不同干扰方式下松江湿地土壤微生物群落结构和功能特征

以松江湿地为研究对象,采用磷脂脂肪酸(PLFA)和BIOLOG微平板法,系统分析4种干扰方式(农业、工业、旅游和保护)对湿地土壤微生物群落结构和功能的影响。结果表明,微生物对碳源利用能力由强到弱依次为:滨江湿地(保护)金河湾湿地(旅游)白鱼泡湿地(旅游)太阳岛湿地(旅游)呼兰河口湿地(农业)阿什河湿地(工业)。松江湿地土壤微生物对羧酸类、糖类和氨基酸类碳源利用率较高,而对多聚物类、酚类和胺类的利用率较低,其中羧酸类和糖类是影响微生物群落代谢功能的敏感碳源。松江湿地土壤微生物以细菌为主,占总PLFA的69.72%—80.97%,真菌次之(9. 20%—23. 51%),放线菌最少(6.77%—9.82%); Shannon多样性指数以滨江湿地最高(2.994),阿什河湿地最低(2.881)。RDA分析表明,受工业、农业干扰的阿什河湿地和呼兰河口湿地微生物群落结构与TN、NO_3~--N和NH_4~+-N呈显著正相关(P0.05);受旅游干扰的太阳岛湿地微生物群落结构与pH呈显著正相关;而同样受旅游干扰的白鱼泡和金河湾湿地微生物群落结构与p H呈显著负相关;受保护的滨江湿地微生物群落结构主要受TC/TN影响。

Structural and functional characteristics of soil microbial community in the Songjiang wetland under different interferences

In this study, we systematically analyzed the effect of four kinds of disturbances (agriculture, industry, tourism, and protection) on the structure and function of soil microbial communities in the Songjiang wetland using phospholipid fatty acid (PLFA) and BIOLOG micro plate methods. The results showed that the order of the from high to low microbial utilization of carbon sources was as follows: Binjiang wetland (protection) > Jinhe Bay wetland (tourism) > Baiyupao wetland (tourism) > Sun Island wetland (tourism) > Hulan Estuary wetland (agriculture) > Ashi River wetland (industry). The soil microbes utilized carboxylic acids, carbohydrates, and amino acids at a higher rate than polymers, phenols, and amines in the Songjiang wetland. Carboxylic acids and carbohydrates were sensitive carbon sources that affected the metabolic function of microbial communities. The dominant microorganisms in the Songjiang wetland were bacteria accounting for 69.72%-80.97% of the total microbial PLFA, followed by fungi (9.20%-23.51%), and Actinomyces (6.77%-9.82%). The highest bacterial Shannon diversity index occurred in the Binjiang wetland (2.994), whereas the lowest was observed in the Ashi River wetland (2.881). An RDA analysis showed that the microbial community structure in the Ashi River (industrial interference) and Hulan Estuary (agricultural interference) wetlands had a significantly positive correlation with TN, NO₃^--N, and NH₄⁺-N (P<0.05); the microbial community structure in the Sun Island wetland (tourism interference) was significantly positively correlated with pH, whereas it showed a significant negative correlation with pH in Baiyupao and Jinhe Bay wetlands, which were also influenced by tourism disturbance; the microbial community structure was mainly influenced by TC/TN in the Binjiang wetland, which was protected.