Mari Annala’s research while affiliated with Finnish Environment Institute and other places

After drainage for forestry and agriculture, peat extraction is one of the most important causes of peatland degradation. When peat extraction is ceased, multiple after-use options exist, including abandonment, restoration, and replacement (e.g., forestry and agricultural use). However, there is a lack of a global synthesis of after-use research. Through a systematic review of 356 peer-reviewed scientific articles, we address this research gap and examine (1) what after-use options have been studied, (2) what the studied and recognized impacts of the after-use options are, and (3) what one can learn in terms of best practices and research gaps. The research has concentrated on the impacts of restoration (N = 162), abandonment (N = 72), and replacement (N = 94), the latter of which consists of afforestation (N = 46), cultivation (N = 34) and creation of water bodies (N = 14). The studies on abandonment, restoration, and creation of water bodies have focused mostly on analyzing vegetation and greenhouse gas (GHG) fluxes, while the studies assessing afforestation and cultivation sites mostly evaluate the provisioning ecosystem services. The studies show that active restoration measures speed-up vegetation recolonization on bare peat areas, reduce GHG emissions and decrease negative impacts on water systems. The most notable research gap is the lack of studies comparing the environmental and social impacts of the after-use options. Additionally, there is a lack of studies focusing on social impacts and downstream hydrology, as well as long-term monitoring of GHG fluxes. Based on the reviewed studies, a comparison of the impacts of the after-use options is not straightforward. We emphasize a need for comparative empirical research in the extracted sites with a broad socio-ecological and geographical context.

Currently, in Finland, thousands of hectares of peat production areas are being transformed to the after-use phase for which there are multiple options, such as restoration, afforestation, cultivation, and production of solar and wind power. In Finland, the landowner decides what after-use option is implemented. When the after-use of the peat production areas is planned, multiple factors need to be accounted for, including environmental site characteristics, and landowner and stakeholder preferen-ces. Therefore, there is a need for tools that help to choose the new land-uses for the areas. We have developed a multi-criteria assessment approach that is based on stakeholder workshops and includes eight steps: identification of stakeholders, definition of objectives for the after-use, examination of site characteristics, identification of after-use options, after-use impact assessment, weighting of objectives, synthesizing the results, and communicating the plan. We pilot the approach through three workshops in the Turvesuo-Miehonsuo peat production area in Oulu, northern Finland. The following three main after-use options have been identified: rewetting (including shallow water bodies, and active and passive restoration), spontaneous revegetation, and afforestation. It has been assessed which after-use option is suitable for which sub-area of the former peat production site and what kind of environmental impacts the after-uses have. The developed approach is suitable particularly to precede the detailed after-use planning when the different after-use options are scoped. Furthermore, the approach and the discussions in the workshops enable systematic evaluation of the after-use planning and social learning.