Abstract
With increasing nitrogen (N) deposition, soil nitrous oxide (N2O) emission is expected to increase, causing positive feedback to global warming. However, the substrates of soil N2O emission, especially their responses to N addition, are still unclear. Here, we conducted an in situ 15N tracing experiment to study the substrates of N2O (i.e., ammonium-derived, nitrate-derived and organic N-derived N2O emission) under N addition treatment in a temperate forest in northeast China. Nitrate derived N2O through denitrification contributed most to the total N2O emission, pointing to the importance of denitrification under ambient N deposition. NH4NO3 addition of 50 kg N ha−1 yr−1 significantly increased organic N derived N2O on the 6th day after N addition, which suggests that heterotrophic nitrification may be the dominating process with higher N deposition rate. However, because soil pH and the examined functional genes did not change after N addition, future studies should be carried out to understand if the increase of heterotrophic nitrification is transient. Our study emphasizes the role of organic N pool in soil N2O emissions, highlighting the importance of considering the heterotrophic nitrification process while studying soil N cycling or modeling soil N2O emission.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
