Sökning: "increased grazing pressure"

Visar resultat 6 - 10 av 20 avhandlingar innehållade orden increased grazing pressure.

  1. 6. Uptake and toxicity of brominated flame retardants and pesticides : Studies on littoral organisms and model communities

    Författare :Kerstin Gustafsson; Nils Kautsky; Kirsten Christoffersen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aquatic ecotoxicology; ecological interactions; indirect effects; model community studies; toxicity; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : In this thesis, brackish and freshwater littoral model communities (microcosms) of varying size and complexity were used to study the effects of brominated flame retardants (BFRs) and pesticides. The brackish water microcosms consisted of natural water, sediment and associated organisms, while the larger freshwater microcosms also contained submersed macrophytes (Elodea canadensis). LÄS MER

  3. 7. Benthic cryptofauna and internal bioeroders on coral reefs

    Författare :Helena Strömberg; Charlotta Kvarnemo; Pat Hutchings; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bioerosion; cryptofauna; coral; invertebrates; damselfish; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : The cryptofauna of coral reefs may act as a food source for fish, while being grazers or predators themselves, and hence constitute an important group in the coral reef food web. In addition, the actively eroding taxa of the cryptofauna contribute to the decomposition and recirculation of calcium carbonate and are consequently essential for the rebuilding new coral. LÄS MER

  4. 8. Holocene Environmental Change of Southern Öland, Sweden

    Författare :Kerstin Alm Kübler; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Pollen analysis; Öland; Sweden; heath vegetation; landscape history; Fagus; beach ridges; numerical analysis; Geovetenskap; Earth sciences; Geovetenskap; Quarternary Geology; kvartärgeologi;

    Sammanfattning : This thesis describes Holocene environmental change in Ottenby, southern Öland,Sweden. Analyses of pollen sequences collected distally in the Littorina ridge and in fentroughs between lower laying beach ridges show the vegetation history during twoperiods, the first around 8000 BP and the second from 0/500 AD to about present time. LÄS MER

  5. 9. Interactions between ungulates and forest insects

    Författare :Michelle Nordkvist; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In forest ecosystems ungulates and insect herbivores often co-occur and utilise the same host trees. Herbivores that share a host plant can indirectly affect each other through plant induced responses. Such changes may affect plant growth, interactions with other species, and population dynamics. LÄS MER

  7. 10. A Phytoplankton Invasion: Population Genetics, Phylogeography, and Invasion Success of Gonyostomum semen

    Författare :Karen Lebret; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : nvasive species is a major threat to ecosystems and biodiversity. Invasions by macroorganisms have been intensively studied, but little is known concerning microbial invasions. In aquatic environments, phytoplankton, i.e. LÄS MER