Could continuous cover forestry on drained peatlands increase the carbon sink of Finnish forests? 

Land-based mitigation measures are needed to achieve climate targets. One option is mitigation of currently high greenhouse gas (GHG) emissions of nutrient-rich drained peatland forest soils. Continuous cover forestry (CCF) has been proposed as a measure to manage this GHG emission source; however, its emission reduction potential and impact on timber production at regional and national scale have not been analysed. To quantify the potential emission reduction, we simulated four management scenarios for Finnish forests: (i) clearcutting of nutrient-rich drained peatlands replaced by selection harvesting (CCF) and (ii) the current prevailing forest management regime (BAU), and both at two harvest levels, namely (i) the mean annual harvesting (2016–2018) and (ii) the maximum sustainable yield. The simulations were conducted with a forest simulator (MELA) coupled with hydrological model (SpaFHy), soil C model (Yasso07) and empirical GHG exchange models. Simulations showed that the management scenario (CCF) that avoided clear-cutting on nutrient-rich drained peatlands produced approximately 1 Tg CO2 eq. higher carbon sinks annually compared to the BAU at equal harvest level for Finland. This emission reduction can be attributed to the maintenance of higher biomass sink and to the mitigation of soil emissions from nutrient-rich drained peatland sites.