| Study goal and motivation
Natural peatlands are highly valuable landscape elements whose functions and management are covered by 5 out of 16 National Environmental Goals and 2 milestone targets of the Swedish EPA. Over the past century, however, about 1.5 million hectares (i.e. ~25%) of Swedish peatlands have been drained and afforested. Current management strategies for these drained peat soils include various practices within nature restoration (i.e. rewetting via ditch blocking) and forestry (i.e. ditch maintenance to increase drainage). While we know that these practices largely affect the soil biogeochemistry, their overall impact on greenhouse gas (GHG) emissions from drained peat soils is highly uncertain.
The main project objectives are to:
1) investigate drainage impacts on GHG balances of forested peatlands in boreal Sweden
2) evaluate the impacts of nature restoration and forestry practices (i.e. rewetting and ditch maintenance) on GHG emissions from peat soils.
Thus, this project addresses key issues related to nature conservation and soil management according to the main criteria of this call.
Background
Northern peatlands play an important role in regulating the global climate system by sequestering atmospheric CO2 as peat organic matter and releasing CH4 to the atmosphere. While undisturbed peatlands provide a sink for atmospheric CO2 and have a long-term cooling impact on the global climate, drained peat soils may act as major GHG sources due to enhanced CO2 and N2O emissions. To date, however, data on contemporary GHG balances of drained forested peatlands are lacking especially for the vast areas with nutrient-poor soils in boreal Sweden.
Current management strategies for these drained peat soils include different practices that severely affect their biogeochemistry and GHG balance. On the one hand, nature conservation projects are aiming at restoring drained peatlands through rewetting. On the other hand, forest owners are considering ditch maintenance activities to improve soil drainage prior to harvest. Since the effects on soil conditions from the various practices will differ, the choice of management strategy might largely affect the GHG balance of boreal landscapes. Our current understanding of impacts from nature conservation and forestry practices on GHG emissions from drained peat soils is, however, very limited.
Project description
Eddy-covariance measurements of the full ecosystem GHG exchange of a forested peatland will be complemented with data on soil GHG fluxes, forest production and stream C export in work package 1 (WP1). The impact of rewetting and ditch maintenance activities on the GHG balance of drained forested peatlands will be investigated experimentally in WP2 and WP3, respectively, in collaboration with Länsstyrelsen and Skogstyrelsen. We already received funding from FORMAS for a 2-year Post-Doc, instrumentation and running costs. Thus, all required operational support for a PhD-project is secured. Here we apply for funding of a PhD-student salary.
Deliverables
This project will deliver novel data of GHG budgets for drained forested peatlands in boreal Sweden and provide policy makers as well as nature conservation and forestry stakeholders with valuable science-based decision support. |