有机质对城市湿地微生物丰度的影响

摘要

Urban wetland suffers from not only the constant increase of organic matter load,but also the issue of organic matter in the topsoil is damaged in the process of urban development and construction. By adding the dissolved organic matter(DOM)solution of Cinnamomum camphora leaves,together with real-time fluorescence quantitative PCR,the effects of exogenous organic matter on the abundance of microorganisms in the topsoil(0-5 cm)was studied in simulative way. The results showed that changes in soil structure significantly affected the abundances of bacteria,archaea and functional genes associated with nitrogen cycles. The abundances of bacteria and functional genes associated with nitrogen cycles decreased significantly while soil organic matter content decreased(P <0.05). The addition of nitrogen and DOM in the overlying water remarkably increased the abundances of microorganism and nitrogen functional genes in wetland. The exogenous DOM significantly affected the two genes in the transformation process of NO2--N to N2O and NO.%城市湿地不仅面临着外源有机质负荷不断增加的问题,而且湿地表层土壤的有机质在城市建设过程中会被破坏.通过外加樟树树叶浸出液,利用实时荧光定量PCR技术,模拟研究了外源有机质增加对湿地土壤表层微生物丰度影响.结果表明,土壤结构的改变显著影响细菌、古菌及氮循环各环节功能基因的丰度.土壤有机质含量下降,细菌及氮循环相关功能基因的丰度都显著降低(P<0.05).同时提高上覆水中的外源氮和DOM含量会显著促进湿地微生物以及氮功能基因丰度的增加.外加DOM会显著影响NO2--N向N 2O、NO的转化过程的两个基因.