Avancerad sökning

Visar resultat 1 - 5 av 89 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Trophic interactions and behaviour : Studies relevant to a Baltic Sea biomanipulation

   Författare :Per B. Holliland; Sture Hansson; Elena Gorokhova; Peter Tiselius; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; zooplankton; non-indigenous species; selectivity; food web; rearing environment; fish stocking; Sander lucioperca; diel vertical migration; ontogeny; ovigerous; Marine Ecology; marin ekologi;

   Sammanfattning : The main theme of this thesis is the interactions of animals with the environment and each other. The thesis was written within the framework of a biomanipulation project “Pikeperch in Himmerfjärden”. LÄS MER

3. 2. The effects of crayfish on interactions in freshwater benthic communities

   Författare :Per Nyström; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; exotic species; trophic cascades; omnivory; crayfish; Trophic interactions; freshwater; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

   Sammanfattning : This thesis examines how freshwater crayfish affect community interactions in benthic food webs. I have mainly studied the influence of the introduced signal crayfish (Pacifastacus leniusculus) on littoral communities, but also the influence of the native noble crayfish (Astacus astacus). LÄS MER

4. 3. 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

5. 4. The role of young-of-the-year fish in lake ecosystems

   Författare :Pia Romare; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; Rutilus rutilus; Perca fluviatilis; diet-dependent growth; density dependent growth; behavioural cascade; 0 fish behaviour; horizontal echo sounding; biomanipulation; trophic cascade; predation pressure; young-of-the-year fish; trophic interactions; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

   Sammanfattning : Food chain theory is based on consumption; that is, presupposing that the only important interaction between organisms is that they actually meet in an unstructured environment and that one of them is consumed. Recently, studies, including biomanipulation projects, have indicated that trophic interactions are more complex than predicted by food chain theory. LÄS MER

7. 5. Nutrient Stoichiometry in Benthic Food Webs – Interactions Between Algae, Herbivores and Fish

   Författare :Antonia Liess; Peter Eklöv; Dag Hessen; Uppsala universitet; []
   Nyckelord :Ecology; ecologial stoichiometry; periphyton; grazer; benthos; trophic interactions; nutrient; algae; Ekologi;

   Sammanfattning : The aim of this thesis was to identify general structuring mechanisms in benthic food webs within the framework of ecological stoichiometry theory. Ecological stoichiometry is defined as the balance of multiple chemical substances in ecological interactions and explicitly considers the combined dynamics of key elements such as carbon (C), nitrogen (N) and phosphorus (P). LÄS MER