03G1
Mountain Grey alder (Alnus incana) galleries
Relationships with habitat classifications. EUNIS: G1.1216 Balkan Range Grey alder galleries, G1.1217 Rhodopi Grey alder galleries; PAL. CLASS.: 44.216 Balkan Range Grey alder galleries, 44.217 Rhodopi Grey alder galleries; HD 92/43: 91E0 *Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae); Bondev (1991): 24 White alder (Alneta incanae) forests, partly of secondary origin, replacing spruce (Picea abies (L.) Karst.) forests.
Conservation status. BDA, BC, HD.
Category. Vulnerable [VU – A1, 2 B1 C1 D2 E2 F1 G1 H1 J L2].
General characteristics. The grey alder (Alnus incana) is a cold-resistant species and is not demanding of soil richness and light quantity, hence it can develop successfully in harsh climatic conditions. The mountain galleries in which Alnus incana prevails develop on alluvial soils (Fluvisols) along the rivers in the mid-mountain, fir-beech vegetation belt, i.e. at altitudes that are higher compared to the similar forests of Alnus glutinosa and Fraxinus oxycarpa. The projective cover of the tree layer is about 60 to 80%. In certain places Abies alba, Alnus glutinosa, Betula pendula, Fagus sylvatica, Fraxinus excelsior, Picea abies and other tree species have relatively high abundance. The following shrubs also occur: Corylus avellana, Crataegus monogyna, Ribes petraeum, salix triandra, Sambucus nigra, Sorbus aucuparia, etc. The projective cover of the herbaceous layer is from 40 to 80%. The following species are more abundant: Impatiens noli-tangere, Oxalis acetosella, Urtica dioica and Galium aparine. Aremonia agrimonoides, Cardamine pectinata, Cirsium appendiculatum, Dryopteris filix-mas, Euphorbia amygdaloides, Filipendula ulmaria, Geranium robertianum, Lamiastrum galeobdolon, Mycelis muralis, Petasites albus, Poa nemoralis, Pulmonaria officinalis, Telekia speciosa, etc. also often occur. Syntaxonomically the montane galleries of the grey alder belong to class Populetea albae, order Fraxinetalia and alliance Alnion incanae.
Characteristic taxa.
- Vascular plants: Abies alba, Ajuga reptans, Alnus glutinosa, A. incana, Aremonia agrimonoides, Betula pendula, Cardamine impatiens, C. pectinata, Cirsium appendiculatum, Dryopteris filix-mas, Equisetum hiemale, Euphorbia amygdaloides, Fagus sylvatica, Filipendula ulmaria, Fraxinus excelsior, Galium aparine, G. odoratum, Geranium robertianum, G. phaeum, Geum rivale, Impatiens noli-tangere, Lamiastrum galeobdolon, Mycelis muralis, Oxalis acetosella, Petasites albus, Picea abies, Poa nemoralis, Pulmonaria officinalis, Senecio nemorensis, Stachys sylvatica, Telekia speciosa, Tussilago farfara, Urtica dioica, Veronica urticifolia.
- Fungi: Macromycetes – Lachnum virgineum, Macrotyphula fistulosa, Naucoria alnetorum, N. escharoides, Panellus serotinus, Phellinus igniarius, Pyrenopeziza benesuada; Micromycetes – Apiognomonia alniella, Taphrina amentorum (on Alnus incana), Melampsora salicis-albae (on Salix alba), Phyllactinia guttata, Septoria alni (on Alnus glutinosa).
Distribution in Bulgaria. The habitat occurs in most of the Bulgarian mountains: Balkan Range, Vitosha Mts., Rila Mts., West Rhodopi Mts., West Frontier Mts., etc.; 800 to 1500 m alt.
Conservation importance. The mountain galleries of the grey alder are an important habitat for many hygrophilic animals and plants. The fungus of conservation importance Macrotyphula fistulosa also occurs in this habitat.
Threats. The phytocoenoses of the Grey alder have a fragmented distribution and, like other riverside habitats, are very sensitive to changes in environmental conditions, but mostly to changes of the hydrological regime. The biggest threats are construction of micro-water electric power stations and other pieces of infrastructure; redirections and cleaning of the riverbeds; unregulated and wrongly-conducted felling.
Conservation measures taken. The habitat is included in Annex №1 of the national Biodiversity Act and is of conservation priority. Parts of this habitat are within Vitosha Nature Park, Rila and Pirin National Parks, Stara Reka Strict Nature Reserve as well as in sites of the European Ecological Network NATURA 2000 in Bulgaria (Central Rhodopi, West Rhodopi cites, etc.).
Conservation measures needed. Detailed phytocoenological studies; expansion of the protected areas that encompass parts of the habitat; prohibition of logging in the riverside forests; mapping and monitoring of this habitat; prohibition of building of micro-water electric power stations inside or close to the habitat localities.
References. Bondev 1991.
Authors: Marius Dimitrov, Alexandar Tashev
