Current projections suggest that climate warming will be accompanied by more frequent and severe drought events. Peatlands store ca. one third of the world’s soil organic carbon. Warming and drought may cause peatlands to become carbon sources through stimulation of microbial activity increasing ecosystem respiration, with positive feedback effect on global warming. Micro-eukaryotes play a key role in the carbon cycle through food web interactions and therefore, alterations in their community structure and diversity may affect ecosystem functioning and could reflect these changes. We assessed the diversity and community composition of Sphagnum-associated eukaryotic microorganisms inhabiting peatlands and their response to experimental drought and warming using high throughput sequencing of environmental DNA. Under drier conditions, micro-eukaryotic diversity decreased, the relative abundance of autotrophs increased and that of osmotrophs (including Fungi and Peronosporomycetes) decreased. Furthermore, we identified climate change indicators that could be used as early indicators of change in peatland microbial communities and ecosystem functioning. The changes we observed indicate a shift towards a more “terrestrial” community in response to drought, in line with observed changes in the functioning of the ecosystem.

中文翻译：

---

使用高通量测序评估泥炭藓微型真核生物对气候变化的响应

目前的预测表明，气候变暖将伴随着更频繁和更严重的干旱事件。泥炭地商店约。占世界土壤有机碳的三分之一。变暖和干旱可能通过刺激微生物活动增加生态系统呼吸使泥炭地成为碳源，对全球变暖具有正反馈效应。微型真核生物通过食物网相互作用在碳循环中发挥关键作用，因此，其群落结构和多样性的改变可能会影响生态系统功能并反映这些变化。我们使用环境 DNA 的高通量测序评估了栖息在泥炭地的泥炭藓相关真核微生物的多样性和群落组成及其对实验性干旱和变暖的反应。在较干燥的条件下，微真核生物多样性下降，自养生物相对丰度增加，渗透养生物（包括真菌和霜冻孢子菌）相对丰度下降。此外，我们确定了气候变化指标，可用作泥炭地微生物群落和生态系统功能变化的早期指标。我们观察到的变化表明，为了应对干旱，向更“陆地”社区的转变，与观察到的生态系统功能的变化一致。