Future scenarios of N2O and NO emissions from European forest soils

Abstract

In this study we investigated possible feedbacks of predicted future climate change on forest soil NO and N2O emissions in Europe. For this we used two climate scenarios, one representing a 10‐year period of present‐day climate (1991–2000) and a 9‐year period for future climate conditions (2031–2039). The climate scenarios were used to drive the GIS‐coupled biogeochemical model Photosynthesis‐Evapotranspiration‐Model–Denitrification‐Decomposition‐Model (PnET‐N‐DNDC), which has currently been tested for its predicting capability for soil N trace gas emissions for various sites across Europe. The model results show a complex, spatially differentiated pattern of changes in future N2O and NO emissions from the forest soils across Europe, which were driven by the combined effect of changes in precipitation and temperature. Overall, the model predicted that N2O emissions from the European forest soils will on average decrease by 6%. This decrease was mainly due to the shift in N2O:N2 ratio driven by enhanced denitrification. NO emissions were found to increase by 9%. The increases in NO emissions were mainly due to increases in temperature. Only for the regions where soil moisture was predicted to markedly increase or suffer from water stress during the vegetation period, a reduction of NO emissions was simulated. The simulations show the possibility and feasibility for assessing climate change feedbacks on biogenic N trace gas emissions from soils at a regional scale.