Warming reduces the increase in N 2 O emission under nitrogen fertilization in a boreal peatland

• Published in: The Science of the total environment Vol. 664; p. 72
• Main Authors: Gong, Yu, Wu, Jianghua, Vogt, Judith, Le, Thuong Ba
• Format: Journal Article
• Language: English
• Published: Netherlands 10-05-2019
• Subjects: Dissolved organic carbon; Warming; Nitrogen fertilization; Boreal peatlands; Nitrous oxide; Total nitrogen
• ISSN: 1879-1026
• DOI: 10.1016/j.scitotenv.2019.02.012

Peatlands are known as N
O sinks or low N
O sources due to nitrogen (N) limitation. However, climate warming and N deposition can modulate this limitation, and little is known about the combinative effects of them on N
O emission from boreal peatlands. In this study, experimental warming and N fertilization treatments were conducted at a boreal peatland in western Newfoundland, Canada. Contrary to previous studies on permafrost peatland and alpine meadows, the effect of warming treatment on N
O flux was not detectable during the growing seasons of 2015 and 2016. The N fertilization treatment significantly increased the N
O flux by 1.61 nmol m
 s
due to increased N availability. Noticeably, warming reduced the effect of N fertilization treatment on N
O flux with high significance in the middle growing season of 2015. This can be attributed to low N availability caused by stimulated vegetation growth in the warming treatment. In addition, the results showed that total nitrogen was the main control on N
O emission under N fertilization, while dissolved organic carbon was the main driver under the combined treatment of warming and N fertilization. Due to elevated N
O emissions under N deposition/fertilization, the contribution of N
O to global warming and ozone depletion should not be ignored.