NATURA 2000:
Lycaena dispar
Coordinates: 22° 42’ 16’’ E, 42° 25’ 45’’ N —
Altitude: 970 m —
Area: 6069 ha
Description: Zemen Gorge is situated between the Zemen Mountain and the Risha Hill of the Konyavo Mountain. Starting southwest of the town of Zemen and ending at the village of Razhdavitsa, the gorge is 20 kilometres long. The slopes of the fencing mountains are rocky, mainly composed of Triassic limestone, sandstone, and dolomites. The southern part of the gorge is composed of young Tertiary clay, sand, and conglomerates of Pliocene age. Here the Struma River forms meanders in some parts. The bottom of the gorge is not very developed and often coincides with the river bed. The original vegetation in the Zemen Gorge consists of two main groups: nemoral (tree communities dominated by deciduous species) and steppe. At the same time the penetration of Mediterranean climatic influence along the valley of the Struma River gives rise to the development of Mediterranean communities and species, giving a specific character to the vegetation cover. The xerothermic oak forest belt is dominated by Quercus cerris,Q. frainetto, and Q. pubescens, often forming mixed and rarely pure communities, composed also of Carpinus orientalis, Fraxinus ornus, Acer campestre, Cornus mas, Crataegus monogyna, etc. These communities are made up of sprout trees, which are very thin and characterised by the development of bush and grass complexes. Next come the Carpinus orientalis communities occupying the parts where the oaks have been completely eradicated. In the parts where the soils are highly eroded, the Carpinus orientalis forests and bushes have become very sparse and form separate groups. The rest of the area is occupied by xerothermic grass communities, composed of Chrysopogon gryllus, Dichantium ischaemum, Poa bulbosa, Satureja montana, etc. The xerothermic oak belt is also grown with communities of Syringa vulgaris most common for the rocky areas. Often these communities also comprise Berberis vulgaris, Cotinus coggygria, Amygdalus nana, etc. The Zemen Gorge belongs to the Konyavo-Zemen Region of Sofia District of the Ilirian (Balkan) phytogeograpic Province. The plant variety of the Zemen Gorge region comprises a great number of natural habitats, characteristic for the low mountainous regions of West Bulgaria. There have been identified 5 main habitat types, including over 30 simple habitat units. The presence of a great number of Balkan and Bulgarian endemic taxa and rarer and more southern (Mediterranean and Submediterranean) species makes the habitat picture unique and unconventional.
The following habitats are considered to be conservationally important according to Habitats Directive 92/43 aiming at taking special conservation measures: 3260. Running waters in the valleys and mountains covered with vegetation of Ranunculion fluitantis and Callitricho-Batrachion communities; 4090. Endemic Montane-mediterranean communities of low thorny bushes [31.782 Mizian Astragalus angustifolius communities]; 40A0. Bushes along the edge of the Panonian area [31.8B122 Prunus fruticosa, Amygdalus nana, and Rosa pimpinellifolia]; 5210. Juniperus ssp. communities [32.1311 Juniperus oxycedrus communities]; 6220. Pseudo-steppes grown with corn species and annual plants of the Thero-Brachypodietea type (34.532 Greek-Bulgarian communities composed of lowgrass and terrophytic species); 6240. Subpanonian steppe communities [34.311 Greek-Bulgarian steppes grown with aromatic plants, 34.31611 Mizian-Carpathian steppes grown with Stipa and Festuca, 34.31612 Mizian-Carpathian steppes and 34.31611 Mizian meadow steppes grown with Chrysopogon]; 62A0. East Submediterranean dry grass communities (Scorzonetalia villosae) [34.7513 Grass Chrysopogon and Asphodelus communities 34.7516 Grass Chrysopogon and Paeonia communities 34.7523 Carex humilis grass communities 34.755 Balkan Submediterranean Sesleria grass communties]; 6430. Hydrophytic highgrass communities along the banks of the water basins in the mountain and valley regions of the alpine belt [37.16 mixed continental ‘curtains’ of riverbank vegetation]; 91E0. Tidal Alnus glutinosa and Fraxinus excelsior forests (Alno-Padion, Alnion incanae, Salicion albae) [44.132 East European poplar-willow forests and 44.3341 East European ash-alder forests]; 91M0 Panonian-Balkan oak forests [41.76 Balkan-Anatolian thermophytic oak forests]. The list of the conservationally important habitats in the Zemen Gorge can be expanded with the following habitats listed in Annex 1 of Resolution 4 (1996) of the Bern Convention Standing Committee: 41.7372 Mizian Quercus pubescens forests; 41.8222 Mizian Carpinus orientalis forests; 41. 8223 Syringa vulgaris and Carpinus orientalis forests. There have also been established ‘riverbank Salix alba and Populus alba strips’, which are a protected habitat according to Annex 1 of the Biodiversity Law. The flora f the higher plants is rich and varied (more than 600 taxa); characterised by a high degree of endemism (25 taxa of the plants are related to endemic element) and a typical phytogeographic nature (a combination of middle European, Mediterranean, Submediterranean, and Pontic-Central-Asian floral elements).
