Relationships with habitat classifications. EUNIS: E4.4 Calcareous alpine and subalpine grassland, E4.42 Wind edge Kobresia myosuroides swards, E4.427 Pirin Naked rush swards; PAL. CLASS.: 36.42 Wind edge Naked rush swards, 36.427 Pirin Naked rush swards; HD 92/43: 6170 Alpine and subalpine calcareous grasslands; Bondev (1991): 2 Calciphilous cryphytous grass (Kobresieta myosuroides, Cariceta kitaibelianae, Seslerieta korabensis etc.) and shrub (Dryeta octopetalae, Saliceta reticulatae etc.) communities.
Conservation status. BDA, HD.
Category. Endangered [EN – A1, 2 B2 C3 D2 E2 H2 I J].
Genaral characteristics. These habitats have a very limited distribution in the Bulgarian mountains. The main ecological factors that play significant role for the formation of these habitats and the floristic composition of their coenoses are the high altitude (from above 2300 up to 2700 m alt), strong winds and the bed rock – calcareous schists and marbles. The soils most often are poorly developed, 10–30 cm thick, rarely thicker, strongly skeletal, with rock outcrops. They are slightly to moderately alkaline. The habitats occur on mountain ridges, slopes of the highest Bulgarian peaks, and on bulging relief shapes in small depressions. The slope can be insignificant, but very often the areas can be more or less steep. The exposure, most often northern, is also an important factor for the composition of the vegetation cover. The habitats under consideration occur in Rila and Pirin Mts., and the vegetation in each mountain has its own specificities.
There are several small areas with calcareous bedrock in the alpine belt of Rila Mts.: In tow of them, on the ridge of Riletz peak, where the exposure is northern or with northern component, the major coenoses-forming species is Kobresia myosuroides (= Elyna bellardii). One of the localities is approx. 30° steep, facing north, while the other locality is almost flat. They are both exposed to strong winds and low temperatures. Kobresia myosuroides has a relatively high abundance and, together with other species including many lichens (Alectoria ochroleuca, Cetraria aculeata, C. islandica, Flavocetraria nivalis, Thamnolia vermicularis), cover about 50–60% of the soil surface. In some places, mainly due to the lichens, the covered surface is even larger. Another rare and relic species of the Bulgarian flora, Carex rupestris participates in some of these coenoses. Apart from the species typical for this habitat type (e.g. Cerastium alpinum, Erigeron alpinus, Gentianella bulgarica, Oxytropis campestris, Saxifraga oppositifolia, Silene acaulis), others (e.g. Salix reticulate) as well as many species from the neighbouring vegetation developing on the acidic rocks and soils occur: Carex curvula, Dianthus microlepis, Festuca riloensis, Poa media, Sesleria comosa, etc. Only one small locality is known in the literature from Pirin Mts. where Kobresia myosuroides is the edificator. It covers only 4 m2 and is more a fragment than a developed phytocoenosis. In reality there are several phytocoenoses, each of them covering an area of 0,5 ha. They cover bulging relief shapes, that are very stony, with slight slope and poorly developed soil. Festuca riloensis, Sesleria comosa are absent from the phytocoenoses. The abundance of Carex curvula, Poa media, Festuca airoides is limited, while Antennaria dioica, Anthyllis vulneraria, Carex kitaibeliana, Erigeron alpinus, Galium anisophyllon, Hieracium alpicola, Jasione laevis subsp. orbiculata, Juniperus sibirica, Minuartia verna, Primula minima, Sesleria coerulans, Trifolium repens subsp. orbelicum, Vaccinium uliginosum occur more frequently. The floristic composition includes species rare for Bulgaria: Androsace villosa, Campanula cochlearifolia, Centaurea achtarovii, Festuca pirinica, Oxytropis urumovii, Rhodax alpestris, Thymus perinicus, etc. The species diversity of lichens is high in these phytocoenoses as well, but their projective cover is mostly limited. Brodoa intestiniformis, Flavocetraria nivalis, Cetraria aculeata, C. tristis, Lecanora polytropa etc. occur.
The phytocoenoses under consideration are relic and rare for the vegetation cover of Bulgaria. No tendencies towards an enlargement of the area of these phytocoenoses have been registered. The phytocoenoses in Rila Mts. are united in the association Seslerio-Elynetum bellardii from the alliance Oxytropido-Elynion.The association Elynetum pirinicum from Pirin Mts is invalidly published (art. 2c from the Code of Phytocoenological Nomenclature (2002)).
Carex rupestris is another edificator that dominates in several, places that are very limited in size. They occur on limestone in Rila Mts. (Deno peak) and Pirin Mts. is. In some places the exposure of these localities has a southern component and the slope varies from 0° to 45°. The floristic composition is similar to that of the coenoses of Kobresia myosuroides,but in Pirin Mts. some additional local endemics occur as well: Alyssum cuneifolium subsp. pirinicum, Papaver degenii, Saxifraga ferdinandi-coburgi, Thymus perinicus etc The Balkan endemics (Poa macedonica, Sesleria korabensis, etc.) are also registered. The projective cover varies and in some places reaches 30%.
Distribution in Bulgaria.Pirin and Rila Mts., above 2300 m alt.
Conservation importance.The habitat includes many rare and endangered relic and endemic phytocoenoses and plant species: Alyssum cuneifolium subsp. pirinicum, Androsace villosa, Campanula cochlearifolia, Carex rupestris, Festuca pirinensis, F. pirinica, Kobresia myosuroides, Oxytropis campestris, O. urumovii, Papaver degenii, Pedicularis oederi, Poa macedonica, Saxifraga ferdinandi-coburgi, S. rocheliana, Thymus perinicus, Viola grisebachiana, etc. and the fungus Hygrocybe murinacea is of conservation importance.
Threats. Intensive tourism – the localities are crossed by tourist paths. The increasing number of visitors directly threatens the habitat. Future construction of tourism facilities will destroy these habitats completely.
Conservation measures taken. The habitat is included in Annex № 1 of the Biodiversity Act. The coenoses are within the borders of Rila and Pirin National Parks. Some localities are in sites of the European Ecological Network NATURA 2000.
Conservation measures needed. Monitoring of the habitat state and strict implementation of the regulations for the national parks.
References. Roussakova 1995, 2000, Simon 1958, Velchev 1998.
Author: Veska Roussakova