PHYTOSOCIOLOGICAL ANALYSIS OF QUERCUS CERRIS WOODS IN THE SUB-MEDITERRANEAN PHYTOGEOGRAPHICAL REGION OF SLOVENIA FITOCENOLOŠKA ANALIZA GOZDOV CERA (QUERCUS CERRIS) V SUBMEDITERANSKEM FITOGEOGRAFSKEM OBMOČJU SLOVENIJE Igor DAKSKOBLER1, Zvone SADAR2 & Andraž ČARNI3 http://dx.doi.org/10.3986/fbg0026 ABSTRACT IZVLEČEK Phytosociological analysis of Quercus cerris woods in the Fitocenološka analiza gozdov cera (Quercus cerris) v sub- sub-Mediterranean phytogeographical region of Slovenia mediteranskem fitogeografskem območju Slovenije We conducted a phytosociological analysis of mixed de- Fitocenološko smo analizirali mešane listnate gozdove ciduous forests on flysch and mixed flysch-limestone bed- na flišni in mešani flišno-apnenčasti matični podlagi v Sred- rock in the Central Soča Valley, the Karst, the Brkini Hills njem Posočju, na Krasu, v Brkinih in v Slovenski Istri, kjer v and in Slovenian Istria with dominating Quercus cerris in drevesni plasti prevladuje cer (Quercus cerris). Na podlagi the upper tree layer. Based on the comparison with similar primerjave s podobnimi cerovimi združbami v Sloveniji, Quercus cerris communities in Slovenia, Italy, Hungary and Italiji, Madžarski in Bosni in Hercegovini smo opisali novo Bosnia and Herzegovina we described a new association, Se- asociacijo Seslerio autumnalis-Quercetum cerridis, ki jo slerio autumnalis-Quercetum cerridis, which we classified uvrščamo v zvezo Carpinion orientalis. Členili smo jo na tri into the alliance Carpinion orientalis. We subdivided it into subasociaciji: -asparagetosum acutifolii (cerovi sestoji v Slov- three subassociations: -asparagetosum acutifolii (Quercus enski Istri, kjer se ta drevesna vrsta dobro pomlajuje in cerris stands in Slovenian Istria where this tree species reju- ohranja skozi več generacij), -hieracietosum sabaudi (oblika venates successfully and keeps through many generations), na nekoliko zakisanih flišnih tleh, prav tako v Istri) in -cam- -hieracietosum sabaudi (a form on slightly acid flysch soil, panuletosum rapunculoidis (drugotna cerova združba na po- also in Istria) and -campanuletosum rapunculoidis (a second- tencialno bukovih rastiščih). Kljub temu, da opisane cerove ary Quercus cerris community on potential beech sites). sestoje štejemo za drugotne (pionirske), zaradi precejšnjih Even though the described Quercus cerris stands are consid- površin, ki jih poraščajo, predlagamo nov habitatni in gozd- ered secondary (pioneer), they overgrow very large areas and ni rastiščni tip primorsko cerovje na flišu. we therefore propose they be classified as a new habitat and Ključne besede: fitocenologija, sinsistematika, Seslerio forest site type, littoral Quercus cerris woods on flysch. autumnalis-Quercetum cerridis, Carpinion orientalis, Istra, Key words: phytosociology, synsystematics, Seslerio au- Slovenija tumnalis-Quercetum cerridis, Carpinion orientalis, Istria, Slovenia 1 Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Regional Research Unit Tol- min, Brunov drevored 13, SI-5220 Tolmin and Biotechnical Faculty of the University in Ljubljana, Department of Forestry and Renewable Forest Resources, Večna pot 83, SI-1000 Ljubljana, [email protected] 2 Zavod za gozdove Slovenije, Območna enota Sežana, Krajevna enota Kozina, Hrpelje, Reška cesta 14, SI-6240 Kozina, zvone. [email protected] 3 Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Novi trg 2, SI-1000 Ljubljana and University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica, [email protected] FOLIA BIOLOGICA ET GEOLOGICA 58/2, 5–43, LJUBLJANA 2017 DAKSKOBLER, SADAR, ČARNI: PHYTOSOCIOLOGICAL ANALYSIS OF QUERCUS CERRIS WOODS IN THE SUB-MEDITERRANEAN 1 INTRODUCTION Quercus cerris is a southeastern-European-southwest- oriental hornbeam communities in the sub-Mediterra- ern-Asian species, a character species of the alliance nean phytogeographical region and in the hilly, sub- Carpinion orientalis (Aeschimann et al. 2004a: 224). It montane and lower montane belts in the interior of the is relatively common in the western, southern and country (e.g. in the stands of associations Seslerio au- eastern parts of Slovenia, but very rare in the Alpine tumnalis-Ostryetum, Amelanchiero ovalis-Ostryetum, phytogeographical region (Figure 1, Kotar 1999). It Aristolochio-Quercetum pubescentis, Seslerio autumna- frequently occurs accompanied by other oaks (Q. pe- lis-Quercetum petraeae, Seslerio autumnalis-Querce- traea, Q. pubescens), with European hop hornbeam tum pubescentis, Querco-Carpinetum orientalis, Quer- and oriental hornbeam (Ostrya carpinifolia, Carpinus co pubescenti-Ostryetum carpinifoliae, Serratulo tincto- orientalis), flowering ash (Fraxinus ornus), in places riae-Quercetum petraeae, syn. Lathyro nigri-Querce- even