My research concerns effects of environmental and climate change on the productivity and the food web structure of northern aquatic ecosystems.
Special focus within my research lies in studying the importance of organic matter (humic substances), nutrients (nitrogen and phosphorus) and calcium for lake ecosystem productivity and food web structure. My current research projects concern how global climate change affects lake water biogeochemistry, and what possible impacts these biogeochemical changes have on lake productivity and the ecosystem services of northern pristine lakes. We assess how nutrient- and calcium availability, and the N:P stoichiometry, in lakes are affected by changes in atmospheric nitrogen deposition and by warming, and its effects on nutrient limitation of phytoplankton and zooplankton, nutrient regeneration, fatty acid availability and trophic transfer efficiencies, and productivity in northern boreal and subarctic lakes. Different approaches are used including lake surveys and experimental approaches integrated with using long-term in situ lake- and satellite-based monitoring data with modeling and machine learning.
I teach on bachelor- and master courses at the department.
Global environmental changes reduce the levels of omega-3 polyunsaturated fatty acids in plankton of northern lakes, thereby lowering their supply to wildlife and humans.
This video summarizes the main findings of the research article: Lau, D. C. P., Jonsson, A., Isles, P. D., Creed, I. F., & Bergström, A.-K. (2021). Lowered nutritional quality of plankton caused by global environmental changes. Global Change Biology. https://doi.org/10.1111/gcb.15887
This video summarizes the main findings of the research article:
Isolde Callisto Puts, Jenny Ask, Matthias B. Siewert, Ryan A. Sponseller, Dag O. Hessen, Ann-Kristin Bergström (2022). Landscape determinants of pelagic and benthic primary production in northern lakes. Global change biology.