Department of Environmental Science and Policy, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
Sci Total Environ. 2013 Jan 15;443:725-32. doi: 10.1016/j.scitotenv.2012.11.052. Epub 2012 Dec 7.
We used multi-tag pyrosequencing of 16S ribosomal DNA to characterize bacterial communities of wetland soils collected from created and natural wetlands located in the Virginia piedmont. Soils were also evaluated for their physicochemical properties [i.e., percent moisture, pH, soil organic matter (SOM), total organic carbon (TOC), total nitrogen (TN), and C:N ratio]. Soil moisture varied from 15% up to 55% among the wetlands. Soil pH ranged between 4.2 and 5.8, showing the typical characteristic of acidic soils in the Piedmont region. Soil organic matter contents ranged from 3% up to 6%. Soil bacterial community structures and their differences between the wetlands were distinguished by pyrosequencing. Soil bacterial communities in the created wetlands were less dissimilar to each other than to those of either natural wetland, with little difference in diversity (Shannon's H') between created and natural wetlands, except one natural wetland consistently showing a lower H'. The greatest difference of bacterial community structure was observed between the two natural wetlands (R=0.937, p<0.05), suggesting these two natural wetlands were actually quite different reflecting differences in their soil physicochemistry. The major phylogenic groups of all soils included Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Gemmatinomadetes, Nitrospira, and Proteobacteria with Proteobacteria being the majority of the community composition. Acidobacteria group was more abundant in natural wetlands than in created wetlands. We found a significant association between bacterial community structures and physicochemical properties of soils such as C:N ratio (ρ=0.43, p<0.01) and pH (ρ=0.39, p<0.01). The outcomes of the study show that the development of ecological functions, mostly mediated by microbial communities, is connected with the development of soil properties in created wetlands. Soil properties should be carefully monitored to examine the progress of functional wetland mitigation.
我们使用 16S 核糖体 DNA 的多标签焦磷酸测序来描述弗吉尼亚山麓地区人工湿地和天然湿地土壤中的细菌群落。还评估了土壤的理化性质[即水分百分比、pH 值、土壤有机质（SOM）、总有机碳（TOC）、总氮（TN）和 C:N 比]。湿地间土壤水分含量在 15%至 55%之间变化。土壤 pH 值在 4.2 到 5.8 之间，显示出皮埃蒙特地区酸性土壤的典型特征。土壤有机质含量范围在 3%到 6%之间。通过焦磷酸测序可以区分湿地间土壤细菌群落结构及其差异。人工湿地中的土壤细菌群落彼此之间的相似性低于天然湿地，除了一个天然湿地的多样性（Shannon's H'）始终较低外，人工湿地和天然湿地之间的多样性差异不大。在两个天然湿地之间观察到细菌群落结构的最大差异（R=0.937，p<0.05），这表明这两个天然湿地实际上非常不同，反映了它们土壤理化性质的差异。所有土壤的主要系统发育群包括 Acidobacteria、Actinobacteria、Bacteroidetes、Chloroflexi、Firmicutes、Gemmatimonadetes、Nitrospira 和 Proteobacteria，其中 Proteobacteria 是群落组成的主要部分。与人工湿地相比，自然湿地中的 Acidobacteria 组更为丰富。我们发现细菌群落结构与土壤理化性质之间存在显著关联，例如 C:N 比（ρ=0.43，p<0.01）和 pH 值（ρ=0.39，p<0.01）。研究结果表明，生态功能的发展，主要由微生物群落介导，与人工湿地土壤特性的发展有关。应仔细监测土壤特性，以检查功能湿地缓解的进展。
