Sökning: "Betula"
Visar resultat 1 - 5 av 81 avhandlingar innehållade ordet Betula.
1. Reproductive patterns of birches (Betula spp.) in northern Sweden
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
2. Juvenile birch in Sweden : Selected stem characteristics for interior and furniture applications
Sammanfattning : 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. LÄS MER
3. On the importance of oxidizable structures in bleached kraft pulps
Sammanfattning : 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. LÄS MER
4. Evolutionary history and chloroplast DNA variation in three plant genera: Betula, Corylus and Salix. : The impact of post-glacial colonisation and hybridisation
Sammanfattning : 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. LÄS MER
5. Engaged lifestyle and episodic and semantic memory : longitudinal studies from the betula project
Sammanfattning : 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. LÄS MER