Search for dissertations about: "Ann-Kristin Bergström"

Showing result 1 - 5 of 6 swedish dissertations containing the words Ann-Kristin Bergström.

  1. 1. Effects of inorganic nitrogen and organic carbon on pelagic food webs in boreal lakes

    Author : Anne Deininger; Ann-Kristin Bergström; Jan Karlsson; Antonia Liess; Carolyn L. Faithfull; John A. Downing; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; autochthony; basal production; boreal; global change; dissolved organic carbon; food web efficiency; N deposition; phytoplankton; seston stoichiometry; whole lake enrichment; zooplankton; limnologi; Limnology;

    Abstract : Anthropogenic activities are increasing inorganic nitrogen (N) loadings to lakes in the northern hemisphere. In many boreal lakes phytoplankton are N limited, wherefore enhanced N input may affect the productivity of pelagic food webs. READ MORE

  2. 2. Productivity and carbon transfer in pelagic food webs in response to carbon, nutrients and light

    Author : Carolyn Faithfull; Ann-Kristin Bergström; Tobias Vrede; Kathryn Cottingham; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; bacterial production; phytoplankton production; mesocosms; food webs; carbon; nutrients; light; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; limnologi; Limnology;

    Abstract : Some of the major problems we face today are human induced changes to the nitrogen (N), phosphorus (P) and carbon (C) cycles. Predicted increases in rainfall and temperature due to climate change, may also increase dissolved organic matter (DOM) inflows to freshwater ecosystems in the boreal zone. READ MORE

  3. 3. Water Quality in Swedish Lakes and Watercourses : Modeling the Intra-Annual Variability

    Author : Julia Hytteborn; Kevin H. Bishop; Andreas C. Bryhn; Johan Temnerud; Bergström Ann-Kristin; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Total organic carbon; cyanobacteria; seasonality; water quality modeling; climate change; surface water; Earth Science with specialization in Environmental Analysis; Geovetenskap med inriktning mot miljöanalys;

    Abstract : Water quality is of great importance for ecosystems and society. This thesis characterized and modeled the variation in several key constituents of Swedish surface waters, with particular consideration given to intra-annual variability and sensitivity to climate change. READ MORE

  4. 4. The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change

    Author : Maria Myrstener; Ryan A. Sponseller; Reiner Giesler; Ann-Kristin Bergström; Tenna Riis; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Nutrients; Stream; Arctic; Boreal; Primary productivity; Algae; Biofilm; Nutrient limitation; Nitrogen; Phosphorus;

    Abstract : Arctic and sub-Arctic freshwaters are currently experiencing substantial ecosystem changes due to the effects of global warming. Global warming effects on these freshwaters include increasing water temperatures, altered hydrological patterns, shifts in riparian vegetation and changes in the export of nutrients and carbon from soils. READ MORE

  5. 5. Biophysical controls on CO2 evasion from Arctic inland waters

    Author : Gerard Rocher-Ros; Reiner Giesler; Ryan A. Sponseller; Ann-Kristin Bergström; Paul del Giorgio; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Inland waters; carbon dioxide; organic carbon; inorganic carbon; arctic; CO2 evasion; DOC; DIC; streams; metabolism; oxygen; Limnology; limnologi;

    Abstract : CO2 evasion to the atmosphere from inland waters is a major component of the global carbon (C) cycle. Yet spatial patterns of CO2 evasion and the sources of C that fuel evasion remain poorly understood. READ MORE