Extreme drought triggers transition to an alternative soil microbial state
Extreme drought triggers transition to an alternative soil microbial state
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DOI：
10.1101/2021.12.10.472086
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发表时间：
2021-12
期刊：
影响因子：
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通讯作者：
Irene Cordero;A. Leizeaga;L. Hicks;J. Rousk;R. Bardgett
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作者：
Irene Cordero;A. Leizeaga;L. Hicks;J. Rousk;R. Bardgett
土壤微生物群落在调节生态系统功能方面发挥着关键作用1，但它们越来越受到人类驱动的扰动的威胁，包括气候极端事件，预计随着气候变化，极端气候事件的频率和强度将增加2。已经证明，土壤微生物群落对气候极端情况很敏感，例如干旱3，4，而且这种影响可以是长期的5，6。然而，关于土壤微生物群落对气候极端情况的强度和频率的增加的反应及其引发向替代的和可能有害的分类和功能状态的转变的可能性，仍然存在相当大的不确定性。在这里，我们证明了极端频繁的干旱会导致土壤微生物状态的转变，其特征是细菌和真菌群落结构的强烈变化，降低了复杂性和功能性。此外，我们发现，这种干旱诱导的替代微生物状态在土壤恢复到以前的水分状态后仍然存在。然而，细菌群落能够通过增加它们的生长能力来适应，尽管多样性减少。在水生和陆生植物群落中，有很好的记录表明，在人类诱导的扰动，包括气候极端8，9的情况下，向替代状态的突然转变是有充分证据的。我们的结果提供了实验证据，表明土壤微生物群落也会发生这种转变，以响应极端干旱，从而对土壤健康产生潜在的有害后果。
Soil microbial communities play a pivotal role in regulating ecosystem functioning1 but they are increasingly threatened by human-driven perturbations, including climate extremes, which are predicted to increase in frequency and intensity with climate change2. It has been demonstrated that soil microbial communities are sensitive to climate extremes, such as drought3,4, and that effects can be long-lasting5,6. However, considerable uncertainties remain concerning the response of soil microbial communities to increases in the intensity and frequency of climate extremes, and their potential to trigger transitions to alternative, and potentially deleterious, taxonomic and functional states7. Here we demonstrate that extreme, frequent drought induces a shift to an alternative soil microbial state characterised by strongly altered bacterial and fungal community structure of reduced complexity and functionality. Moreover, we found that this drought-induced alternative microbial state persisted after returning soil to its previous moisture status. However, bacterial communities were able to adapt by increasing their growth capacity, despite being of reduced diversity. Abrupt transitions to alternative states are well documented in aquatic and terrestrial plant communities in response to human-induced perturbations, including climate extremes8,9. Our results provide experimental evidence that such transitions also occur in soil microbial communities in response to extreme drought with potentially deleterious consequences for soil health.