S. Mahunka szerk.: Folia Entomologica Hungarica 51. (Budapest, 1990)
mitic grassland. These two stages contain a lot of common species of plants (Jakucs 1981) and Coleoptera. This plant community is almost closed, therefore, its diversity and abundance are greater than those of the previous stage . Due to the increasing value of cover and diversity of plant community, the diversity value of beetle communities also increased in the case of ground-dwelling species (Buse 198,4) and the aquatic ones (Nilsson 1984 ). Beley et al. (1982) found the same relationship between the vegetation structure and the whole arthropod community. Brown and Hyman (1986) found such a trend only in the early stages of succession in phytophagous beetles. The sessile-turkey oak forest is the mature stage having developed from the grassy communities after a long period of time. The long time and the stages between the steppe and forest phases are the reasons for the small portion of common species, though the species numbers andabuiidances are similar to those of the Coleoptera community of the steppe meadow. The classical theory of succession (Margalef 1968, Odum 1969, Price 1984) gives predictions to the changes of a lot of ecological characteristics, for example to the species richness, abundance, and diversity. These features are supposed to increase during succession. Some of the studies on arthropods also supported these results (Beley et al. 1982, Nilsson 1984, Hendrix et al. 1988). Our results showed some deviations from these expected changes in the case of diversity, and equitability (Table 6). The lower values of diversity, and equit ability in the mature community are due to the extreme abundance of a few species: Geotrupes vernalis , Carabus convexus and Nicrophorus vespillo . There are many differences in the results of ecological succession studied at different groups of animals and in different habitats. The abundance generally increases during the succession of vertebrate communities (Mehlhop and Lynch 1973, Schwartz and Whitson 1986), but not always the highest in the climax stage (Glowacinski 1981). In phytophagous beetles Brown and Hyman (1986) found that the middle stages showed the highest diversity values. Their findings in phytophagous beetles and our results concerning ground -dwelling Coleoptera revealed that the classical model of ecological succession cannot be applied to beetles . We recorded predominantly the ground-dwelling beetles by pitfall trapping which is only a part of the beetle community of the woodland. There are only a few records in our data about the leaf- and tree-dwelling species of the forest (for example: Cryptarcha strigata) .On the other hand, the pitfall trapping for grassland-dwelling beetles gives samples from the whole community, so our comparison mainly concerns the ground-living beetles. ACKNOWLEDGEMENTS I am particularly grateful to L. Ádám, who collected and identified the beetles. I thank G. Hraskó for his help in the field work and T. Szép for his help at computation. Cs. Moskát gave helpful comments on the manuscript. This study was made within the framework of the "Succession Project" of the Hungarian Natural History Museum, supported by the Hungarian Academy of Sciences. REFERENCES Beley, J.R., Ditsworth, T.M., Butt, S.M. and Johnson, CD. (1982): Arhtropods, plants and transmission lines in Arizona: community dinamics during secondary succession in a Pinyon-juniper chaparral habitat. - The Southwestern Naturalist, 27: 325-333. Brown, V.K. and Hyman, P.S. (1986): Successional communities of plants and phytophagous coleoptera. - Journal of Ecology, 7_4: 963-975. Buse, A. (1988): Habitat selection and grouping of beetles Coleoptera . - Holarctic Ecology, LI: 241-247. Clements, F.E. (1916): Plant succession: an analysis of the development of vege tation. - Carnegie Inst. Wash. Publ. 242 : 1-512. Connel, J.H. and Slatyer, R.O. (1977): Mechanisms of succession in natural communities and their role in community stability and organization. - American Naturalist, 111: 1119-1144.
