Richness and Diversity of Pontic Flora on Serpentine of Serbia
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Cent. Eur. J. Biol. • 6(2) • 2011 • 260-274 DOI: 10.2478/s11535-010-0110-5 Central European Journal of Biology Richness and diversity of Pontic flora on serpentine of Serbia Research Article Ksenija Jakovljević*, Dmitar Lakušić, Snežana Vukojičić, Gordana Tomović, Jasmina Šinžar-Sekulić, Vladimir Stevanović Institute of Botany and Botanical Garden, Faculty of Biology, University of Belgrade, 11000 Belgrade, Serbia Received 23 June 2010; Accepted 08 November 2010 Abstract: Serpentine substrate in Serbia covers wide areas mainly in Kosovo and in central, western and south-western part of the country. On the serpentines of Serbia, particularly on the skeleton soils of hills and on lower elevation mountain slopes, there are some xerophilous and steppe-like vegetations. These xerophilous grasslands include mostly Pontic, Pontic- Submediterranean and/or Mediterranean- Submediterranean-Pontic plants. The distribution of 161 taxa of Pontic, Pontic- Submediterranean and Mediterranean-Submediterranean-Pontic areal - types on serpentinites of Serbia was analyzed in order to distinguish centers of richness and diversity. The distribution of taxa was analyzed with respect to geographic, ecological and climatic factors. The qualitative composition of Pontic flora on the serpentine areas was also compared. The greatest floristic richness and the center of diversity of Pontic flora on serpentine of Serbia was recorded in central part of the area investigated. Keywords: Phytogeography • Pontic • Richness • Diversity • Flora • Serpentine • Serbia © Versita Sp. z o.o. serpentine zones located primarily in central, western 1. Introduction and south-western Serbia and in Kosovo. Some of these Serpentine (ophiolithic, ultramafic) rock belongs to areas are: Brdjanska gorge, Mt Suvobor, Mt Maljen, Mt the group of siliceous rocks characterized by calcium Tara, Mt Zlatibor, Mt Mokra Gora, Mt Goč, Mt Stolovi, deficiency, high concentrations of iron, magnesium, Mt Kopaonik, the Ibar valley, Peć and surroundings, nickel, cobalt and chromium, and reduced nutrients. Orahovac and Koznik, Mt Ostrovica (Figure 1B). In contrast to other acid siliceous rocks, the pH values The real steppes of southeastern Europe are of serpentine substrate vary from basic to ultrabasic present in the Pannonian and Wallachian Plain, Dobruja (pH 5.5-8). Many interesting basiphilous-calcifuge and Thracean Plain [2,3]. On the Balkan peninsula, plants flourish on serpentine owing to this factor. It is particularly on the skeleton soils of hills and on lower one of the most important reasons why the serpentine elevation mountain slopes, there are some xerophilous flora, differing from that occurring on limestone or and steppe-like vegetation. The steppe-like vegetation is other siliceous substrates, presents taxonomical, particularly well-developed in limestone and serpentine phytogeographical and ecological phenomenon of great habitats of the Moesian subregion in Serbia, Bulgaria interest wherever it occurs [1]. and Macedonia [4-9]. The degradation of forests The largest serpentine areas in Europe are in the and shrub formations in the temperate-continental Balkan peninsula (Epirus, Thessaly and Sterea Ellas in (central and eastern) parts of the Balkan Peninsula, Greece, north, north-central and south-eastern Albania, has only increased the extent of the steppe biome. central and east Bosnia, western, south-western and These xerophilous grasslands include mostly Pontic, central Serbia, east and central Rhodopes mountains Pontic-Submediterranean and/or Mediterranean- in Bulgaria and gorge of river Pcinja and south-eastern Submediterranean-Pontic plants, but they also contain slopes of Sara mountain in north-eastern part of Republic a substantial number of endemic species. Thus, they of Macedonia) (Figure 1A). In Serbia there are several represent important centers of xerothermic flora that * E-mail: [email protected] 260 K. Jakovljević et al. A C B Figure 1. Distribution of serpentine bedrock: (A) in Balkans [1] (Cro-Croatia, B&H-Bosnia &Hercegovina, Mg-Montenegro, Sr-Serbia, Al-Albania, RM-Romania, BU-Bulgaria, GR-Greece, FYRMa-Former Yugoslav Republic of Macedonia, Tu-Turkey); (B) in Serbia; (C) serpentine groups studied in Serbia (1-north-western Serbia, 2-western Serbia, 3-central Serbia I, 4-central Serbia II, 5-south-western Serbia, 6-Metochia, 7-south & central Kosovo)). used to be widely distributed throughout the Balkan Peninsula, have a special phytogeographic importance. peninsula in the last glacial and postglacial period The spread of Pontic flora throughout the central and [10,11]. east Balkans was particularly pronounced during Ice The occurrence of the Pontic, Pontic- Age (Pleistocene) [2]. Serpentine