Sökning: "coniferous"

Visar resultat 21 - 25 av 68 avhandlingar innehållade ordet coniferous.

  1. 21. How could Christmas trees remain evergreen? : photosynthetic acclimation of Scots pine and Norway spruce needles during winter

    Författare :Pushan Bag; Stefan Jansson; Fransis Andre Wollman; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Scots Pine; Norway spruce; Photosynthesis; Winter adaptation; biologisk kemi; biological chemistry; biology; biologi; molekylärbiologi; Molecular Biology; Physiological Botany; fysiologisk botanik;

    Sammanfattning : Plants and other green organisms harvest sunlight by green chlorophyll pigments and covertit to chemical energy (sugars) and oxygen in a process called photosynthesis providing the foundation for life on Earth. Although it is unanimously believed that oceanic phytoplanktons are the main contributors to the global photosynthesis, the contribution of coniferous boreal forests distributed across vast regions of the northern hemisphere cannot be undermined. LÄS MER

  3. 22. Masking of wind turbine sound by ambient noise

    Författare :Karl Bolin; Mats Åbom; Sten Ljunggren; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

    Sammanfattning : The main objective of this work was to gain an increasing understanding of the properties of vegetation noise and also to the relative ratios of different natural ambient noises to mask wind turbine sound. A discrete vegetation noise model was developed and compared to an earlier model showing improved estimations, especially at frequencies below 0. LÄS MER

  4. 23. Intensification of wood production in NW Russia's Komi Republic : forest landscape history and biophysical conditions for tree growth

    Författare :Vladimir Naumov; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Globally, countries with forests and woodlands make attempts to manage their resources in sustainable way. In the boreal biome this has resulted in several policy documents regulating forest planning and operations at multiple levels of governance. LÄS MER

  5. 24. Vegetation and land-use in the Småland Uplands, southern Sweden, during the last 6000 years

    Författare :Per Lagerås; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geologi; physical geography; Sweden; Geology; Småland Uplands; land-use history; pollen analysis; Holocene vegetation history; mineral magnetic analysis; AMS dating; clearance cairns; hay production; shifting cultivation; Picea migration; slash-and-burn cultivation; fysisk geografi;

    Sammanfattning : Palaeoecological methods were applied to peat and sediment cores recovered from one bog (Bråtamossen) and two lakes (Avegöl and Femtingagölen) in the Småland Uplands, southern Sweden. The general aim was to reconstruct the landuse and vegetation history for the last 6000 years in this agriculturally marginal region. LÄS MER

  7. 25. Trace metals in the atmosphere : the wet deposition of trace metals : the selenium cycle

    Författare :Howard B. Ross; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Cd, Cu, Fe, Mn, Pb and Zn concentrations in wet deposition have been monitored in Sweden since the autumn of 1983. Concentrations of these elements are highest in southern Sweden and decrease northward. Examination of enrichment factors, relative to crustal material, indicate that the major source of Cd, Cu, Pb and Zn is anthropogenic emissions. LÄS MER