This study, based within the catchment area of the River Frome, an important chalk stream in the south of England, compared ciliated protozoan communities associated with three species of aquatic macrophyte common to lotic habitats: Ranunculus penicillatus subsp. pseudofluitans, Nasturtium officinale and Sparganium emersum. A total of 77 ciliate species were counted. No species-specific ciliate...

Geographical analysis has shown that Sparganium hyperboreum is most widespread in the forest-tundra and subarctic tundra subzone. In Western Siberia, this species grows low slightly mineralized acidic/neutral/slightly alkaline cool waters with fluctuating water level. It forms both monodominant communities (Sparganietum hyperborei purum association), which it an edificator. southern tundra, S. ...