Sökning: "trophic effects"

Visar resultat 31 - 35 av 148 avhandlingar innehållade orden trophic effects.

1. 31. Anthropogenic Disturbances and Shifts in Tropical Seagrass Ecosystems

   Författare :Johan S. Eklöf; Nils Kautsky; Patrik Rönnbäck; Teresa Alcoverro; Stockholms universitet; []
   Nyckelord :Aquaculture; feedback mechanisms; Kenya; management; overgrazing; regime shift; resilience; seagrass; seaweed farming; sea urchins; Tanzania; trophic cascades; Zanzibar; NATURAL SCIENCES; NATURVETENSKAP; Marine Ecotoxicology; marin ekotoxikologi;

   Sammanfattning : Seagrasses constitute the basis for diverse and productive ecosystems worldwide. In East Africa, they provide important ecosystem services (e.g. fisheries) but are potentially threatened by increasing resource use and lack of enforced management regulations. LÄS MER

3. 32. 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

4. 33. The fate and effect of pharmaceuticals in boreal surface waters

   Författare :Johan Fahlman; Jonatan Klaminder; Jan Karlsson; Fredrik Jutfelt; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aquatic ecosystems; behavioural effects; ecotoxicology; acoustic telemetry; field verification; social network; ekotoxikologi; Ecotoxicology; environmental science; miljövetenskap;

   Sammanfattning : Traces of pharmaceuticals are often found in streams, rivers, and lakes as the result of effluent water discharge. This dissertation aims to create a better understanding of the fate of drugs in aquatic ecosystems and how oxazepam, an anxiolytic pharmaceutical commonly detected in surface waters, affects the behavior of perch (Perca fluviatilis). LÄS MER

5. 34. Complexity and Change in a Simple Food Web : Studies in the Baltic Sea (FAO Area 27.IIId)

   Författare :Henrik Österblom; Sture Hansson; Robert W Furness; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Avian cholera; Bottom-up; Bycatch; Clupea harengus; Ecosystem; Food web; Gadus morhua; Halichoerus grypus; Regime shift; Sprattus sprattus; Top-down; Trophic cascade; Uria aalge; Marine ecology; Marin ekologi;

   Sammanfattning : An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod Gadus morhua stock in the 1980s, its main prey sprat Sprattus sprattus increased dramatically. LÄS MER

7. 35. Understanding the urban ecosystem : interactions between plants, animals, and people

   Författare :Johan Kjellberg Jensen; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; air pollution; avian physiology; fatty acids; human-nature interactions; nature connection; non-native plants; nutrition; trophic interactions; urban ecology; urbanization; air pollution; avian physiology; fatty acids; human-nature interactions; nature connection; non-native plants; nutrition; trophic interactions; urban ecology; urbanization;

   Sammanfattning : Cities are the pinnacle of human change to the environment, creating unique types of ecosystems which present many challenges to local organisms: habitat fragmentation, introduced species, and various pollutants. Being crucibles of anthropogenic effects, urban ecosystems offer opportunities to understand how humans impact nature. LÄS MER