Sökning: "carbon nitrogen ratio"

Visar resultat 1 - 5 av 56 avhandlingar innehållade orden carbon nitrogen ratio.

  1. 1. Quantity and quality of soil organic matter in permafrost terrain

    Detta är en avhandling från Stockholm : Department of Physical Geography and Quaternary Geology (INK), Stockholm University

    Författare :Gustaf Hugelius; Stockholms universitet.; [2011]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbon; soil organic matter; soil organic carbon; permafrost; arctic; upscaling; peat plateau; cryoturbation; active layer; thermokarst; carbon nitrogen ratio; stable isotopes; humification; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; geografi med naturgeografisk inriktning; Physical Geography;

    Sammanfattning : High latitude terrestrial ecosystems are considered key components in the global carbon (C) cycle and hold large reservoirs of soil organic carbon (SOC). Much of this is stored as soil organic matter (SOM) in permafrost soils and peat deposits and is vulnerable to remobilization under future global warming. LÄS MER

  2. 2. Landscape partitioning and burial processes of soil organic carbon in contrasting areas of continuous permafrost

    Detta är en avhandling från Stockholm : Department of Physical Geography, Stockholm University

    Författare :Juri Palmtag; Stockholms universitet.; [2017]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; soil organic carbon; total nitrogen; permafrost; cryoturbation; geomorphology; land cover classification; slope processes; texture; upscaling; carbon nitrogen ratio; Physical Geography; naturgeografi;

    Sammanfattning : Recent studies have shown that permafrost soils in the northern circumpolar region store almost twice as much carbon as the atmosphere. Since soil organic carbon (SOC) pools have large regional and landscape-level variability, detailed SOC inventories from across the northern permafrost region are needed to assess potential remobilization of SOC with permafrost degradation and to quantify the permafrost carbon-climate feedback on global warming. LÄS MER

  3. 3. Varved lake sediments and diagenetic processes

    Detta är en avhandling från Umeå : Ekologi, miljö och geovetenskap

    Författare :Veronika Gälman; Umeå universitet.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; NATURAL SCIENCES Earth sciences; NATURVETENSKAP Geovetenskap;

    Sammanfattning : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. LÄS MER

  4. 4. Productivity and carbon transfer in pelagic food webs in response to carbon, nutrients and light

    Detta är en avhandling från Umeå : Institutionen för ekologi, miljö och geovetenskap, Umeå universitet

    Författare :Carolyn Faithfull; Umeå universitet.; [2011]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bacterial production; phytoplankton production; mesocosms; food webs; carbon; nutrients; light; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi; limnologi; Limnology;

    Sammanfattning : Some of the major problems we face today are human induced changes to the nitrogen (N), phosphorus (P) and carbon (C) cycles. Predicted increases in rainfall and temperature due to climate change, may also increase dissolved organic matter (DOM) inflows to freshwater ecosystems in the boreal zone. LÄS MER

  5. 5. Temporal and spatial dynamics in subarctic peat plateaus and thermokarst lakes

    Detta är en avhandling från Stockholm : Department of Physical Geography and Quaternary Geology (INK), Stockholm University

    Författare :A. Britta K. Sannel; Stockholms universitet.; [2010]
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER