Sökning: "soil cover change"

Visar resultat 6 - 10 av 48 avhandlingar innehållade orden soil cover change.

  1. 6. Long-lasting ecological legacies of reindeer on tundra vegetation

    Författare :Dagmar D. Egelkraut; Johan Olofsson; Bruce Forbes; Hans Tømmervik; René van der Wal; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Alternative stable state; Herbivory; Historical contingency; Nutrient cycling; Plant-herbivore interactions; Plant-soil feedbacks; Rangifer tarandus; Reindeer herding; Traditional land use; Tundra vegetation;

    Sammanfattning : Reindeer can have strong effects on the plant species composition and functioning of tundra ecosystems, and often promote a transition towards a graminoid-dominated vegetation type. As a result, they influence many ecological processes, such as nutrient dynamics, soil biotic composition and functioning, and carbon storage. LÄS MER

  3. 7. 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

  4. 8. The role of vegetation dynamics in the control of atmospheric CO2 content

    Författare :Stephen Sitch; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atmospheric CO2 content; climate change; plant functional types; terrestrial biosphere model; DGVM; vegetation dynamics; land use; land cover change; Plant ecology; Växtekologi;

    Sammanfattning : This thesis contains a description of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) and its application to infer the role of vegetation dynamics on atmospheric CO2 content at different time-scales. The model combines vegetation dynamics and biogeochemistry in a modular framework. LÄS MER

  5. 9. Soil Modification by adding small amounts of binders : A laboratory study

    Författare :Wathiq Jasim Al-Jabban; Jan Laue; Sven Knutsson; Nadhir Al-Ansari; Paolo Simonini; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Soil Mechanics; Geoteknik;

    Sammanfattning : Soil stabilization through addition of a hydraulic binder is a method frequently used to modify and improve engineering properties of soft soils. Additives like cement and lime are typically used as stabilizers. More recently, industrial by-products, such as fly ashes, cement kiln dust, blast furnace slags and other slags have been used. LÄS MER

  7. 10. Changing land cover as a driver of surface water browning

    Författare :Martin Skerlep; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; organic matter; iron; land cover; browning; afforestation; biogeochemistry; spruce;

    Sammanfattning : Streams, rivers and lakes across wide areas of the Northern hemisphere have been subject to an increase in water color over the last decades. This increase, also known as browning, is a result of rising dissolved organic matter (DOM) and iron (Fe) concentrations in the water. LÄS MER