Sökning: "Dissolved Organic Carbon DOC"

Visar resultat 21 - 25 av 70 avhandlingar innehållade orden Dissolved Organic Carbon DOC.

1. 21. Causes and consequences of Gonyostomum semen blooms

   Författare :Karla Münzner; Eva S. Lindström; Lars J. Tranvik; Gesa A. Weyhenmeyer; Silke Langenheder; Ann-Kristin Bergström; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gonyostomum semen; algal blooms; brown water lakes; lake browning; iron; dissolved organic carbon DOC ; carbon cycling; pCO2; CO2; organic matter; sedimentation; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

   Sammanfattning : Aquatic ecosystems provide essential ecosystem services, but are also highly vulnerable to global change. Climate change, eutrophication and browning, for example, collectively drive the increase of harmful algal blooms in freshwaters. LÄS MER

3. 22. Impact of root and mycorrhizal exudation on soil carbon fluxes : influence of elevated CO2 and metals

   Författare :Emma M. Johansson; Patrick van Hees; Bert Allard; Phil Ineson; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; amino acids; 13C; carbon cycle; ectomycorrhiza; elevated CO2; exudation; DOC; LMWOA; metal stress; monosaccharides; oxalate; Pinus sylvestris; saprotrophic fungi; soil respiration; NATURAL SCIENCES; NATURVETENSKAP; Environmental chemistry; Miljökemi; Enviromental Science; Miljövetenskap;

   Sammanfattning : The thesis concerns the behavior of root and ectomycorrhizal (ECM) exudates. In particular, the dynamics of soluble low molecular weight (LMW) organic compounds such as organic acids (LMWOAs), amino acids, monosaccharides, and dissolved organic carbon (DOC) have been studied. LÄS MER

4. 23. Arsenic in Alluvial Aquifers in the Meghna Basin, Southeastern Bangladesh : Hydrogeological and Geochemical Characterisation

   Författare :Md. Aziz Hasan; Prosun Bhattacharya; William Burgess; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Alluvial aquifer; groundwater; arsenic mobilisation; geology; Meghna basin; Bangladesh; Water engineering; Vattenteknik;

   Sammanfattning :  Elevated levels of arsenic (As) in Bangladesh groundwater has emerged as a massive calamity exposing a large population to the risk of As toxicity from drinking water sources and agricultural products. Holocene alluvial aquifers in the delta- and flood-plains of the Ganges-Brahmaputra- Meghna (GBM) river systems are severely affected by high levels of As in groundwater. LÄS MER

5. 24. A palaeolimnological study of the anthropogenic impact on dissolved organic carbon in South Swedish lakes

   Författare :Petra Bragée; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; DOC; Brownification; Landscape Reconstruction Algorithm; Land-use changes; Lake sediments; Anthropogenic impact;

   Sammanfattning : During the past three decades, increases have been observed in dissolved organic carbon (DOC) concentrations and colour in the surface waters of lakes and rivers in parts of Europe and North America, raising concern about the effects on the quality of aquatic environments with consequences for biodiversity, resource availability and recreational use. Various hypotheses have been put forward to explain the recent increases in DOC concentration and numerous studies have been published linking them to declining anthropogenic atmospherically deposited sulphur. LÄS MER

7. 25. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

   Författare :Anders Tengberg; Göteborgs universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

   Sammanfattning : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). LÄS MER