Effect of mowing on N2O and CH4 fluxes emissions from the meadow-steppe grasslands of Inner Mongolia

To assess the impacts of mowing on N 2 O and CH 4 fluxes emissions from the meadow-steppe grasslands of Inner Mongolia, China, two regimes were investigated: unmown since 2005 (UM), and mown once every three years since 2009 (M3). On-site measurements were conducted continuously during a year-round period (August 2011 to August 2012). During the observation period, three diurnal cycles were also measured. In addition, a targeted laboratory experiment was conducted to make up for the few measurements in winter. A large pulse of N 2 O emissions related to freeze-thaw cycles was observed at M3 during the spring thaw. Results showed that the meadow-steppes played a role as a sink for CH 4 and a source for N 2 O. Significantly lower mean CH 4 uptake at UM (40.3 μg C·m −2 ·h −1 ) as compared to M3 (70.5 μg C ·m −2 ·h −1 ) ( p