Sökning: "träd"

Visar resultat 21 - 25 av 129 avhandlingar innehållade ordet träd.

  1. 21. Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization

    Författare :Nils Fagerberg; Johan Bergh; Peter Lohmander; Stergios Adamopoulos; Hubert Hasenauer; Linnéuniversitetet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; continuous cover forestry; selective cutting; Picea abies; uneven-aged; single-tree-selection; growth model; knot size model; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : Individual-tree-selection (ITS) is a continuous cover forestry method that aims to utilize the uneven-sized stand structure through optimized individual tree selections. ITS is an interesting management alternative to rotation forestry in terms of production of multiple benefits and forest owner profitability. LÄS MER

  3. 22. Metapopulation ecology of Osmoderma eremita - dispersal, habitat quality and habitat history

    Författare :Jonas Hedin; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; extinction debt; habitat history; habitat quality; pheromone; telemetry; capture-mark-recapture; metapopulation; dispersal; oak; Osmoderma eremita; beetle; Animal ecology; Djurekologi;

    Sammanfattning : This thesis starts with a review of different biodiversity assessment methods in forests and the rest deals with the metapopulation ecology of Osmoderma eremita, a threatened beetle living in hollow trees. I concentrate on the effect of dispersal, habitat quality and habitat history for the presence, population size and future survival of this species. LÄS MER

  4. 23. 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. 24. Phytophthora and Oak Decline - Impact on Seedlings and Mature Trees in Forest Soils

    Författare :Ulrika Jönsson Belyazid; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; microbial competition; carbon allocation; nutrients; water availability; soil chemistry; mature oaks; seedlings; acid soils; Phytophthora quercina; Quercus robur;

    Sammanfattning : This thesis investigated the occurrence of soilborne species of the plant pathogenic genus Phytophthora in southern Swedish oak forests and their possible involvement in southern Swedish oak decline. The emphasis was on the impact of P. quercina on Quercus robur in acid forest soils. LÄS MER

  7. 25. Tree phenology modelling in the boreal and temperate climate zones : Timing of spring and autumn events

    Författare :Cecilia Olsson; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Plant phenology in the boreal and temperate climate zones is synchronised with seasonal changes in temperature and photoperiod. For deciduous trees, timing of budburst and leaf colouring define the growing season length and express adaptations to trade-offs in growth and risks. LÄS MER