In freshwater model ecosystems nutrient additions resulted in significant short-term increases in periphyton biomass. Effects of applications of both nutrients and the insecticide chlorpyrifos caused a larger and more prolonged increase in periphytic algae. After three to four weeks this bloom of periphytic algae was controlled by non-arthropod grazers, which increased in numbers after insecticide application. The study indicates that the top-down control of periphyton by grazers is an important regulatory mechanism in macrophyte-dominated aquatic ecosystems. Insecticides, by poisoning arthropod grazers, may indirectly stimulate periphytic algae, as long as resources and non-arthropod grazers permit this.
|Journal||Archiv für Hydrobiologie|
|Publication status||Published - 1995|
Brock, T. C. M., Roijackers, R. M. M., Rollon, R., Bransen, F., & van der Heyden, L. (1995). Effects of nutrient loading and insecticide application on the ecology of Elodea-dominated freshwater microcosms. II. Responses of macrophytes, periphyton and macroinvertebrate grazers. Archiv für Hydrobiologie, 134, 53-74.