11F2

F. Shrub communities

Mountain communities of Vaccinium spp.

Relationships with habitat classifications. EUNIS: F2.2A2 Balkan-Hellenic dwarf bilberry heaths; PAL. CLASS: 31.4A2 Balkan-Hellenic dwarf bilberry heaths; HD 92/43: 4060 Alpine and boreal heaths; Bondev (1991): 3 Scrub community (Pineta mugi) partly mixed with potential shrubs (Alneta viridis, Saliceta waldsteinianae etc.) and secondary shrub (Junipereta sibiricae etc.), dwarf shrub (Vaccinieta vitis-idaeae etc.) and grass (Nardeta strictae, Festuceta validae etc.) community, 6 Siberian juniper community (Junipereta sibiricae) mostly mixed with secondary shrub (Chamaecytiseta absinthioides, Vaccinieta myrtilli, Vaccinieta vitis-idaeae, Vaccinieta uliginosi etc.) and grass (Nardeta strictae, Festuceta validae etc.) communities.

Conservation status. BDA, HD.

Category. Nearly Threatened [NT – A1, 2 B1 F2 H2 I L3].

General characteristics. This habitat type encompasses the phytocoenoses in which the edificators are the boreal berries: Vaccinium uliginosum, V. myrtillus,and V. vitis-idaea, distributed in the subalpine belt of the mountains in Bulgaria. In some parts of their distribution areas they make mixed communities, all of which relate to silicate rocks and acidic soils. However, each species has its specific ecological and phytocoenological amplitude, determined by a variety of different factors.

The communities of Vaccinium uliginosum are related to the upper sub-alpine sub-belt (differing from these related to the alpine phytocoenoses and belonging to class Loiseleurio-Vaccinietea). In the high mountains, Rila and Pirin Mts., they rarely occur below 2200 m alt. In the mid-high mountains their lower boundary of distribution is about 1600–1700 m alt. Vaccinium uliginosum is a very cold-resistant species that needs relatively high air and soil humidity. The main exposure of the areas of these communities is northern, northeastern or northwestern, mostly close to the mountain ridges but also on the ridges and peaks. The slant is small, but in some places can reach 45–50°. Some of the habitats are stony or without rock outcrops and the soils are relatively weakly developed, poor, sometimes eroded and rather acidic. In these cases the anthropogenic impact is limited and the phytocoenoses are of primary origin. The group of the phytocoenoses that have replaced destroyed vegetation, mostly in places of burned coenoses of Siberian juniper is bigger. In these secondary coenoses of Vaccinium uliginosum the soil can be stronger – up to 60 cm thick and rich in organic substances throughout its whole profile. The area of the patches is small, up to 100 ha.

The phytocoenoses of Vaccinium uliginosum in the sub-alpine belt have more complex vertical structure and considerably richer floristic composition compared to the ones in the alpine belt. The tallest species are Luzula luzuloides, Calamagrostis arundinacea, Festuca nigrescens, Luzula sylvatica, but these species rarely have high abundance and only the first two species occur more often in the phytocoenoses. Most of the plants are 20–30 cm high. Apart from the edificator that always has high abundance most frequent are Agrostis rupestris, Antennaria dioica, Avenula versicolor, Bruckenthalia spiculifolia, Carex kitaibeliana, Festuca airoides, Juncus trifidus, Juniperus sibirica, Nardus stricta, Poa media, Potentilla ternata, Primula minima, Sesleria comosa, and Vaccinium myrtillus. Anthoxanthum odoratum, Bistorta vivipara (= Polygonum viviparum), Campanula patula subsp. abietina, Crocus veluchensis, Galium verum, Genista depressa, Geum montanum, Homogyne alpina, Hypericum richeri, Scabiosa balcanica, Senecio carpathicus, Silene roemeri,etc. occur more rarely. Some rare and protected species also occur: Daphne blagayana, Gentiana lutea, G. punctata, Lathyrus linifolius, Meum athamanticum, Phyteuma confusum, etc. In some areas, mostly in the primary phytocoenoses, some mosses and lichens also occur: Cetraria islandica, Hylocomium splendens, Pleurozium schreberi, etc. The total projective cover of the vegetation varies between 90 and 100%. Most of the coenoses under consideration are monodominant, but there are some in which the abundance of other species is also high.

The phytocoenoses of Vaccinium myrtillus occur between 1500 and 2000 m alt. in the mid-high mountains, although in Rila and Pirin Mts they reach up to 2200 m alt. (although the species itself has much higher vertical range of distribution). The primary coenoses that belong to this group are very rare. Almost all phytocoenoses have replaced wood and shrub coenoses which have been cut-off or burned in order to increase the areas of the pasture vegetation. After the burning of the juniper, Vaccinium myrtillus recovers quickly and in a year or two forms communities persistent in time. In some cases such as in Rila and Rhodopi Mts., the Vaccinium communities develop in coenoses of Pinus sylvestris, Pinus peuce and Picea abies, covering open areas that are the results of fires or logging.