The butterflies of the region are sufficiently well studied. Regional investigation results were published by Ganev (
1983a). The reasons for including the region is the presence of important populations of 16 of the target species [see a list below], especially
Pieris ergane,
Lycaena dispar and
Maculinea alcon.
—
Target species: Thymelicus acteon,
Zerynthia polyxena,
Parnassius mnemosyne,
Pieris ergane,
Lycaena dispar,
Pseudophilotes vicrama,
Scolitantides orion,
Glaucopsyche alexis,
Maculinea alcon,
Plebejus sephirus,
Erebia medusa,
Apatura ilia,
Neptis sappho,
Melitaea trivia,
M. aurelia,
Brenthis hecate.
Karst terrain with scattered Juniperus bushes on the crest of Zemenska Planina. Habitat of Pyrgus carthami,
Pieris ergane, Melanargia larissa (Photo S. Beshkov, May 2006).
Grass communities in the vicinity of Juniperus bushes, Zemenska Planina. Habitat of Erynnis tages, Coenonympha pamphilus,
Erebia medusa,
Melitaea trivia (Photo S. Beshkov, May 2006).
Protection & threats: The region comprises two protected areas: (1) the natural sight of Zemenski Skali declared as such by Order 1120/02.07.1968 with an area of 13 hectares in the surroundings of the village of Zlogosh; (2) the natural sight of Skakavitsa Waterfall declared as such by Order 1120/02.07.1968 with an area of 0.1 hectares in the surroundings of the village of Polska Skakavitsa. Zemen Gorge is part of the CORINE European ecological network (code number F00001700). A procedure of proclaiming an extension of the Zemen Gorge protected area is under way (the public discussion has already taken place). The region comprises a stone quarry servicing the maintenance and construction of the railway infrastructure of the area (exercising a strong negative influence on the environment). There are investment plans for the construction of hydropower plants by using the water of the Struma River, which shall cause serious damage to the river ecosystem and riverbank habitats, leading to extinction of species (including target species).
Other remarks: Some conservationally important and rare butterfly and moth species established in the region are: Spialia phlomidis, Zerynthia cerisy, Leptidea duponcheli, Pieris krueperi, Poecilocampa alpina, Trichiura verenae, Lemonia balcanica, Perisomena caecigena, Eumera regina, Lignioptera fumidaria, Erannis declinans, Nychiodes dalmatina, Proserpinus proserpina, Peridea korbi, Paradrymonia vittata streckfussi, Dichagyris renigera renigera, Spaelotis senna contorta, Conisania renati meszarosi, Perigrapha i-cinctum, Cucullia scopariae, Calocucullia celsiae, Amephana dalmatica, Lithophane lapidea, Dryobotodes sevardei, Agrochola wolfschlageri, Agrochola thurneri, Moma alpium, Amphipyra micans, Polyphaenis subsericata, Pseudoxestia apfelbecki, Caradrina terrea, Praestilbia armeniaca, Pyrrhia victorina, Nycteola siculana, Simplicia rectalis, Orectis proboscidata, Ocnogyna parasita linaea, Phragmatobia placida, Euplagia quadripunctaria. The last species was listed in Annex II of the Habitats Directive 92/43 of the European Union.
Map of Zemen Gorge area.