Rossen Tzonev

Beech forest communities in Bulgaria

Beech forests occupy considerable areas in the Bulgarian mountains. They are represented by communities of Fagus sylvatica (incl. F. moesiaca) and F. orientalis, and also by mixed stands of beech with Abies alba, Carpinus betulus, Quercus cerris, Q. dalechampii and Q. polycarpa. 494 releves sampled across the country were analysed by numerical methods. They were classified into 12 groups of Fagus sylvatica forests and 3 groups of Fagus orientalis forests. The analysis of Bulgarian Fagus sylvatica communities did not show a distinct pattern of geographic differentiation and did not support the concept of the alliance Fagion moesiacum, as accepted by many earlier authors. The differentiation patterns in the Bulgarian Fagus sylvatica forests mainly follow the gradients in soils and climate, and are similar to those in the Central European beech forests. Therefore we accept a syntaxonomical scheme, which emphasizes variation due to edaphic and local topoclimatic factors rather than due to large-scale geographical differentiation. This scheme is very close to that proposed by Willner (2002) for the southern Central European beech forests, and includes the alliances Luzulo-Fagion (acidophilous beech forests), Asperulo-Fagion (nutrient-rich beech forests), and Cephalanthero-Fagion (thermophilous beech forests). The communities of Fagus orientalis are markedly different from the communities of Fagus sylvatica, have a distinct floristic composition, and belong to the Euxinian alliance Fagion orientalis.

European Red List of Habitats : Part 2. Terrestrial and freshwater habitats

The first ever European Red List of Habitats reviews the current status of all natural and semi-natural terrestrial, freshwater and marine habitats and highlights the pressures they face. Using a modified version of the IUCN Red List of Ecosystems categories and criteria, it covers the EU28, plus Iceland, Norway, Switzerland and the Balkan countries and their neighbouring seas. Over 230 terrestrial and freshwater habitats were assessed. The European Red List of Habitats provides an entirely new and all embracing tool to review commitments for environmental protection and restoration within the EU2020 Biodiversity Strategy. In addition to the assessment of threat, a unique set of information underlies the Red List for every habitat: from a full description to distribution maps, images, links to other classification systems, details of occurrence and trends in each country and lists of threats with information on restoration potential. All of this is publicly available in PDF and database format (see links below), so the Red List can be used for a wide range of analysis. The Red List complements the data collected on Annex I habitat types through Article 17 reporting as it covers a much wider set of habitats than those legally protected under the Habitats Directive.

The Halophytic Vegetation in South-East Bulgaria and Along the Black Sea Coast

The Halophytic Vegetation in South-East Bulgaria and Along the Black Sea Coast The paper presents results of a syntaxonomic analysis of the herbaceous phytocoenoses on the salt steppes, meadows and marshes in Southeastern Bulgaria, and along the Southern Black Sea Coast. The halophytic vegetation is distributed mostly in the Tundzha Lowland and the large salt lakes along the Black Sea Coast, where the saline soils occupy large territories. Most syntaxa identified in the paper are well-known and wide-spread in Central and Eastern Europe (Salicornietum prostratae, Suaedetum maritimae, Juncetum maritimae etc.), but there are also some specific vegetation types, which are presented by endemic associations as Petrosimonio brachiatae-Puccinellietum convolutae, Bupleuro tenuissimae-Camphorosmetum monspeliacae. The most widespread one is Diantho pallidiflori-Puccinellietum convolutae. It demonstrates a big variation in the appearance and the dominant structure of the described phytocoenoses. The comparision of the Bulgarian halophytic vegetation with other places in Europe shows its similarities with these vegetation types distributed in the Eastern Mediterranean and Central and Eastern Europe. V članku so predstavljeni rezultati sintaksonomske analize zeliščnih fitocenoz slanih step, travišč in močvirij v jugovzhodni Bolgariji in ob južni črnomorski obali. Halofitska vegetacija je najbolj pogosta v nižini Tundzha in v velikih slanih jezerih ob obali Črnega morja, kjer slana tla zavzemajo velika območja. Večina obravnavanih sintaksonov je dobro znanih in splošno razširjenih v srednji in vzhodni Evropi (Salicornietum prostratae, Suaedetum maritimae, Juncetum maritimae itd.), nekaj pa je posebnih vegetacijskih tipov, ki jih predstavljajo endemične asociacije Petrosimonio brachiatae-Puccinellietum convolutae, Bupleuro tenuissimae-Camphorosmetum monspeliacae. Najbolj razširjena je združba, ki jo uvrščamo v asociacijo Diantho pallidiflori-PuccineHietum convolutae, za katero je značilna velika variabilnost v videzu in dominantni strukturi. Primerjava halofitske vegetacije iz Bolgarije je pokazala podobnosti z vegetacijskimi tipi, razširjenimi v vzhodnem Sredozemlju ter srednji in vzhodni Evropi.