areas were suitable Submediterranean and Mediterranean- habitats for these plants during this period, so steppe Submediterranean-Pontic plants on serpentine is relicts could represent current remnants of this flora. intriguing from a biogeographic standpoint because The main goal of this paper is to determine the their populations in serpentine areas of the Balkans extent to which the serpentine areas of Serbia represent are isolated with respect to their common distribution in an important region of south-eastern Europe for the the steppe regions of south-eastern Europe. The open xerothermic flora of the Pontic, Pontic-Submediterranean serpentine habitats are characterized by a pronounced and Mediterranean-Submediterranean-Pontic species. thermophilous character and xeric conditions. The In south-eastern Europe serpentine areas are quite rare xerothermic character of serpentine plants is also and unique, especially those serpentine areas that are enhanced by the specific chemical composition of the inhabited by xerothermic flora. Therefore, these unique serpentine substrate. Among the numerous xerophytes areas are of the great importance in phytogeographical on the serpentine of the Balkans, the species of the sense. The objectives of our research were to determine Pontic, Pontic-Submediterranean and Mediterranean- the richness and distribution of species belonging to Submediterranean-Pontic areal-types are most Pontic, Pontic-Submediterranean and Mediterranean- prominent. The steppe relicts with Pontic distribution Submediterranean-Pontic species on the serpentine of (for example, Astragalus dasyanthus, Oxytropis Serbia and how that varies with respect to geographic, pilosa (Fabaceae), Vinca herbacea (Apocynaceae), ecological and climatic factors. The degree of floristic Echium russicum (Boraginaceae), Galatella lynosiris similarity among serpentine groups will be determined, (Asteraceae), Peucedanum officinale (Apiaceae), and the most important centers of diversity of Pontic etc.), growing on serpentinite in the central part of flora on serpentine soils will be broadly determined. 261 Richness and diversity of Pontic flora on serpentine of Serbia 2. Experimental Procedures A regression analysis was performed in order to identify the dependency level of variation in species richness, The mapping and analyses of the distribution of with regard to the basic geographical, ecological and Pontic species on serpentines in Serbia was based on bioclimatic characteristics of defined serpentine groups. herbarium specimens from the Herbarium of University The regression analysis included only the groups north- of Belgrade (BEOU) and the Herbarium of Natural western Serbia, western Serbia, central Serbia I and History Museum of Belgrade (BEO), published data central Serbia II, which are approximately of the same [9,12-39] as well as on personal field observations. size. Each serpentine group was regressed onto the The nomenclature is consistent with the latest check- following factors: area, E-long centroid, N-lat centroid, lists, papers, monographs and databases [40-45; altitude, annual mean temperature, annual precipitation, http://ww2.bgbm.org/EuroPlusMed/; http://plantnet. precipitation of driest month, precipitation of driest rbgsyd.nsw.gov.au/iopi/iopihome.htm]. quarter, diversity of potential vegetation, average The serpentine areas in Serbia were divided into distance from the steppe regions and minimal distance the following groups according to their orographic from the steppe regions. The bioclimatic characteristics connections: of the groups were extracted from the WorldClim set of 1. north-western Serbia (including the areas of global climate layers [55]. The extraction of selected Mt Maljen, Mt Suvobor, vicinity of Gornji Milanovac); bioclimatic parameters was done by using DIVA-GIS 2. western Serbia (including the areas of Mt Tara, 5.2 software (Version 5.2; http://www.diva-gis.org). Mt Mokra Gora, Mt Zlatibor, Priboj, and the Uvac valley); The diversity of the vegetation that would exist at 3. central Serbia I (including the northern part of Ibar defined serpentine groups under the current climatic valley, with areas of Mt Stolovi, Mt Čemerno, Mt Goč, and geomorphologic conditions but without any human Mt Studena Planina); impact (potential vegetation) was established on the 4. central Serbia II (including the central and southern basis of the Map of the Natural Vegetation of Europe part of Ibar valley, with areas of Mt Željin, Mt Kopaonik, [4]. The diversity of potential vegetation is presented as Mt Rogozna); number of different mapping units per serpentine group. 5. south-western Serbia (including the areas of Floristic similarities between each set of analyzed groups Sjenica and Mt Ozren); were analyzed using the clustering method based on 6.