Sökning: "Lars Tranvik"

Visar resultat 6 - 10 av 20 avhandlingar innehållade orden Lars Tranvik.

1. 6. Adsorption of dissolved organic matter in aquatic ecosystems : Effects on composition and reactivity

   Författare :Marloes M. Groeneveld; Lars Tranvik; Dolly Kothawala; Suzanne Tank; Uppsala universitet; []
   Nyckelord :dissolved organic matter; DOM; carbon; aquatic; adsorption; mineral particles; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

   Sammanfattning : Inland waters receive organic matter from terrestrial ecosystems and in situ production. In transit from land to the ocean, dissolved organic carbon (DOC) may be mineralised to inorganic forms (CO2 and CH4) by microbial degradation and photodegradation. LÄS MER

3. 7. 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

4. 8. Attached Bacterial Communities in Lakes – Habitat-Specific Differences

   Författare :Ann-Louise Haglund; Lars Tranvik; Helmut Fischer; Bengt Boström; Erik Törnblom; Paul del Giorgio; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; bacteria; freshwater; sediment; epiphyton; bacterioplankton; metabolically active; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : For many years, the importance of microorganisms attached to surfaces in littoral zones and wetlands has been disregarded when describing aquatic ecosystem dynamics. Supporting evidence is scarce but convincing that these microbial communities are not only very productive but can often serve as major regulators of nutrient and carbon dynamics in many freshwaters. LÄS MER

5. 9. 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

7. 10. Links Between Structure and Function of Heterotrophic Aquatic Bacterial Communities

   Författare :Silke Langenheder; Lars Tranvik; Eva Lindström; David Kirchman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; heterotrophic bacteria; dissolved organic matter; diversity; community composition; ecosystem functioning; salinity; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : Heterotrophic bacteria utilize dissolved organic matter, and the carbon flow through an ecosystem depends on the fractions of the utilized carbon that is either respired or transferred to higher trophic levels. The major aim this thesis is to investigate 1) the relationship between composition and functioning in heterotrophic bacterioplankton communities and 2) the influence of environmental conditions on both parameters. LÄS MER