Sökning: "food-webs"

Visar resultat 11 - 15 av 110 avhandlingar innehållade ordet food-webs.

1. 11. Species interactions and energy transfer in aquatic food webs

   Författare :Jens Munk Nielsen; Monika Winder; Sture Hansson; Michael T. Brett; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aquatic food webs; zooplankton; stable isotope analysis amino acids; molecular diet analysis; Marine Ecology; marin ekologi;

   Sammanfattning : Food webs are structured by intricate nodes of species interactions which govern the flow of organic matter in natural systems. Despite being long recognized as a key component in ecology, estimation of food web functioning is still challenging due to the difficulty in accurately measuring species interactions within a food web. LÄS MER

3. 12. Direct and indirect effects of fish predation and excretion in aquatic food webs

   Författare :José Luiz Attayde; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; Hydrobiology; zooplankton; resilience; predation; phytoplankton; nutrient enrichment; nutrient recycling; interaction strength; herbivory; food webs; food chain; excretion; fish; detritus; detritivory; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

   Sammanfattning : The aim of this thesis was to elucidate the mechanisms by which planktivorous fish can affect planktonic communities in lakes and how they may affect benthic communities through their effects on planktonic communities. In a laboratory experiment, nutrients released by fish increased algal biomass and altered phytoplankton community structure, suggesting that fish can affect phytoplankton by directly releasing nutrients. LÄS MER

4. 13. The Spider and the Sea : Effects of marine subsidies on the role of spiders in terrestrial food webs

   Författare :Kajsa Mellbrand; Peter Hambäck; Lena Kautsky; David Wise; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marine subsidies; food webs; stable isotopes; shore ecosystems; predators; spiders; Pardosa; algae; emerging insects; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Plant Ecology; växtekologi;

   Sammanfattning : The purpose of this study was to identify if terrestrial arthropod predators on Baltic Sea shores vary in their use of marine versus terrestrial food items, and to construct a bottom-up food web for Baltic Sea shores. The inflow of marine nutrients in the area consists mainly of marine algal detritus and emerging aquatic insects (e.g. LÄS MER

5. 14. Methylmercury in boreal freshwater food webs

   Författare :Pianpian Wu; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Mercury (Hg) and bioaccumulation of its organic form methylmercury (MeHg) has long been regarded as a global issue for human and wildlife health. This is of particular concern for Sweden, where forest harvests and wetlands remain hotspots of MeHg export to boreal freshwaters. LÄS MER

7. 15. Productivity and carbon transfer in pelagic food webs in response to carbon, nutrients and light

   Författare :Carolyn Faithfull; Ann-Kristin Bergström; Tobias Vrede; Kathryn Cottingham; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bacterial production; phytoplankton production; mesocosms; food webs; carbon; nutrients; light; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; limnologi; Limnology;

   Sammanfattning : Some of the major problems we face today are human induced changes to the nitrogen (N), phosphorus (P) and carbon (C) cycles. Predicted increases in rainfall and temperature due to climate change, may also increase dissolved organic matter (DOM) inflows to freshwater ecosystems in the boreal zone. LÄS MER