Coastal salt marshes are some of the most productive ecosystems on Earth, providing numerous services such as soil carbon storage, flood protection and nutrient filtering, several of which are mediated by the sediment microbiome associated with marsh vegetation. Here, nutrient filtering (nitrate removal through denitrification) was examined by determining microbial (bacteria and archaea) community structure (16S rRNA gene iTag sequencing), diversity, denitrification rates and metabolic potential (assembled metagenomic sequences) in collocated patches of Spartina alterniflora (Spartina) and Juncus roemerianus (Juncus) sediments. The iTag data showed that diversity and richness in Spartina and Juncus sediment microbial communities were highly similar. However, microbial community evenness differed significantly, with the most even communities observed in Juncus sediments. Further, denitrification rates were significantly higher in Juncus compared to Spartina, suggesting oscillations in microbial abundances and in particular the core microbiome identified herein, along with plant diversity influence marsh nitrogen (N) removal. Amplicon and assembled metagenome sequences pointed to a potentially important, yet unappreciated Planctomycetes role in N removal in the salt marsh. Thus, ecosystem perturbations that alter marsh vegetation distribution could impact microbial diversity and may ultimately influence the ecologically important ecosystem functions the marsh sediment microbiome provides.

沿海盐沼是地球上生产力最高的生态系统之一，可提供多种服务，例如土壤碳存储，防洪和养分过滤，其中一些是由与沼泽植被相关的沉积物微生物组介导的。在这里，营养素过滤（通过反硝化作用去除硝酸盐）通过确定微生物（细菌和古细菌）的群落结构（16S rRNA基因iTag测序），多样性，反硝化率和代谢潜能（组装的宏基因组序列）来检查互花米草（Spartina）的并置斑块。）和Juncus roemerianus（Juncus）沉积物。iTag数据显示，斯巴达纳州（Spartina）和juncus沉积物微生物群落高度相似。但是，微生物群落的均匀度差异很大，在准Jun斯沉积物中观察到的菌群最多。此外，脱硝率在显著较高灯心草相比，互花米草，表明微生物丰度的振荡，特别是本文确定的核心微生物组的振荡，以及植物多样性影响沼泽氮（N）的去除。扩增子和组装的元基因组序列指出了盐沼中氮的去除中潜在的重要但尚未被认识的菌苗作用。因此，改变沼泽植被分布的生态系统扰动可能会影响微生物多样性，并可能最终影响沼泽沉积物微生物组提供的具有重要生态意义的生态系统功能。