Sökning: "population structure"

Visar resultat 6 - 10 av 733 avhandlingar innehållade orden population structure.

  1. 6. Population ecology and management of waders breeding on coastal meadows

    Författare :Richard Ottvall; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal ecology; Djurekologi; grazing management; population modelling; demography; genetic structure; population decline; Tringa totanus;

    Sammanfattning : Many wader (Charadrii) populations are declining throughout in Europe, but the underlying causes are often poorly known and diverse. To fully grasp the reasons behind declines in vulnerable wader populations, it is crucial to understand the demography. LÄS MER

  3. 7. Molecular population genetics of inducible defense genes in Populus tremula

    Författare :Carolina Bernhardsson; Stefan Jansson; Santiago González-Martinez; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Populus; herbivore defense; adaptation; population genetics; population structure; association mapping; complex traits; evolutionär genetik; evolutionary genetics;

    Sammanfattning : Plant-herbivore interactions are among the most common of ecological interactions. It is therefore not surprising that plants have evolved multiple mechanisms to defend themselves, using both constitutive chemical and physical barriers and by induced responses which are only expressed after herbivory has occurred. LÄS MER

  4. 8. Population size, viability and genetic diversity in the orchid Gymnadenia conopsea

    Författare :Linus Söderquist; Nina Sletvold; Sophie Karrenberg; Hans Jacquemyn; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; demography; extinction probability; genetic diversity; genetic rescue; genetic structure; Gymnadenia conopsea; orchid conservation; population viability; population size; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : In this thesis, I combined controlled crosses with genetic and demographic data to examine how a main conservation value indicator, population size, was associated with estimates of population viability. I focused on the still common, but decreasing, perennial orchid Gymnadenia conopsea at two spatial scales—locally on the island Öland, in SE Sweden, and regionally across Scandinavia. LÄS MER

  5. 9. Effects of size-dependent predation and competition on population and community dynamics

    Författare :Karin Nilsson; Lennart Persson; Volker Rudolf; Umeå universitet; []
    Nyckelord :size-structure; cannibalism; resource competition; predation; emergent facilitation; population regulation; population dynamics; overcompensation; density-dependence; cycles; zooekologi; Animal Ecology;

    Sammanfattning : Most animals grow substantially during their lifetime and change in competitive ability, predatory capacity and their susceptibility to predation as they grow. This thesis addresses the implications of this on regulation and dynamics within populations as well as between population interactions. LÄS MER

  7. 10. Lake bathymetry as driver of salmonid population size structure and biomass

    Författare :Sven Norman; Pär Byström; Karin A. Nilsson; Jan Karlsson; Per-Arne Amundsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake bathymetry; habitat-specific resource production; ontogenetic niche shifts; size structure; Arctic char; brown trout; populationsbiologi; Population Biology; Limnology; limnologi; zooekologi; Animal Ecology;

    Sammanfattning : Most fish species undergo ontogenetic niche shifts from feeding on pelagic zooplankton, to larger benthic invertebrates and in some cases also to fish. These ontogenetic niche shifts have strong impact on the interactions within and between species, with effects on individual growth, population abundance and food web dynamics. LÄS MER