Tools and means for managing peatland forests - how to diminish impacts on water and climate (TurVI)

Participants

Finnish Environment Institute (SYKE)

Description

Duration: 2020–2023

Drainage of peatlands is a risk for receiving water bodies. Negative effects are emphasized by the longterm nature of loading. Forestry-based loading is also usually targeted to the most sensitive topwaters, which are otherwise only slightly affected by human actions. The loading to water bodies caused by forest management measures mainly consists of nutrients, solid substances (SS), organic carbon and heavy metal emissions. The SS-loading from ditch network maintenance is classified as one of the most significant emissions from forestry operations. The SS-loading and SS-bound nutrients are most pronounced and long-lasting in areas where ditches’ bases consist of clay and fine soils, and where the ditches have extended all the way down to the mineral soil beneath the peat. Drainage increases the decomposition of peat, which also increases the leaching of nutrients and organic carbon to the runoff waters. Changes in the quality of runoff strongly affect the status of receiving water bodies. Increased peat decomposition also increases the amount of carbon dioxide released into the atmosphere. Although drainage reduces the release of a stronger greenhouse gas, methane, from the peat into the atmosphere, a drained peatland has been estimated to be methane-neutral at its best, since the ditches continue to release methane and may have a significant impact on the carbon balance of the dried area. The project 'Tools and means for managing peatland forests - how to diminish impacts on water and climate (TurVI)' aims to determine the criteria for sufficient ditching depths for tree growth, and to implement tailor-made ditching depths in order to reduce harmful loading to receiving water bodies, and also to control the greenhouse gas emissions.

Further information

Mirkka Visuri, Researcher, mirkka.visuri@ymparisto.fi