Search for dissertations about: "betula"

Showing result 1 - 5 of 78 swedish dissertations containing the word betula.

  2. 1. Reproductive patterns of birches (Betula spp.) in northern Sweden

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

    Abstract : 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. READ MORE

  4. 2. Juvenile birch in Sweden : Selected stem characteristics for interior and furniture applications

    Author : Josefin A. Nilsson; Åsa Blom; Jimmy Johansson; Nylinder Mats; Linnéuniversitetet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Betula pendula; Betula pubescens; wood density; birch bark; Forestry and Wood Technology; Skog och träteknik;

    Abstract : In response to the furniture industry’s growing demand for raw material, large volumes of juvenile silver birch and downy birch stems available from pre-commercial thinning operations in Sweden’s forests could offer solutions. However, such stems are not currently used on an industrial scale, and most research conducted on birch stems in general has neither focussed on young trees nor the potential use of the central stem part around the tree pith. READ MORE

  5. 3. On the importance of oxidizable structures in bleached kraft pulps

    Author : Olena Sevastyanova; Göran Gellerstedt; Colodette Jorge; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bleached pulps; betula; eucalyptus; 5-formyl-2furancarboxylic acid; 2-furancarboxylic acid; hexenuronic acid; kappa number; kraft pulps; oxidation equivalents; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Abstract : After cooking, kraft pulps always contain not only residual lignin but also significant amounts of hexenuronic acid and other non-lignin structures oxidizable by permanganate under the standard kappa number determination conditions. These here referred to as false lignin. READ MORE

  6. 4. Evolutionary history and chloroplast DNA variation in three plant genera: Betula, Corylus and Salix. : The impact of post-glacial colonisation and hybridisation

    Author : Anna Palmé; Andrew Lowe; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; chloroplast DNA; phylogeography; hybridization; phylogeny; Salix caprea; Betula pendula; Corylus avellana; Biologi; Biology; Biologi; naturvårdsbiologi; Conservation Biology;

    Abstract : The great difference in the level of chloroplast variation and its geographic structure among the three main species studied here demonstrates that forest species do not form a homogeneous group. Hazel shows a genetic structure similar to many other thermophilous species and this structure, in combination with fossil evidence, indicates that the post-glacial colonisation of most of Europe originated in a refugium in western France while the Balkan and Italy were colonised from a south-eastern refugium. READ MORE

  7. 5. Engaged lifestyle and episodic and semantic memory : longitudinal studies from the betula project

    Author : S. M. Hossein Mousavi-Nasab; Reza Kormi- Nouri; Lars-Göran Nilsson; Tore Helstrup; Örebro universitet; []
    Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Psykologi; Psychology;

    Abstract : This dissertation examines whether some aspects of engaged lifestyle, marital status and leisure activity, influence memory performance in adulthood and old age. Direct effects and indirect effects, via health, are investigated. All the studies in the dissertation examine participants in the Betula project, aged 35 to 85 years. READ MORE