文献类型：期刊文献

英文题名：Carbon availability affects soil respiration response to drying-rewetting cycles in semiarid grasslands of China under nitrogen deposition

作者：He, Yunlong[1,2] Qi, Yuchun[1] Peng, Qin[1] Dong, Yunshe[1] Guo, Shufang[1] Yan, Zhongqing[1] Li, Zhaolin[1]

第一作者：He, Yunlong;贺云龙

通信作者：Dong, YS[1]

机构：[1]Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Land Surface Pattern & Simulat, Beijing 100101, Peoples R China;[2]Chinese Acad Forestry, Res Inst Forestry, State Forestry Adm, Key Lab Forest Silviculture, Beijing 100091, Peoples R China

年份：2019

卷号：93

外文期刊名：EUROPEAN JOURNAL OF SOIL BIOLOGY

收录：;Scopus(收录号：2-s2.0-85066118711);WOS:【SCI-EXPANDED(收录号:WOS:000479022600004)】；

基金：This work was supported by the National Natural Science Foundation of China (No. 41573131, 41673086, and 41330528). We gratefully acknowledge the Inner Mongolia Grassland Ecosystem Research Station for assistance in the field as well as the support of the national science & technology infrastructure supports. Finally, we thank the editors and the anonymous reviewers for their valuable comments on this manuscript.

语种：英文

外文关键词：Soil respiration; Carbon availability; Nitrogen deposition; Soil microbes; Drying-rewetting cycle

摘要：Soil carbon (C) availability is an important limiting factor affecting the magnitude of soil respiration with increasing the drying-rewetting cycle number. Previous studies have reported that because of a deficiency in available C, improved nitrogen (N) availability has no effects on soil respiration in semiarid grasslands. However, it is not well understood whether the effects of N availability on soil respiration in response to drying-rewetting cycles is regulated by C availability in semiarid grasslands under N deposition scenarios. A field experiment was conducted in a semiarid grassland of northern China to investigate the response of soil CO2 efflux to drying-rewetting cycles (natural precipitation events) with the addition of labile C (glucose, 48 g C m(-2) a(-1)) and N (NH4NO3, 10 g N m(-2) a(-1)) in August 2014. The drying-rewetting cycle significantly increased soil respiration rate in the treatments with both C and N additions, whereas it did not significantly increase soil respiration rate in the treatments with added N alone. After the first drying-rewetting cycle, a significant increase in soil microbial biomass C (MBC) content was observed in the treatments with both C and N additions but was not observed in the treatment with added N alone. After a series of drying-rewetting cycles, the cumulative CO2 efflux over the observed period was significantly higher in the treatments with both C and N additions than that in the treatment with added N alone. These findings imply that improved N availability during the period of 20 days has no effects on soil respiration in response to the drying-rewetting cycle due to microbial C limitation under N deposition scenarios in a semiarid grassland.