29E5

E. Herbaceous communities and communities of lichens and mosses

Riverside tall-herb communities in the mountains

Relationships with habitat classifications. EUNIS: E5.572 Moesian tall herb communities; PAL. CLASS.: 37.872 Moesian tall herb communities; HD 92/43: 6430 Hydrophilous tall herb fringe communities of plans and of mountain to alpine levels.

Conservation status. BDA, HD.

Category. Vulnerable [VU – A1, 2 B2 C1 D2 E2 F2 G2 H2 I J L1].

General characteristics. The main condition necessary for the development of tall-herb vegetation is the presence of high soil and air humidity. Most often the tall-herb coenoses develop along rivers and streams. The habitat has a specific character: the slope can vary between 5–10° and 60°. The exposure also varies but does not play a determining role for the species composition. These coenoses strictly follow the water streams, sometimes for hundreds of meters without a break. As a rule, the conditions change significantly on a strip that is several meters wide. Close to the water and beside the water stream itself the lower parts of the plants are permanently in submerged. Avoiding the large stones the plants occupy the places with deposited sand and gravel. The soil strip that is on the bank, but in close proximity to the water, is also permanently wet. Away from the water the soil humidity decreases, the stones are fewer, the rich alluvial-coluvial soil becomes thicker. This changing environment is rich in species with different ecology and size. No layers can be distinguished in the tall-herb vegetation – plants with various heights cover the surface from the water level up to 1,5–2 m. The projective cover of the vegetation is almost always 100%.

The main part of the tall-herb phytocoenoses occurs in the subalpine belt, above 1600 up to 1900–2200 m and rarely reach 2500 m alt. Therefore these coenoses are neighbouring different coniferous phytocoenoses from with which many species are common. These coenoses also occur in the beech belt and some can reach down to the mountain foothills. The soil and climatic conditions and high conservatism of the biotope create favourable conditions for the development of Balkan and Balkan-Carpathian endemics such as Angelica pancicii, Cicerbita pancicii, Cirsium appendiculatum, Geum bulgaricum, G. coccineum, G. rhodopaeum, Hypericum richeri subsp. grisebachii etc. The species composition of the tall-herb communities is very rich. Syntaxonomically the vegetation belongs to class Mulgedio-Aconitetea (Betulo-Ademostyletea) and order Adenostyletalia alliariae due to the participation of species typical for these syntaxa: Adenostyles alliariae, Carduus personata, Cicerbita alpina, Geranium sylvaticum, Milium effusum, Myosotis sylvatica, Polygonatum verticillatum, Ranunculus platanifolius, Rumex alpinus, Senecio nemorensis, Tozzia alpina, Veratrum album subsp. lobelianum, and Viola biflora etc. The specificity of the tall-herb vegetation on the Balkans is outlined by the regional alliance Cirsion appendiculati. The species that are peculiar for it and separates it from the alliance Adenostylion alliariae from central Europe are the Balkan endemics Angelica pancicii, Cirsium appendiculatum, Cicerbita pancicii (Rila Mts.), Geum coccineum, and G. rhodopaeum, together with some other species that are not endemics but do not occur in the related coenoses outside the Balkans: Aconitum variegatum subsp. judenbergense, A. lamarkii, Anthriscus nemorosa, Heracleum verticillatum. Many of them are major edificators, with high abundance and wide distribution that strongly contributes to the regional specificity of these groups of coenoses on the Balkans and determines the regional alliance. There are some common species, Balkan and central European elements, for the two alliances,: Alnus viridis, Doronicum austriacum and Stellaria nemorum, but the coenoses structured by these species are not common. The main association that encompasses a large number of the tall-herb coenoses in the Bulgarian mountains is Angelico-Heracleetum verticillati.Its floristic composition is rich. Although the different coenoses differ in species there is a number of species that are common for all coenoses. The constant species are Cirsium appendiculatum, Deschampsia caespitosa, Geum coccineum and Heracleum verticillatum as well as the frequent species Cicerbita alpina, Myosotis sylvatica, Rumex alpinus, Saxifraga rotundifolia, Senecio nemorensis, Stellaria nemorum, Telekia speciosa, Veratrum album subsp. lobelianum,etc.

The tall-herb vegetation of the upper, subalpine belt also develops in humid places with accumulated fine soil and gravel that are mostly at the base of the rocky outcrops and in the furrows between the rock ribs. The soil is rich in nutrients and well aerated. Aquilegia aurea, Calamagrostis arundinacea, Chaerophyllum hirsutum, Cirsium appendiculatum, Gentiana lutea, G. punctata, Geranium sylvaticum, Geum bulgaricum, Heracleum verticillatum, Homogyne alpina, Luzula spadicea, Pedicularis oederi, Ranunculus crenatus, R. incomparabilis, R. platanifolius, Soldanella alpina, Swertia perennis, Thalictrum aquilegifolium etc. mainly participate in these coenoses. Phytocoenoses strongly dominated by Petasites albus develop on wet and stony places, while the coenoses of P. hybridus develop along the rivers and streams at lower altitudes. Some species typical for the neighbouring forest coenoses also enter the tall-herb coenoses: Athyrium filix-femina, Dryopteris carthusiana, Dryopteris filix-mas, Chamaenerion angustifolium (= Epilobium angustifolium), Gentiana asclepiadea, G. lutea, Geranium sylvaticum, Homogyne alpina, Hypericum maculatum, Lapsana communis, Ligusticum mutellina, Luzula luzuloides, L. sylvatica, Milium effusum, Oxalis acetosella, Ranunculus montanus, Ribes alpinum, Senecio nemorensis, Urtica dioica, Veronica serpyllifolia, etc.

Characteristic taxa.

Distribution in Bulgaria. All mountains of Bulgaria.

Conservation importance. The tall-herb vegetation in the Bulgarian mountains does not cover large areas but plays an important role in water regulation and is an important part of the coenotic and species diversity of the country. A large number of the coenoses are unique and many protected and endemic species participate in their composition: Angelica pancicii, Aquilegia aurea, Barbarea bracteosa, Geum rhodopaeum, Heracleum angustisectum, Petasites kablikianus, Rhynchocorys elephas, Senecio pancicii, Trollius europaeus, etc.

Threats. Changes in the water regime of the habitats, destruction of the autochthonous vegetation mainly through construction activities, destruction of the forest and shrub ecosystems in the mountains.

Conservation measures taken. The habitat is included in Annex № 1 of BDA. Many phytocoenoses are within the borders of protected areas - Rila, Pirin and Central Balkan National Parks and in sites from the European Ecological Network NATURA 2000.

Conservation measures needed. Detailed phytocoenological study and identification of the threatened coenoses, and respectively their habitats; protection of the forest and shrub ecosystems.

References. Bondev 1959; Roussakova 2000; Stojanov 1948.

Author: Veska Roussakova


Riverside tall-herb communities in the mountains (distribution map)