Aridity thresholds of soil microbial metabolic indices along a 3,200 km transect across arid and semi-arid regions in Northern China

doi:10.7717/peerj.6712

	Aridity thresholds of soil microbial metabolic indices along a 3,200 km transect across arid and semi-arid regions in Northern China
	Hou, Jianfeng 1,2; Dijkstra, Feike A.3; Zhang, Xiuwei 1,4,5; Wang, Chao 1; Lu, Xiaotao 1; Wang, Peng 1; Han, Xingguo 6; Cheng, Weixin 1,7
刊名	PEERJ
	2019-04-09
卷号	7 页码:19
关键词	Respiration Microbial metabolism Metabolic quotient Carbon limitation Microbial biomass Microbial biomass
ISSN号	2167-8359
DOI	10.7717/peerj.6712
英文摘要	Soil microbial processes are crucial for understanding the ecological functions of arid and semi-arid lands which occupy approximately 40% of the global terrestrial ecosystems. However, how soil microbial metabolic activities may change across a wide aridity gradient in drylands remains unclear. Here, we investigated three soil microbial metabolic indices (soil organic carbon (SOC)-based microbial respiration, metabolic quotient, and microbial biomass as a proportion of total SOC) and the degree of carbon limitation for microbial respiration along a 3,200 km transect with a wide aridity gradient. The aridity gradient was customarily expressed using the aridity index (AI) which was calculated as the ratio of mean annual precipitation to mean annual evaporation, therefore, a lower AI value indicated a higher degree of aridity. Our results showed non-linear relationships between AI values and the metabolic indices with a clear aridity threshold for each of the three metabolic indices along the aridity gradient, respectively (AI = 0.13 for basal respiration, AI = 0.17 for metabolic quotient, and AI = 0.17 for MBC:SOC ratio). These metabolic indices linearly declined when AI was above the thresholds, but did not show any clear patterns when AI was below the thresholds. We also found that soil microbial respiration was highly limited by available carbon substrates at locations with higher primary production and relatively lower level of water limitation when AI was above the threshold, a counter-intuitive pattern that microbes were more starved in ecosystems with more substrate input. However, the increasing level of carbon limitation did correspond to the declining trend of the three metabolic indices along the AI gradient, which indicates that the carbon limitation influences microbial metabolism. We also found that the ratio of microbial biomass carbon to SOC in arid regions (AI < 0.2) with extremely low precipitation and primary production were not quantitatively related to SOC content. Overall, our results imply that microbial metabolism is distinctively different in arid lands than in non-arid lands.
资助项目	National Key R&D projects in China[2016YFA0600801] ; National Basic Research Program of China (973 Program)[2015CB150802] ; National Natural Science Foundation of China[31470527]
WOS研究方向	Science & Technology - Other Topics
语种	英语
出版者	PEERJ INC
WOS记录号	WOS:000463857900006
内容类型	期刊论文
源URL	[http://210.72.129.5/handle/321005/124031]
专题	中国科学院沈阳应用生态研究所
通讯作者	Hou, Jianfeng; Cheng, Weixin
作者单位	1.Chinese Acad Sci, Inst Appl Ecol, Erguna Forest Steppe Ecotone Res Stn, Shenyang, Liaoning, Peoples R China 2.Univ Chinese Acad Sci, Beijing, Peoples R China 3.Univ Sydney, Sch Life & Environm Sci, Sydney Inst Agr, Camden, NSW, Australia 4.Taizhou Univ, Inst Wetland Ecol & Clone Ecol, Taizhou, Zhejiang, Peoples R China 5.Taizhou Univ, Zhejiang Prov Key Lab Evolutionary Ecol & Conserv, Taizhou, Zhejiang, Peoples R China 6.Chinese Acad Sci, Inst Bot, Beijing, Peoples R China 7.Univ Calif Santa Cruz, Environm Studies Dept, Santa Cruz, CA 95064 USA
推荐引用方式 GB/T 7714	Hou, Jianfeng,Dijkstra, Feike A.,Zhang, Xiuwei,et al. Aridity thresholds of soil microbial metabolic indices along a 3,200 km transect across arid and semi-arid regions in Northern China[J]. PEERJ,2019,7:19.
APA	Hou, Jianfeng.,Dijkstra, Feike A..,Zhang, Xiuwei.,Wang, Chao.,Lu, Xiaotao.,...&Cheng, Weixin.(2019).Aridity thresholds of soil microbial metabolic indices along a 3,200 km transect across arid and semi-arid regions in Northern China.PEERJ,7,19.
MLA	Hou, Jianfeng,et al."Aridity thresholds of soil microbial metabolic indices along a 3,200 km transect across arid and semi-arid regions in Northern China".PEERJ 7(2019):19.