Decreasing carbon emissions in boreal peatland forests using fertilization and less intensive drainage in current and changing climate

Different climate scenarios predict a clear rise in temperatures and a modest increase in precipitation to high latitudes. In forested peatlands, the consequent lowering of the water table and increasing peat temperature will enhance organic matter decomposition leading to higher nutrient release and CO2 emissions from the peat. These biogechemical changes will fundamentally alter the management schemes of peatland forests. Hydrological and biogeochemical processes in forested peatlands are complicated, interlinked and characterized by different feedback mechanisms. In addition, all these are dependent on weather conditions, peat characteristics, drainage dimensions, and stand structure.  High-resolution geospatial data combined with process-based ecosystem models provides a solution in searching for new forest management schemes that balance between different ecosystem services. We have developed this kind of ecosystem model, peatland simulator SUSI, and applied it to study how manipulation of drain network, ash fertilization and forest management affect tree growth, greenhouse gas balance and nutrient export to water courses under different temperature and rainfall scenarios. We found that without a change in the water management, the stand growth, the soil C emissions and nitrogen export to water courses will increase substantially. However, less intensive drainage together with ash fertilization helped to mitigate the harmful effects of changing climate whilst keeping the stand growth in adequate level.