Diversity of wetland vegetation in the Bulgarian h

Authors: Petra Hájková Michal Hájek Iva Apostolova

Publish Date: 2006/01/05

Volume: 184, Issue: 1, Pages: 111-130

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Abstract

We fill a gap in understanding wetland vegetation diversity and relationship with environmental determinants in Bulgarian high mountains A total of 615 phytosociological samples were taken from springs mires wet meadows and tallforb habitats throughout Bulgaria of which 234 relevés are from mire and spring vegetation above timberline The vegetation was classified by TWINSPAN and the resulting vegetation types were reproduced by the formal definitions using the combination of Cocktail species groups based on phicoefficient of joint cooccurrence of the species Nine vegetation types of springs and fens have been clearly delimited above the timberline All vegetation types include Balkan endemic species the representation of which varies Fens generally harbour more Balkan endemics than do springs with the exception of speciespoor highaltitude Drepanocladetum exannulati The gradient structure of the vegetation was revealed by DCA and by CCA with forward selection of environmental factors The major determinants of vegetation variation strongly differ above and below the timberline and likewise between springs and fens The baserichness gradient controls the floristic variation of Bulgarian submontane fens whereas the complete data set including both submontane and subalpine fens is governed by the altitude gradient from lowland and basin fens to subalpine fens rich in Balkan endemics When focusing on sites above the timberline only the first DCA axis separates fens from springs without organic matter The major species turnover in springs follows the variation in water pH and mineral content in water whereas fen vegetation variation is primarily controlled by succession gradient of peat accumulation Altitude remains an important factor in all cases Weak correlation between water pH and conductivity was found This correlation was even statistically insignificant in fens above the timberline Water pH is not influenced by mineral richness in Bulgarian high mountains since it is buffered by decomposition of organic matter in fens In springs pH reaches maximum values due to strong aeration caused by water flow The plant species richness decreases significantly with increasing altitude The increase of species richness towards circumneutral pH often found in mires was not confirmed in Bulgarian high mountains The correlation between species richness and pH was significant only when arcticalpine species and allied European highmountain species were considered separately The richness of boreal species was independent on pH Some of them had their optima shifted to more acidic fens as compared to regions below the timberline Our results suggest that subalpine spring and fen vegetation should be analysed separately with respect to vegetationenvironment correlations Separate analysis of fens below and above timberline is quite appropriateThe authors want to express their thanks to the Grant Agency of the Czech Academy of Sciences project no B6163302 We are also very grateful to Tenyo Meshinev for crucial help with organisation of our common field investigations Martin Kočí and Kateřina Kočí are especially acknowledged for a very pleasant field help and for providing the unpublished data of tallforb vegetation We would like to express our thanks also to Anna Ganeva Rossen Tzonev Stoyan Stoyanov Zuzana Rozbrojová Marcela Havlová Petr Wolf Jitka Wolfová Michaela Sedlářová Natálie Wernerová and Jiří Honěk who participated in particular field excursions We are also obliged to Jan Roleček and two anonymous reviewers for the valuable comments to the manuscript The research was performed within the longterm research plans of Botanical Institute of Czech Academy of Sciences no AVZ0Z60050516 and of Masaryk University Brno no MSM00216 224161 European highmountain species EHArenaria biflora Campanula alpina Carex ferruginea Doronicum columnae Epilobium nutans Gagea fistulosa Gentiana utriculosa Geum montanum Homogyne alpina Ligusticum mutellina Luzula alpinopilosa Pinus mugo Plantago atrata Poa cenisia Primula minima Ranunculus crenatus Ranunculus montanus Rumex alpinus Saxifraga rotundifolia Silene pusilla Soldanella pusilla Swertia perennis Veronica bellidioides2 Arctoalpine species AAAllium sibiricum Arabis alpina Bartsia alpina Carex rupestris Cerastium cerastoides Epilobium alsinifolium Juniperus communis subsp sibirica Omalotheca supina Phleum alpinum Polygonum viviparum Potentilla crantzii Pseudorchis albida Salix herbacea Saxifraga stellaris Selaginella selaginoides Viola biflora3 Carpathian–Balkan species CBAchillea clusiana Bruckenthalia spiculifolia Cirsium heterotrichum Dactylorhiza cordigera Euphrasia liburnica Gentianella bulgarica Jasione laevis subsp orbiculata Juncus thomasii Oenanthe banatica Plantago gentianoides Poa media Pseudorchis frivaldii Pulmonaria rubra4 Balkan species BAAngelica pancicii Barbarea balcana Cardamine amara subsp balcanica Carex kitaibeliana Cirsium appendiculatum Crocus veluchensis Geum coccineum Heracleum verticillatum Hieracium naegelianum Pinguicula balcanica Saxifraga ferdinandicoburgi Senecio pancicii Onobrychis montana subsp scardica Primula farinosa subsp exigua Soldanella pindicola/chrysostricta Taraxacum apenninum Alopecurus riloensis Carex bulgarica Leontodon rilaensis Myosotis orbelica Primula deorum5 Boreal species BOCarex canescens Carex flava ss Carex panicea Carex rostrata Carex serotina Drosera rotundifolia Eleocharis mamillata Empetrum nigrum Eriophorum angustifolium Eriophorum latifolium Eriophorum vaginatum Juncus articulatus Parnassia palustris Trichophorum cespitosum Utricularia minor Vaccinium myrtillus Vaccinium uliginosum Vaccinium vitisidea

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