Biogeographic variability of coastal perennial grasslands at the European scale

Question: Coastal environments have often been described as azonal. While this characteristic is clear for the foredune system, it seems less evident for more inland fixed dunes, which host habitats of major conservation concern, whose features seem to be more related to local climatic conditions. We hypothesized that, unlike other coastal habitats, dune perennial grasslands differ floristically and structurally across their European range and that patterns of variation are linked to the corresponding climate. Location: European coasts (Atlantic Ocean, Baltic, Mediterranean, Black Sea). Methods: We used a large data set of phytosociological releves, representative of coastal grasslands throughout their European range. The role of climatic variables (temperature, precipitation and continentality) in determining the variability in species composition and vegetation structure (by means of life forms) was investigated through CCA, DCA and GLM. The degree of concentration of species occurrences within groups was calculated through the Phi coefficient. Results: Through multivariate analyses we identified seven major types of coastal grassland, corresponding to different geographic areas. The groups significantly differed in their climatic envelope, as well as in their species composition and community structure. Conclusion: Our results confirm the hypothesis that coastal dune perennial grasslands are subjected to local climate, which exerts significant effects on both floristic composition and community structure. As a consequence, coastal grasslands are particularly prone to the effect of possible climate change, which may alter species composition and distribution, and lead to shifts in the distribution of native plant communities.

Contribution to the knowledge of Bulgarian serpentine grasslands and their relationships with Balkan serpentine syntaxa

Serpentine areas, including those in Bulgaria, are rich in endemic taxa, and still remain to be investigated phytocoenologically. We analyse the vegetation types in various sites and compare them with those in other Balkan countries. The main objectives were (1) to explore and describe the relationships between the vegetation in the serpentine areas investigated in Bulgaria with those in the Balkan Peninsula and (2) to explore and classify the diversity of vegetation in grasslands on serpentine rocks in eastern Rhodope, Bulgaria. The classic methodology of the Braun-Blanquet school was applied to the exploration of the vegetation. Average linkage method (unweighted pair group method with arithmetic mean) and principal coordinate analysis were used to evaluate floristic and synoptic similarities. As a result, the new endemic association Onosmo pavlovae-Festucetum dalmaticae was proposed. This association can be included in the alliance Alyssion heldreichii Bergmeier et al. 2009, newly described on serpentine rocks in northern Greece. Our data confirmed the existence of similar or vicariant endemic syntaxa (associations) on isolated serpentine terrains in northern Greece and south-eastern Bulgaria.

Bromo Moesiacae-Stipetum Epilosae - a New Association from the Relict Mountain Steppe Vegetation in South-Western Bulgaria

Bromo Moesiacae-Stipetum Epilosae - a New Association from the Relict Mountain Steppe Vegetation in South-Western Bulgaria A syntaxonomical analysis of the dry grasslands (Festuco-Brometea) in Bosnek karst region, Mt Vitosha (SW Bulgaria) has been carried out. These grasslands are part of the intrazonal vegetation distributed within the belts of xerophilous oak and mesophilous beech forest in the south-western foothills of the mountain. The bedrock is carbonate, the soils are dry and shallow, climate - moderate continental. This vegetation grows mostly on steep slopes, with southern and south-western exposition. Apart from the typical for Festuco-Brometea calcicoles, the studied vegetation is characterized by many endemic (regional and local) species and at the same time includes a lot of Mediterranean species. As a result of the analysis, a new association, Bromo moesiacae-Stipetum epilosae ass. nova, has been established that belongs to the alliance Saturejon montanae. A comparison with related syntaxa from other karst mountains from SW Bulgaria and E Serbia is made, and some conclusions about the origin of the steppe vegetation in that region are drawn. Naredili smo sintaksonomsko analizo suhih travnikov (Festuco-Brometea) v kraškem območju Bosnek v gorovju Vitoša (jugozahodna Bolgarija). Ti travniki so del intraconalne vegetacije, razširjene v pasu kserofilnih hrastovih in mezofilnih bukovih gozdov na jugozahodnih vznožjih hribovja. Matična podlaga je karbonatna, tla so suha in plitva, podnebje je zmerno celinsko. Vegetacija uspeva na strmih naklonih z južno in jugozahodno ekspozicijo. Poleg značilnih vrst razreda Festuco-Brometea označujejo preučevano vegetacijo številne endemične (regionalne in lokalne) vrste in številne sredozemske vrste. Kot rezultat smo opisali novo asociacijo Bromo moesiacae-Stipetum epilosae ass. nova, ki jo uvršč amo v zvezo Saturejon montanae. Naredili smo tudi primerjavo s sorodnimi sintaksoni s kraških gorovij jugozahodne Bolgarije in vzhodne Srbije in podali nekaj zaključkov o izvoru stepske vegetacije v preučevanem območju.

