Authors: Xiaoqi Zhou Chengrong Chen Yanfen Wang Zhihong Xu Zhengyi Hu Xiaoyong Cui Yanbin Hao
Publish Date: 2012/04/25
Volume: 48, Issue: 7, Pages: 859-866
Abstract
Understanding the responses of soil C mineralization to climate change is critical for evaluating soil C cycling in future climatic scenarios Here we took advantage of a multifactor experiment to investigate the individual and combined effects of experimental warming and increased precipitation on soil C mineralization and 13C and 15N natural abundances at two soil depths 0–10 and 10–20 cm in a semiarid Inner Mongolian grassland since April 2005 For each soil sample we calculated potentially mineralizable organic C C 0 from cumulative CO2C evolved as indicators for labile organic C The experimental warming significantly decreased soil C mineralization and C 0 at the 10–20cm depth P 005 Increased precipitation however significantly increased soil pH NO 3 − N content soil C mineralization and C 0 at the 0–10cm depth and moisture and NO 3 − N content at the 10–20cm depth all P 005 while significantly decreased exchangeable NH 4 + N content and 13C natural abundances at the two depths both P 005 There were significant warming and increased precipitation interactions on soil C mineralization and C 0 indicating that multifactor interactions should be taken into account in future climatic scenarios Significantly negative correlations were found between soil C mineralization C 0 and 13C natural abundances across the treatments both P 005 implying more plantderived C input into the soils under increased precipitation Overall our results showed that experimental warming and increased precipitation exerted different influences on soil C mineralization which may have significant implications for C cycling in response to climate change in semiarid and arid regionsThis study was conducted as part of a comprehensive research project Global Change Multifactor Experiment—Duolun sponsored by the Institute of Botany Chinese Academy of Sciences This research was supported by the National Science Foundation of China no 30925009 The authors thank Prof Shiqiang Wan for accessing the experimental site and Prof P Nannipieri EditorinChief and two reviewers for helpful comments on the early version of the manuscript
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