Sökning: "LAKE-SEDIMENTS"

Visar resultat 1 - 5 av 71 avhandlingar innehållade ordet LAKE-SEDIMENTS.

  1. 1. Lake sediments around the Antarctic Peninsula : archives of climatic and environmental changes

    Författare :Rolf Zale; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake sediments; Antarctic Peninsula; radiocarbon dating; climatic and environmental changes; sediment chemistry; naturgeografi; Physical Geography;

    Sammanfattning : Lakes and lake sediments from four areas around the Antarctic Peninsula are described.The concentrations of trace metals in sediment are found to be a useful tool in distinguishing between the different sedimentary phases during a transition from marine to limnic environment. LÄS MER

  3. 2. Microcystis in lake sediments : its potential role in phosphorus exchange between sediment and lake water

    Författare :Anna-Kristina Brunberg; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  4. 3. Boreal Lake Sediments as Sources and Sinks of Carbon

    Författare :Cristian Gudasz; Tranvik Lars; David Bastviken; Susan Ziegler; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; boreal lakes; allochthonous; lake sediments; sediment mineralization; bacterial production; bacterial biomass; carbon cycle; Freshwater ecology; Limnisk ekologi; Limnologi; Limnology;

    Sammanfattning : Inland waters process large amounts of organic carbon, contributing to CO2 and CH4 emissions, as well as storing organic carbon (OC) over geological timescales. Recently, it has been shown that the magnitude of these processes is of global significance. LÄS MER

  5. 4. Acidification trends in Swedish lakes : an assessment of past water chemistry conditions using lake sediments

    Författare :Tom Korsman; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Palaeolimnology; acidification history; alkalization; acid deposition; land-use; lake sediments; near infrared spectroscopy; diatoms; multivariate calibration; Sweden;

    Sammanfattning : This thesis presents temporal perspectives of lake acidification in Sweden. Sediment records have been used to study timing, trends and causes of acidification, and two different techniques for assessing past lake-water acidity are presented. LÄS MER

  7. 5. Studies of an elusive element : processes that influence the net retention of mercury in lake sediments and peatlands

    Författare :Johan Rydberg; Richard Bindler; Carl Lamborg; Umeå universitet; []
    Nyckelord :Mercury; retention; lake sediments; peatlands; environmental archives; sedimentation; diagenesis; vegetation; permafrost; Environmental Science; miljövetenskap;

    Sammanfattning : Because of its toxic nature mercury is a threat to both wildlife and human health, and thus, it is an element of concern in the environment. Currently much of the mercury emitted to the atmosphere is derived from anthropogenic sources – both direct emissions and re-emission of already deposited anthropogenic mercury. LÄS MER