Phytosociological survey of remnant Alnus glutinosa ssp. barbata communities in the lowland Caspian forests of northern Iran
Hamzeh'ee, Behnam; Naqinezhad, Alireza; Attar, Farideh; Ghahreman, Ahmad; Assadi, Mostafa; Prieditis, Normunds
The lowland forest zone, one of the altitudinal zones of Hyrcanian (Caspian) forests in the north of Iran, is characterized by small fragmented remnant alderwoods, dominated or subdominated by Alnus glutinosa ssp. barbata - an Euxino-Hyrcanian element. Relevés from this conservationally important vegetation have been classified by Analyse Factorielle des Correspondance (AFC) and Classification Ascendant Hierarchique (CAH) using ANAPHYTO software and synsystematically treated following the Braun-Blanquet approach. The 89 relevés collected belong to six associations and three subassociations: Galio elongatae-Alnetum barbatae, Ulmo minoris-Alnetum barbatae, Carici acutiformis-Alnetum barbatae, Populo caspicae-Alnetum barbatae, Pterocaryo fraxinifoliae-Alnetum barbatae and Pterido dentatae-Alnetum barbatae (with three subassociations: subass. typicum, subass. buxetosum, subass. ilicetosum). These associations were considered in a new alliance, Smilaco excelsae-Alnion barbatae and an order, Alnetalia subcordatae that includes the wet or alluvial alder forests of the Hyrcanian area. A regional comparison between this new alliance and other described Euxino-Hyrcanian alliances has been summarized in a synoptic table.