Search for dissertations about: "Local extinction"

Showing result 1 - 5 of 49 swedish dissertations containing the words Local extinction.

  1. 1. Species extinctions in food webs : local and regional processes

    Author : Anna Eklöf; Bo Ebenman; Peter Münger; Marcel Holyoak; Linköpings universitet; []
    Keywords : Extinction; food web; metacommunity; dispersal; species loss; migration; habitat fragmentation; connectance; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : Loss of biodiversity is one of the most severe threats to the ecosystems of the world. The major causes behind the high population and species extinction rates are anthropogenic activities such as overharvesting of natural populations, pollution, climate change and destruction and fragmentation of natural habitats. READ MORE

  2. 2. Cascading extinctions in food webs : local and regional processes

    Author : Anna Eklöf; Linköpings universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Cascading extinctions; complexity; connectance; dispersal; food web; local dynamics; regional dynamics; resistance; spatial structure; species loss;

    Abstract : Ecological communities all over the world are loosing biodiversity due to different kinds of human activities and there is an urgent need of understanding how those losses affect the function of the ecosystems on which we all depend. The community's response to species losses is likely to depend on both the structure of the local community as well as its interactions with surrounding communities. READ MORE

  3. 3. Investigating genetic factors behind the decline of a threatened plant species – Tephroseris integrifolia (Asteraceae)

    Author : Kerstin Isaksson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantitative genetics.; AFLP; local genetic variation; relict populations; fragmentation; small populations; sporophytic self-incompatibility; extinction; threatened species; Inbreeding depression; population structure;

    Abstract : Landscape change in Europe has caused the decline of many grassland species. Tephroseris integrifolia (Asteraceae) is one species which has declined rapidly in Sweden since the 19th century. READ MORE

  4. 4. Dynamics of ecological communities in variable environments : local and spatial processes

    Author : Linda Kaneryd; Bo Ebenman; Peter Münger; Michael S. Fowler; Linköpings universitet; []
    Keywords : ;

    Abstract : The ecosystems of the world are currently facing a variety of anthropogenic perturbations, such as climate change, fragmentation and destruction of habitat, overexploitation of natural resources and invasions of alien species. How the ecosystems will be affected is not only dependent on the direct effects of the perturbations on individual species but also on the trophic structure and interaction patterns of the ecological community. READ MORE

  5. 5. Extragalactic extinction and spectral properties of Type Ia supernovae

    Author : Linda Östman; Ariel Goobar; Avishay Gal-Yam; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Type Ia supernovae; cosmology; spectroscopy; dust extinction; quasars; axions; Physics; Fysik; fysik; Physics;

    Abstract : The use of Type Ia supernovae as standardisable candles for probing cosmological parameters with high precision requires good knowledge about how the supernova light is affected along the line of sight and how the intrinsic brightness varies between objects. The work in this thesis addresses these topics. READ MORE