30E6

E. Herbaceous communities and communities of lichens and mosses

Saline steppes, pastures and marshes

Relationships with habitat classifications. EUNIS: E6.221 Western Pontic saline steppes, E6.223 Western Pontic solonetz hollows; PAL. CLASS.: 15.A211 Western Pontic saline steppes, 15.A213 Western Pontic solonetz hollows; HD 92/43: 1530 *Pannonic salt steppes and salt marshes; Bondev (1991): 146 Halophytic grass communities with the prevalence of Puccinelieta convolutae, Limonieta gmelinii, Aeluropeta littoralis, Salicornieta europaeae etc. partly of secondary origin; Ganchev et al. 1971: I. Class formations of euhalophytic vegetation.

Conservation status. BDA, BC, HD.

Category. Endangered [EN - A1, 2 B1 C2 D2 E2 F2 G2 H2 I].

General characteristics. This habitat type is related with the typical halophyte phytocoenoses, that are distributed in the river valleys, where salination of the soils is observed as a result of high underground waters, spring floods, summer evaporation, etc. In some of them the salinity is low, but the soil dries up considerably in summers and xerophytization is observed that become stronger due to intensive grazing. In others the spring humidity is good because they are covered by a thin water layer but in summers the high underground waters bring to the surface many diluted salts that “blume” on the surface. Depending on the level of salinity and humidity of the soils as well as the climate in North and South Bulgaria the coenoses that develop there can be determined as halophyte pastures and steppes and typical “solista” (saline marshes and swamps). These coenoses are distributed throughout the whole country below 300 m alt. Large areas occur along the Danube and Toundzha rivers, but they can also be found along Osam, Yantra, Maritza rivers and some smaller rivers like Studena and Skat rivers (Danubian plain), Mochuritsa, Sazliika, Blatnitsa rivers (Toundzha Hilly Country), as well as on the banks of the saline lakes at the Black Sea coast and in Burgas lowland. The halophyte coenoses can be classified in two main groups: continental, distributed in North Bulgaria, and transitional Mediterranean, mainly in South-East Bulgaria.

1. Saline pastures and steppes. Along the Danube and most of its feeders the halophyte coenoses occur in the depressions of the river valleys. The salinity of the deposit soils is a result of the spring floods, high underground waters and intensive summer evaporation in conditions of the continental climate. Usually such places are intensively used as pastures and the plant communities are a result of the grazing, soil and climatic conditions. The phytocoenoses of the association Trifolio fragiferi-Cynodonetum prevail. The dominant is Cynodon dactylon, but Agrostis stolonifera, Galega officinalis, Inula britannica, Juncus gerardii, Lolium perenne, Medicago lupulina, Mentha pulegium, Potentilla reptans, and Trifolium fragiferum subsp. bonannii also participate. Communities of Hordeum hystrix and Crypsis schoenoides develop on limited areas in the places where the springs floods last longer and the soil is dense and clayey,. Many facultative and obligate halophytes such as Bupleurum tenuissimum, Cerastium dubium, Lepidium ruderale, Myosurus minimus, Puccinellia convoluta, Scorzonera laciniata, Taraxacum bessarabicum occur in these communities. Most representative are the coenoses in the valley of Studena River.

Secondary processes of salination and aridisation took place in the 1970s and 1980s in the valley of this river (Russe and Veliko Tarnovo districts) where the halophyte coenoses develop on typical saline soils – “solonchaks”. These processes were related with the redirection of the bed of Studena River and the termination of the spring floods. The association Limonietum bulgaricum occurs in this locality. Apart from the regional endemic Limonium bulgaricum which is a dominant in some places, many mesophytes, xerophytes and ruderals also participate in its floristic composition,. Typical for these saline steppes are Artemisia santonicum, Bupleurum tenuissimum, Cerastium dubium, Cichorium intybus, Cynodon dactylon, Festuca valesiaca, Lactuca saligna, Lepidium perfoliatum, Scorzonera laciniata, and Verbascum blattaria.

