Drought legacy affects microbial community trait distributions related to moisture along a savannah grassland precipitation gradient
Drought legacy affects microbial community trait distributions related to moisture along a savannah grassland precipitation gradient
复制标题
干旱遗留影响与沿稀树草原降水梯度的湿度相关的微生物群落性状分布
作者：
A. Leizeaga;L. Hicks;L. Manoharan;C. Hawkes;J. Rousk
生态系统模型通常使用稳态假设来预测土壤微生物功能对环境变化的响应。然而，过去的气候条件会影响微生物的功能反应，从而产生“遗留效应”。例如，暴露在田间更干燥的条件下可能会影响土壤微生物群落对随后的干旱和干旱和复湿(DRW)事件的反应。在美国得克萨斯州，我们研究了微生物对低湿度水平的耐受性(“抵抗力”)以及在DRW扰动(“恢复力”)跨越陡峭的降水梯度后的恢复能力。尽管降水制度的不同并没有导致土壤微生物的抗旱性和抗逆性的差异，但微生物群落似乎总体上具有跨梯度的抗旱性和抗逆性，这表明频繁的干旱暴露是微生物群落特征分布的特征。此外，来自历史上较干燥地点的微生物群落在DRW扰动期间更有效地利用碳，这表明长期干旱历史对微生物功能留下了遗留影响。这可能是由于降水引起的初级生产力差异引起的干旱的间接影响，影响了土壤有机质对微生物的有效性。或者，不同的干旱暴露可能塑造了微生物应对DRW干扰的“准备”。微生物群落组成也与干旱史有关，但与功能变化无关。综合。干旱可对土壤微生物群落产生直接和间接影响，从而对其控制的功能产生持久的遗留影响。
Ecosystem models commonly use stable‐state assumptions to predict responses of soil microbial functions to environmental change. However, past climatic conditions can shape microbial functional responses resulting in a ‘legacy effect’. For instance, exposure to drier conditions in the field may shape how soil microbial communities respond to subsequent drought and drying and rewetting (DRW) events. We investigated microbial tolerance to low moisture levels (‘resistance’) and ability to recover after a DRW perturbation (‘resilience’) across a steep precipitation gradient in Texas, USA. Although differences in precipitation regime did not result in differences in resistance and resilience of soil microbes, microbial communities appeared to be generally resilient and resistant across the gradient, suggesting that frequent exposure to drought had characterised the trait distributions of microbial communities. Moreover, microbial communities from historically drier sites used carbon more efficiently during a DRW perturbation suggesting that long‐term drought history leaves a legacy effect on microbial functions. This may have been due to an indirect effect of drought caused via precipitation‐induced differences in primary productivity, influencing the availability of soil organic matter to microbes. Alternatively, different exposures to drought might have shaped the microbial ‘readiness’ to cope with the DRW disturbance. Microbial community composition was also linked to drought history, but was unrelated to variation in function. Synthesis. Exposure to drought can have both direct and indirect effects on soil microbial communities, which can result in lasting legacy effects on the functions they control.
DOI：
10.1073/pnas.1514435112
发表时间：
2015-11-24
影响因子：
11.1
作者：
Guhr, Alexander;Borken, Werner;Matzner, Egbert
通讯作者：
Matzner, Egbert