03F2
Bog bilberry (Vaccinium uliginosum) alpine communities
Relationships with habitat classifications. EUNIS: F2.213 Rhodopide and Balkan dwarf wind heaths [Vaccinium]; PAL. CLASS.: 31.4123 Rhodopide and Balkan dwarf wind heaths [Vaccinium]; HD 92/43: 4060 Alpine and boreal heaths; Bondev (1991): 1 Acidophilic and psychrophitous grass communities (Cariceta curvulae, Festuceta riloensis, Seslerieta comosae, Junceta trifidi, Festuceta airoides, Agrostideta rupestris, etc.) and dwarf shrub (Saliceta herbaceae, Saliceta retusae, Empetreta nigrae, Vaccinieta uliginosi, etc.).
Conservation status. BDA, HD.
Category. Vulnerable [VU – A1, 2 B1 C2 D2 E2 H2 I].
General characteristics. The habitat encompasses phytocoenoses of the Bog bilberry (Vaccinium uliginosum), that occur mostly in rocky areas in the alpine belt on the northern slopes of the summit ridges in Rila and Pirin Mts. More rarely the slopes can face East, and exceptionally South or West. The slopes are subjected to strong, mainly northwestern winds that blow away the snow cover in winter. Very rarely these phytocoenoses occur on small terraces on steep, rock outcrops. In the mid-high mountains in Bulgaria this habitat type occurs above timberline, in utterly unfavourable environmental conditions. The slant of the localities is different – from flat areas to very steep slopes. The soils are shallow, skeletal, most often in the primary stage of formation, with low pH. They remain relatively humid throughout the whole vegetation season. Very often a significant part of the localities are rock outcrops and soil is almost absent. The area of the separate localities is very small – from several to hundred square meters, rarely reaching one decare.
Vaccinum uliginosum is a deciduous small shrub that belongs to the group of boreal elements in the Bulgarian flora. The species has a very wide distribution, i.e. apart from the alpine belt, it dominates some phytocoenoses, mostly of secondary origin, in the subalpine belt of some Bulgarian mountains. The Bog bilberry is a very small plant in the alpine phytocoenoses. These phytocoenoses have only one layer and the presence of lichens is considerable. The total projective cover in most cases varies between 60% and 90%. Since the environmental conditions are extremely harsh the floristic composition of the plant communities is poor. In some of the coenoses only two species, Vaccinium uliginosum and Cetraria islandica, have high abundance. Additionally Thamnolia vermicularis, Flavocetraria nivalis, and Alectoria ochroleuca occur permanently. The alpine coenoses of the Bog bilberry are among the coenoses that are richest in lichens in the Bulgarian mountains. In many coenoses the high projective cover (90%) is due to the lichens. Some species typical for the alpine, herbaceous coenoses like Festuca riloensis, Sesleria comosa, Dianthus microlepis, Juncus trifidus, etc. also occur. Empetrum nigrum also occurs in some places that are on low slopes that face North and with more soil. The group of coenoses under consideration is almost always of primary origin. They are persistent and their successional development leads to the establishment of herbaceous communities. However, these processes are very slow due to the unfavourable abiotic conditions. These coenoses belong to alliance Loiseleurio-Vaccinion.
Characteristic taxa.
- Vascular plants: Avenula versicolor, Carex curvula, Campanula alpina subsp. orbelica, Dianthus microlepis, Empetrum nigrum, Festuca riloensis, Juncus trifidus, Primula minima, Sesleria comosa, S. coerulans, Vaccinium uliginosum.
- Fungi: Macromycetes – Hymenoscyphus repandus;Micromycetes – Exobasidium vaccinii, Naohidemyces vaccinorum, Podosphaera myrtillina var. major, Pucciniastrum vaccinii, Septoria vaccini-uliginosi (on Vaccinium uliginosum); Lichens – Alectoria ochroleuca, Cetraria islandica, Flavocetraria nivalis, Thamnolia vermicularis.
Distribution in Bulgaria. Rila, Pirin and Vitosha Mts and the Balkan Range; (2000) 2500–2700 m alt.
Conservation importance. Some species protected by law participate in these coenoses such as Anemone narcissiflora.
Threats. Intensive tourism and construction of tourism facilities; grazing, mass collection (especially with the so called “combs”) of the fruits of the Bog bilberry.
Conservation measures taken. The habitat is included in Annex 1 of BDA. It is also within the borders of Rila, Pirin and Central Balkan National Parks. Parts of the habitat are within sites of the European Ecological Network NATURA 2000 in Bulgaria.
Conservation measures needed. Monitoring of the habitat and effective implementation of the legal regulations concerning the protected areas.
References. Roussakova 2000; Simon 1958.
Author: Veska Roussakova
