Sökning: "trophic effects"
Visar resultat 16 - 20 av 137 avhandlingar innehållade orden trophic effects.
Sammanfattning : Background: There is no cure for paralysis. The only drug therapy presently in use, acute high-dose methylprednisolone, has only modest effects on outcome. There is therefore a great need for new therapies. LÄS MER
Sammanfattning : In this thesis I have investigated the effects of pesticide exposure on the ecosystem level using various types of experimental ecosystems, i.e. microcosms. The direct effect of exposure to cyperemthrin, a pyretroid insecticide, was a rapid decrease of crustancean zooplankton in enclosures in a lake. LÄS MER
Sammanfattning : Large carnivores affect prey species, with cascading effects on entire ecosystems. In anthropogenic regions large carnivores come into conflicts with humans, especially in rural areas where farming and hunting traditions are widespread. As a result, large carnivores have been eradicated from many regions across their historical distribution. LÄS MER
19. The Invasion of the Zebra Mussel - Effects on Phytoplankton Community Structure and Ecosystem Function
Sammanfattning : Biological invasion has become a major threat to economy, ecology, global biodiversity and ecosystem function of aquatic ecosystems. The main aim of the thesis was to study the effects of the zebra mussel (Dreissena polymorpha), a versatile invasive species, on phytoplankton dynamics and ecosystem function of lakes. LÄS MER
Sammanfattning : The flagellate Gonyostomum semen forms dense late-summer blooms in humic lakes and is a nuisance to swimmers because it forms a slimy coat on the skin, causing irritation in sensitive individuals. Increasing occurrence and bloom incidence of G. LÄS MER