The influence of Alternanthera philoxeroide (alligator weed) invasion on wetland organic matter (OM) accumulation and bacterial changes is rarely studied, but is possibly an important step for revealing the invasion mechanism. Thus, the distribution characteristics of light fraction organic carbon and nitrogen (LFOC and LFON), and heavy fractions organic carbon and nitrogen (HFOC and HFON) were analyzed. Sampling was done on two sediment depths (0–15 cm and 15–25 cm) of invaded and normal habitats of two natural wetlands and two constructed wetlands, and bacterial taxa and composition in surface sediments were also analyzed by high-throughput sequencing. In the surface sediments, the LFOC and LFON contents were significantly higher in the constructed wetlands (0.791 and 0.043 g·kg⁻¹) than in the natural wetlands (0.500 and 0.022 g·kg⁻¹), and the contents of the C and N fractions were also prominently higher in the invaded areas than in normal wetland habitats. The OM storage was relatively stable. Proteobacteria (55.94%), Bacteroidetes (5.74%), Acidobacteria (6.66%), and Chloroflexi (4.67%) were the dominant bacterial phyla in the wetlands. The abundance of Acidobacteria, Actinobacteria, and Gemmatimonadetes were significantly higher in the invaded areas than in the normal habitats. The relative high abundance-based coverage estimator (ACE) index in the constructed wetlands and invaded areas suggested the corresponding high bacterial diversity. The significant and positive relationship between Acidobacteria and organic nitrogen concentrations suggested their potential and positive interrelationships. This study demonstrated that the alligator weed invasion could significantly change the compositions of sediment organic matterand bacteria, thus further changing the nutrition cycle and wetland microhabitat.

中文翻译：

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湿地嗜爱碱菌入侵下有机质和细菌群落的组成特征。

的影响莲子草philoxeroide（空心莲子草）入侵对湿地有机物（OM）的积累和细菌的变化很少研究，但是可能用于揭示入侵机制的一个重要步骤。因此，分析了轻质有机碳和氮（LFOC和LFON）和重质有机碳和氮（HFOC和HFON）的分布特征。在两个自然湿地和两个人工湿地的入侵和正常生境的两个沉积物深度（0-15 cm和15-25 cm）上进行采样，并且还通过高通量测序分析了地表沉积物中的细菌类群和组成。在表层沉积物中，人工湿地中的LFOC和LFON含量明显较高（0.791和0.043 g·kg ^-1）比自然湿地（0.500和0.022 g·kg ^-1），而入侵地区的C和N含量也明显高于正常湿地生境。OM存储相对稳定。在湿地中，细菌杆菌（55.94％），拟杆菌（5.74％），酸杆菌（6.66％）和绿弯曲菌（4.67％）是优势菌门。入侵地区的酸性细菌，放线菌和芽孢杆菌的丰度明显高于正常栖息地。在人工湿地和入侵区域中相对较高的基于丰度的覆盖率估计值（ACE）指数表明相应的较高细菌多样性。酸性细菌与有机氮浓度之间的显着正相关关系表明它们之间存在潜在的正相关关系。