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REFORMWATER

Reducing the effects of forest management to inland waters

Project Coordinator

Jukka Pumpanen: jukka.pumpanen@uef.fi

Institution: University of Agricultural Scienses

Country: Sweden

Abstract

The largest lakes in Nordic countries, which are among the most important raw water supplies for the major cities, are showing brownification i.e. increase in dissolved organic matter and humic substances. This phenomenon, common across much of the northern latitudes, has primarily been suggested to result from processes related to the recovery from acid deposition and increase in winter precipitation. However, in the Nordic countries, land use primarily related to forest management on drained peatlands has also been shown to play an important role in the large scale brownification. As the demand for timber, pulpwood, renewable energy sources and biodegradable materials is increasing, there is an ongoing pressure to use the large timber stock on drained peatlands and to carry out ditch network maintenance (DNM) to allow for reestablishment of new forests. There is significant timber stock in the large drained peatland forests that are soon coming to harvesting age. Since 62-72% of the land area in these countries is covered by forests of which up to 25% on drained peatlands, related increases in dissolved organic matter (DOM) and accompanying nutrient fluxes from such forest under management regime is a major threat to water quality. Large scale DNM will possibly result in increased brownification and eutrophication of water bodies, thus affecting the water quality in recipient water bodies.

The aim of this study is therefore to quantify the effects of current management practices (harvesting and subsequent ditch network maintenance (DNM)) on peatland forests on the transport of DOM and its quality to aquatic systems. In addition, we will develop a novel tool based on biochar application to decrease the DOM and nutrient load on aquatic systems. Finally, we aim to develop state-of the art process-modelling techniques for assessing the effects of forest management practices on water quality in peatland-dominated catchments, and for optimizing the production in such a way that enables wood production while keeping the adverse environmental impacts to a minimum.

The project will be based on field experiments where the effects of different forest management techniques on water quality are tested. We will also carry out detailed laboratory experiments for determining the effect of DOM quality on greenhouse gas production from aquatic systems. The project is based on multidisciplinary collaboration between foresters, soil scientists and limnologists.

Funder of the project:

Academy of Finland (Finland)

A Swedish Research Council for Sustainable Development, FORMAS (Sweden)

Estonian Research Council, ETAG (Estonia)

Environmental Protection Agency, EPA (Ireland)

Photo of the Research Team:

team.jpg