• Medientyp: E-Artikel
  • Titel: Plankton and Water Chemistry in the Montreal River Lake-Stream System, Saskatchewan
  • Beteiligte: Cushing,, Colbert E.
  • Erschienen: Duke University Press, 1964
  • Erschienen in: Ecology, 45 (1964) 2, Seite 306-313
  • Sprache: Englisch
  • ISSN: 0012-9658; 1939-9170
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  • Beschreibung: The relations between dissolved solids, water exchange, and productivity were studied in a lake-stream system. Detached epilithic algae composed the plankton of the upper stream, but all other stations displayed a lentic plankton. Turbidity and unsuitable substrate prevented the development of sessile algae on the bottom of the slow-flowing river sections (lakes), but the macrophytes provided a surface for the development of these communities. The concentrations of total dissolved solids and those ions essential for photosynthesis and phyto- and zooplankton numbers. The different rates of the decrease of these nutrients in the upper stream and lake-stream section and probably related to the greater populations of the upper stream and lake-steam section are probably related to the greater populations of autotrophic biota in the latter section. Assuming that nutrients are being added to the system through its course, then the downstream decrease indicates that the increasingly large autotrophic populations are assimilating these nutrients at a rate greater than they are being added. Thus, the deciding factor regulating the accumulation or removal of dissolved nutrients in a lake-stream system appears to be the degree of autotrophic enrichment of the system.