly of those species are brachypterous, excluding: Harpalus rufipes, Platynus assimilis, Pterostichus melanarius and P. oblongopunctatus. The common species found were, in order of decreasing mean relative frequency: Aptinus bombarda, Abax parallelepipedus, Carabus scheidleri, Pterostichus melas and P. melanarius. A. bombarda the most common carabid was caught, comprising, on the average, 23 per cent of the total catch. The large part of its limited distribution area is situated in Hungary (Casale and Vigna Taglianti 1983), where it occurs mainly in oak and beech forests (Szél 1996). It is a typical forest living species in Hungary (Kádár and Szél 1993). The second in the row is A. parallelepipedus comprising 15 per cent of the total catch; adapted well to the forest habitat (see e.g. Loreau 1983). But, it appears clearly in a study of Petit and Burel (1993) that the hedgerow network may also support populations of A. parallelepipedus, because its small populations can settle in those and survive there, at least for some time.