UiT The Arctic University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway.
GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany.
Sci Rep. 2020 Dec 29;10(1):22412. doi: 10.1038/s41598-020-79773-2.
Northern peatlands typically develop through succession from fens dominated by the moss family Amblystegiaceae to bogs dominated by the moss genus Sphagnum. How the different plants and abiotic environmental conditions provided in Amblystegiaceae and Sphagnum peat shape the respective moss associated microbial communities is unknown. Through a large-scale molecular and biogeochemical study spanning Arctic, sub-Arctic and temperate regions we assessed how the endo- and epiphytic microbial communities of natural northern peatland mosses relate to peatland type (Sphagnum and Amblystegiaceae), location, moss taxa and abiotic environmental variables. Microbial diversity and community structure were distinctly different between Amblystegiaceae and Sphagnum peatlands, and within each of these two peatland types moss taxon explained the largest part of microbial community variation. Sphagnum and Amblystegiaceae shared few (< 1% of all operational taxonomic units (OTUs)) but strikingly abundant (up to 65% of relative abundance) OTUs. This core community overlapped by one third with the Sphagnum-specific core-community. Thus, the most abundant microorganisms in Sphagnum that are also found in all the Sphagnum plants studied, are the same OTUs as those few shared with Amblystegiaceae. Finally, we could confirm that these highly abundant OTUs were endophytes in Sphagnum, but epiphytes on Amblystegiaceae. We conclude that moss taxa and abiotic environmental variables associate with particular microbial communities. While moss taxon was the most influential parameter, hydrology, pH and temperature also had significant effects on the microbial communities. A small though highly abundant core community is shared between Sphagnum and Amblystegiaceae.
北方泥炭地通常通过演替从以 Amblystegiaceae 科苔藓为主的沼泽发展到以 Sphagnum 属苔藓为主的泥炭地。不同的植物和非生物环境条件在 Amblystegiaceae 和 Sphagnum 泥炭中是如何塑造各自与苔藓相关的微生物群落的尚不清楚。通过一项跨越北极、亚北极和温带地区的大规模分子和生物地球化学研究，我们评估了自然北方泥炭地苔藓的内生和外生微生物群落与泥炭地类型（Sphagnum 和 Amblystegiaceae）、位置、苔藓分类群和非生物环境变量的关系。内生和外生微生物群落在 Amblystegiaceae 和 Sphagnum 泥炭地之间存在明显差异，在这两种泥炭地类型中，苔藓分类群解释了微生物群落变化的最大部分。Sphagnum 和 Amblystegiaceae 共享的操作分类单元（OTUs）很少（<所有 OTUs 的 1%），但丰富度极高（相对丰度高达 65%）的 OTUs。这个核心群落与 Sphagnum 特有的核心群落重叠了三分之一。因此，Sphagnum 中最丰富的微生物也是所有研究的 Sphagnum 植物中发现的最丰富的微生物，它们与与 Amblystegiaceae 共享的少数 OTUs 相同。最后，我们可以确认这些高度丰富的 OTUs 是 Sphagnum 的内生菌，但 Amblystegiaceae 的外生菌。我们得出结论，苔藓分类群和非生物环境变量与特定的微生物群落相关。虽然苔藓分类群是最具影响力的参数，但水文学、pH 值和温度对微生物群落也有显著影响。Sphagnum 和 Amblystegiaceae 之间存在一个虽然小但高度丰富的核心群落。
