Search for dissertations about: "Sjöar"

Showing result 1 - 5 of 89 swedish dissertations containing the word Sjöar.

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

    Author : Sivakiruthika Natchimuthu; David Bastviken; Åsa Danielsson; Peter A. Raymond; Linköpings universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Coarse detritus in oligotrophic lake littoral zones : utilization by intervertebrates and contribution to carbon flow

    Author : Irene Bohman; Jan Herrman; Lars Tranvik; Jan Stenson; Mark O. Gessner; Högskolan i Kalmar; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Shredders; Biodiversity; Ecosystem; Limnology; Nattsländor; Sjöar; Kol; Biologisk nedbrytning; Freshwater ecology; Limnisk ekologi; Akvatisk ekologi; Aquatic Ecology;

    Abstract : Syftet med denna avhandling är att öka förståelsen av hur grovt organiskt material, sk grovdetritus, tex löv och makrofytrester, bryts ner i sjöars strandzoner. Motivet bakom intresset för detta är att små näringsfattiga sjöar i skogsrika områden ofta är beroende av tillförsel av energi utifrån och att nedbrytningen av grovdetritus är relativt lite undersökt i sjöar. READ MORE

  5. 3. Local and global contaminants in Swedish waters : studies on PCBs, DDTs, 4,5,6-trichloroguaiacol and their transformation products in fish and sediments

    Author : Maria Söderström; Åke Bergman; Bert van Bavel; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; PCB; DDT; HCB; trichloroguaiacol; transformation products; dimerisation; bromination; environmental pollutants; eutrophication; lakes; fresh water; baltic sea; monitoring; sediments; fish; phytoplankton; PCB; DDT; HCB; triklorguajakol; omvandlingsprodukter; dimerisering; bromering; miljöföroreningar; eutrofiering; sjöar; sötvatten; östersjön; miljöövervakning; sediment; fisk; fytoplankton; miljökemi; Environmental Chemistry;

    Abstract : This thesis is focused on studies on the environmental fate and methodological improvements for determination of the global contaminants, PCBs and DDTs, and locally discharged phenolics, e.g. 4,5,6-trichloroguaiacol (4,5,6-TCG), and their transformation products. READ MORE

  6. 4. Molecular analysis of lake-sediment organic matter : long-term dynamics and environmental implications in boreal lakes

    Author : Sofia Ninnes; Richard Bindler; Xiao-Ru Wang; Christian Bigler; Hendrik Vogel; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Lake sediment; Holocene; organic matter; Pyrolysis-GC MS; mid-infrared spectroscopy; boreal;

    Abstract : Lake sediment organic matter is material composed of residues from plants, algae, animals, fungi and bacteria. Its molecular composition is dependent on the sources as well as secondary biotic and abiotic transformations, which combined generates a highly complex matrix. READ MORE

  7. 5. Impacts of global change on primary production in northern lakes

    Author : Isolde Callisto Puts; Ann-Kristin Bergström; Jenny Ask; Tom H. Andersen; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Primary production; global change; warming; browning; lake; carbon dioxide; organic carbon; inorganic carbon; boreal; arctic; DOC; DIC; CO2; allochthonous organic carbon; benthic; periphyton; environmental change; miljöförändringar; environmental science; miljövetenskap; biology; biologi; climate change; klimatförändringar;

    Abstract : Algae are primary producers, a major component of the aquatic foodweb, and changes in primary production affect aquatic ecology in general. Global changes such as warming, recovery of acidification and changes in land-use have caused warming and browning of northern lakes. READ MORE