Responses to increases in temperature of heterotrophic micro-organisms in soils from the maritime Antarctic
Responses to increases in temperature of heterotrophic micro-organisms in soils from the maritime Antarctic
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DOI：
10.1007/s00300-015-1673-4
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发表时间：
2015-08-01
期刊：
影响因子：
1.7
通讯作者：
Hopkins, David W.
中科院分区：
文献类型：
--
作者：
Laudicina, Vito Armando;Sun Benhua;Hopkins, David W.
了解环境变化与土壤微生物呼吸之间的关系对于预测土壤有机碳（SOC）通量和含量的变化至关重要。南极海域正在经历世界上变暖速度最快的地区之一，因此是研究温度对土壤微生物呼吸对 SOC 矿化影响的关键地点。然而，相对于总 SOC 而言，不稳定底物在较高温度下的消耗以及 SOC 顽抗成分的更大温度敏感性混淆了对变暖影响的简单解释。我们通过比较生物质特定呼吸速率随温度的增加与每单位 SOC 呼吸速率的增加来测试异养土壤微生物的呼吸不会随着温度升高而下调的假设，从而解决了这些问题。我们使用了来自南极海域的五种不同纬度和 SOC 含量的土壤，并在持续长达 31 天的实验室培养中测量了土壤对 2 至 50 A 摄氏度温度范围的呼吸反应。在所有情况下，土壤呼吸随着温度高达 50 A 摄氏度而增加，即使这超出了通常经历的温度，这表明该群落具有足够的生理多样性，能够在较大的温度范围内进行呼吸。生物量特定呼吸速率和 SOC 矿化总速率均随温度升高而增加，我们将其解释为土壤微生物的呼吸作用，而不是相对于温度下调。
Understanding relationships between environmental changes and soil microbial respiration is critical for predicting changes in soil organic carbon (SOC) fluxes and content. The maritime Antarctic is experiencing one of the fastest rates of warming in the world and is therefore a key location to examine the effect of temperature on SOC mineralization by the respiration of soil micro-organisms. However, depletion of the labile substrates at higher temperatures relative to the total SOC and greater temperature sensitivity of recalcitrant components of the SOC confound simple interpretations of the effects of warming. We have addressed these issues by testing the hypothesis that respiration by heterotrophic soil micro-organisms is not down-regulated with increasing temperature by comparing the increase in biomass-specific respiration rate with temperature to the increase in respiration rate per unit SOC. We used five soils from the maritime Antarctic ranging in latitude and SOC content and measured the soil respiratory responses to temperatures ranging from 2 to 50 A degrees C in laboratory incubations lasting up to 31 days. In all cases, soil respiration increased with temperature up to 50 A degrees C, even though this exceeds the temperatures normally be experienced, indicating that the community contained sufficient physiological diversity to be able to respire over large temperature ranges. Both the biomass-specific respiration rate and the overall rate of SOC mineralization increased with temperature, which we interpret as respiration by soil micro-organisms not down-regulating relative to temperature.