National Plateau Wetlands Research Center/Wetlands College, Southwest Forestry University, Kunming 650224, People's Republic of China; School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, People's Republic of China.
National Plateau Wetlands Research Center/Wetlands College, Southwest Forestry University, Kunming 650224, People's Republic of China.
Sci Total Environ. 2021 Jan 20;753:142194. doi: 10.1016/j.scitotenv.2020.142194. Epub 2020 Sep 3.
Phyllospheric microbes play a crucial role in the biological decomposition of plant litter in wetland ecosystems. Previous studies have mainly focused on single stages of decomposition process, and to date there have been no reports on dynamic changes in the composition of phyllospheric microbes during the multiple stages of decomposition from living plant to death. Here we investigated fungal and bacterial community succession in the leaf litter of Schoenoplectus tabernaemontani, a wetland plant species using sequencing of the both fungal ITS and bacterial 16S genes. Our results revealed that, over the whole period of decomposition, the fungal communities underwent more distinct succession than did the bacterial communities. Proteobacteria dominated throughout the entire period, while, across different decomposition stages, the Ascomycete fungi were gradually replaced by the Ciliophora and Rozellomycota as the dominant fungi. Network analysis revealed higher degrees of species segregation and shorter average path lengths between species of fungi compared with species of bacteria. This suggests that fungal communities may harbor more niches and functional diversity and are potentially more susceptible to external interference than are bacterial communities. During decomposition, the contents of leaf cellulose, hemicellulose and lignin in the litter were significantly (p < 0.01) correlated with the fungal communities, and abiotic factors accounted for 89.8% of the total variation in the fungal communities. In contract, abiotic factors only explained 6.10% of the total variation in bacterial communities, suggesting external environments as drivers of fungal community succession. Overall, we provide evidence that the complex litter decay in wetlands is the result of a dynamic cross-kingdom succession, and this process is accompanied by distinct phyllospheric fungal community dynamics.
叶际微生物在湿地生态系统中植物凋落物的生物分解过程中起着至关重要的作用。以前的研究主要集中在分解过程的单一阶段，迄今为止，还没有关于从活体植物死亡到分解的多个阶段中叶际微生物组成的动态变化的报道。在这里，我们使用真菌 ITS 和细菌 16S 基因测序，研究了湿地植物种茭白叶凋落物中真菌和细菌群落的演替。我们的结果表明，在整个分解过程中，真菌群落的演替比细菌群落更为明显。变形菌门在整个时期都占主导地位，而在不同的分解阶段，子囊菌门真菌逐渐被纤毛菌门和裂殖菌门真菌取代，成为优势真菌。网络分析显示，与细菌相比，真菌之间的物种隔离程度更高，种间平均路径长度更短。这表明真菌群落可能具有更多的生态位和功能多样性，并且比细菌群落更容易受到外部干扰。在分解过程中，凋落物中叶片纤维素、半纤维素和木质素的含量与真菌群落显著相关（p<0.01），而生物因素占真菌群落总变异的 89.8%。相比之下，生物因素仅解释了细菌群落总变异的 6.10%，这表明外部环境是真菌群落演替的驱动因素。总的来说，我们提供的证据表明，湿地中复杂的凋落物分解是一个动态的跨域演替的结果，这一过程伴随着明显的叶际真菌群落动态。
