Stable isotope natural abundance of nitrous oxide emitted from Antarctic tundra soils: effects of sea animal excrement depositions
Article first published online: 19 OCT 2008
Copyright © 2008 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 22, Issue 22, pages 3570–3578, 30 November 2008
How to Cite
Zhu, R., Liu, Y., Li, X., Sun, J., Xu, H. and Sun, L. (2008), Stable isotope natural abundance of nitrous oxide emitted from Antarctic tundra soils: effects of sea animal excrement depositions. Rapid Commun. Mass Spectrom., 22: 3570–3578. doi: 10.1002/rcm.3762
- Issue published online: 19 OCT 2008
- Article first published online: 19 OCT 2008
- Manuscript Accepted: 12 SEP 2008
- Manuscript Revised: 4 SEP 2008
- Manuscript Received: 15 JUN 2008
- National Natural Science Foundation of China. Grant Numbers: 40676005, 40676004
Nitrous oxide (N2O), a greenhouse gas, is mainly emitted from soils during the nitrification and denitrification processes. N2O stable isotope investigations can help to characterize the N2O sources and N2O production mechanisms. N2O isotope measurements have been conducted for different types of global terrestrial ecosystems. However, no isotopic data of N2O emitted from Antarctic tundra ecosystems have been reported although the coastal ice-free tundra around Antarctic continent is the largest sea animal colony on the global scale. Here, we report for the first time stable isotope composition of N2O emitted from Antarctic sea animal colonies (including penguin, seal and skua colonies) and normal tundra soils using insitu field observations and laboratory incubations, and we have analyzed the effects of sea animal excrement depositions on stable isotope natural abundance of N2O. For all the field sites, the soil-emitted N2O was 15N- and 18O-depleted compared with N2O in local ambient air. The mean δ values of the soil-emitted N2O were δ15N = −13.5 ± 3.2‰ and δ18O = 26.2 ± 1.4‰ for the penguin colony, δ15N = −11.5 ± 5.1‰ and δ18O = 26.4 ± 3.5‰ for the skua colony and δ15N = −18.9 ± 0.7‰ and δ18O = 28.8 ± 1.3‰ for the seal colony. In the soil incubations, the isotopic composition of N2O was measured under N2 and under ambient air conditions. The soils incubated under the ambient air emitted very little N2O (2.93 µg N2ON kg−1). Under N2 conditions, much more N2O was formed (9.74 µg N2ON kg−1), and the mean δ15N and δ18O values of N2O were −19.1 ± 8.0‰ and 21.3 ± 4.3‰, respectively, from penguin colony soils, and −17.0 ± 4.2‰ and 20.6 ± 3.5‰, respectively, from seal colony soils. The data from in situ field observations and laboratory experiments point to denitrification as the predominant N2O source from Antarctic sea animal colonies. Copyright © 2008 John Wiley & Sons, Ltd.