Soil microbial respiration in arctic soil does not acclimate to temperature
Soil microbial respiration in arctic soil does not acclimate to temperature
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DOI：
10.1111/j.1461-0248.2008.01223.x
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发表时间：
2008-10-01
期刊：
影响因子：
8.8
通讯作者：
Wookey, Philip A.
中科院分区：
文献类型：
--
作者：
Hartley, Iain P.;Hopkins, David W.;Wookey, Philip A.
变暖导致北极土壤中大量碳（C）储存释放二氧化碳可能会加速气候变化。然而，在长期实验中，土壤呼吸对变暖的反应下降表明，微生物活动适应温度，大大降低了碳损失增加的可能性。由于随着时间的推移，呼吸速率降低同样可能是由基质消耗引起的，热驯化的证据仍然存在争议。为了克服这个问题，我们进行了一个冷却实验，从北极瑞典的土壤。如果驯化导致实验升温后观察到的土壤呼吸减少，那么它应该随后导致冷却后呼吸速率的增加。我们证明，热驯化没有发生冷却后。相反，在冷却后的90天内，观察到土壤呼吸速率进一步降低，只有延长再暴露于更温暖的温度才能逆转。我们的结论是，在几个星期到几个月的时间尺度上，变暖引起的变化，在北极土壤中的微生物群落将放大瞬时增加的CO2生产率，从而提高碳损失可能加快速度的21世纪世纪气候变化。
Warming-induced release of CO2 from the large carbon (C) stores in arctic soils could accelerate climate change. However, declines in the response of soil respiration to warming in long-term experiments suggest that microbial activity acclimates to temperature, greatly reducing the potential for enhanced C losses. As reduced respiration rates with time could be equally caused by substrate depletion, evidence for thermal acclimation remains controversial. To overcome this problem, we carried out a cooling experiment with soils from arctic Sweden. If acclimation causes the reduction in soil respiration observed after experimental warming, then it should subsequently lead to an increase in respiration rates after cooling. We demonstrate that thermal acclimation did not occur following cooling. Rather, during the 90 days after cooling, a further reduction in the soil respiration rate was observed, which was only reversed by extended re-exposure to warmer temperatures. We conclude that over the time scale of a few weeks to months, warming-induced changes in the microbial community in arctic soils will amplify the instantaneous increase in the rates of CO2 production and thus enhance C losses potentially accelerating the rate of 21st century climate change.