ECCO: Catchment processes and export of DOC and nutrients
This Project is the intergarl part of WP2 of the ECCO Project (Effects of climate change on boreal lake ecosystems: Productivity and community responses) led by Prof. Dag Hessen et Dept. of Biosciences, UiO.
The study lake Langtjern in Norefjell
The ECCO address the ecosystem effects on nutrient-poor (oligotrophic) boreal lakes in Norway and Fenno-Scandia, under the combined stresses of climate change, atmospheric deposition of nitrogen (N) and sulphur (S), and change in land vegetation cover. Export from land to water of dissolved organic carbon (DOC) along with the elements nitrogen (N), phosphorus (P) and silicate (Si) is expected to respond to changing climate patterns and nitrogen loading on a time scale from years to centuries. These elements are key drivers of light attenuation and productivity, which in turn will affect species composition.
About the sub project
Catchment processes and export of DOC and nutrients.
Climate change is expected to affect lake ecosystems in many ways. In boreal systems, changes in dissolved organic matter and nutrients will affect light levels, thermal regimes, productivity and community structure. This project will address these responses by use of existing databases, refinement and integration of existing models and by experiments and field studies. The multidisciplinary project group will build on the extensive databases on lakes and boreal catchments in Norway, Sweden and Finland combined with predictive steady-state (space-for-time) models that have recently been developed and tested for Norwegian catchments as well as existing, dynamic, process-oriented models. The goal is to establish causal links between the drivers climate change and N+S deposition and catchment properties on export fluxes of dissolved organic carbon (DOC), and the key nutrient elements nitrogen (N) and phosphorus (P).
Process-understanding of climatic drivers of DOC and nutrients in boreal catchments, upscaled in time (future climate) and space (Norway/Nordic scale)
The findings will serve as input to the physical lake models (WP3), lake productivity and size structure (WP4) and biological community response studies (WP5) as outlined in the ECCO homepage.
Catchment processes and export of DOC and nutrients (inorganic N and P) will be studied at a highly instrumented lake catchment (Langtjern). P in boreal lakes is primarily organic and thus assumed to be linked to variations in DOM.
Task 2.1 Langtjern- detailed process understanding of climatic responses
The Langtjern lake catchment (high frequency monitoring of weather, lake temperature and oxygen, hydrology, outlet chemistry, and DOM quality with in-situ sensors and real-time data transfer; classical monitoring of water chemistry with weekly intervals with start in 1972) will be used to test, validate, and further develop processoriented models (INCA-C, MAGIC-CN, and MyLake). Statistical analysis of both weekly long-term monitoring and high-frequency episode studies will be used to increase the understanding of the links between climatic factors and variability and physical and chemical conditions in the lake. Effects on NO3 and DOM quality and quantity will be investigated through e.g. seasonal comparisons (e.g. cold vs. mild winters, wet vs. dry autumns), studies of short-term events (snow melt, summer drought), and by comparing rain events in different seasons (de Wit et al. 2008).
The Project is funded by the Research Council of Norway (RCN)
The Research will be conducted in close cooperation with Dr. Heleen de Wit and Dr. Kari Austnes at NIVA.
EMMA, MINEQL, MINITAB