Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland.
Environ Microbiol. 2021 Apr;23(4):2152-2168. doi: 10.1111/1462-2920.15383. Epub 2021 Jan 12.
Due to climate warming, alpine ecosystems are changing rapidly. Ongoing upward migrations of plants and thus an increase of easily decomposable substrates will strongly affect the soil microbiome. To understand how belowground communities will respond to such changes, we set up an incubation experiment with permafrost and active soil layers from northern (NW) and southern (SE) slopes of a mountain ridge on Muot da Barba Peider in the Swiss Alps and incubated them with or without artificial root exudates (AREs) at two temperatures, 4°C or 15°C. The addition of AREs resulted in elevated respiration across all soil types. Bacterial and fungal alpha diversity decreased significantly, coinciding with strong shifts in microbial community structure in ARE-treated soils. These shifts in bacterial community structure were driven by an increased abundance of fast-growing copiotrophic taxa. Fungal communities were predominantly affected by AREs in SE active layer soils and shifted towards fast-growing opportunistic yeast. In contrast, in the colder NW facing active layer and permafrost soils fungal communities were more influenced by temperature changes. These findings demonstrate the sensitivity of soil microbial communities in high alpine ecosystems to climate change and how shifts in these communities may lead to functional changes impacting biogeochemical processes.
由于气候变暖，高山生态系统正在迅速变化。植物不断向上迁移，从而增加了易于分解的底物，这将强烈影响土壤微生物组。为了了解地下群落将如何应对这些变化，我们在瑞士阿尔卑斯山脉穆特达巴贝拉峰的山脊的北（NW）和南（SE）坡设置了一个包含永冻层和活动层土壤的培养实验，并用或不用人工根分泌物（AREs）在两个温度（4°C 或 15°C）下进行培养。添加 AREs 会导致所有土壤类型的呼吸作用升高。细菌和真菌的 alpha 多样性显著降低，同时微生物群落结构也发生了强烈变化。在 ARE 处理的土壤中，细菌群落结构的这些变化是由快速生长的富营养型分类群的丰度增加驱动的。真菌群落主要受到 SE 活动层土壤中 AREs 的影响，并向快速生长的机会性酵母转移。相比之下，在较冷的 NW 面活动层和永冻层土壤中，真菌群落受温度变化的影响更大。这些发现表明，高山生态系统土壤微生物群落对气候变化非常敏感，以及这些群落的变化如何可能导致影响生物地球化学过程的功能变化。
