Sökning: "biologiska faktorer"

Visar resultat 1 - 5 av 138 avhandlingar innehållade orden biologiska faktorer.

  1. 1. Natural enemies: Functional aspects of local management in agricultural landscapes

    Författare :Helena Hanson; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Agricultural intensification; sustainable agriculture; land use; management intensity; landscape scale; ecosystem services; biological control; species trait; pesticides; predatory arthropods; parasitoids; pollen beetles;

    Sammanfattning : Agricultural intensification has raised the global food production but also caused major concerns about environmental and health effects, including contamination by pesticides. Pesticide applications may induce toxicity not only on the target pest species but especially on non-target species. LÄS MER

  3. 2. Biodiversity in Agricultural Landscapes: Landscape and Scale-Dependent Effects of Organic Farming

    Författare :Maj Rundlöf; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Djurekologi; Natural science; Naturvetenskap; Ekologi; Animal ecology; plants; spatial scales; species richness; Ecology; landscape ecology; agri-environment schemes; farming practice; conservation; butterflies; bumble bees;

    Sammanfattning : Declines in the distribution and abundance of many farmland species during recent decades have been attributed to agricultural intensification. Agri-environment schemes are commonly used in Europe to reduce this loss of farmland biodiversity, but their effectiveness may depend on several external factors. LÄS MER

  4. 3. Tillage practices and their impact on soil organic carbon and the microbial community

    Författare :Sofia Hydbom; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tillage; Agriculture; Long-term field experiment; Microorganism; Clayey soil; Soil organic carbon; Farmer; Sweden;

    Sammanfattning : Soil microorganisms are important for climate regulation as well as for plant nutrition. In agricultural soils the microorganisms are affected by management choices, like which type of tillage that is used. LÄS MER

  5. 4. Intraspecific variation in Rhinanthus angustifolius. Local adaptation, phenotypic plasticity and geographical structure

    Författare :Anneli Jonstrup; Biodiversitet; []
    Nyckelord :Ecotype; Local adaptation; Phenotypic plasticity; Parallel evolution; Geographical structure; Hemiparasite; Rhinanthus;

    Sammanfattning : Plant species often adapt to local environmental conditions, which can result in the formation of genetically and phenotypically distinct ecotypes. Ecotypes can evolve rapidly, and may be a first step in the process of ecological speciation. LÄS MER

  7. 5. The MHC genes: variation and impact on life-history traits in house sparrwos

    Författare :Maria Karlsson; MEMEG; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MHC-I; house sparrow; 454-amplicon sequencing; cDNA; functional clustering; trans-species evolution; nestling survival; mate-choice;

    Sammanfattning : In birds the major histocompatibility complex (MHC) organization differs both among and within orders. Galliformes often have simple arrangements with few transcribed MHC genes whilst many songbirds (Passeriformes) have a complex arrangement with many MHC genes and also presence of pseudo-genes. LÄS MER