School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Carnegie's Department of Plant Biology, Stanford, CA 94305, USA.
Environ Int. 2020 Jan;134:105198. doi: 10.1016/j.envint.2019.105198. Epub 2019 Nov 5.
The importance of microbial communities in the function of lotic ecosystems is unequivocal. However, traditional watershed studies on biodiversity have mostly focused on benthic macroinvertebrates, macroalgae and fish assemblages. Here, we investigated the diversity and interaction patterns of microbial communities in water and bed sediment of streams impacted by intensive watershed activities versus streams with relatively pristine conditions via next-generation sequencing of 16S rRNA amplicons using Illumina HiSeq platform. Both water and sediment microbial communities at forested sites had higher mean alpha-diversity than developed sites. Although microbial alpha-diversity indices were generally higher in bed sediment than water, they were comparable at forested sites. In addition, losses of taxa important in nitrogen cycle were evident particularly in bed sediment of developed sites. Interactions among microorganisms visualized by microbial network were more complex at forested sites versus developed sites, with more keystone taxa predominantly from sediment. Together, these findings suggest stream water and bed sediment microbial communities may be affected by watershed disturbances in distinctive ways, and losses of important functional microbial players and keystone taxa in bed sediment may result in decline of ecosystem functions and services. Therefore, cautions should be taken when implementing remediation strategies such as sediment dredging, and reseeding contaminated sites with key microbial players may catalyze the recovery of ecosystems.
微生物群落对于流水生态系统功能的重要性是不言而喻的。然而，传统的生物多样性流域研究主要集中在底栖大型无脊椎动物、藻类和鱼类群落上。在这里，我们通过 Illumina HiSeq 平台对 16S rRNA 扩增子进行下一代测序，调查了受集约化流域活动影响的溪流和相对原始条件的溪流中水体和底泥微生物群落的多样性和相互作用模式。森林地区的水体和底泥微生物群落的平均α多样性均高于开发地区。尽管底泥中的微生物α多样性指数通常高于水体，但在森林地区两者相当。此外，在开发地区的底泥中，氮循环中重要类群的损失尤为明显。通过微生物网络可视化的微生物相互作用在森林地区比开发地区更为复杂，关键类群主要来自底泥。总之，这些发现表明溪流的水和底泥微生物群落可能以独特的方式受到流域干扰的影响，而底泥中重要功能微生物类群和关键类群的损失可能导致生态系统功能和服务的下降。因此，在实施沉积物疏浚等修复策略时应谨慎，而向受污染的地点重新引入关键微生物类群可能会促进生态系统的恢复。
