Distribution patterns of Cyclotella trichonidea EC.AM. sensu lato in the plankton succession of the lakes Trichonis and Avrakia, Greece
Economou-Amilli, A.; Tafas, T.
Archiv für Hydrobiologie Volume 147 Number 4 (2000), p. 559 - 575
published: Feb 11, 2000
ArtNo. ESP141014704010, Price: 29.00 €
Individual abundance and biomass data of the diatoms Cyclotella trichonidea EC.-AM. and C. trichonidea var.parva EC.-AM., both thriving in the warm monomictic lakes Trichonis and Amvrakia (central western Greece), allow distribution patterns to be analysed in relation to non-biotic variables. These taxa indicated a triacmic (three-peaked) annual growth pattern (less well-defined in lake Amvrakia), one peak coinciding with the spring phytoplankton bloom, and the other two occurring from the middle to the end of stratification. C. trichonidea seems to be highly dependent upon the availability of P and N, its abundance showing a positive response to higher P concentration values. Although successive decline in nitrate and phosphates seems to regulate the growth of the species C. trichonidea, the smaller-sized variety parva still flourishes and remains the most competitive phytoplankter. Both taxa also seem to tolerate the very low silica concentrations prevailing during stratification, provided that nitrogen and phosphorus are available for their subsequent abundance peaks.