酸处理对花岗岩土壤细菌群落结构及多样性的影响

发布时间：2019-03-21 15:00

【摘要】：酸沉降显著影响着土壤生态系统的结构组成与系统功能,但对我国南方花岗岩发育的酸性土壤细菌群落结构及多样性的影响还知之甚少。因此,本文以酸沉降影响严重的亚热带地区花岗岩发育的剖面(0~100 cm)土壤为对象,采用不同酸度的HCl-NH_4Cl溶液(pH=3.5,4.5,5.5)对A层(0~12 cm)、B层(12~50 cm)与C层(50~100 cm)土壤分别进行分批次淋溶实验(Batch方法),探讨在此特定实验条件下酸溶液作用前后土壤细菌群落结构及多样性的变异特征。研究结果表明,利用Miseq技术对土壤细菌16S r RNA基因进行高通量测序与分析发现酸溶液可以显著降低A层、B层和C层土壤的细菌多样性,pH3.5酸处理土壤的细菌多样性降低幅度最大,pH4.5酸处理土壤的降低幅度最小。HCl-NH_4Cl酸溶液可显著影响花岗岩土壤细菌的群落结构,并导致土壤细菌的优势种群发生变化,其中,A层土壤细菌优势种群由酸杆菌门(Acidobacteria)转变为变形菌门(Proteobacteria),B层和C层土壤细菌优势种群由变形菌门(Proteobacteria)转变为放线菌门(Actinobacteria)。细菌相对丰度变化特征和主成分分析结果表明,pH3.5、pH4.5和pH5.5三种酸处理之间没有明显差异,但不同层次土壤细菌群落结构对同一pH酸溶液的响应不一致,这是由A、B、C层土壤理化性质的差异性,从而对酸处理的响应不同所致。因此,HCl-NH_4Cl酸溶液对土壤细菌群落结构、优势种群和多样性产生的显著影响与土壤的性质密切相关,并反作用于土壤发生、演变及生态系统演替。
[Abstract]:Acid deposition significantly affected the structure and function of soil ecosystem, but little was known about the effect of acid deposition on the bacterial community structure and diversity of acid soil developed by granite in southern China. Therefore, in this paper, the soil of granite development profile (0 / 100 cm) in subtropical region affected seriously by acid deposition was studied by using HCl-NH_4Cl solution (pH=3.5,4.5,5.5) with different acidity to treat layer A (0? 12 cm),). A batch leaching experiment (Batch method) was carried out in layer B (12 ~ 50 cm) and layer C (50 ~ 100 cm) to investigate the variation characteristics of soil bacterial community structure and diversity before and after acid solution treatment. The results showed that high throughput sequencing and analysis of 16s r RNA gene of soil bacteria by Miseq showed that acid solution could significantly reduce the bacterial diversity of soil in layer A, layer B and layer C, and that the bacterial diversity of soil in layer A, layer B and layer C could be significantly reduced by acid solution. The decrease of bacterial diversity was the greatest in pH3.5 acid treated soil and the smallest in pH4.5 acid treated soil. The bacterial community structure of granite soil was significantly affected by HCl-NH_4Cl acid solution. The dominant population of soil bacteria changed, in which the dominant population of soil bacteria in layer A changed from (Acidobacteria) to (Proteobacteria),. The dominant population of soil bacteria in layer B and layer C changed from (Proteobacteria) to (Actinobacteria). The variation characteristics of relative abundance of bacteria and the results of principal component analysis showed that there was no significant difference among the three acid treatments of pH3.5,pH4.5 and pH5.5, but the response of bacterial community structure of different soil layers to the same pH acid solution was not consistent. This is due to the difference of physical and chemical properties of A, B, C layer soil, so that the response to acid treatment is different. Therefore, the significant effects of HCl-NH_4Cl acid solution on soil bacterial community structure, dominant population and diversity are closely related to soil properties, and react to soil occurrence, evolution and ecosystem succession.
【作者单位】：南京信息工程大学应用气象学院;中国科学院南京土壤研究所;
【基金】：国家自然科学基金项目(41471176;41071141)资助
【分类号】：S154.3

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