模拟气候升温对湿地土壤微生物群落及磷素形态的影响

通过构建微宇宙湿地柱模拟气候升温的方法,采用高通量测序和核磁共振技术,分别研究了湿地土壤微生物群落和磷素形态对暖化作用的响应特征.结果表明,暖化作用导致了Firmicutes、Clostridia、Clostridiales、Clostridiaceae和Clostridium的相对丰度分别显著下降65%~98%、69%~87%、67%~87%、73%~97%和74%~93%,这表明暖化作用对不同分类水平上的物种Firmicutes到Clostridium具有显著的抑制效应.通过主坐标分析和聚类分析,不同湿地柱采样点的暖化组与对照组样本表现出显著的分离特征,揭示了暖化作用能够诱导微生物群落组成发生显著性变化.磷酸单酯和正磷酸盐是各湿地柱土壤主导的磷素形态,同时暖化作用导致了XX湿地柱采样点的磷酸单酯和正磷酸盐相对丰度分别显著升高275%和下降20%,JH湿地柱采样点的磷酸单酯和多聚磷酸盐相对丰度分别显著升高85%和下降49%,这表明不同磷素形态对暖化作用的响应具有土壤异质性特征.通过典型对应分析,揭示了暖化条件下微生物群落组成的显著变化对磷素形态具有显著的影响效应.

Effect of Simulated Climate Warming on Microbial Community and Phosphorus Forms in Wetland Soils

Microbial community and phosphorus forms in response to simulated climate warming were studied by high-throughput sequencing and ³¹P nuclear magnetic resonance(³¹P-NMR) respectively, which were from wetland soils in constructed microcosm columns. The results revealed that relative abundances of Firmicutes, Clostridia, Clostridiales, Clostridiaceae and Clostridium were significantly decreased by 65%-98%, 69%-87%, 67%-87%, 73%-97% and 74%-93% under warming condition respectively, suggesting warming had a significant inhibitory effect on the bacterial lineage from Firmicutes to Clostridium at different taxonomic level. Particularly, principal coordinate analysis and cluster analysis also demonstrated warming had a significant effect on microbial community structure with obvious separation of samples between control and warmed groups from each wetland column site. Phosphorus forms were dominated by phosphomonoester and orthophosphate in each wetland column soil, which were significantly increased and decreased by 275% and 20% in XX wetland column soil respectively. Similarly, phosphomonoester and polyphosphate were also found to be increased and decreased by 85% and 49% in JH wetland column soil respectively, indicating that phosphorus forms in response to warming had soil heterogeneity. Canonical correspondence analysis showed that obvious changes in microbial community composition had significant effects on phosphorus forms under warming condition.