Sökning: "Arctic and subarctic tundra"

Hittade 5 avhandlingar innehållade orden Arctic and subarctic tundra.

  1. 1. Surface energy exchange and land-atmosphere interactions of Arctic and subarctic tundra ecosystems under climate change

    Författare :Christian Stiegler; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Surface energy exchange; Arctic and subarctic tundra; climate change; permafrost; eddy covariance; snow cover; micrometeorology;

    Sammanfattning : The surface energy balance determines the functioning of any ecosystem on the Earth but is still poorly understood in Arctic and subarctic biomes. In a dynamic system, such as the Earth’s climate, any change in its characteristics modifies the exchange of energy, water, and greenhouse gases between the surface and the atmosphere. LÄS MER

  3. 2. The hidden life of plants : fine root dynamics in northern ecosystems

    Författare :Gesche Blume-Werry; Roland Jansson; Ann Milbau; Scott D. Wilson; Isla Myers-Smith; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic; belowground; boreal; climate change; fine roots; heath; meadow; minirhizotron; permafrost; phenology; plant community; root biomass; root growth; root litter; root production; subarctic; tundra;

    Sammanfattning : Fine roots constitute a large part of the primary production in northern (arctic and boreal) ecosystems, and are key players in ecosystem fluxes of water, nutrients and carbon. Data on root dynamics are generally rare, especially so in northern ecosystems. LÄS MER

  4. 3. The role of biogeophysical feedbacks and their impacts in the arctic and boreal climate system

    Författare :Wenxin Zhang; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic and boreal vegetation change; Biogeophysical feedbacks; Albedo; Latent heat; Carbon budget; Representative concentration pathways; Eearth system model; LPJ-GUESS; RCA; Sea ice;

    Sammanfattning : The physical environment in the northern high latitudes including the Arctic cryosphere has undergone dramatic changes due to anthropogenic greenhouse gas warming, which since pre-industrial times has been twice or more the rate of global mean warming. Global climate models predict that this accelerated warming will continue for at least the next few decades. LÄS MER

  5. 4. A green future with thawing permafrost mires? : a study of climate-vegetation interactions in European subarctic peatlands

    Författare :Julia Bosiö; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fennoscandia; carbon; greenhouse gas; photosynthesis; PAR; snow; climate change; permafrost; peatland; subarctic;

    Sammanfattning : Climate projections indicate that Arctic and sub-Arctic regions are facing a significant change in climate during the 21st century. With warmer temperatures precipitation is also expected to increase, and in particular winter precipitation. LÄS MER

  7. 5. Spatial and temporal dynamics of subarctic birch forest carbon exchange

    Författare :Michal Heliasz; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mountain birch; eddy covariance; carbon budget; insect outbreak; forest expansion; temporal variability; spatial variability;

    Sammanfattning : 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. LÄS MER