Sökning: "tree mortality"

Visar resultat 1 - 5 av 26 avhandlingar innehållade orden tree mortality.

  1. 1. Embryonic Mortality and Sex Ratios in the Tree Sparrow

    Författare :Magnus Svensson; Jan Ekman; Jacob Höglund; Kathryn Arnold; Uppsala universitet; []
    Nyckelord :Ecology; Hatching success; Embryonic mortality; Sex ratio; Density dependence; Parasites; Ekologi; Passer montanus;

    Sammanfattning : Tree sparrows (Passer montanus) have been studied in two areas in Sweden since 1997. At both sites, tree sparrow eggs had remarkably low hatching success. On average only 60% of the eggs hatched. Analyses have shown that this was caused by embryonic mortality, which was highly sex biased. LÄS MER

  3. 2. The importance of small forest set-asides for saproxylic biodiversity at stand- landscape- and regional scales

    Författare :Mari Therese Jönsson; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; boreal forest; colonization-extinction dynamics; dendrochronology; dead-wood dynamics; disturbance dynamics; forest history; fragmentation; metapopulations; national inventories; old-growth forest; picea abies; saproxylic species; set asides; spatiotemporal dynamics; stand reconstructions; tree mortality; woody debris; wood-decaying fungi; woodland key habitats; Biology; Biologi;

    Sammanfattning : .... LÄS MER

  4. 3. Evolution of Plants : a mathematical perspective

    Författare :Magnus Lindh; Åke Brännström; Jacob Johansson; Mats G Larson; Lennart Persson; Claus Rüffler; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Evolution; plants; mathematics; optimization; optimal control; adaptive dynamics; flowering; seasons; tree crown; drought; taproot; trade-off; strategy; trait; ESS; NPP; LAI; Red Queen; Mathematics; matematik;

    Sammanfattning : The Earth harbors around 300 000 plant species. The rich and complex environment provided by plants is considered a key factor for the extraordinary diversity of the terrestrial fauna by, for example, providing food and shelter. LÄS MER

  5. 4. Game of crops : genetic composition and adaptation of seed orchard crops

    Författare :Alisa Heuchel; Xiao-Ru Wang; David Hall; Ulfstand Wennström; Jaroslaw Burczyk; Umeå universitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; seed orchards; GBS; linear deployment; tree improvement; genetic diversity; adapation; topgrafting; Scots pine; Norway spruce; improved reforestation material; field performance; flowering stimulation; fertility variation; Genetics; genetik; environmental science; miljövetenskap;

    Sammanfattning : Orchard populations are artificial and intensively managed populations of elite, best-performing trees that are established for mass production of genetically improved seeds. Seed orchards connect cycles of selection, breeding, and testing of plus-trees with the deployment of the improved seeds at the operational plantations. LÄS MER

  7. 5. Occurrence and pathogenicity of tree-pathogenic fungi vectored by bark beetles

    Författare :Kateryna Davydenko; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Fungal pathogens associated with bark beetles represent one of the most significant problems to forest health. Among these fungi, ophiostomatoid group are known to be most commonly associated with bark beetles. LÄS MER