Ref ID : 3189
P.J. Schroevers; [Hydrobiologische Waarnemingen in Noord-West Overijssel. II. Het Bezinkingsplankton van het Kippenest bij Wanneperveen]. Biol.Jb.Dodonaea:267-342, 1965
Reprint
In File
Notes
This report is the first of a series, dedicated to the broad- and marshland region of N.W.Overijssel in the Netherlands. The samples have been taken from a peat-pit, partly overgrown with a Hydrochareto-Stratiotetum. Methods of sampling and examination are discussed. Chemical data are interpreted as far as possible. The phanerogamic vegetation seems to involve a Phosphorus-deficit by chemical linkage, thus favouring oligotrophic circumstances. Further research is needed. Conclusions have been drawn from the planktonlist with reference to the << biological environment >>, based upon a modified quotient of Nygaard. Pro and contra are discussed. In instable situations the quotient can not be used. The relative relations between Desmids and Bluegreen algae can give information about this problem. According to this analysis, the open water of the << Kippenest >> is eutrophic, with a certain tendency to the mesotrophic type, slightly including towards a pollution, probably due to a periodical moving up of bottom deposits and washing in of organic material from the surrounding, especially excrements of birds. It is necessary in ecological research, based upon qualitative plankton observations, to give an account for species-distinguishment. The variation of the characteristics within the material itself must form the base for this work, apart from the question, whether or not the types are taxonomic species of real value. The account is given. Special attention is drawn towards the genus Scenedesmus, which, with 31 species, is represented very well.