Sökning: "Lakes"

Visar resultat 11 - 15 av 381 avhandlingar innehållade ordet Lakes.

  1. 11. Regulation of carbon dioxide emission from Swedish boreal lakes and the Gulf of Bothnia

    Författare :Grete Algesten; Mats Jansson; Pirkko Kortelainen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography and sedimentology; lakes; boreal; Gulf of bothnia; CO2; NEE; DOC; mineralization; sediment; catchment; net heterotrophy; Naturgeografi och sedimentologi; Physical geography; Naturgeografi; naturgeografi; Physical Geography;

    Sammanfattning : The global carbon cycle is subject to intense research, where sources and sinks for greenhouse gases, carbon dioxide in particular, are estimated for various systems and biomes. Lakes have previously been neglected in carbon balance estimations, but have recently been recognized to be significant net sources of CO2. LÄS MER

  2. 12. Carbon metabolism in clear-water and brown-water lakes

    Författare :Jenny Ask; Jan Karlsson; Mats Jansson; Rolf Vinebrooke; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; clear-water lakes; brown-water lakes; primary production; bacterial production; benthic; pelagic; net ecosystem production; allochthonous organic carbon; CO2; DOC; Physical geography; Naturgeografi; Freshwater ecology; Limnisk ekologi; limnologi; Limnology; naturgeografi; Physical Geography;

    Sammanfattning : The trophic state of lakes is commonly defined by the concentration of nutrients in the water column. High nutrient concentrations generate high phytoplankton production, and lakes with low nutrient concentrations are considered low-productive. LÄS MER

  3. 13. On denitrification in lakes

    Författare :Torbjörn Tirén; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  4. 14. Molecular-level dissolved organic matter dynamics in lakes : Constraints on reactivity and persistence

    Författare :Anne Marie Kellerman; Lars J. Tranvik; Dolly N. Kothawala; Thorsten Dittmar; Robert G. M. Spencer; Uppsala universitet; []
    Nyckelord :dissolved organic matter; DOM; dissolved organic carbon; organic matter characterization; fluorescence; PARAFAC; molecular weight; mass spectrometry; FT-ICR-MS; boreal lakes; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

    Sammanfattning : Dissolved organic matter (DOM) is a central component of the global carbon cycle. Thus, small changes to the amount of DOM imported, processed and produced within lakes can have a large effect on regional carbon budgets. In addition to being a vital energy source at the base of the aquatic food web, DOM is physico-chemically reactive. LÄS MER

  5. 15. Freshwater methane and carbon dioxide fluxes : Spatio-temporal variability and an integrated assessment of lake and stream emissions in a catchment

    Författare :Sivakiruthika Natchimuthu; David Bastviken; Åsa Danielsson; Peter A. Raymond; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Lakes; streams; spatio-temporal variability; CH4 flux; CO2 flux; gas transfer velocity; Sjöar; vattendrag; rumsliga och tidsmässiga variationer; CH4-flöden; CO2-flöden; gasutbyteshastighet;

    Sammanfattning : Freshwater bodies such as lakes and streams release the greenhouse gases methane (CH4) and carbon dioxide (CO2) into the atmosphere. Global freshwater CH4 and CO2 emissions have been estimated to be of a similar magnitude to the global land or ocean carbon sink, and are thus significant components of global carbon budgets. LÄS MER