Freie Universität Berlin, Institut für Biologie, Plant Ecology, Berlin, Germany.
Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany.
Sci Rep. 2020 May 22;10(1):8533. doi: 10.1038/s41598-020-65329-x.
Climate change can trigger shifts in community structure and may therefore pose a severe threat to soil microbial communities, especially in high northern latitudes such as the Arctic. Arctic soils are covered by snow and ice throughout most of the year. This insulation shields them from high temperature variability and low surface temperatures. If this protective layer thaws, these soils are predicted to warm up at 1.5x to 4x the rate of other terrestrial biomes. In this study, we sampled arctic soils from sites with different elevations in Alaska, incubated them for 5 months with a simulated, gradual or abrupt temperature increase of +5 °C, and compared bacterial and fungal community compositions after the incubation. We hypothesized that the microbial communities would not significantly change with a gradual temperature treatment, whereas an abrupt temperature increase would decrease microbial diversity and shift community composition. The only differences in community composition that we observed were, however, related to the two elevations. The abrupt and gradual temperature increase treatments did not change the microbial community composition as compared to the control indicating resistance of the microbial community to changes in temperature. This points to the potential importance of microbial dormancy and resting stages in the formation of a "buffer" against elevated temperatures. Microbial resting stages might heavily contribute to microbial biomass and thus drive the responsiveness of arctic ecosystems to climate change.
气候变化可能引发群落结构的变化，因此可能对土壤微生物群落构成严重威胁，特别是在北极等高纬度地区。北极地区的土壤在一年中的大部分时间都被冰雪覆盖。这种绝缘作用使它们免受高温变化和低温的影响。如果这层保护层融化，这些土壤的升温速度预计将是其他陆地生物群落的 1.5 到 4 倍。在这项研究中，我们从阿拉斯加不同海拔高度的地点采集了北极土壤，用模拟的、逐渐的或突然的 +5°C 的温度升高对其进行了 5 个月的培养，并在培养后比较了细菌和真菌群落的组成。我们假设，微生物群落不会因逐渐的温度处理而显著变化，而突然的温度升高会降低微生物多样性并改变群落组成。然而，我们观察到的唯一群落组成差异与这两个海拔高度有关。与对照相比，突然和逐渐的温度升高处理并没有改变微生物群落组成，这表明微生物群落对温度变化具有抵抗力。这表明微生物休眠和静止阶段在形成对高温的“缓冲”方面具有潜在的重要性。微生物静止阶段可能对微生物生物量有很大贡献，从而推动北极生态系统对气候变化的响应。
