Diatom communities from alkaline environments of the Brogger peninsula, north-west Spitsbergen

A total of 131 non-marine diatoms is reported from the Bragger Peninsula in Spitsbergen. Most of the diatoms listed are alkaliphilous. A TWINSPAN anal ysis revealed four assemblages. The Navicula atomus var, atomus assemblage was found in a small, fastflowing riverlet and was clearly separated from t he other three assemblages. The second assemblage, i.e. the Caloneis backma nii-Hantzschia amphioxys assemblage, groups all samples originating from ve ry shallow, small pools. The samples contain a considerable number of aerop hilous species. The Achnanthes minutissima var, minutissima-Achnanthes pete rsenii assemblage was taken from larger pools. The last assemblage, i.e. th e Achnanthes petersenii-Fragilaria sp. 1 contains very few species from tem porary shallow brooks, formed by meltwater.