Sökning: "Trophic interactions"

Visar resultat 31 - 35 av 89 avhandlingar innehållade orden Trophic interactions.

1. 31. Determining food web transfer of radionuclides in marine benthic ecosystems

   Författare :Isak Holmerin; Clare Bradshaw; Nicholas Fisher; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; trophic transfer; radionuclides; benthic; ecosystem approach; Baltic Sea; Fukushima; Marine Ecotoxicology; marin ekotoxikologi;

   Sammanfattning : Food web interactions are vital in any functioning ecosystem and facilitate transfer of energy and nutrients between trophic levels. Unfortunately, they also facilitate transfer of contaminants such as anthropogenic radionuclides found in effluents from nuclear power plants (NPPs). LÄS MER

3. 32. Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective

   Författare :Melanie Hedgespeth; Enhet akvatisk ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ecotoxicology; aquatic; trophic level; pharmaceutical; SSRI; beta-blocker; sertraline; fluoxetine; propranolol; fish; daphnia; snail; predator; prey; behavior; life history; multiple stressor;

   Sammanfattning : Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. LÄS MER

4. 33. Ontogenetic bottlenecks : effects on intraguild predation systems and ecosystem efficiency

   Författare :Birte Reichstein; Lennart Persson; André M. De Roos; Priyanga Amarasekare; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mixed interactions; cannibalism; life-history omnivory; ontogenetic niche shift; biomass overcompensation; biomass production; ontogenetic asymmetry; indirect effects; biology; biologi; zooekologi; Animal Ecology;

   Sammanfattning : Size-dependent differences between individuals in size-structured organisms have fundamental effect on population and community dynamics. Intraguild predation (IGP) is one specifically interesting constellation that often arises when two size-structured populations interact. LÄS MER

5. 34. Role of ecological processes in determining effects of contaminants in aquatic ecosystems

   Författare :Anna-Lea Golz; Clare Bradshaw; Karen Kidd; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ecosystem approach; ionizing radiation; HBCDD; microcosm; species interactions; indirect effects; marin ekotoxikologi; Marine Ecotoxicology;

   Sammanfattning : Aquatic ecosystems cover approximately 70% of the Earth’s surface and support a wide range of ecosystem services. Despite their importance, aquatic ecosystems are increasingly exposed to anthropogenic stressors, such as contaminants and climate change impacts. LÄS MER

7. 35. Persistent organic pollutants in benthic foodwebs

   Författare :Niklas Holmqvist; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; Intraspecific interactions; streams; nutrients; lakes; crayfish; eels; Persistent organic pollutants; Benthic foodwebs; akvatisk ekologi; Environmental chemistry; Miljökemi;

   Sammanfattning : Concentrations of persistent organic pollutants (POPs) in aquatic biota are dependent on several factors both on individual and on system level. Bioaccumulation of POPs in pelagic biota in lakes as well as fish in streams has been shown to be dependent on nutrient regime of the system. LÄS MER