31G1
Grey alder (Alnus incana) woods
Relationships with habitat classifications. EUNIS: G1.B24 Rhodopi Grey alder woods; PAL. CLASS.: 41.C24 Rhodopi Grey alder woods; Bondev (1991): 24 White alder (Alneta incanae), partly of secondary origin replacing spruce (Picea abies) forests (humid areas on the slopes of West Rhodopi Mt).
Conservation status. None.
Category. Endangered [EN – B1 C3 D3 E2 F2 G2 H1 H1 L1].
General characteristics. Grey alder (Alnus incana) is a hygrophyte, adapted to wet, alluvial soils. Very rarely it forms mesophytic phytocoenoses, distant from the river beds. Such forests are of pioneer type and are of restricted distribution in the Bulgarian mountains. Grey alder forests in Rhodopi and Rila Mts. cover areas with moderate slope, from 700 up to 1500 m alt. They grow on relatively deep, wet Cambisols. The tree cover is 60–70%. In some places, together with the ediphicator, Silver birch (Betula pendula), Silver fir (Abies alba),Norway spruce (Picea abies) also occur and some other tree species with low abundance. Shrubs are represented by Dogwood (Cornus sanguinea),Hawthorn (Crataegus monogyna) and Elder (Sambucus nigra).Grey alder woods are strongly affected by felling as a result of which some highly mobile species have entered the herbaceous synusium such as Brachypodium sylvaticum, Dactylis glomerata, Galium aparine, Knautia drymeia, Luzula luzuloides, Poa nemoralis, Urtica dioica, etc. Geum urbanum, Oxalis acetosella, Petasites hybridus, etc. also occur in places with wetter soils. Some of the phytocoenoses of Alnus incana have originated in places of extinct deciduous or coniferous forests. From a syntaxonomic point of view the Grey alder forests, distant from river beds, belong to the intrazonal vegetation from class Populetea albae, order fraxinetalia, and alliance Alnion incanae. They establish floristic, ecological and syntaxonomic continuum with plant communities of Fagion sylvaticae and Piceion excelsae (suballiance Abieti-Piceenion) alliances.
Characteristic taxa.
- Vascular plants: Abies alba, Alnus incana, Betula pendula, Brachypodium sylvaticum, Cornus sanguinea, Crataegus monogyna, Dactylis glomerata, Dryopteris filix-mas, Galium aparine, Geranium robertianum, Knautia drymeia, Luzula luzuloides, Moehringia trinervia, Mycelis muralis, Picea abies, Poa nemoralis, Sambucus nigra, S. racemosa, Stellaria nemorum, Trifolium montanum, Tussilago farfara, Urtica dioica, etc.
Distribution in Bulgaria. Grey alder forests are of restricted distribution in Rhodopi and Rila Mts.; 700 to 1500 m alt.
Conservation importance. One of the rarest habitats in Bulgaria.
Threats. Irregular and wrongly planned logging, fires, building of infrastructure facilities are among the major threats.
Conservation measures taken. Parts of this habitat type are within the borders of Rila National Park and NATURA 2000 West Rhodopi protected area.
Conservation measures needed. Detailed phytocoenological studies, expansion of the borders of relevant protected areas, termination of logging, mapping and monitoring of this habitat type.
References. Bondev 1991.
Authors: Veska Roussakova, Marius Dimitrov
