Nitrous oxide production pathways in Australian forest soils

Pan, B., Zhang, Y., Xia, L., Lam, S. K., Hu, H.-W., & Chen, D. “Nitrous oxide production pathways in Australian forest soils.” Geoderma, 420, 115871. DOI: 10.1016/j.geoderma.2022.115871

Forest soils are a major source of N₂O emissions from terrestrial ecosystems. However, the magnitude and contribution of N₂O production from different pathways in Australian forest soils remain uncertain. We conducted a ¹⁵N tracing laboratory incubation experiment on 13 forest soils sampled from subtropical, temperate and arid regions across Australia and found that forest soils in temperate areas had the highest N₂O emission rate (19.5 µg N kg⁻¹ soil d^-1), followed by subtropical and arid soils (3.84 and 3.80 µg N kg⁻¹ soil d^-1, respectively). N₂O production in Australian forest soils was mainly derived from the organic nitrogen (N) pool; its contribution followed the order of arid (78%) > subtropical (69%) > temperate (59%). N₂O emission potentially from heterotrophic nitrification was negatively correlated with latitude (p < 0.05) and the contribution of soil organic N to N₂O production was negatively correlated with soil total N and total carbon (C) content (p < 0.01). Our study improves the understanding of N₂O production pathways from warm arid to cool temperate regions in Australian forest soils.