Picea abies- and Fraxinus excelsior-dominated wetland forest communities in Latvia

This paper reports on the syntaxonomical structure, the ecological, physiognomical and phytogeographical differentiation of wetland forests in Latvia dominated by Picea abies and Fraxinus excelsior. Data were collected following the Braun-Blanquet approach and treated by the GROUPAGE, TWINSPAN and CANOCO programs. Spruce forests (Sphagno girgensohnii-Piceetum var. Crepis paludosa, S.g.-P. myrtilletosum) form a well-defined community mostly in shallow and medium deep (0.2–1.3 m) peatland. Assemblages of spruce wetlands in NEE Europe point to amazing similarity and little variation from NE Poland and Fennoscandia over the Baltic States to the central parts of Russia. Ash-dominated wetlands (Carici elongatae-Alnetum, Carici remotae-Fraxinetum) refer only to particular localities of the country and lie on wet mineral, gleyey soils, usually along brooks and on undulating ground rich in subsoil streams, mostly in sites without an evident accumulation of peat. In Latvia, these reach the northernmost limit of distribution and are poorer in species compared with the ash wetlands of Central Europe.