Influence of forest management changes and reuse of peat production areas on water quality in a northern river.

• A challenge in land use is related to use of peatlands for bioenergy production. • We created storylines for land use of peat fields together with climate change. • We modelled their influence on water quality by process-based models. • Conversion to arable land may pose a risk to the ecological status of the river. • Sustainable development in energy production leads to the best water quality. In Northern Finland, the most significant land use challenges are related to bioenergy production from peat extraction and forest biomass. Increasing societal demand for bioenergy may increase production rates. However, environmental impacts of peat extraction are of increasing concern, which has led to a decline in production, thereby freeing up these areas for other uses. Using storylines for different societal futures and process-based models (PERSiST and INCA), we simulated the effect of simultaneous land use change and climate change on water quality (phosphorus, nitrogen and suspended sediments concentration). Conversion of peat extraction areas to arable land, together with climate change, may pose a risk for deterioration of ecological status. On the other hand, continuous forestry may have positive impacts on water quality. Suspended sediment concentrations in the river do not exceed water quality requirements for salmonids, but nitrogen concentrations may exceed threshold values especially during high flows. A storyline emphasizing sustainable development in energy production led to the best outcome in terms of water protection. [ABSTRACT FROM AUTHOR]