2. “Solista” – saline marshes and swamps. They occur mainly in SE Bulgaria: Thracian lowland – Belozem village and other places; Toundzha Hilly Country – along Toundzha River and its smaller feeders – Blatnitsa, Mochurista rivers; Black Sea coast – around Burgas lakes (Mandra, Vaya and Atanasovsko lakes). The soils are typical saline soils – Solonetz and Solonchaks. They are derivatives of Chernozems like meadow soils and meadow bog soils, the salinity of which is a result of the appearance of spring marshes and consequent intensive evaporation of the water as well as of salty, high underground waters or the neighbouring large saline water bodies. The salts are mainly of sodium – carbonates, chlorides, sulphates. They “bloom” on the surface like white or grayish areas almost without vegetation. The projective cover of the phytocoenoses that have been adapted to the high composition of water soluble salts is most often low – up to 20–30%. The main halophytes make patches that are limited in size and are dominated by one or two species. These are Artemisia santonicum, Camphorosma annua, C. monspeliaca, Cynodon dactylon, Puccinellia distans, P. limosa, Suaeda maritima on the typical “solista”. On the drying saline bottom of the temporary marshes and flooded areas the pioneer communities are formed by Crypsis aculeata, C. alopecuroides, Juncus gerardii, Mentha pulegium. The tufts of Camphorosma monspeliaca are typical. They raise several centimeters above the surrounding relief like microelevations. Many species, mostly halophytes, participate in these communities: Atriplex hastata, A. tatarica, Bromus scoparius, Bupleurum tenuissimum, Centaurea calcitrapa, Dianthus campestris subsp. pallidiflorus, Eragrostis minor, Hainardia cylindrica, Heliotropium europaeum, Lepidium ruderale, Limonium gmelinii, L. vulgare, Lolium perenne, Lotus tenuis, Pholiurus pannonicus, Plantago cornutii, P. coronopus, P. lanceolata, P. major var. uliginosa, P. tenuiflora, Poa bulbosa, Scilla autumnalis, Scorzonera laciniata, Spergularia marina, S. media, Taraxacum bessarabicum, Trifolium fragiferum subsp. bonannii. Despite their low forage qualities, many of these phytocoenoses have been used as pastures. Domestic animals graze mainly Puccinellia species. As a result of the grazing, the ruderalization and nitriphication of these communities increases. In some places, e.g. near Kermen town, after draining of the spring-flooded areas, the salinity of the soil decreased and the halophyte phytocoenoses have changed considerably.

Characteristic taxa.

Distribution in Bulgaria. Danubian plain – the lowlands along the Danube (Karaboaz, Svistov-Belene, Brashlen, Tsibar lowlands) and along some of the Danube feeders – Skat, Osam, Vit, Yantra, Studena, Chervenska Bara rivers; Thracian lowland – Plovdiv district; Tundzha Hilly Country – the regions of Yambol, Nova Zagora, Kermen, Radnevo, Karnobat, Starldzha towns (the former Straldzha swamp). South Black Sea coast – around Burgas lakes – Vaya, Mandra, Atanasovsko lakes.

Conservation importance. The habitat is endangered in Bulgaria because the halophytic coenoses develop at very specific conditions and usually the areas they cover are not large and are isolated from one another. Some rare, endangered and protected species participate in the composition of these coenoses: Planatgo cornutii, P. tenuiflora, Taraxacum bessarabicum. Among them some are regional endemics such as Limonium bulgaricum (along Studena River in the Danubian Plain) and L. asterotrichum (on the territory of the former Straldzha swamp).

Threats. Ploughing; overgrazing and consequent ruderalization and degradation; general climate aridisation; draining of wetlands and correction of the river beds; building of industrial enterprises and pollution of the soils with household and industrial wastes; building of transport and communication facilities (e.g. part of a highway will pass through one of the typical “solista” between Bikovo village and Kermen town); purposeful attempts to decrease the salinity of some of the areas (e.g. near Belozem village, Plovdiv district), etc.

Conservation measures taken. The habitat is included in Annex № 1 of the ational Biodiversity Act and is of conservation priority. Some of the localities are within protected areas (Persina Nature Park, Kalimok-Brashlen Protected Site), as well as in sites of the European Ecological Network NATURA 2000 in Bulgaria.

Conservation measures needed. Monitoring of selected, representative phytocoenoses for the saline steppes and pastures as well as of the typical “solista” places. Proclamation of some of the representative, e.g. near Atolovo, Blates, Zheljo Voivoda, and Karamanovo villages, as protected areas.

References. Ganchev et al. 1971; Ganchev & Kochev 1962; Tzonev 2002, 2009; Tzonev et al. 2008.

Authors: Rossen Tzonev, Chavdar Gussev


Saline steppes, pastures and marshes (distribution map)