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Visar resultat 1 - 5 av 8 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Summer cyanobacterial blooms in the Baltic Sea - implications for copepod recruitment

   Författare :Hedvig Hogfors; Sture Hansson; Wim Kimmerer; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cyanobacteria; Calanoid copepods; Food web interactions; Harmful algae blooms; Zooplankton; Nodularin; Allelopathy; Baltic Sea; Biochemical markers; RNA-based indices; Acidification; Global Climate Change; Marine Ecology; marin ekologi;

   Sammanfattning : During summer, the Baltic Sea is subjected to the world’s largest cyanobacterial blooms. These blooms are linked to eutrophication and raise many questions concerning their effects on the ecosystem. To understand their impacts on the food web dynamics, it is essential to assess growth responses of grazers to these cyanobacteria. LÄS MER

3. 2. Multiple threat responses in zooplankton - from communities to individuals

   Författare :Mikael Ekvall; Enhet akvatisk ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Most organisms on Earth live a life where they are exposed to multiple and variable threats. In order to maximise survival they need to be able to perceive and respond to these threats. Two common threats that crustacean zooplankton are faced with are predation and ultraviolet radiation (UVR). LÄS MER

4. 3. Uptake and toxicity of brominated flame retardants and pesticides : Studies on littoral organisms and model communities

   Författare :Kerstin Gustafsson; Nils Kautsky; Kirsten Christoffersen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aquatic ecotoxicology; ecological interactions; indirect effects; model community studies; toxicity; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : In this thesis, brackish and freshwater littoral model communities (microcosms) of varying size and complexity were used to study the effects of brominated flame retardants (BFRs) and pesticides. The brackish water microcosms consisted of natural water, sediment and associated organisms, while the larger freshwater microcosms also contained submersed macrophytes (Elodea canadensis). LÄS MER

5. 4. Food web structures and carbon transfer efficiencies in a brackish water ecosystem

   Författare :Kristin Dahlgren; Ulf Båmstedt; Agneta Andersson; Marja Koski; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon transfer efficiency; Food web efficiency; zooplankton; production; pelagic; benthic; fatty acids; wax esters; Marine ecology; Marin ekologi;

   Sammanfattning : Two differently structured food webs can be distinguished in the pelagic habitat of aquatic systems; the classical one (autotrophic) with phytoplankton as a base and the microbial food web (heterotrophic) with bacteria as a base. Energy (produced at the basal trophic level) reaches higher trophic levels, i.e. LÄS MER

7. 5. Ecology of zooplankton communities: climate, dormancy, and benthic-pelagic coupling

   Författare :Mikael Gyllström; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnologi; akvatisk ekologi; limnology; Hydrobiology; marine biology; aquatic ecology; phytoplankton; temporal stability; recruitment; seasonal succession; environmental cues; diapause; shallow lakes; predation; enrichment; climate; temperature;

   Sammanfattning : This thesis describes how influences, such as top down and bottom up forces, shape zooplankton communities in shallow lakes. I have also extended the traditional food-web theory by investigating the effects of climate on total biomass, taxonomic composition, and temporal properties of zooplankton communities. LÄS MER