Trajectory of Topsoil Nitrogen Transformations Along a Thermo-Erosion Gully on the Tibetan Plateau

doi:10.1029/2018JG004805

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	Trajectory of Topsoil Nitrogen Transformations Along a Thermo-Erosion Gully on the Tibetan Plateau
	Mao, Chao 3; Kou, Dan 3; Wang, Guanqin 3; Peng, Yunfeng ; Yang, Guibiao 3; Liu, Futing 3; Zhang, Jinbo 2; Yang, Yuanhe 3
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
	2019
卷号	124 期号:5 页码:1342-1354
关键词	carbon-nitrogen interactions gross nitrogen mineralization gross nitrification microbial nitrogen limitation permafrost thaw thermokarst
ISSN号	2169-8953
DOI	10.1029/2018JG004805
文献子类	Article
英文摘要	Permafrost thaw, especially thermokarst formation, that is, ground collapse due to thawing of ice-rich permafrost, is expected to alter soil gross nitrogen (N) transformations, which can regulate plant productivity and ecosystem carbon cycle. However, it remains unclear how thermokarst formation modifies soil N processes in permafrost ecosystems. Here N-15 pool dilution techniques were used to evaluate changes in topsoil gross N transformations during various thaw stages (early, middle, and late stages) along a thermo-erosion gully on the Tibetan Plateau. Structural equation modeling was then conducted to explore the relative importance of biotic and abiotic factors in affecting soil gross N transformations. The results showed that topsoil gross N mineralization (GNM) decreased at the three stages, reflecting declined inorganic N production after permafrost collapse. In contrast, topsoil gross nitrification increased only during the early stage. Additionally, the ratio of microbial N immobilization to GNM was enhanced during the middle and late stages, indicating a stronger microbial N limitation after thermokarst formation. The structural equation modeling analysis revealed that soil moisture played an important role in modulating gross N transformations. For GNM, decreased soil moisture had inhibiting effects via regulating the microbial biomass, microbial community, and enzyme activities along the thaw sequence. For gross nitrification, declined soil moisture exerted facilitating effects directly by improving oxygen availability and indirectly by modulating the abundances of ammonia-oxidizing archaea and bacteria during the early stage. Overall, these results demonstrated that thermokarst formation altered soil N processes, potentially triggering interactions between ecosystem N and carbon cycles after permafrost thaw.
学科主题	Environmental Sciences ; Geosciences, Multidisciplinary
电子版国际标准刊号	2169-8961
出版地	WASHINGTON
WOS关键词	AMMONIA-OXIDIZING BACTERIA ; PERMAFROST CARBON ; MICROBIAL COMMUNITY ; EXTRACTION METHOD ; SOIL ; FOREST ; DYNAMICS ; AVAILABILITY ; INCREASES ; PRODUCTIVITY
WOS研究方向	Environmental Sciences & Ecology ; Geology
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000477719600020
资助机构	National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [31670482, 31825006, 91837312] ; Key Research Program of Frontier Sciences, Chinese Academy of Sciences [QYZDB-SSW-SMC049] ; Chinese Academy of Sciences-Peking University Pioneer Cooperation Team ; Strategic Priority Research Program of the Chinese Academy of SciencesChinese Academy of Sciences [XDA19070303]
内容类型	期刊论文
源URL	[http://ir.ibcas.ac.cn/handle/2S10CLM1/19460]
专题	植被与环境变化国家重点实验室
作者单位	1.Nanjing Normal Univ, Sch Geog Sci, Nanjing, Jiangsu, Peoples R China 2.Univ Chinese Acad Sci, Coll Life Sci, Beijing, Peoples R China 3.Chinese Acad Sci, Inst Bot, State Key Lab Vegetat & Environm Change, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Mao, Chao,Kou, Dan,Wang, Guanqin,et al. Trajectory of Topsoil Nitrogen Transformations Along a Thermo-Erosion Gully on the Tibetan Plateau[J]. JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES,2019,124(5):1342-1354.
APA	Mao, Chao.,Kou, Dan.,Wang, Guanqin.,Peng, Yunfeng.,Yang, Guibiao.,...&Yang, Yuanhe.(2019).Trajectory of Topsoil Nitrogen Transformations Along a Thermo-Erosion Gully on the Tibetan Plateau.JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES,124(5),1342-1354.
MLA	Mao, Chao,et al."Trajectory of Topsoil Nitrogen Transformations Along a Thermo-Erosion Gully on the Tibetan Plateau".JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES 124.5(2019):1342-1354.