HACQUETIA 10/1 • 2011, 49-71 DOI: 10.2478/v10028-011-0004-8 SAXIFRAGO FERDIKAnDI-COBURGI-SESLERIETUMACtAROVII - A NEW ASSOCIATION FROM THE SUBALPINE BELT OF THE SlAVIANKA (ORVILOS) MTS. (BULGARIA) Todor KARAKIEVi, Rossen TZONEV2 Abstract The paper discusses the phytosociological and syntaxonomical position of the dry subalpine grasslands in the Slavianka (Alibutoush, Orvilos) Mts. (South-Western Bulgaria, Northern Greece). A new association Saxi-frago ferdinandi-coburgi-Seslerietum actarovii ass. nova has been established as a result of the phytosociological study. It is considered as an endemic vegetation unit from the calcareous subalpine terrains in the Central Balkan Peninsula high mountains (SouthWestern Bulgaria, Former Yugoslav Republic of Macedonia, Northern Greece). The new syntaxon belongs to the alliance Edrajantho-Seslerion Horvat 1949. A comparison with related syntaxa from other calcareous mountains from Northern Greece and the Former Yugoslav Republic of Macedonia is discussed. Keywords: dry calcareous grasslands, phytosociology, syntaxonomy, Slavianka Mts., vegetation, Edraiantho-Seslerion Horvat 1949. Izvleček V članku avtorji obravnavajo fitosociološki in sintaksonomski položaj suhih subalpinskih travnikov v gorovju Slavjanka (Alibutoush, Orvilos) (jugozahodna Bolgarija, severna Grčija). Kot rezultat fitocenoloških raziskav so opisali novo asociacijo Saxifrago ferdinandi-coburgi-Seslerietum actarovii ass. nova. Obravnavajo jo kot endemično vegetacijsko enoto iz subalpinskega pasu visokih gora v srednjem delu Balkanskega polotoka (jugozahodna Bolgarija, Makedonija, severna Grčija). Novoopisani sintakson uvrščajo v zvezo Edrajantho-Se-slerion Horvat 1949. Sintakson so primerjali s sorodnimi sintaksoni iz drugih apneniških gora iz severne Grčije in Makedonije. Ključne besede: suhi travniki na apnencu, fitosociologija, sintaksonomija, gorovje Slavjanka, vegetacija, Edra-jantho-Seslerion Horvat 1949. 1. INTRODUCTION north-east, north and north-west. There are many caves and precipices in the region, which have re- The subalpine region of the Slavianka (Orvi- sulted from the karstic processes. The calcareous los) Mts. (South-western Bulgaria, Northern rocks cover 100 % of the territory. The climate Greece) (Figure 1) comprises the highest part of is transitional Mediterranean with an important the mountain between 1900 and 2212 m includ- mountain influence, especially in the investigated ing the highest peak - Gotzev Vruh /Alibotus. It highest part of the mountain (Georgiev 1991, Ve- covers an area of approximately 15 sq. km. The lev 2002). The Slavianka Mts. (besides Southern region represents a karstic marble area facing Pirin) are the warmest Bulgarian mountains. The 1 Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Science, 2 Gagarin Str., Sofia 1113; karakiev@abv.bg 2 Department of Ecology and Environmental Protection, Sofia University "St. Kliment Ohridski", Faculty of Biology, 8 Dragan Tzankov Blvd., Sofia 1164; rossentzonev@abvbg G A ■. ' • ^ 1 f \ A A Figure 1: Topographic map of subalpine area of the Slavianka Mts. (M 1 : 50 000). In light blue is a study area, in dark blue points are areas of releves. Slika 1: Topografska karta subalpinskega območja gorovja Slavjanka (M 1 : 50 000). Svetlo modro je prikazano obravnavano območje, temnomodre točke pa predstavljajo lokacije popisov. permanent snow cover on the highest mountain parts continues only 90-100 days, while in Northern Pirin - 150 days (Vaptzarov et al.1989). From a geobotanical point of view, the Slavianka Mts. belong to the Slavianka Mountain District - part of the Illyric (Balkan) province of the European deciduous forest region (Bondev 2002). The Slavianka Mts. are a very rich in endemic species. Bondev (2002) indicates 44 species - 38 Balkan and 6 local Bulgarian endemics. Some data for the floristic diversity, phytoge-ography and vegetation of the Slavianka Mts. can be found in the works of Stojanoff (1922); Sto-janov & Stefanoff (1922) and Dryanovski (1934). In the mountains of Northern Greece and the Former Yugoslav Republic of Macedonia, similiar herbaceous communities as in Slavianka Mts. are described, using the Braun-Blanquet methodology. There are no descriptions of such communities from Bulgaria so far. The most similar phytocoenoses in Bulgaria are described in the Pirin Mts. only by Simon (1958) and Mucina et al. (1990). The phytocoenoses described by Simon (1958) are typical alpine ones, while there is no alpine belt on the Slavianka Mts. The alpine and subalpine communities on calcareous screes, rock fissures and snow beds, described by Mucina et al. (1990) on the Pirin Mts. belong to the classes Thlaspietea rotundifolii Braun-Blanquet 1948, Asplenietea trichomanis (Braun-Blanquet in Meier et Braun-Blanquet 1934) Oberd. 1977 and Salicetea herbaceae Braun-Blanquet 1947. Only one association (Hieracio pannosi-Caricetum kitaibelianae Mucina et al. 1990) among them has some similiarities to the grasslands in the Slavianka Mts. METHODS The principles and methods of the zürich-Montpellier School (Braun-Blanquet 1964, Mueller-Dombois & ellenberg 1974, Westhoff & Maarel 1973) were applied. We used plot size of 10x10 m and as a result of the sampling 46 releves were made. At each sampling plot, a complete list of the present species (vascular plants) was recorded, together with their cover-abundance value according to the 7-degree Braun-Blanquet scale (Braun-Blanquet 1932). Eight out of 46 releves dropped out as a result of the cluster analysis made in the SYN-TAX program (Figure 2). The diagnostic table includes 38 releves (Table 1). They repre- sent the new syntaxon described in this article. 8 releves were not included in the phytocoenologic analysis, because they were not typical. Most of the excluded releves were dominated by Festucop-sis sancta. They have been made at a lower altitude - in the open calcareous areas in the coniferous belt of Pinus heldreichii. To facilitate the statistical computer programs the scale of Braun-Blanquet was used, only transformed into ordinal numbers (Westhoff & Maarel 1979). The computer software TurboVeg (Hennekens & Schaminee 2001) was used for digitalizing and storing the data. The sorting of the releves was made in JUICE software (Tichy 2002). For the purpose of the numerical classification the TWINSPAN method (Hill 1979) was applied, integrated in JUICE software. The results of the TWINSPAN analysis were compared using cluster analysis according to the computer program SYN-TAX (Podani 2002). The average linkage method (UPGMA) was used and floristic similarity between releves was evaluated according to the Horn index (Krebs 1999). This index was used also for assessment of similarity among the closest associations. Both dendrograms are presented in the paper (Figure 3). 0.6 0.55 0.5 0.45 0.4 -i^ 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Figure 2: Cluster analysis of the new association - the dendrogram. Slika 2: Klastrska analiza in dendrogram nove asociacije. 0.850.8 t 0.75 i 0.7 t 0.65 i 0.6 t 0.55 T 0.5 t 0.45 T