where V (m3) is the air volume left within the closed chamber after the
open end of the chamber was inserted into the sediment; ΔM (h−1) is
the difference in gas concentration within the chamber; A (m2) is the
surface area of sediment covered by the chamber and ρ (m3 mol−1) is
the volume of gas per mol under the atmospheric pressure then.
CO2-equivalent greenhouse gas fluxes (Fe, mg CO2m−2 h−1) ofN2O
and CH4 were determined following the formula: