Phytosociology and nature conservation value of thermophilous oakforests in a South Hungarian karstarea

摘要

Thermophilous oak forests are among the most diverse forest communities in Europe, and they are important both from a phytosociological and a conservation perspective. In Hungary, they occupy large areas, including the south-facing slopes of karst mountains. Although detailed studies are available from some regions, there has been no in-depth analysis of the thermophilous forests of the Villany Mountains, the southernmost mountain region in Hungary. The aim of this study is to fill thisgap, by providing a basic phytosociological characterization and revealing the conservation importance of four thermophilos forest associations. A total of 200 coeno-logical releves were prepared, which were analyzed by PCoA-ordinations. Significant diagnostic species were identified for the associations. We calculated the number of all species, protected species and red-listed species that are present in two or more of the studied associations, and those that are restricted to only one community. The four associations were also compared based on the proportion of species with mainly Mediterranean distribution. We found that despite their obvious syntaxonomical relations, the four associations had rather different structural characteristics and speciescomposition. Generally, the oak scrub Inulo spiraeifoliae-Quercetum pubescentis seemed to host the highest conservation value; thus the current focus of conservation efforts on oak scrubs can be justified. Nevertheless, we identified several species, including protected and red-listed ones that occurred only in one of the other associations under study. This emphasizes that focusing on one association will not be sufficient; instead, representatives from all associations should be recognized as havinghigh conservation importance. New nature conservation areas would be desirable in two areas, MtTenkes and Mt Csukma, because both of them host all the four studied forest associations, allowing the protection of a high diversity in relatively small areas. Mt Nagy also has an extremely high protection value because of its near-natural oak scrubs.