Lake Gårdsjön catchment (LTER) - Sweden
Lake Gårdsjön catchment (LTER)
Lake Gårdsjön catchment (LTER)
catchment runoff chemistry
The lake Gårdsjön catchment is 2.1 km2 and includes 5 lakes and a number of headwater streams. It is located 50 km north of Göteborg. The whole area has been intensively studied for the last 30 years by scientists from IVL and from other institutes from Sweden and from abroad. Since 1979 several both national and international projects have been carried out. Smaller sub-catchments were used for experiments ranging from clear cutting, liming, fertilisation, sulphur addition and a combination of these treatments. In 1989 two large manipulation experiments were initiated. In the “Roof” experiment catchment G1 was covered by a transparent plastic roof and for 10 years the polluted precipitation was substituted with clean artificial precipitation sprinkled under the roof in a de-acidification experiment. The adjacent catchment G2 has been fertilised with NH4NO3 since 1991 to study several aspects (soil, water, vegetation) transition from N limited to N saturated conditions. Research at Gårdsjön resulted in three books and a large number of publications, covering different environmental problems, a range of pollutants, aquatic and terrestrial parts of the catchment, soils, vegetation and organisms. The site has served as an educational centre with countless visitors both from Sweden and abroad.
General Characteristics, Purpose, History
Through the years the following main themes have been researched: • Acidification of forest soils, streams and lakes and recovery from acidification. Anthropogenic deposition of sulphur dioxide, nitrogen oxides and ammonia has accelerated the level of acidification in Swedish forest soils, streams and lakes. Also, the land use, i.e. forestry, contributes to soil and water acidification. • Eutrophication of terrestrial ecosystems and risk for nitrate leaching. The N deposition to the Gårdsjön area is c. 10 kg N/ha/yr. Most of the incoming N is stored in soils and vegetation. This affects all parts of the ecosystem and it is a potential problem for the future, not the least under changed climate and increased pressure to intensify forest productivity. Studies of N cycling are tightly connected to studies of C cycling. Thus, the eutrophication studies have clear connection to climate change problems. There are also several studies from Gårdsjön dealing with cycling of P. • Climate change is a major driver of future ecosystem change. It must be taken into account in any predictions and extrapolations of ecosystem research results not the least in model predictions. Long-term measurements of climate parameters such as precipitation and temperature in air and soil, wind and solar radiation are monitored at Gårdsjön. • Vegetation changes due to air pollution, land use and climate change is a major environmental concern and it is studied at Gårdsjön in repeated vegetation surveys and by modelling. • Mercury cycling has been studied at Gårdsjön for 20+ years including development of reliable analytical methods to determine the natural background levels of Hg and Me-Hg. Gårdsjön was among the first sites where the Hg budget for a whole catchment was established and where the studies included deposition, processes in both soils and lake. At Gårdsjön, these broad themes are investigated by combining monitoring, small and large scale research experiments and modelling. The width of the research often requires inviting and involving national and international experts from a number of universities and other institutions. The past three decades of research left behind established monitoring on a number of plots and catchments, a wealth of data and a wide range of performed and documented studies.
Affiliation and Network Specific Information