Sökning: "Ann-Kristin Bergström"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Ann-Kristin Bergström.

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

    Författare :Anne Deininger; Ann-Kristin Bergström; Jan Karlsson; Antonia Liess; Carolyn L. Faithfull; John A. Downing; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; 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;

    Sammanfattning : 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. LÄS MER

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

    Författare :Carolyn Faithfull; Ann-Kristin Bergström; Tobias Vrede; Kathryn Cottingham; Umeå universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

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

    Författare :Julia Hytteborn; Kevin H. Bishop; Andreas C. Bryhn; Johan Temnerud; Bergström Ann-Kristin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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;

    Sammanfattning : 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. LÄS MER

  5. 4. 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

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

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

    Sammanfattning : 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. LÄS MER