Natural Communities of Uranium Mining Impacted Area in the Vicinity of the Senokos Village

ABSTRACT Uranium containing wastes accumulated during mine activities have resulted in a multitude of contaminated sites in Bulgaria. The lack of biomonitoring programs limits the environmental impact assessment of uranium impacted areas. The aim of the study was to investigate the health of natural terrestrial (vegetation, soil bacteria and millipedes) and freshwater (macrozoobenthos) communities in the impacted area of former uranium mine Senokos. The mine is one of the forty-nine former uranium mines in Bulgaria, reclaimed in the beginning of the 90s, but the reclamation was compromised due to surface erosion of the protective layers. The vegetation is typical for the region and uranium pollution has not caused any significant adverse affects on it. Adverse affects on soil bacterial communities are recorded only to their activity, but not to the abundance. Soil millipedes are in low density dominated by Pachyiulus cattarensis (Latzel 1884). The benthic community of Luda River is influenced by both uranium loaded sediments and infiltrate water from the mine.

Saxifrago Ferdinandi-Coburgi-Seslerietum Actarovii - A New Association from the Subalpine Belt of the Slavianka (Orvilos) MTS. (Bulgaria)

Saxifrago Ferdinandi-Coburgi-Seslerietum Actarovii - A New Association from the Subalpine Belt of the Slavianka (Orvilos) MTS. (Bulgaria) 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 Saxifrago 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. 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-Seslerion Horvat 1949. Sintakson so primerjali s sorodnimi sintaksoni iz drugih apneniških gora iz severne Grčije in Makedonije.

FLORISTIC INVESTIGATION OF QUERCUS CERRIS AND QUERCUS FRAINETTO COMMUNITIES IN BULGARIA

ABSTRACT The present research is a part of the investigations over the structure of mixed forest communities of Quercus cerris and Quercus frainetto in Bulgaria. The investigated communities are typical for Habitat 91I0—Euro-Siberian steppic woods with Quercus spp., and Habitat 91MO—Pannonian-Balkanic turkey oak-sessile oak forests. The floristic composition of about 100 described plant communities is defined. According to the geobotanical zoning they refer mainly to the European broad-leaved forest district and the Lower Danube province of Eurasian steppic and woodsteppic district. About 598 species of vascular plants and about 24 species of bryophytes have been established during the investigation. The life forms (according to Raunkier) and the floral elements (according to Assyov et al.) for the vascular plants have been determined. Over 60% of the species refer to the families Asteraceae, Fabaceae, Poaceae, Rosaceae, Lamiaceae, Caryophyllaceae, Scrophullariaceae and Liliaceae. In the species composition the participation of the Eur-Asian, Eur-Mediterranean, subMediterranean, Eur-Siberian and the European floral elements is bigger. The life form Hemicryptophyte clearly predominates. A comparative floristic analysis with published data for the investigated communities has been made.

Classification of European and Mediterranean coastal dune vegetation

Aims: Although many phytosociological studies have provided detailed local and regional descriptions of coastal dune vegetation, a unified classification of this vegetation in Europe and the Mediterranean Basin has been missing. Our aim is to produce a formalized classification of this vegetation and to identify the main factors driving its plant species composition at a continental scale. LocationAtlantic and Baltic coasts of Europe, Mediterranean Basin and the Black Sea region. - Methods: We compiled a database of 30,759 plots of coastal vegetation, which were resampled to reduce unbalanced sampling effort, obtaining a data set of 11,769 plots. We classified these plots with TWINSPAN, interpreted the resulting clusters and used them for developing formal definitions of phytosociological alliances of coastal dune vegetation, which were included in an expert system for automatic vegetation classification. We related the alliances to climatic factors and described their biogeographic features and their position in the coastal vegetation zonation. We examined and visualized the floristic relationships among these alliances by means of DCA ordination. - Results: We defined 18 alliances of coastal dune vegetation, including the newly described Centaureo cuneifoliae-Verbascion pinnatifidi from the Aegean region. The main factors underlying the differentiation of these alliances were biogeographic and macroclimatic contrasts between the Atlantic-Baltic, Mediterranean and Black Sea regions, along with ecological differences between shifting and stable dunes. The main difference in species composition was between the Atlantic-Baltic and Mediterranean-Black Sea regions. Within the former region, the main difference was driven by the different ecological conditions between shifting and stable dunes, whereas within the latter, the main difference was biogeographic between the Mediterranean and the Black Sea. - Conclusions: The first formal classification of the European coastal dune vegetation was established, accompanied by an expert system containing the formal definitions of alliances, which can be applied to new data sets. The new classification system critically revised the previous concepts and integrated them into a consistent framework, which reflects the main gradients in species composition driven by biogeographic influences, macroclimate and the position of the sites in the coast-inland zonation of the dune systems. A revision of the class concept used in EuroVegChecklist is also proposed.