beech (Fagus sylvatica), common hornbeam (Car- tum petraeae, Melampyro vulgati-Quercetum petraeae), pinus betulus) and other deciduous trees, usually on occasionally even in common hornbeam and beech sunny slopes of the hilly and submontane belts, rarely communities (such as Ornithogalo pyrenaici-Carpine- also in the lower montane belt up to the elevation of tum betuli, Asaro-Carpinetum betuli, Asperulo-Carpi- around 1000 m, on limestone, marl and flysch bed- netum betuli, Castaneo-Fagetum sylvaticae, Seslerio rock, on relatively deep and fertile soil. It is a heliophil- autumnalis-Fagetum, Ornithogalo pyrenaici-Fagetum, ous and pioneer tree species that establishes itself on Lamio orvalae-Fagetum), in noble hardwood commu- former meadows and pastures, degraded forest areas, nities (Veratro nigri-Fraxinetum, Saxifrago petraeae-Ti- forest clearings and in large stand gaps. Turkey oak lietum, Paeonio officinalis-Tilietum), in pioneer black naturally occurs in sessile oak, pubescent oak and (or) alder stands (Lamio orvalae-Alnetum glutinosae) – Figure 1: Distribution of Quercus cerris in Slovenia according to the FloVegSi database (T. Seliškar, Vreš & A. Seliškar 2003) Slika 1: Razširjenost cera (Quercus cerris) v Sloveniji, po podatkih v bazi FloVegSi (T. Seliškar, Vreš & A. Seliškar 2003) 6 FOLIA BIOLOGICA ET GEOLOGICA 58/2 – 2017 DAKSKOBLER, SADAR, ČARNI: PHYTOSOCIOLOGICAL ANALYSIS OF QUERCUS CERRIS WOODS IN THE SUB-MEDITERRANEAN source FloVegSi database, T. Seliškar, Vreš & A. Seli- ring alongside Quercus robur and Pinus sylvestris. Fre- škar (2003) and Zupančič (1999). Its pioneer stands quent shrub layer species are Ligustrum vulgare, Crata- on submontane beech community sites from the asso- egus monogyna, Cornus sanguinea, Rosa spp., Rubus ciation Hacquetio-Fagetum in the Notranjska region spp. Frequent and diagnostic species of the herb layer are described as the association Hacquetio-Quercetum are Serratula tinctoria, Clinopodium vulgare, Poa ne- cerridis (Marinček & Šilc 1999). The association moralis, Convallaria majalis, Chamaecytisus supinus, Fraxino orni-Quercetum cerridis (Vukelić 2012, Stu- Betonica officinalis, Lathyrus niger and Tanacetum co- par et al. 2015, 2016) occurs in Croatia and Bosnia and rymbosum. In terms of entire species composition and Herzegovina alongside the association Quercetum frai- ecological conditions these Turkey oak-sessile oak netto-cerridis, which is a zonal community that occurs stands are not very similar to the studied Turkey oak in an extensive part of the Balkan Peninsula in the stands from western and southwestern Slovenia. Pi- transitional belt between forests and steppes and is not gnatti (1998) classifies the sub-Mediterranean Turkey comparable with stands from Slovenia. A Quercus cer- oak woods from central Italy mainly into the associa- ris community was described also in Hungary, namely tion Rubio-Quercetum cerridis (E. et S. Pignatti 1968) as the association Paeonio banaticae-Quercetum cerri- Bas Pedroli et al. 1988. Despite certain similarities dis (Kevey 2007). Quercetum cerridis stands in Austria with the stands from western and southwestern Slove- are classified mainly in the association Chamaecytiso nia in terms of ecological conditions (elevations be- supini-Quercetum cerridis Starlinger 2007, whose au- tween 200 and 600 m, geological bedrock composed of thor (Starlinger 2007a,b) characterises it as a sub-Il- flysch, marlstone, even limestone) they occur in much lyrian acidophilus Turkey oak forest. Its stands are dis- warmer and drier, almost Mediterranean climate. tributed in the hilly and submontane belt of the east- As Quercus cerris overgrows large areas in Istria, ern part of the country, mainly on levelled terrain and Brkini, the Karst, Goriška Brda and even the Central gentle slopes, on silicate or mixed calcareous-silicate Soča Valley, we conducted a phytosociological study bedrock. Turkey oak and sessile oak are equally repre- into its stands, arranged their relevés into a table and sented in the tree layer of these stands, in places occur- tried to classify them into a syntaxonomical system. 2 METHODS Phytosociological relevés of Quercus cerris stands were source for the names of vascular plants is Martinčič made applying the standard Central-European meth- & al. 2007), Martinčič (2003, 2011) for the names of od (Braun-Blanquet 1964). We made a total of 35 mosses, and Šilc & Čarni (2012) and Stupar et al. relevés and entered them into the FloVegSi database (T. (2015, 2016) for the names of the syntaxa, except for Seliškar, Vreš & A. Seliškar 2003), which served as the name of the alliance Carpinion orientalis Horvat the basis for Figures 1 and 2. Combined cover-abun- 1958 and class Querco-Fagetea