Diurnal patterns of nitrous oxide fluxes from a seasonal prairie wetland

Wetlands have spatially and temporally dynamic nitrous oxide (N₂O) fluxes. Understanding diurnal patterns in N₂O fluxes in wetlands can reveal short-term drivers and improve process-based models. An automated chamber system was used to determine N₂O flux rates every 2.5 to 4 h in a prairie pothole wetland in North Dakota during the 2013 to 2014 growing seasons under ponded, moist, and dry soil conditions. The wetland generally emitted N₂O under all conditions, although median fluxes during ponded conditions were low over the two-year study. A significant diurnal N₂O pattern was observed under dry soil conditions, but not in moist soil or ponded conditions. When soils were dry, daytime (~ 10:00–14:00; 2.43 ± 0.31 ng m^-2 hr^-1) and late-day (~ 14:00–18:00; 2.20 ± 0.16 ng m^-2 hr^-1) average N₂O fluxes were 77% and 61% greater, respectively, than other times during the 24-hr diel cycle (