The size of the patches and the specificities of the habitats of the phytocoenoses of Vaccinium myrtillus distributed in the different mountains and different parts of the mountains vary. For instance, in Rila Mts., larger areas of these coenoses occur in the western parts of the mountain, in Vitosha Mountain they are not widely distributed and in the Balkan Range they are among the major coenoses of the high-mountain grasslands but the populations are strongly fragmented. The exposure can vary: in some places it can be more southern and in others, more northern. The slant also can vary considerably and can reach 45°. The soils can be shallow or deep, Humic Cambisols or Cambisols, eroded or not, with variable organic substances, but almost always acidic. The projective cover of the vegetation is always high.

Unlikely the coenoses of Vaccinium uliginosum in the coenoses of Vaccinium myrtillus the abundance of Luzula luzuloides, Deschampsia flexuosa can be rather high in some places. The abundance of Agrostis capillaris, Bruckenthalia spiculifolia, Carex caryophyllea, Nardus stricta can be very high sometimes and in some places they can be co-dominants. The abundance of Bellardiochloa variegata (= Bellardiochloa violacea), Festuca rubra, Hieracium hoppeanum, Hypericum maculatum, Thymus vandasii also can be high. A number of species of conservation importance have been registered: Arctostaphylos uva-ursi, Gentiana lutea, G. punctata, Lilium jankae, Meum athamanticum, Phyteuma confusum, Viola balcanica, etc. The associations of Vaccinium myrtillus that have been described on the basis of the dominant method are approximately thirty.

Compared to the other two species the coenoses of Vaccinium vitis-idaea have more limited distribution. This species is more often a sub-dominant or assectator, rather than an edificatory, in the coenoses mostly of Vaccinium myrtillus. It occurs mostly in the lower sub-alpine sub-belt, since it is less cold-resistant compared to the other two species and has some xerothermic features. It occupies mostly stony and rocky meadows in the coniferous forests with different exposure and slant. In most coenoses the soil is shallow and stony. The floristic composition of these phytocoenoses is rich, similar to the composition of the two other Vaccinium species.

Mixed coenoses in which Vaccinium myrtillus and Vaccinium uliginosum have high abundance occur  in many places with prevailing northern exposure. Vaccinium vitis-idaea is most often in a subordinate position. They usually occur near the timberline in places with different slant of the slopes, sometimes with stony blocks on the surface. The soil humidity is most often moderate. Only in some places Arctostaphylos uva-ursi also occurs. The accompanying species are similar to the ones in the monodominant phytocoenoses of Vaccinium species.

Most of the phytocoenoses under consideration are of secondary origin and the floristic composition and syndynamics are related to class Vaccinio-Piceetea. However, some authors combine all small-shrub phytocoenoses in the alpine and sub-alpine belts in class Loiseleurio-Vaccinietea.

Characteristic taxa.

Distribution in Bulgaria. 1. Vaccinium uliginosum communities – West and Central Balkan Range, Vitosha Mts., Ossogovska Mts., Pirin Mts., Rila Mts., West Sredna Gora Mts., West and Central Rhodopi Mts.; 1700–2400 m alt.; 2. Vaccinium myrtillus communities – apart from the mountains already mentioned above these coenoses occur also in Znepole Region, Belasitsa Mts., Slavyanka Mts., Lozenska Mts.; 1600–2200 m alt. 3. Vaccinium vitis-idaea communities – Balkan Range (including eastern part), Pirin Mts., Belasitsa Mts., Rila Mts., West Sredna Gora Mts., West and Central Rhodopi Mts., Vitosha Mts., Plana Mts.; 1600–2200 m alt.

Conservation importance. The phytocoenoses of Vaccinium spp. have great economic importance as pastures with rich species composition. The fruits of the three species are edible, rich in certain acids and vitamin C and, together with the leaves, are used in conventional and folk medicine. Their collection for economic purposes (including export) and for personal consumption threatens the phytocoenoses and their floristic composition. Some rare and protected species like Alchemilla plicatula, A. pyrenaica, Anemone narcissiflora, Daphne blagayana, Gentiana acaulis, G. lutea, G. punctata, Lathyrus linifolius, Lilium jankae, Lycopodium clavatum, Meum athamanticum, Phyteuma confusum, Rhododendron myrtifolium, Sempervivum erythraeum, Viola balcanica, etc. occur.

Threats. The phytocoenoses of Vaccinium spp. are used as pastures due to their rich floristic composition and overgrazing can cause their degradation. However, without grazing the syndynamic processes lead to the restoration of the primary shrub and forest vegetation. Burning of juniper as a preventing measure against the replacing of the small- shrub coenoses by the juniper is anapproach that is not compatible with the modern methods for biodiversity management. Fruit collection very often can cause damage to the Vaccinium plants.

Conservation measures taken. The habitat is included in Annex № 1 of BDA. Part of the phytocoenoses are within the borders of reserves and national and nature parks – Rila and Central Balkan National Parks, Vitosha Nature Park. The exploitation regimes of the Vaccinium resources have been elaborated.

Conservation measures needed. Strict application of the exploitation regimes. Monitoring of the habitat state and changes in the phytocoenoses as a result of the annual fruit collection for commercial purposes of Vaccinium myrtillus and V. vitis-idaea. Establishement of suitable grazing regime .

References. Bondev et al. 1983; Bondev 1966; Ganchev 1961; Roussakova 1976; Velchev et al. 1994; Velchev 1971.

Authors: Antonina Vitkova, Veska Roussakova


Mountain communities of Vaccinium spp. (distribution map)