Soil CN ratio as a scalar parameter to predict nitrous oxide emissions

Abstract

Abstract Forested histosols have been found in some cases to be major, and in other cases minor, sources of the greenhouse gas nitrous oxide (N 2 O). In order to estimate the total national or global emissions of N 2 O from histosols, scaling or mapping parameters that can separate low‐ and high‐emitting sites are needed, and should be included in soil databases. Based on interannual measurements of N 2 O emissions from drained forested histosols in Sweden, we found a strong negative relationship between N 2 O emissions and soil CN ratios ( r 2 adj =0.96, mean annual N 2 O emission= a e (− b CN ratio) ). The same equation could be used to estimate the N 2 O emissions from Finnish and German sites based on CN ratios in published data. We envisage that the correlation between N 2 O emissions and CN ratios could be used to scale N 2 O emissions from histosols determined at sampled sites to national levels. However, at low CN ratios (i.e. below 15–20) other parameters such as climate, pH and groundwater tables increase in importance as regulating factors affecting N 2 O emissions.