Adamczyk Magdalene, Hagedorn Frank, Wipf Sonja, Donhauser Jonathan, Vittoz Pascal, Rixen Christian, Frossard Aline, Theurillat Jean-Paul, Frey Beat
Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland.
Community Ecology, WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland.
Front Microbiol. 2019 May 15;10:1080. doi: 10.3389/fmicb.2019.01080. eCollection 2019.
While vegetation has intensively been surveyed on mountain summits, limited knowledge exists about the diversity and community structure of soil biota. Here, we study how climatic variables, vegetation, parent material, soil properties, and slope aspect affect the soil microbiome on 10 GLORIA (Global Observation Research Initiative in Alpine environments) mountain summits ranging from the lower alpine to the nival zone in Switzerland. At these summits we sampled soils from all four aspects and examined how the bacterial and fungal communities vary by using Illumina MiSeq sequencing. We found that mountain summit soils contain highly diverse microbial communities with a total of 10,406 bacterial and 6,291 fungal taxa. Bacterial α-diversity increased with increasing soil pH and decreased with increasing elevation, whereas fungal α-diversity did not change significantly. Soil pH was the strongest predictor for microbial β-diversity. Bacterial and fungal community structures exhibited a significant positive relationship with plant communities, indicating that summits with a more distinct plant composition also revealed more distinct microbial communities. The influence of elevation was stronger than aspect on the soil microbiome. Several microbial taxa responded to elevation and soil pH. and were significantly more abundant on summits at higher elevations, whereas the relative abundance of and decreased with elevation. Most bacterial OTUs belonging to the phylum were indicators for siliceous parent material and several OTUs belonging to the phylum were associated with calcareous soils. The trends for fungi were less clear. Indicator OTUs belonging to the genera and showed a mixed response to parent material, demonstrating their ubiquitous and opportunistic behaviour in soils. Overall, fungal communities responded weakly to abiotic and biotic factors. In contrast, bacterial communities were strongly influenced by environmental changes suggesting they will be strongly affected by future climate change and associated temperature increase and an upward migration of vegetation. Our results provide the first insights into the soil microbiome of mountain summits in the European Alps that are shaped as a result of highly variable local environmental conditions and may help to predict responses of the soil biota to global climate change.
虽然人们对山顶的植被进行了密集调查，但对土壤生物群的多样性和群落结构了解有限。在此，我们研究气候变量、植被、母质、土壤性质和坡向如何影响瑞士从低山区到雪线带的10个GLORIA（高山环境全球观测研究倡议）山顶的土壤微生物群落。在这些山顶，我们从所有四个坡向采集土壤样本，并使用Illumina MiSeq测序技术研究细菌和真菌群落的差异。我们发现山顶土壤含有高度多样的微生物群落，共有10406个细菌分类单元和6291个真菌分类单元。细菌的α多样性随土壤pH值升高而增加，随海拔升高而降低，而真菌的α多样性没有显著变化。土壤pH值是微生物β多样性的最强预测因子。细菌和真菌群落结构与植物群落呈显著正相关，这表明植物组成更独特的山顶也具有更独特的微生物群落。海拔对土壤微生物群落的影响比坡向更强。几种微生物分类单元对海拔和土壤pH值有响应。[具体物种名称1]和[具体物种名称2]在海拔较高的山顶上显著更为丰富，而[具体物种名称3]和[具体物种名称4]的相对丰度随海拔升高而降低。大多数属于[门名称1]的细菌OTU是硅质母质的指示物，而一些属于[门名称2]的OTU与钙质土壤有关。真菌的趋势不太明显。属于[属名称1]和[属名称2]的指示OTU对母质表现出混合响应，表明它们在土壤中具有普遍存在和机会主义的行为。总体而言，真菌群落对非生物和生物因素的响应较弱。相比之下，细菌群落受到环境变化的强烈影响，这表明它们将受到未来气候变化以及相关温度升高和植被向上迁移的强烈影响。我们的研究结果首次揭示了欧洲阿尔卑斯山山顶土壤微生物群落的情况，这些群落是由高度可变的当地环境条件塑造而成的，可能有助于预测土壤生物群对全球气候变化的响应。
