Department of Ecology and Evolution, University of Lausanne, Lausanne, 1015, Switzerland.
Department of Occupational Health and Environment, Center for Primary Care and Public Health (Unisanté), University of Lausanne, Epalinges, CH-1066, Switzerland.
Environ Microbiol. 2022 Apr;24(4):1689-1702. doi: 10.1111/1462-2920.15686. Epub 2021 Aug 10.
Protists are abundant and play key trophic functions in soil. Documenting how their trophic contributions vary across large environmental gradients is essential to understand and predict how biogeochemical cycles will be impacted by global changes. Here, using amplicon sequencing of environmental DNA in open habitat soil from 161 locations spanning 2600 m of elevation in the Swiss Alps (from 400 to 3000 m), we found that, over the whole study area, soils are dominated by consumers, followed by parasites and phototrophs. In contrast, the proportion of these groups in local communities shows large variations in relation to elevation. While there is, on average, three times more consumers than parasites at low elevation (400-1000 m), this ratio increases to 12 at high elevation (2000-3000 m). This suggests that the decrease in protist host biomass and diversity toward mountains tops impact protist functional composition. Furthermore, the taxonomic composition of protists that infect animals was related to elevation while that of protists that infect plants or of protist consumers was related to soil pH. This study provides a first step to document and understand how soil protist functions vary along the elevational gradient.
原生动物在土壤中丰富存在，并发挥着关键的营养功能。记录它们的营养贡献如何在大的环境梯度上变化，对于理解和预测生物地球化学循环将如何受到全球变化的影响至关重要。在这里，我们使用瑞士阿尔卑斯山 161 个地点（海拔 400 至 3000 米）开阔生境土壤的环境 DNA 扩增子测序，发现整个研究区域的土壤以消费者为主，其次是寄生虫和光合生物。相比之下，这些群体在当地群落中的比例与海拔高度有很大的变化。虽然在低海拔（400-1000 米）地区，消费者的数量平均比寄生虫多三倍，但在高海拔（2000-3000 米）地区，这一比例增加到 12。这表明，原生动物宿主生物量和多样性向山顶减少，会影响原生动物的功能组成。此外，感染动物的原生动物的分类组成与海拔有关，而感染植物或原生动物消费者的原生动物的分类组成与土壤 pH 值有关。本研究提供了记录和理解土壤原生动物功能如何沿海拔梯度变化的第一步。
