The role of the environmental factors in controlling chrysophyte species distribution and biomass structure in Finnish Lapland subarctic lakes

Chrysophytes (Chrysophyceae and Synurophyceae) are known to prefer oligotrophic conditions and are one of the main algal groups characteristic to arctic and subarctic lakes. The chrysophyte flora, along with basic physical and chemical lake water properties from 33 lakes in Finnish Lapland was studied in autumn 2000. The total phytoplankton biomass was dominated by chrysophytes in 15 lakes. Altogether 47 chrysophyte taxa were found, most common taxa being Pseudopedinella sp., Bitrichia chodatii, Dinobryon crenulatum and Uroglena sp. The role of environmental factors in controlling the chrysophyte species distribution was studied using canonical correspondence analysis. SiO2, pH and altitude were shown to be statistically the most significant environmental variables in explaining the distributional patterns.