Sökning: "trophic cascades"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden trophic cascades.

1. 1. 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

3. 2. The spatial and temporal dynamics of plant-animal interactions in the forest herb Actaea spicata

   Författare :Hugo von Zeipel; Johan Ehrlén; Ove Eriksson; Saskya van Nouhuys; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Eupithecia immundata; parasitoid; rodent; seed predation; dispersal; recruitment; multitrophic; metapopulation; trophic cascades; community complexity; Biology; Biologi; Plant Ecology; växtekologi;

   Sammanfattning : Landscape effects on species performance currently receives much attention. Habitat loss and fragmentation are considered major threats to species diversity. Deciduous forests in southern Sweden are previous wooded pastures that have become species-rich communities appearing as islands in agricultural landscapes, varying in species composition. LÄS MER

4. 3. Effects of warming on the ecology of algal-dominated phytobenthic communities in the Baltic Sea

   Författare :Filip Svensson; Pauline Snoeijs; Johan Eklöf; Hans Kautsky; Nils Ekelund; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate change; warming; photosynthesis; trophic cascades; pigments; community traits; temperature gradient; invasive mussel; Marine Ecology; marin ekologi;

   Sammanfattning : Through climate change, the global average air and surface water temperature has risen 0.85°C during the last 100 years. The Baltic Sea experienced one of the most rapid increase in temperature recorded of marine ecosystems. LÄS MER

5. 4. Effects of temperature and terrestrial carbon on primary production in lake ecosystems

   Författare :Mohammed Hamdan; Jan Karlsson; Pär Byström; Erin R. Hotchkiss; Lars-Anders Hansson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lakes; primary production; benthic; pelagic; carbon dioxide limitation; light limitation; nutrient limitation; browning; warming; allochthonous carbon; grazing; trophic cascades;

   Sammanfattning : Climate warming is predicted to affect northern lake food webs in two ways: (1)directly via changes in water temperature and ice conditions, and (2) indirectlyvia changes in catchment characteristics and processes that influence input ofallochthonous coloured dissolved organic matter (cDOM) and nutrients. Input ofcDOM increases carbon dioxide (CO2) availability, causes brownification andreduced light conditions, and may increase nutrient availability especially forpelagic primary producers. LÄS MER

7. 5. Predator-prey interactions in freshwater systems: The importance of chemical communication

   Författare :Kajsa Åbjörnsson; Enhet akvatisk ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi; Hydrobiology; trophic cascades; non-lethal effects; benefits; costs; heredity; predator experience; alarmsubstances; dietary cues; amphibian larvae; invertebrates; visibility; fish; behaviour; Predator-prey; chemical cues;

   Sammanfattning : Predator released chemical cues provide a valuable source of information to prey organisms that can be used to alter their behaviour in order to reduce predation risk. In this thesis, I have examined under what circumstances chemical cues may be used by prey, and if prey discriminate between different cues. LÄS MER