Sökning: "Marine ecosystem"

Visar resultat 6 - 10 av 154 avhandlingar innehållade orden Marine ecosystem.

  1. 6. Marine nitrogen fixation : Cyanobacterial nitrogen fixation and the fate of new nitrogen in the Baltic Sea

    Författare :Isabell Klawonn; Helle Ploug; Lasse Riemann; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biogeochemistry; nitrogen cycling; nitrogen fixation; cyanobacteria; Baltic Sea; Marine Ecology; marin ekologi;

    Sammanfattning : Biogeochemical processes in the marine biosphere are important in global element cycling and greatly influence the gas composition of the Earth’s atmosphere. The nitrogen cycle is a key component of marine biogeochemical cycles. LÄS MER

  3. 7. Global trade, food production and ecosystem support : Making the interactions visible

    Författare :Lisa Deutsch; Carl Folke; Karin Limburg; Max Troell; David Waltner-Toews; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; global trade; food production; ecosystem support; resilience; agriculture; ecosystem performance; food consumption; ecological footprint; indicators; aquaculture; agricultural intensification; fishmeal; vulnerability; Sweden; animal feed; critical natural capital; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : Modern food production is a complex, globalized system in which what we eat and how it is produced are increasingly disconnected. This thesis examines some of the ways in which global trade has changed the mix of inputs to food and feed, and how this affects food security and our perceptions of sustainability. LÄS MER

  4. 8. Radionuclides in the Baltic Sea : Ecosystem models and experiments on transport and fate

    Författare :Linda Kumblad; Nils Kautsky; Ulrik Kautsky; Michael Gilek; Michael Thorne; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; radionuclide; baltic sea; ecosystem model; ecosystem dynamics; risk assessment; safety assessment; benthic invertebrates; bioturbation; bioaccumulation; remobilisation; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : Manmade radionuclides have been introduced to the environment for almost a century. The main source has been the nuclear weapons testing programmes, but accidental releases from the nuclear power production industries have also contributed. The risk to humans from potential releases from nuclear facilities is evaluated in safety assessments. LÄS MER

  5. 9. Aquatic vegetation in coastal ecosystems : The role of biotic interactions and environmental change for ecosystem functions and resilience in the Baltic Sea

    Författare :Åsa Austin; Johan S. Eklöf; Joakim P. Hansen; Serena Donadi; Matthew E. S. Bracken; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biodiversity; ecosystem functions; ecosystem multifunctionality; water clarity; fish recruitment; functional traits; feedbacks; biotic interactions; competition; facilitation; foundation species; seagrass; macrophytes; lagoons; brackish water; Baltic Sea; marin ekologi; Marine Ecology;

    Sammanfattning : Coastal ecosystems are among the most productive on Earth but subjected to many human pressures. In shallow coastal areas, aquatic vegetation constitutes foundation species that sustain secondary production and act as a nutrient filter, which may buffer human impacts. LÄS MER

  7. 10. Seabirds as food for thought : An integrative study on seabird ecology and ecosystem services in changing marine systems

    Författare :Martina Kadin; Thorsten Blenckner; Morten Frederiksen; Olof Olsson; Johan Elmberg; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; seabirds; ecosystem services; social-ecological systems; marine systems; fisheries; foraging ecology; provisioning behaviour; common murre; common guillemot; Uria aalge; Stora Karlsö; Baltic Sea; naturresurshushållning; Natural Resources Management;

    Sammanfattning : The importance of the benefits that humans obtain from the oceans is increasingly recognized, along with the rapid decline in marine resources that threatens these benefits. Studying seabirds – top predators in marine ecosystems, can provide insights about multiple pressures and the state of the oceans. LÄS MER