模拟增温对高寒沼泽草甸土壤细菌群落的影响

Effects of Simulated Warming on Soil Bacterial Communities of Alpine Swamp Meadow in the Qinghai-Tibet Plateau

文章以青藏高原高寒沼泽草甸为研究对象,建造开顶式增温室模拟增温,基于高通量测序技术,并结合土壤理化指标,探讨2种增温处理(W1:1.5~2.5℃;W2:3~5℃)对土壤细菌群落结构及多样性的影响。结果表明:变形菌门(38.717%~53.872%)、酸杆菌门(13.303%~30.484%)和放线菌门(6.031%~13.534%)为优势菌群,优势菌门相对丰度对增温幅度的高低表现出不同的响应趋势。增温抑制了土壤细菌群落多样性,其中,W2处理10~20 cm土层,Shannon和Simpson指数相比对照均显著降低。Mantel分析表明,pH和微生物量氮是影响细菌群落结构的主要驱动因子。Pearson相关性分析表明,pH和铵态氮是影响优势菌门的主要土壤因子。模拟增温使青藏高原土壤细菌类群相对丰度发生改变,土壤细菌群落多样性表现为降低趋势,土壤理化指标对细菌群落影响显著。

In order to investigate the impacts of climate warming on soil bacterial communities of alpine swamp meadow in the Qinghai-Tibet Plateau,a simulated warming experiment was conducted with the experimental facility,i.e.open top chambers(OTCs).The effects of two simulated warming modes(W1:1.5~2.5℃;W2:3~5℃)were explored on the basis of the high-throughput sequencing technique and measuring relevant physico-chemical indicators.Consequently,the experiment presented that the soil dominant bacterial phyla were Proteobacteria(38.717%~53.872%),Acidobacteria(13.303%~30.484%)and Actinobacteria(6.031%~13.534%);the relative abundance of the dominant bacteria was affected by warming magnitude;and the temperature elevation inhibited the diversity of soil bacterial communities:for the example of case W2,in the top-layer(10~20 cm)soil there were notable decline of the Shannon and Simpson indices compared with that of the control case.Additionally,result of the Mantel test showed that pH and soil microbial biomass nitrogen were the main driving factors affecting soil bacterial community structure;and the Pearson correlation analysis suggested that pH and soil ammonium nitrogen were the major soil factors influencing the dominant bacterial phyla.In conclusion,the simulated warming experiment suggested that climate warming would alter the relative abundance of soil bacteria phyla and the diversity of soil bacterial communities in the Qinghai-Tibet Plateau;the soil bacteria communities tended to decline;and the bacterial communities were significantly influenced by the soil physico-chemical indicators.