Universal temperature sensitivity of denitrification nitrogen losses in forest soils

Soil nitrous oxide (N2O) and dinitrogen (N2) emissions from denitrification are crucial to the nitrogen (N) cycle. However, the temperature sensitivities (Q10) of gaseous N losses in forest soils are poorly understood, with implications for prediction of N cycle responses to warming. Here, we quantify temperature sensitivities of denitrification-derived potential N2O and N2 production. Using soils from 18 forest sites in China along a 4,000 km north–south transect we find that N2O and N2 production rates increased with temperature, with large variations across soils. In contrast, the Q10 values for N2O (2.1 ± 0.5) and N2 (2.6 ± 0.6) were similar across soils. N2 was more sensitive to temperature than N2O, suggesting that warming could promote complete denitrification. Moreover, the Q10 for denitrification (2.3 ± 0.5) was comparable to Q10 for aquatic sediments. This finding of universal temperature sensitivity of gaseous N losses from denitrification will facilitate modelling N losses in response to warming globally. Warming affects forest soil denitrification and nitrogen losses. The authors show that temperature enhances nitrous oxide and dinitrogen but varies by soil; temperature sensitivities are similar across soils but are higher for dinitrogen, suggesting complete denitrification in a warmer climate.