COMPETITIVE EXCLUSION AMONG THREE PLANKTONIC BLUE-GREEN ALGAL SPECIES1,2

摘要: SUMMARY Although domination of 1 species in an algal community has often been attributed to toxic effects, nutrient exhaustion can also lead competitive exclusion among species. The bacteria-associated blue-green algae Microcystis aeruginosa, Nostoc muscorum, and Phormidium foveolarum were cultivated Zehnder-Gorham's medium No. 11 individually their combinations. The growth rates reduced by the presence Phormidium. This detrimental effect was apparently not due formation any or allelopathic matter. It caused reduction iron trace metal concentrations levels too low for normal Nostoc. Work with axenic forms 3 indicated a lowering element sufficient sustained Thus, bacteria played no significant role this example exclusion.