Ecological restoration of boreal peat extraction sites: the effects on greenhouse gas emissions, mire vegetation and recipient streams - ENARI

Due to the classification of peat as a fossil fuel in EU, inclusion of peat energy to emissions trading system and increase in the prices of emission allowances have made the burning of peat for energy unprofitable. In Finland, many peat extraction companies have shut down their energy peat extraction operations and initiated the closure and after-use management procedures in a vast number of peat extraction sites. The change in the peat extraction market and business landscape has unprecedented the initial plans for the pace of transition from the use of peat energy to renewable energy sources. The national government programme for 2019-2023 set an initial target to reduce the energy use of peat at least 50 % by 2030. Currently, it seems that this target will be reached much faster than initially expected and energy use of peat and extraction as fuel will likely end completely by that year. EU has initiated the Just Transition Fund (JTF) as a funding tool to mitigate the adverse socioeconomic impacts on businesses and territories that are the most affected by EU’s Green Deal and aims to climate neutrality. In Finland, mitigation of the socioeconomic impacts of the diminishing energy peat extraction is one of the key targets for the fund allocation.

Due to sudden loss of demand for energy peat, numerous peat extraction sites have ended the peat extraction sooner than initially planned and been transitioned from active operation to after-use phase. After the mandatory extraction site management and closure period, the potential after uses of peat extraction sites include active restoration to mires and wetlands, agriculture and crop production, afforestation or land use for solar and wind energy. For the aims and goals of EU’s biodiversity strategy for 2030, Water Framework Directive and Habitats Directive, the restoration of peatlands is likely the best long-term solution to support the aims of these strategies and directives. However, there is currently lack of knowledge on how restoration of former peat extraction sites influences greenhouse gas emission, water quality and ecological status of recipient water bodies in short time intervals and in a long-term. For example, increase in water table and wetted surface area might, at least during initial stages of peatland recovery, temporarily increase erosion of peat sediments and leaching of nutrients and organic carbon from the residual peat layers.

In this project, we will monitor and assess the restoration effectiveness of former peat extraction sites by measuring greenhouse gas emissions, revegetation, run-off water quality and the ecological conditions of recipient stream ecosystems. We will use a chronosequence study design by selecting restored sites with different time elapsed since restoration to assess the initial and long-term effects of restoration intervention. Moreover, we will compare the results to comparable near-natural peatland sites, which are used as reference to assess if restoration has initiated ecosystem recovery towards the desired outcome of near-natural state.