Sökning: "B. pubescens"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden B. pubescens.

  1. 1. Mosses as mediators of climate change : implications for tree seedling establishment in the tundra

    Författare :Signe Lett; Ellen Dorrepaal; David Wardle; Marie-Charlotte Nilsson; Vigdis Vandvik; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; arctic; alpine; B. pubescens; bryophytes; competition; facilitation; mosses; P. sylvestris; precipitation changes; seedlings; traits; tree line; warming;

    Sammanfattning : Alpine and arctic tree line expansion depends on the establishment of tree seedlings above the current tree line, which is expected to occur with climate warming. However, tree lines often fail to respond to higher temperatures. Other environmental factors are therefore likely important for tree seedling establishment. LÄS MER

  3. 2. Structural Growth in Mountain Birch, Betula pubescens ssp. czerepanovii

    Författare :Christina Borg; Brita Svensson; Staffan Karlsson; Seppo Neuvonen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : In this thesis, I have studied long shoot performance in the monoecious, deciduous tree Betula pubescens ssp. czerepanovii. LÄS MER

  4. 3. Reproductive patterns of birches (Betula spp.) in northern Sweden

    Författare :Stig-Olov Holm; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reproduction; Betula; seed-quality; seed-set; pollination; pollen-limitation; pollen-competition; tree-line; environmental gradient; seed weight; seedling survival; Semudobia;

    Sammanfattning : The aim of this thesis was to study patterns of reproduction of Betula pendula and B. pubescens coll. along an altitudinal, coastal-inland, gradient in northern Sweden. The altitudinal variation was related to the distribution of the birch taxa along the gradient. LÄS MER

  5. 4. Applications of visible and near infrared spectroscopy for sorting and identification of tree seeds

    Författare :Mostafa Farhadi; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Seeds are the most commonly used regeneration material for reforestation purpose; hence interest in “precision sowing” among nurseries is high due to the high cost of containerized seedling production. In addition, the increased interest in growing hybrid larch in commercial forestry has raised concerns about the purity of hybrid larch seed lots, as there are large proportions of pure parental seeds mixed with hybrid larch seed lots. LÄS MER

  7. 5. Impact of tree species on carbon in forest soils

    Författare :Karna Hansson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Different tree species differ in productivity, litter quality and quantity, canopy structure and nitrogen deposition. Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and birch (Betula pendula and B. pubescens) are the three dominant tree species in Sweden. LÄS MER