干旱区生态环境知识资源中心(Arid): Biology and carbon lability of sub-surface nutrient patches in High Arctic polar deserts drives the probability and magnitude of nitrous oxide emissions

Arid

DOI	10.1016/j.soilbio.2020.108001
	Biology and carbon lability of sub-surface nutrient patches in High Arctic polar deserts drives the probability and magnitude of nitrous oxide emissions
	Ota, Mitsuaki; Siciliano, Steven D.
通讯作者	Siciliano, SD
来源期刊	SOIL BIOLOGY & BIOCHEMISTRY
ISSN	0038-0717
出版年	2020
卷号	150
英文摘要	High Arctic polar deserts cover 26% of the Arctic. Climate change is expected to increase cryoturbation in these polar deserts, including frost boils and diapirs. Diapirism-cryoturbic intrusion into the overlying horizon-creates subsurface nutrient patches with low biodegradability and is thought to regulate greenhouse gas emissions, including the potent nitrous oxide. Although nitrous oxide emissions have been observed in polar deserts at a rate comparable to vegetated tundra ecosystems, the underlying mechanism by which nitrous oxide is produced in these environments remains unclear. In this study, we investigated ammonia-oxidizing archaea, which were detected in a previous study, and used stable isotope techniques to characterize the pattern of nitrous oxide emissions from frost boils. Ammonia-oxidizing archaea would be tightly linked to nitrous oxide emissions under aerobic condition whereas low degradable diapiric nutrient would limit denitirification under wet conditions. We hypothesized that (1) diapirism (i.e. diapiric frost boil) would not primarily drive nitrous oxide emissions and therefore abundance of ammonia-oxidizing archaea would be linked to the increase in nitrous oxide emissions under dry conditions favouring nitrification, and (2) diapirism decreases nitrous oxide emissions relative to non-diapiric frost boil under wet conditions that favour denitrification because of the recalcitrant nature of diapiric organic carbon. We used soil samples collected from two High Arctic polar deserts (dolomite and granite) near Alexandra Fjord (78 degrees 51'N, 75 degrees 54'W), Ellesmere Island, Nunavut, Canada from July-august 2013. Ammonia-oxidizing archaea did not differ in abundance between diapiric and non-diapiric frost boils within the dolomitic desert; however, within the granitic desert amoA abundance was 22% higher in diapiric frost boils. In both deserts, the increased abundance of archaeal amoA genes was linked to increased nitrous oxide emissions under dry conditions. Under higher soil moisture conditions favouring denitrification, diapiric frost boils emit N2O with higher probability, but at a lower rate, than non-diapiric frost boils. For example, in the dolomitic desert, diaprism increased the probability of N2O emissions by 104% but decreased the LS mean value of the emission rate by 36%. Similarly, diapirism increased the emission probability by 26% but decreased the LS mean value by 68% within the granitic desert. Under wet conditions, site preference values suggested that fungal and bacterial denitrification were important nitrous oxide emission processes. Our study shows that diapirism is a key cryoturbation process for nitrous oxide emissions in polar deserts primarily through diapirism's alteration of emission probability and the magnitude of the emissions.
英文关键词	Polar desert Cryoturbation (frost boils and diapirism) Nitrous oxide emissions Permafrost degradation Feedbacks to climate change
类型	Article
语种	英语
开放获取类型	hybrid
收录类别	SCI-E
WOS记录号	WOS:000581509300003
WOS关键词	AMMONIA-OXIDIZING ARCHAEA ; GREENHOUSE-GAS PRODUCTION ; SOILS ; N2O ; VEGETATION ; ECOSYSTEM ; DYNAMICS ; DIAPIRISM ; LANDFORMS ; BACTERIA
WOS类目	Soil Science
WOS研究方向	Agriculture
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/327054
作者单位	[Ota, Mitsuaki; Siciliano, Steven D.] Univ Saskatchewan, Dept Soil Sci, 51 Campus Dr, Saskatoon, SK S7N 5A8, Canada
推荐引用方式 GB/T 7714	Ota, Mitsuaki,Siciliano, Steven D.. Biology and carbon lability of sub-surface nutrient patches in High Arctic polar deserts drives the probability and magnitude of nitrous oxide emissions[J],2020,150.
APA	Ota, Mitsuaki,&Siciliano, Steven D..(2020).Biology and carbon lability of sub-surface nutrient patches in High Arctic polar deserts drives the probability and magnitude of nitrous oxide emissions.SOIL BIOLOGY & BIOCHEMISTRY,150.
MLA	Ota, Mitsuaki,et al."Biology and carbon lability of sub-surface nutrient patches in High Arctic polar deserts drives the probability and magnitude of nitrous oxide emissions".SOIL BIOLOGY & BIOCHEMISTRY 150(2020).