Projects using this infrastructure
Read more at https://www.slu.se/krycklan
Research in Krycklan started over 100 years ago with the study of paludification effects on forest growth. In the 1970’s, the Svartberget field station was established. Research then was focused more on forest hydrology and biogeochemical cycling.During the 1990’s, a decade of more intensive work on the role of acid deposition on stream water chemistry contributed to new views of anthropogenic acidification and natural acidity in organic carbon-rich boreal waters. In recent years, the research scope expanded substantially to include more work on biogeochemistry, carbon cycling, hydrology and ecology. More intensive research also began on the connections between soils and surface waters, leading to a process-based understanding of the regulation of stream water chemistry.
Recognition of the need to work at the landscape scale when addressing climatic influences on aquatic ecology led to the expansion of the Svartberget catchment from 50 ha to the 6800 ha Krycklan catchment in 2002. This has further increased the research scope to include both fundamental research questions as well as management issues that are currently addressed. In recent years, Krycklan has transformed into a unique experimental platform for testing pure and applied research questions in a natural environment. The platform continuously attracts new scientific projects as well as directly collaborates with the Swedish Nuclear Waste Program, Swedish EPA, Sveaskog and others.
The 68 km² Krycklan catchment encompasses the natural mosaic of boreal landscapes consisting of forests, mires, streams and lakes that make up 70% of the area in Sweden, and which is representative of 30% of the world’s forest cover.
Krycklan is an integral part of the Svartberget field research infrastructure and the ongoing field activities include over 50 research projects, involving several hundred scientists from all major universities in Sweden and 30 countries.
Discharge has been measured since 1980 at at site 7, since 1994 at sites 2 and 4 and the remaining stations from 2004. There are 18 regularly sampled water quality monitoring stations, six of which are in heated houses for year around measurements.
The riparian zone and the s-transect
The riparian zone has a disproportional large impact on the stream biogeochemistry. Partly this is because it is the large last environment the soil water meets before becoming surface water. But this large influence also has to do with the fact that the riparian soil in the boreal region is rich in organic compounts, and therefore very different compared to most other soils in the catchment. The S-transect was installed 1997 and has been sampled monthly since.
The transect consists of ceramic suction lysimeters at 5-7 depths in three plots: in the riparian zone 4m from the stream (S04), 12m from the stream (S12) and in the upslope mineral soil 22m from the stream (S22).
The installations are made so that samples can be collected all year by using a heating cable where the water passes through the frozen soil. The hydrology is focused in the upper horizons due to the hydrological conductivity which increases exponentially towards the soil surface.
The soil frost experiment
The soil frost experiment begun 2002 which makes it the longest ongoing experiment of its kind in the world. Winter conditions in the soil are strongly dependent on the timing and amount of snow. Little snow gives very cold soils, whereas early and large amounts of snow will result in “warm” soils.
Colder soils and deeper soil frost gives higher DOC concentrations in the upper soil layers. Colder soils also gives rise to higher DOC concentration in the streams during spring flood.
The Kallkäls mire is the source area for stream C4, and the location of the “Russians wells”. The “Russian wells” are a set of piezometers allowing sampling at different depth in, and below the mire.
In total, close to 20 wells are installed spanning from 5 m to over 150 m depth. The installations were made to cover the entire catchment to investigate regional groundwater as well as to allow more local studies of water pathways. The first wells were installed by the Swedish Geological Survey (SGU) in the 1980s and have been monitored since, whereas the majority was installed in 2012.
Lake studies and Stortjärn infrastructure
Lake Stortjärn is one of the most expansive research sites in Krycklan both in terms of new projects and infrastructure development.
Recent additions to our lake infrastructure include a static platform close to the deepest point of the lake where we have logging equipment for physical variables in both the lake water and the air. Furthermore, during summer we have a floating platform with 20 mesocosms and logging equipment for water manipilation experiments.