07F2
High-mountain ericoid communities of mountain crowberry (Empetrum nigrum) and heather (Vaccinium spp.)
Relationships with habitat classifications. EUNIS: F2.24 Alpigenic high mountain crowberry ‑ heather heaths; PAL. CLASS.: 31.44 High mountain Empetrum-Vaccinium heaths; HD 92/43: 4060 Alpine and Boreal heaths.
Conservation status. BDA, HD.
Category. Critically endangered [CR – A1, 2 C2 D3 E3 F2 H3].
General characteristics. Empetrum nigrum is a mesophytic, Arctic-Alpine nanophanerophyte and a glacial relic in the Bulgarian flora. Its phytocoenoses are rare and do not show tendencies towards a development of new localities or expanding of the existing ones. The localities are mostly on northern, steep to slanting rocky slopes. The soils are relatively better developed compared to the ones in the alpine phytocoenoses of the bog berry (Vaccinium uliginosum). The soil humidity is permanent. The occupied areas are mostly smaller than 100 m2, sometimes even about a decare. The phytocoenoses occur mostly on the border between the subalpine and the alpine belts, in some cases at 2200 m alt. Therefore the influence of the strong winds on the biotic and abiotic conditions is relatively smaller compared to that in the alpine belt where the habitats of the alpine bog berry phytocoenoses occur. However, the localities in the subalpine belt are very rarely covered by snow and the temperature remains very low. Still, the environment is less harsh and the phytocoenoses have two, well developed two layers differing from the single-layered phytocoenoses of Vaccinium uliginosum in the alpine belt. The projective cover of the vascular plants is higher. The floristic composition is relatively rich although in some communities the species are not many. Their total projective cover is between 70 and 90%. Almost always the abundance of Vaccinium uliginosum in these phytocoenoses is high. Most often Empetrum nigrum has well expressed functions of a dominant and edificator, while Vaccinium uliginosum is a subdominant or assectator. Only in some case the bog berry dominates. The abundance of Cetraria islandica, and in some places Thamnolia vermicularis, is exceptionally high. Vaccinium myrtillus (in some place well represented), Vaccinium vitis-idaea, Juniperus sibirica, more rarely Pinus mugo,many mosses and lichens participate in the composition of the phytocoenoses as a rule. Species from the neighbouring phytocoenoses also occur: Avenula versicolor, Campanula alpina, Carex curvula, Dianthus microlepis, Festuca airoides, F. riloensis, Homogyne alpina, Juncus trifidus, Primula minima, Sesleria comosa, etc. The communities of Empetrum nigrum from Rila and Pirin Mts. have similar floristic composition. However, Cetraria islandica is rarer in Pirin Mts. In the same time Sesleria coerulans and some Pirin endemics can occur in certain phytocoenoses in Pirin Mts. The Bulgarian phytocoenoses of Empetrum nigrum and Vaccinium uliginosum have been classified as a subassociation in the described from the Alps association Empetro-Vaccinietum seslerietosum comosae from alliance Loiseleurio-Vaccinion.
Characteristic taxa.
- Vascular plants: Anemone narcissiflora, Arctostaphylos uva-ursi, Avenula versicolor, Carex bulgarica, C. gracilis, C. rangiferina, Diphasium alpinum, Empetrum nigrum, Festuca airoides, F. picta, Gentiana punctata, Gentianella bulgarica, Geum bulgaricum, Homogyne alpina, Huperzia selago, Juncus trifidus, Juniperus sibirica, Sesleria comosa, Vaccinium myrtillus, V. uliginosum, V. vitis-idaea,etc.; mosses – Barbilophozia lycopodioides, Hylocomium splendens, Pleurozium schreberi, Rhytidiadelphus triquetrus.
- Lichens: Cetraria islandica, Cladonia arbuscula, Peltigera aphthosa.
Distribution in Bulgaria. Rila and Pirin Mts.; 2200–2700 m alt.
Conservation importance. It comprises rare and threatened phytocoenoses and plant species protected by law (Anemone narcissiflora, Diphasium alpinum, Empetrum nigrum, etc.).
Threats. Any human activity in the localities of the habitat and the neighbouring territories.
Conservation measures taken. The habitat is included in Annex № 1 of BDA. The localities are within the borders of Rila and Central Balkan National Parks and in sites from the European Ecological Network NATURA 2000.
Conservation measures needed. Monitoring of the habitat, limitation of the anthropogenic impact and effective implementation of the legal documents and regimes in the protected areas.
References. Bondev 1959; Ganchev 1963; Roussakova 2000.
Author: Veska Roussakova
