Freshwater and terrestrial moss diatom assemblages of the Cambridge Bay area, Victoria Island (Nunavut, Canada)

A total of 226 freshwater diatoms is reported from the Cambridge Bay area. (Victoria Island, Nunavut). The diatom flora of this area is mostly characterised by alkaliphilous genera, such as Cymbella. Due to the Low Arctic location of the sampling area, cosmopolitan diatom taxa dominate the flora while typical Arctic taxa play only a subdominant role. Ordination analysis revealed the presence of three different assemblages. The Nitzschia amphibia - Nitzschia fossilis assemblage is clearly separated from the other two assemblages and seems to be typical of terrestrial mosses. The samples of this assemblage reflect different stages in the drying process of the terrestrial moss vegetation. The remaining two assemblages are recorded from aquatic environments with the Achnanthes petersenii - Cymbella arctica assemblage present in slightly alkaline running waters and the Pinnularia balfouriana - Diatoma tenuis assemblage found in standing water bodies.