A paper by a Grenfell researcher regarding the effects of soil nitrogen on peatland greenhouse gas emissions has caught the attention of Communications Biology, a Nature.com satellite journal, which publishes papers that “represent significant advances bringing new biological insight to a specialized area of research”, and has been published online.
Dr. Jianghua Wu of Grenfell’s School of Science and the Environment, along with several research partners, studied whether soil nitrogen would determine northern peatland greenhouse gas emissions under concurrent warming and vegetation shifting.
Members of his research team included Dr. Junwei Luan, a post-doctorial research fellow, now associate research professor at the International Centre of Bamboo and Rattan, Beijing, China, who made an equal contribution to the paper and shared in the design of the experimental set-up; collaborator Dr. Nigel Roulet at McGill University; collaborator Dr. Shirong Liu at the Chinese Academy of Forestry Science, who was Dr. Luan’s PhD supervisor; and Dr. Mei Wang, associate professor at the School of Geographic Sciences, South China Normal University, Guangzhou, China. At the time of the study, Dr. Wang was Dr. Wu’s PhD student and in addition to helping develop the conceptual model, assisted in the field sampling and sample analysis.
Peatlands and Climate Change
“Peatlands store almost 30% of the total global soil carbon; therefore, they play an important role in global carbon cycling and global climate change,”
said Dr. Wu.
“This study was to attempt to understand the correlation between peatland carbon cycling and greenhouse gas emissions from peatlands and climate change. Specifically, we aimed to examine how the projected warming and elevated nitrogen deposition would alter greenhouse gas emissions from peatlands and how these alterations can be modulated by changes in vegetation compositions.”
After collecting a year’s worth of data, the team found that elevated nitrogen deposition will mitigate the effects of global warming on methane emissions, but global warming would enhance the effects of elevated nitrogen deposition on nitrous oxide emissions.
“Moreover, a shift in vegetation composition will either mitigate or enhance these interactive effects, depending on the specific shifts in vegetation composition,”
said Dr. Wu.
This study was based on a manipulative field experiment, where air was manually warmed to simulate global warming; nitrogen fertilizer was used to simulate increased nitrogen deposition and selected vegetation removed to simulate the shift in vegetation composition.
Caution and Further Study
While the results are encouraging, Dr. Wu cautions that the outcomes are based on solely one year’s data.
“We are continuing this study to see if this finding would stand in the long term,”
he said, adding that two PhD students will continue the study for their PhD thesis research.
“We would like to know if this effect was only a short-term or it would be a sustainable long-term effect – only then could we state that this could be a solution for controlling global warming. Our study helped understand how the natural ecosystem would respond to global warming, but the solution of global warming largely still depends on human efforts to reduce greenhouse gas emissions.”