The chrysophycean algae from glacial lakes of Polar Ural (Russia)

In recent years there has been an increasing interest in the biogeography of chrysophytes from the Polar region in Russia (Siver et al. 2005. Voloshko 2007). The Polar Ural represents one of the last true wilderness areas in Europe. Future effects of global climate changes and local anthropogenic disturbances (e.g. coal-mining and gas pipeline building) can be especially significant in the Arctic region. First investigations of chrysophytes in oligotrophic waterbodies showed a relatively diverse and abundant flora, including 45 different taxa from the genera Chrysosphaerella (2), Dinobryon (2), Hydrants ( I), Mallomonas (19), Paraphysomonas (5), Spiniferomonas (6), and Synura (10). Forty-three species are new records for the region and two species are new to Russia (Mallomonas corcontica and Spiniferomonas septispina). Two recently described taxa of Mallomonas (M. striata var. getseniae and M. striata var. balonovii) were found. New records for the rare species M. crassisquama var. papillosa are reported. The most frequently distributed species were Mallomonas alpina, M. striata var. striata, M. akrokomos, Synura petersenii var. petersenii. Spiniferomonas trioralis, Hydrurus foetidus, and Paraphysomonas vestita. Hydrants foetidus forms a continuous cover with an offensive odor on the coastal substrate of mountain streams. The majority of taxa are cosmopolitan and more temperate than arctic in nature. The Sorensen quotient demonstrates a rather low degree of similarity between the floras of the study lakes. Only in 23% of the comparisons was the quotient equal to at least 50%, and in other waterbodies the similarity did not exceed 9-37%. The species composition of chrysophytes in the region shows a rather high similarity with the floras of Bolshezemelskaya tundra (61%) and Finland (51%). These findings extend the knowledge on the geographical distribution of many chrysophyte taxa in cold northern regions. The occurrence and distribution of the flora in relation to some ecological data are discussed.