Sökning: "humification"

Visar resultat 1 - 5 av 10 avhandlingar innehållade ordet humification.

  1. 1. Late Holocene humidity variability in central Sweden

    Författare :Sofia Andersson; Stefan Wastegård; Gunhild Rosqvist; Kristian Schoning; Frank Chambers; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; humidity change; stable isotopes; Chara spp; Pisidium spp; testate amoebae assemblages; humification; C N ratio; late Holocene; central Sweden; Quaternary geology; Kvartärgeologi; kvartärgeologi; Quarternary Geology;

    Sammanfattning : The aim of this thesis was to reconstruct humidity variability in central Sweden during the late Holocene. A multi-proxy approach was used to infer humidity changes as recorded in a lake and a mire. Age-models were constructed based on radiocarbon dating and the Askja-1875 tephra. LÄS MER

  3. 2. Bacteria that escape predation : waterborne pathogens and their relatives

    Författare :Karolina I. A. Eriksson; Agneta Andersson; Johanna Thelaus; Jon Ahlinder; David Sundell; Klaus Jürgens; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bacterial pathogens; protozoa; predation resistance; aquatic microbiology; climate change; opportunists; humification; iron; environmental science; miljövetenskap; mikrobiologi; Microbiology;

    Sammanfattning : The hidden presence of opportunistic bacterial pathogens in the environment evokes concerns about emerging diseases, especially in the light of climate change. The co-evolution of bacteria and their predators (protozoa) has led to bacterial defence strategies of which some contribute to the ability of bacteria to cause disease. LÄS MER

  4. 3. Incorporation and preservation of geochemical fingerprints in peat archives

    Författare :Sophia V. Hansson; Richard Bindler; Dominik Weiss; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Peat; Beryllium; bulk density; C N-ratio; decomposition; deposition; downwash; elemental mobility; geochemistry; humification; lead; light transmission; mercury; peat accumulation; precipitation; Environmental Science; miljövetenskap;

    Sammanfattning : The present status of the environment, including environmental problems such as heavy metal accumulation in aquatic and terrestrial ecosystems, is in part the consequence of long-term changes. Cores from peatlands and other natural archives provide us with the potential to study aspects of the atmospheric cycling of elements, such as metal pollutants, on timescales much longer than the decade or two available to us with atmospheric deposition monitoring programs. LÄS MER

  5. 4. Quantity and quality of soil organic matter in permafrost terrain

    Författare :Gustaf Hugelius; Peter Kuhry; Philip Wookey; Stockholms universitet; []
    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; Physical geography; 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

  7. 5. The colour of climate : A study of raised bogs in south-central Sweden

    Författare :Anders Borgmark; Stefan Wastegård; Ann-Marie Robertsson; Bas van Geel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Holocene; south-central Sweden; peat humification; bog hydrology; climate variation; spectral analysis; Quaternary geology; Kvartärgeologi;

    Sammanfattning : This thesis focuses on responses in raised bogs to changes in the effective humidity during the Holocene. Raised bogs are terrestrial deposits that can provide contiguous records of past climate changes. Information on and knowledge about past changes in climate is crucial for our understanding of natural climate variability. LÄS MER