Cross-biome patterns in soil microbial respiration predictable from evolutionary theory on thermal adaptation
Cross-biome patterns in soil microbial respiration predictable from evolutionary theory on thermal adaptation
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DOI：
10.1038/s41559-018-0771-4
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发表时间：
2019-02-01
影响因子：
16.8
通讯作者：
Fierer, Noah
中科院分区：
文献类型：
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作者：
Bradford, Mark A.;McCulley, Rebecca L.;Fierer, Noah
气候变暖可能会刺激土壤碳的微生物代谢，导致碳循环-气候反馈，从而将碳从土壤重新分配到大气CO2中。这种反馈的幅度是不确定的，部分原因是变暖引起的微生物生理和/或群落组成的变化可能会延迟或加速土壤碳损失。在这里，我们测量微生物呼吸速率从22个地点收集的土壤在3年的每一年，在北方到热带气候的位置。在实验室中用标准温度、湿度和过量碳基质测量呼吸，以使生理和群落效应独立于这些非生物控制的影响而被检测。在整个气候梯度收集的土壤呼吸模式是一致的进化理论的生理反应，补偿温度对新陈代谢的积极影响。从年平均温度为-2.0 ℃的地点取样的土壤每单位微生物生物量的呼吸速率比从21.7 ℃取样的土壤高2.6倍。随后的100天的孵育表明，在可塑性的微生物群落之间的热响应，与社区采样的网站具有较高的年平均温度有更多的塑料反应。我们的研究结果与在植物和动物中也观察到的对对比热制度的适应性代谢反应一致。这些结果可能有助于建立信心，土壤碳气候反馈预测，提高理解微生物过程中所代表的地球化学模型。
Climate warming may stimulate microbial metabolism of soil carbon, causing a carbon-cycle-climate feedback whereby carbon is redistributed from the soil to atmospheric CO2. The magnitude of this feedback is uncertain, in part because warming-induced shifts in microbial physiology and/or community composition could retard or accelerate soil carbon losses. Here, we measure microbial respiration rates for soils collected from 22 sites in each of 3 years, at locations spanning boreal to tropical climates. Respiration was measured in the laboratory with standard temperatures, moisture and excess carbon substrate, to allow physiological and community effects to be detected independent of the influence of these abiotic controls. Patterns in respiration for soils collected across the climate gradient are consistent with evolutionary theory on physiological responses that compensate for positive effects of temperature on metabolism. Respiration rates per unit microbial biomass were as much as 2.6 times higher for soils sampled from sites with a mean annual temperature of -2.0 versus 21.7 degrees C. Subsequent 100-d incubations suggested differences in the plasticity of the thermal response among microbial communities, with communities sampled from sites with higher mean annual temperature having a more plastic response. Our findings are consistent with adaptive metabolic responses to contrasting thermal regimes that are also observed in plants and animals. These results may help build confidence in soil-carbon-climate feedback projections by improving understanding of microbial processes represented in biogeochemical models.