Catchment water source variation drives aquatic microbial processes and trace gas climate feedbacks

Background: Arctic and Boreal freshwater ecosystems are rapidly changing due to heightened warming in northern regions compared to lower latitudes. These changes, driven by climate-induced shifts in the Arctic water cycle, can alter hydrological regimes of northern catchments. For instance, changes in the seasonality of snow melt and rainfall patterns might shift microbial community composition and function and further affect northern catchments CO2 and CH4 dynamics. Catchment hydrology plays a vital role in transporting organic and inorganic carbon, which serves as a crucial energy source for northern freshwater ecosystems. The quantity and quality of carbon vary depending on the water source, influencing biochemical processes and microbial community composition of freshwater systems. Microbial-driven carbon cycling is significant, as it influences greenhouse gas emissions, particularly CO2 and CH4, in northern regions. Given that Arctic and Boreal ecosystems store a substantial portion of global soil carbon, understanding the processes governing GHG exchange between northern land surfaces and freshwater systems is imperative. However, the contribution of small freshwater systems and their microbially induced ecosystem processes within large peatland areas remains poorly understood due to insufficient data from northern regions.

PhD project description: We are seeking talented and motivated doctoral researcher for this highly multidisciplinary project, which combines measurements of abiotic (water source, carbon, and GHG) and biotic (microbial communities) components in northern streams and lakes. Multidisciplinary approach used in this project is crucial for comprehending the holistic functioning of northern catchments and to enhance our understanding of how seasonal water source variability influences microbial community processes and their connection to GHG dynamics. The doctoral researcher will be integrating and combining data from existing major research programs of University of Oulu and Finnish Meteorological Institute. The doctoral researcher will utilize/collect field data from sub-arctic freshwater systems by using state-of-the-art in-situ measurement techniques. In addition to the project supervisors the work will be conducted in close collaboration with Senior Research Scientist Kaisa-Leena Huttunen from SYKE and Dr. Kaisa Lehosmaa and Academy Research Fellow Janne Koskimäki from University of Oulu, as well as other collaborators in DIWA. Fieldwork will mainly take place at study sites in the Pallas Atmosphere-Ecosystem Supersite.

The PhD position requires an active approach, attention to detail, and collaborative skills, along with a willingness to collaborate within a team and a keenness to acquire new knowledge from several research fields. A master’s degree in disciplines like biology, ecohydrology, ecology, microbiology or a related environmental science field is required. Given the nature of the PhD project described, prior experience in molecular methods is required. In addition, proficiency in the following areas will be advantageous: (1) Strong background in molecular laboratory methods such as microbial DNA/RNA extractions; (2) Proficient and demonstrable skills in bioinformatics and subsequent statistical community ecology analysis, as well as familiarity with programming languages such as R or Python etc.; (3) Prior experience in stream ecological research; (4) Prior experience in GHG research.

FMI

Ecology and Genetics Research Unit/Faculty of Science

Prof. Jeffrey M. Welker

Dr. Kaisa-Riikka Mustonen

Senior Researcher Sari Juutinen, FMI

Senior Researcher Sari Juutinen, FMI