What is the net climate impact of rewetted peatland forests in boreal Sweden?

Between 1.5 and 2.0 million ha of natural peatlands in Sweden have been drained for forestry during the past century. Recently, these areas have been identified as potentially major greenhouse gas (GHG) emission sources.

This concern has sparked interest among the Swedish governmental agencies in rewetting drained peatland forests as a strategy for mitigating GHG emissions.

It is noteworthy, however, that reduced CO2 emissions from rewetted peat soils might be offset by a concurrent increase in the emission of CH4.

In addition, changes in aquatic export and surface albedo following rewetting have been mostly unaccounted for in current assessments. The gained climate benefit from the rewetting measures is thus highly uncertain. The overall aim of this project is to determine the net climate impact of a rewetted peatland forest in boreal Sweden.

This will be achieved by detailed investigations on rewetting effects on the individual net CO2 exchange components in WP1, followed by a first-time estimate of full C and GHG balances (incl. terrestrial and aquatic fluxes) for a rewetted boreal peatland forest in WP2.

In WP3, the net climate impact of the rewetting measures will be assessed by accounting for the radiative forcing from both GHG balance and surface albedo changes.

Thus, this project will provide the various Swedish decision-makers invaluable empirical data to support climate-responsible management strategies and facilitate development towards a low carbon society.