Warming reduces the increase in N2O emission under nitrogen fertilization in a boreal peatland

Yu Gong; Jianghua Wu; Judith Vogt; Thuong Ba Le

doi:10.1016/j.scitotenv.2019.02.012

Warming reduces the increase in N₂O emission under nitrogen fertilization in a boreal peatland

Sci Total Environ. 2019 May 10:664:72-78. doi: 10.1016/j.scitotenv.2019.02.012. Epub 2019 Feb 2.

Authors

Yu Gong¹, Jianghua Wu², Judith Vogt¹, Thuong Ba Le¹

Affiliations

¹ Environment and Sustainability, School of Science and the Environment, Memorial University of Newfoundland, Corner Brook, NL A2H 5G4, Canada; Graduate Program in Environmental Science, Memorial University of Newfoundland, St. John's, NL, Canada.
² Environment and Sustainability, School of Science and the Environment, Memorial University of Newfoundland, Corner Brook, NL A2H 5G4, Canada; Graduate Program in Environmental Science, Memorial University of Newfoundland, St. John's, NL, Canada. Electronic address: jwu@grenfell.mun.ca.

PMID: 30743132
DOI: 10.1016/j.scitotenv.2019.02.012

Abstract

Peatlands are known as N₂O sinks or low N₂O 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 N₂O 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 N₂O flux was not detectable during the growing seasons of 2015 and 2016. The N fertilization treatment significantly increased the N₂O flux by 1.61 nmol m^-2 s^-1 due to increased N availability. Noticeably, warming reduced the effect of N fertilization treatment on N₂O 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 N₂O emission under N fertilization, while dissolved organic carbon was the main driver under the combined treatment of warming and N fertilization. Due to elevated N₂O emissions under N deposition/fertilization, the contribution of N₂O to global warming and ozone depletion should not be ignored.

Keywords: Boreal peatlands; Dissolved organic carbon; Nitrogen fertilization; Nitrous oxide; Total nitrogen; Warming.

MeSH terms

Global Warming*
Newfoundland and Labrador
Nitrogen
Nitrogen Dioxide / analysis*
Permafrost*
Seasons

Substances

Nitrogen
Nitrogen Dioxide