| 黄土高原草地土壤细菌群落结构对于降水变化的响应 |
| 摘要点击 1460 全文点击 560 投稿时间：2019-12-23 修订日期：2020-03-14 |
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| 中文关键词 黄土高原 降水变化 土壤微生物 群落结构 高通量测序 |
| 英文关键词 loess plateau precipitation change soil microorganisms community structure high throughput sequencing |
| 作者 | 单位 | E-mail | | 李娜 | 西北农林科技大学水土保持研究所, 黄土高原土壤侵蚀与旱地农业国家重点实验室, 杨凌 712100 | nali_912@163.com | | 王宝荣 | 中国科学院水利部水土保持与生态环境研究中心, 杨凌 712100
中国科学院大学, 北京 100049 | | | 安韶山 | 西北农林科技大学水土保持研究所, 黄土高原土壤侵蚀与旱地农业国家重点实验室, 杨凌 712100
中国科学院大学, 北京 100049 | shan@ms.iswc.ac.cn | | 焦峰 | 西北农林科技大学水土保持研究所, 黄土高原土壤侵蚀与旱地农业国家重点实验室, 杨凌 712100 | | | 黄倩 | 西北农林科技大学资源环境学院, 杨凌 712100 | |
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| 中文摘要 |
| 微生物作为生态系统功能的主要参与者，对降水变化引起的土壤水分变化的响应是科学评估气候变化对半干旱生态系统影响的一个非常重要的方面.为研究降水变化对土壤微生物群落结构多样性的影响，在黄土高原进行了为期2 a的原位模拟降雨变化实验，设置了5种降水梯度，即减少自然降雨的80%和40%、自然降雨和增加自然降雨的40%和80%（编号为D80、D40、NP、I40和I80）.结果表明：①减雨或增雨80%处理中C/N较低，而增雨40%（I40）时最大，0~20 cm土层的均值为10.76；MBC/MBN在减雨80%（D80）和增雨80%（I80）处理中随土层变化显著，D80时最大值为14.15.②黄土高原天然草地土壤中，主要的优势菌门为放线菌门（Actinobacteria）、变形菌门（Proteobacteria）、绿弯菌门（Chloroflexi）、酸杆菌门（Acidobacteria），主要的优势菌纲为放线菌纲（Actinobacteria）、酸杆菌纲（Acidobacteria）、α-变形杆菌纲（α-Proteobacteria）和热微菌纲（Thermomicrobia）.③ RDA分析显示，在降水处理条件下，土壤溶解性有机碳、可溶性有机氮、电导率、pH值的变化是影响该研究区土壤细菌分布的主要因素.总之，干旱或极端降水对黄土高原区土壤活性有机质含量和土壤细菌种群多样性及丰度影响显著. |
| 英文摘要 |
| As the main participants of ecosystem functions, the response of microorganisms to variations in soil moisture caused by the changes in precipitation amounts should be quantified to evaluate the impact of climate change on semi-arid ecosystems. For this purpose, a two-year simulation of the changes in the rainfall patterns was conducted on the Loess Plateau, and five precipitation treatments (80% and 40% decrease in precipitation, D80, D40; natural precipitation, NP; 40% and 80% increase in precipitation, I40, I80) were set up. The results showed that: ① Compared with NP, the carbon-to-nitrogen ratio (C/N) was lower in DP80 or IP80, while it reached the maximum value in I40. The mean C/N value of the 0-20 cm soil layer was 10.76. The microbial biomass carbon to microbial biomass nitrogen ratio (MBC/MBN) varied significantly with the soil layer in the treatments of D80 and I80, and the maximum value was 14.15 in D80. ② In the grassland soil naturally growing on the Loess Plateau, at the phylum level, the dominant phyla were Actinobacteria, Proteobacteria, Chloroflexi, and Acidobacteria. At the class level, Actinobacteria, Acidobacteria, α-Proteobacteria, and Thermomicrobia were predominant. ③ RDA analysis showed that changes in soil dissolve organic carbon (DOC), dissolved organic nitrogen (DON), elemental carbon (EC), and pH values were the main factors affecting the distribution of soil bacteria under the five precipitation treatments in the study area. Overall, 80% increase or decrease in precipitation has a significant impact on soil active organic carbon content and bacterial abundance, especially D80. In conclusion, drought or extreme precipitation may considerably change the active organic matter content and bacterial community diversity and abundance in the soils of the Loess Plateau. |
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