Investigating the long‐term legacy of drought and warming on the soil microbial community across five European shrubland ecosystems
Investigating the long‐term legacy of drought and warming on the soil microbial community across five European shrubland ecosystems
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DOI：
10.1111/gcb.12338
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发表时间：
2013-12
影响因子：
11.6
通讯作者：
J. Rousk;Andrew R. Smith;Davey L. Jones
中科院分区：
文献类型：
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作者：
J. Rousk;Andrew R. Smith;Davey L. Jones
我们研究了气候变暖和夏季干旱对微生物群落的影响，并在欧洲（EU - FP7）进行了五种不同的长期重复（bbb10年）实地实验。为了明确地关注遗留效应（即环境因素的间接而不是直接影响），我们在相同的湿度和温度下进行了简短的筛选，并在稳定的条件下进行了预孵育。具体来说，我们研究了土壤微生物群落（PLFA）的大小和组成，以及细菌（亮氨酸掺入）和真菌（麦角甾醇中乙酸掺入）生长速率的测量，之前显示对环境因素和微生物呼吸的变化高度敏感。我们发现，在我们的实验设置中使用的效应大小（0.6°C，约30%降水减少），对微生物群落规模、组成、生长速率或基础呼吸速率没有遗留影响。我们的研究结果支持了以往单个短期生态系统研究的报告，从而为长期、大规模的推广提供了明确的证据基础。我们的研究表明，在本研究的效应范围内，气候变暖和夏季干旱不会对微生物群落及其过程产生遗留效应。虽然在扰动周期中对微生物过程的遗留影响，如干燥-再湿，以及对干旱和变暖的耐受性仍有待研究，但我们的研究结果表明，对整个生态系统过程的任何影响将相当有限。因此，在模拟当代土壤生物地球化学过程速率时，不应优先考虑气候变暖和干旱的影响。
We investigated how the legacy of warming and summer drought affected microbial communities in five different replicated long‐term (>10 years) field experiments across Europe (EU‐FP7 INCREASE infrastructure). To focus explicitly on legacy effects (i.e., indirect rather than direct effects of the environmental factors), we measured microbial variables under the same moisture and temperature in a brief screening, and following a pre‐incubation at stable conditions. Specifically, we investigated the size and composition of the soil microbial community (PLFA) alongside measurements of bacterial (leucine incorporation) and fungal (acetate in ergosterol incorporation) growth rates, previously shown to be highly responsive to changes in environmental factors, and microbial respiration. We found no legacy effects on the microbial community size, composition, growth rates, or basal respiration rates at the effect sizes used in our experimental setup (0.6 °C, about 30% precipitation reduction). Our findings support previous reports from single short‐term ecosystem studies thereby providing a clear evidence base to allow long‐term, broad‐scale generalizations to be made. The implication of our study is that warming and summer drought will not result in legacy effects on the microbial community and their processes within the effect sizes here studied. While legacy effects on microbial processes during perturbation cycles, such as drying–rewetting, and on tolerance to drought and warming remain to be studied, our results suggest that any effects on overall ecosystem processes will be rather limited. Thus, the legacies of warming and drought should not be prioritized factors to consider when modeling contemporary rates of biogeochemical processes in soil.