Pedosphere (6): 838--848, 2023
ISSN 1002-0160/CN 32-1315/P
©2023 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Drying-rewetting cycles reduce bacterial diversity and carbon loss in soil on the Loess Plateau of China |
Panpan JIAO1,2,3, Haibing XIAO1,2,4, Zhongwu LI1,2,5 , Lei YANG3,6, Peng ZHENG1,2,3 |
1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling 712100(China);
2 Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100(China);
3 University of Chinese Academy of Sciences, Beijing 100049(China);
4 State Environmental Protection Key Laboratory of Soil Health and Green Remediation, Huazhong Agricultural University, Wuhan 430070(China);
5 College of Resources and Environmental Sciences, Hunan Normal University, Changsha 410081(China);
6 Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008(China) |
| ABSTRACT |
| With global climate change, soil drying-rewetting (DRW) events have intensified and occurred frequently on the Loess Plateau of China. However, the extent to which the DRW cycles with different wetting intensities and cycle numbers alter microbial community and respiration is barely understood. Here, indoor DRW one and four cycles treatments were implemented on soil samples obtained from the Loess Plateau, involving increase of soil moisture from 10% water-holding capacity (WHC) to 60% and 90% WHC (i.e., 10%-60% and 10%-90% WHC, respectively). Constant soil moistures of 10%, 60%, and 90% WHC were used as the controls. The results showed that bacterial diversity and richness decreased and those of fungi remained unchanged under DRW treatments compared to the controls. Under all moisture levels, Actinobacteriota and Ascomycota were the most dominant bacterial and fungal phyla, respectively. The bacterial network was more complex than that of fungi, indicating that bacteria had a greater potential for interaction and niche sharing under DRW treatments. The pulse of respiration rate declined as the DRW cycle increased under 10%-60% WHC, but remained similar for different cycles under 10%-90% WHC. Moreover, the DRW treatments reduced the overall carbon loss, and the direct carbon release under 10%-60% WHC was larger than that under 10%-90% WHC. The cumulative CO2 emissions after four DRW cycles were significantly positively correlated with microbial biomass carbon and negatively correlated with fungal richness (Chao 1). |
| Key Words: bacterial network,cumulative CO2 emissions,fungal richness,microbial biomass carbon,microbial community,respiration rate,soil moisture |
| Citation: Jiao P P, Xiao H B, Li Z W, Yang L, Zheng P. 2023. Drying-rewetting cycles reduce bacterial diversity and carbon loss in soil on the Loess Plateau of China. Pedosphere. 33(6): 838-848. |
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