Sökning: "Betula spp."

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Betula spp..

  1. 1. 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

  3. 2. Greenhouse Gas Fluxes and Carbon Sequestration in Young Norway Spruce Stands : The Effects of Fertilization

    Författare :Charlotta Håkansson; Johan Bergh; Per-Ola Hedwall; Monika Strömgren; Anna M. Jensen; Tomas Lundmark; Tobias Rütting; Linnéuniversitetet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; carbon balance; young mixed forests; Picea abies L. Karst. ; Betula spp; chamber measurements; forest floor greenhouse gas fluxes; eddy-flux technology; above ground biomass; carbon dioxide; methane; nitrous oxide; kolbalans; ung blandskog; Picea abies L. Karst. ; Betula spp; kammarmätningar; markflöden av växthusgaser; eddy-fluxteknik; biomassa ovan jord; koldioxid; metan; lustgas; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : The enormous challenge of climate change is discussed and debated today because of its major impact on life on Earth. The forests have an important role to play as the plants absorb carbon dioxide (CO2) from the atmosphere through their photosynthesis and the growing tree retain carbon (C). LÄS MER

  4. 3. Birch Stem and Wood Traits in Genetic and Silviculture Trials in Southern Sweden

    Författare :Grace Jones; Stergios Adamopoulos; Mateusz Liziniewicz; Mikael Andersson; Sheikh Ali Ahmed; Erkki Verkasalo; Linnéuniversitetet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; acoustic velocity; Betula spp.; dynamic MOE; genetic parameters; grain angle; hardwood; Itrax densitometry; mixed forests; non-destructive testing; stem form; akustisk velocitet; Betula spp.; blandskog; densitometri; genetiska parametrar; icke destruktiva metoder; Itrax; lövträ; skogsodling; stamkvalitet; vedsegenskaper; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : Swedish tree species of birch (silver: Betula pendula and downy: B. pubescens) are often neglected during forest management activities, resulting in low value logs. This thesis investigated birch stem characteristics and wood properties important for solid wood products, in genetics and management trials in southern Sweden. LÄS MER

  5. 4. Population dynamics of birch (Betula spp.) and coexisting tree species in relation to the environment

    Författare :Theo Verwijst; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  7. 5. Dieback of Fraxinus excelsior in the Baltic Sea Region : associated fungi, their pathogenicity and implications for silviculture

    Författare :Remigijus Bakys; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : This thesis is comprised of three main studies: (1) the wood-inhabiting fungi found in declining European ash (Fraxinus excelsior L.) and their pathogenicity; (2) the relationship between F. excelsior phenology, site density and the susceptibility to the dieback; and (3) the potential of natural regeneration of dieback affected ash stands. LÄS MER