Comparing microbial carbon sequestration and priming in the subsoil   versus topsoil of a Qinghai-Tibetan alpine grassland

doi:10.1016/j.soilbio.2016.10.018

CORC > 北京大学 > 城市与环境学院

	Comparing microbial carbon sequestration and priming in the subsoil versus topsoil of a Qinghai-Tibetan alpine grassland
	Jia, Juan ; Feng, Xiaojuan ; He, Jin-Sheng ; He, Hongbo ; Lin, Li ; Liu, Zongguang
刊名	SOIL BIOLOGY & BIOCHEMISTRY
	2017
关键词	Warming Priming effect Amino sugar C-13 Microbial necromass Carbon accumulation efficiency (CAE) SOC degradability SOIL ORGANIC-MATTER FUMIGATION-EXTRACTION METHOD USE EFFICIENCY CLIMATE-CHANGE AMINO SUGAR BIOMASS-C DECOMPOSITION PLATEAU AVAILABILITY STABILIZATION
DOI	10.1016/j.soilbio.2016.10.018
英文摘要	Subsoils of alpine grasslands on the Qinghai-Tibetan Plateau represent a tremendous yet poorly investigated reservoir of soil organic carbon (SOC) on a global "hotspot" of warming. Compared with the temperature sensitivity of SOC decomposition, microbial anabolism of new carbon and priming of native SOC remain poorly constrained under warming-enhanced labile carbon input in these subsoils. Here we employed an innovative approach to investigate the sequestration of freshly added carbon in microbial necromass versus SOC priming in the top- (0-10 cm) and subsoils (30-40 cm) from a field experiment that simulated varied warming scenarios in an alpine grassland on the Qinghai-Tibetan Plateau. The C-13 composition of microbial necromass-derived amino sugars was analyzed in tandem with respired CO2 and dissolved SOC components (including dissolved lignin) in an 86-day laboratory incubation with C-13-labeled glucose. A higher fraction of freshly added carbon was respired while a smaller proportion was stabilized as amino sugars in the subsoil relative to the topsoil, leading to a much lower microbial carbon accumulation efficiency at depth. Meanwhile, a higher relative priming effect was observed in the subsoil (47 +/- 14%) compared to the topsoil (14 +/- 4%), suggesting a higher vulnerability to substrate-induced SOC loss at depth, although such changes may be associated with higher glucose addition rate (relative to SOC) in the subsoil. Furthermore, enhanced winter warming significantly reduced degradable SOC (assessed by SOC mineralization and dissolved lignin content) in the subsoil and potentially intensified nitrogen limitation under labile carbon additions, which further decreased microbial carbon accumulation (in the form of amino sugars) in the subsoil without affecting the topsoil. These results collectively indicate a limited microbial carbon sequestration potential and a higher vulnerability to warming induced substrate changes in the subsoil of this alpine grassland, which warrants better understanding to predict soil carbon responses to climate warming on the Qinghai-Tibetan Plateau. (C) 2016 Elsevier Ltd. All rights reserved.; Chinese National Key Development Program for Basic Research [2014CB954003, 2015CB954201]; National Natural Science Foundation of China [31370491, 41422304]; National Thousand Young Talents recruiting plan of China; SCI(E); ARTICLE; 141-151; 104
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/476528]
专题	城市与环境学院
推荐引用方式 GB/T 7714	Jia, Juan,Feng, Xiaojuan,He, Jin-Sheng,et al. Comparing microbial carbon sequestration and priming in the subsoil versus topsoil of a Qinghai-Tibetan alpine grassland[J]. SOIL BIOLOGY & BIOCHEMISTRY,2017.
APA	Jia, Juan,Feng, Xiaojuan,He, Jin-Sheng,He, Hongbo,Lin, Li,&Liu, Zongguang.(2017).Comparing microbial carbon sequestration and priming in the subsoil versus topsoil of a Qinghai-Tibetan alpine grassland.SOIL BIOLOGY & BIOCHEMISTRY.
MLA	Jia, Juan,et al."Comparing microbial carbon sequestration and priming in the subsoil versus topsoil of a Qinghai-Tibetan alpine grassland".SOIL BIOLOGY & BIOCHEMISTRY (2017).