F. Shrub communities

Spiky heath (Bruckenthalia spiculifolia) heaths

Relationships with habitat classifications. EUNIS: F2.261 Rhodopide Bruckenthalia heaths; F2.2631 Balkan range Bruckenthalia heaths; PAL. CLASS.: 31.461 Rhodopide Bruckenthalia heaths, 31.4631 Balkan range Bruckenthalia heaths, HD 92/43: 4060 Alpine and Boreal heaths; Bondev (1991): 7 Community of Bruckenthalia spiculifolia.

Conservation status. BDA, BC, HD.

Category. Nearly Threatened [NT – A1, 2 B1 D2 E2 H2].

General characteristics. The Spiky heath (Bruckenthalia spiculifolia) is a small, evergreen shrub, 10–25 cm high. During flowering, from June to August, the small shrubs with their pink flowers give a beautiful aspect to the mountain slopes. The species occurs in South-East Europe (including South Carpathians) and North-West Asia. The spike heath forms relatively rarely primary phytocoenoses. It increases its distribution after the destruction of the communities of the dwarf pine. Typical habitats are the stony and rocky places - protruding, flat or moderately slanting and more rarely steep (up to 35–40°) areas. Sunny exposure prevails, although northern exposure is also possible. The vertical range of distribution is not very high, from 1000 up to 2300 m alt. The phytocoenoses dominated by this species occur mostly above 1400 m alt. The bed rock is mainly silicate, rarely limestone, but the soils are always acidic and belong to the group of Umbrosols or Cambisols. Most often they are relatively shallow, rarely strong, more or less dry. Almost always they are eroded to a certain extent, mainly with high composition of skeletal material in the different horizons and on their surface. In Bulgaria the Spiky heath occurs also in the marshy fens in the subalpine and mountain vegetation belts, but its abundance is rarely high and the species rarely forms independent phytocoenoses.

The communities of the Spiky heath are most often open, with projective cover between 65 and 80%, rarely reaching 100%. Although Bruckenthalia spiculifolia is a southern species, in the composition of its communities participate mainly arctic-alpine and circumpolar species, most of which are xeromesophytic, oligotrophic, heliophilic and acidophilic species. Small shrubs like Chamaecytisus spp., Genista depressa, Juniperus sibirica, Vaccinium myrtillus, V. uliginosum, and V. vitis-idaea occur in almost all localities. Their abundance varies.. The frequency and abundance of the herbaceous species Deschampsia flexuosa is high. Bellardiochloa variegata (= Bellardiochloa violacea), Campanula velebitica, Cetraria islandica, Festuca airoides, F. nigrescens, Geum montanum, Jasione bulgarica, Nardus stricta, Polytrichum juniperinum, P. pilliferum, Potentilla ternata, Thymus spp., Veronica bellidioides are also frequent. The abundance of Carex caryophyllea, C. kitaibeliana, Juncus trifidus, Sesleria comosa, etc. can also be high in some phytocoenoses. The floristic composition is high, but most often varies between 20 and 30 species in the separate phytocoenoses. A considerable number of the species occurring in the phytocoenoses of Bruckenthalia spiculifolia, including the edificator, are indicators for poor, dry and eroded soils.

The outstanding specificity of the habitats of the Spiky heath is the reason for the relatively high similarity in the floristic composition of its phytocoenoses in the different mountains on the Balkan, e.g. the mountains in former Yugoslavia, R Macedonia, and to a certain extent in Greece. Bellardiochloa variegata, Deschampsia flexuosa, Juniperus sibirica, Thymus spp., Vaccinium myrtillus, V. uliginosum are among the species that always or very frequently occur in the phytocoenoses under consideration. A considerable part of the mentioned species and many of the species with more restricted distribution are diagnostic species for Seslerietalia comosae. The high presence and abundance of Vaccinium species, Siberian juniper and Deschampsia flexuosa are the reason these phytocoenoses to be affiliated to the alliance Pinion mugo. These phytocoenoses are often replaced by the phytocoenoses of the Spiky heath. A separate alliance has also been identified – Bruckenthalion spiculifoliae, belonging to order Rhododendro-Vaccinietalia of class Loiseleurio-Vaccinietea.

Characteristic taxa.

Distribution in Bulgaria. All mountains above 1500 m alt., but the largest areas are in the Balkan Range, especially at the region of Tri Kukli peak, between Ribaritsa pass and Kositsa peak, Osogovska Mt, etc.; (1000) 1500–2300 m alt.

Conservation importance. The communities are very important for their anti-erosion function and have very good aesthetic features.

Threats. These communities have been used as pastures. Therefore, overgrazing can cause changes in their floristic composition and decrease of the projective cover of the plants.

Conservation measures taken. The habitat is included in Annex № 1 of BDA. A significant number of its localities are within protected areas – Rila, Pirin and Central Balkan National Park, Vitosha Nature Park, etc. and sites from the European Ecological Network NATURA 2000.

Conservation measures needed. Monitoring of the habitat and strict implementation of the measures provided for the protected areas management.

References. Bondev 1959; Meshinev et al. 2000; Roussakova 2000.

Author: Veska Roussakova

Spiky heath (Bruckenthalia spiculifolia) heaths (distribution map)