Search for dissertations about: "northern high latitudes"

Showing result 11 - 15 of 38 swedish dissertations containing the words northern high latitudes.

  1. 11. Spatial and temporal dynamics of subarctic birch forest carbon exchange

    University dissertation from Department of Physical Geography and Ecosystem Science, Lund University

    Author : Michal Heliasz; Lund University.; Lunds universitet.; [2012]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; mountain birch; eddy covariance; carbon budget; insect outbreak; forest expansion; temporal variability; spatial variability;

    Abstract : High northern latitudes are of special importance for the global carbon budget as they store large amounts of organic matter in the soil and are expected to be the most strongly affected by climate change. Here we investigate carbon exchange in the subarctic mountain birch forest growing on the limit where tree growth is possible. READ MORE

  2. 12. Molecular control of activity - dormancy transitions in Populus

    University dissertation from Department of Physical Geography and Ecosystem Science, Lund University

    Author : Madeleine Englund; Sveriges lantbruksuniversitet.; [2010]
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : Perennials such as woody plants, growing in the high northern part of the earth have to cope with seasonal changes alternating between mild summer and the harsh winter periods. To survive and adapt their reproductive phase to the most favorable environmental conditions trees cycle between periods of active growth during summer and a state of growth arrest during winter, referred to as the activity- dormancy cycle. READ MORE

  3. 13. Temporal and spatial dynamics in subarctic peat plateaus and thermokarst lakes

    University dissertation from Stockholm : Department of Physical Geography and Quaternary Geology (INK), Stockholm University

    Author : A. Britta K. Sannel; Stockholms universitet.; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Peatlands; permafrost; subarctic; peat plateau; thermokarst lake; macrofossil analysis; carbon nitrogen ratio; peat accumulation; carbon accumulation; remote sensing; binary encoding; time-series analysis; Physical Geography; naturgeografi;

    Abstract : Permafrost peatlands are widespread at high northern latitudes and are important soil organic carbon reservoirs. A future warming in these areas, as suggested by global climate models, can cause thawing and increased ground subsidence (thermokarst), resulting in changes in surface hydrology and ecosystem functioning. READ MORE

  4. 14. Hempseed cake as a protein feed for ruminants

    University dissertation from Stockholm : Department of Physical Geography and Quaternary Geology (INK), Stockholm University

    Author : Linda Karlsson; Sveriges lantbruksuniversitet.; [2010]
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : Increasing the use of locally produced protein feeds in ruminant production systems in northern Europe would be a valuable development. Hemp (Cannabis sativa L.) can be cultivated at high latitudes and cold-pressing the seeds to extract the oil produces a residue, hempseed cake (HC), with a high protein content. READ MORE

  5. 15. Towards a changed view on greenhouse gas exchange in the Arctic: new findings and improved techniques

    University dissertation from Lund University

    Author : Mikhail Mastepanov; Lund University.; Lunds universitet.; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; methane; carbon dioxide; greenhouse gas; chamber; Arctic; fen; permafrost;

    Abstract : Arctic ecosystems represent an important component in the global terrestrial exchange of greenhouse gases and energy with the atmosphere. In the changing climate, which is most pronounced in the Arctic, the possible scenarios of greenhouse gas exchange response should be seriously considered in predictive climate modelling efforts. READ MORE