Biologia 63/3: 368—377, 2008 Section Botany DOI: 10.2478/s11756-008-0059-2 Mire vegetation of the Muránska Planina Mts – formalised classification, ecology, main environmental gradient and influence of geographical position Richard Hrivnák 1 , Michal Hájek 2,3 , Drahoš Blanár 4 , Judita Kochjarová 5 & Petra Hájková 2,3 1 Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 14, SK–84523 Bratislava, Slovakia; e-mail: richard.hrivnak@savba.sk 2 Institute of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, CZ–61137 Brno, Czech Republic; e-mails: hajek@sci.muni.cz, buriana@sci.muni.cz 3 Department of Ecology, Institute of Botany, Academy of Sciences of the Czech Republic, Poříčí 3b, CZ–60300, Czech Republic 4 State Nature Conservancy, National Park Muránska planina Mts, J. Kráľa 12, SK–05001 Revúca, Slovakia; e-mail: blanar@sopsr.sk 5 Botanical Garden, Comenius University, SK–03815 Blatnica č. 315, Slovakia; e-mail: kochjarova@rec.uniba.sk Abstract: Mire vegetation of the Muránska planina Mts and adjacent parts of neighbouring orographical units was studied in 1998–2005 using the standard Z¨ urich-Montpellier (Braun-Blanquet) approach. We applied the defined phytosociological species groups and national formal definitions of mire associations in data processing. Within the classes Scheuchzerio- Caricetea fuscae and Oxycocco-Sphagnetea, seven associations (Caricetum davallianae, Carici flavae-Cratoneuretum fil- icini, Valeriano simplicifoliae-Caricetum flavae, Caricetum goodenowii, Carici echinatae-Sphagnetum, Carici rostratae- Sphagnetum and Pino mugo-Sphagnetum) were classified using formal classification criteria. Two other communities (Sphagno warnstorfii-Caricetum davallianae and Eriophoro vaginati-Sphagnetum recurvi) were not classified due to the lack of sufficient number of diagnostic species from species groups. The first DCA axis followed the mineral richness gradi- ent. Vegetation plots were arranged from rich fens over moderately rich fens towards poor Sphagnum fens and raised bog. This fact was confirmed by a strong and significant correlation of the DCA site scores on the first axis with the measured pH and water conductivity as a surrogate of mineral richness. The second DCA axis correlated with mean Ellenberg’s indi- cator values for both temperature and soil nutrients. This pattern corresponds to that found in other regions of diversified Central-European landscape. We can therefore conclude that marginal geographical position and climatic specifity of the region under study did not alter gradient structure of the mire vegetation. When diversity of mire vegetation was compared to other regions in Slovakia by applying the same formal definitions to different regions, the study region was found to be conspicuously less diverse than the distribution centres of mire habitats in Slovakia (Orava and Vysoké Tatry regions), but more diverse than most of other marginal regions of mire distribution. Relatively high beta diversity of mires was probably caused by variable bedrock and local climate. Key words: formal definition; peatlands; poor-rich gradient; vegetation survey Introduction Muránska planina Mts belongs admittedly to the most interesting mountains of the Western Carpathi- ans namely for a high diversity of plant species and their communities. At the moment, 1480 taxa of vascu- lar plants, 372 taxa of bryophytes and 140 plant com- munities are known from this area and adjacent moun- tains and basins (Hrivnák et al. 2004; Kochjarová et al. 2004; Šoltés et al. 2004). This extraordinary diver- sity is mostly caused by variable geological and geomor- phological conditions as well as by the position on the margin of the Inner West Carpathians, which is pre- dominantly warmer and drier as opposed to the central parts of this mountain range. Large part of the studied area belongs to moderately cool climatic subregion with an average July temperature between 12–16 ◦ C, which is similar to other areas of the Inner Western Carpathi- ans. On the other hand, the southern part of Murán- ska planina (surroundings of the villages Tisovec and Muráň), where we collected a relatively large data set, is markedly warmer (warm and humid climatic region with average July temperature more than 16 ◦ C). Only few kilometers apart from the southern margin of the Muránska planina Mts., a warm and moderately humid region occurs (Lapin et al. 2002). Mean annual precip- itation reaches 700–1000 mm (Faško & Šťastný 2002), which is markedly lower than annual precipitation in the distribution centre of mire habitats in Slovakia (e.g. High Tatra Mts, the Orava region). c 2008 Institute of Botany, Slovak Academy of Sciences