Wildfire effects on biogeochemistry of soil and surface water

Knowledge on aquatic effects of wildfire is important, because little data exist and increased frequency of wildfire is expected as a consequence of climate change. Pyrowater will focusing on major chemical and biological effects of wildfire in aquatic ec osystems. 3 catchment affected by wildfire, 3 affected by both wildfire and salvage logging, and 3 control catchments will be incorprated. The field work will be conducted in the large wildfired area in Froland, Aust-Agder County, where 2600 ha burned in June 2008. Main topics to be studied: - Short end long term changes in major chemical compounds in soilwater, stream and lake water, including changes in critical loads. - Qualittative and quantitative changes in PAH by distance from the fire, based on a regional survey on PAH in soil, sediment and fish (PAH metabolites in bile). - Variations in stable sulphure isotope ratio (d34S) in precipitation, soil- and stream-water, from base flow and during high flow periods, in order to improve the knowledge a bout temporary variations in sinks and sources of SO42- in acidified ecosystems. - Qualitative and quantitative changes in phyto- and zoo-plankton in lakes caused by changes in essential nutrients (base cations, N, P, S and C) - Changes in accumulation of PAH and Hg in fish as enhanced productivity and restructured aquatic food web are expected consequences of wildfire. Stable isotope analyses of carbon (d13C) and nitrogen (d15N) will be included. - Evaluate the miRNA technique as a new tool to reveal int ernal biological/genetic response mechanisms related to specific environmental pressures, as acid, Al rich water. A pilotstudy will be implemented on brown trout under laboratory conditions. If success, similar analyses will be performed on wild fish from the fired area Telemark University College will lead the project and 3 Norwegian universities and 2 research institutes will participate.