Temperature adaptation of soil microbial respiration in alpine, boreal and tropical soils: An application of the square root (Ratkowsky) model
Temperature adaptation of soil microbial respiration in alpine, boreal and tropical soils: An application of the square root (Ratkowsky) model
复制标题
高山、北方和热带土壤微生物呼吸的温度适应：平方根（Ratkowsky）模型的应用
DOI：
10.1111/gcb.15476
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发表时间：
2020-12-18
影响因子：
11.6
通讯作者：
Nie, Ming
中科院分区：
文献类型：
--
作者：
Li, Jinquan;Baath, Erland;Nie, Ming
变暖预计将刺激土壤微生物呼吸，从而引发土壤碳-气候正反馈循环，但对于这种反馈的程度仍难以达成共识。这部分是由于我们对土壤微生物呼吸的温度适应性响应的了解有限，特别是在广泛的气候尺度上。我们采用平方根（Ratkowsky）模型计算了年平均气温（MAT）范围为-6℃至+25℃的青藏高原高寒草原和中国森林生态系统的298个土壤样本的土壤微生物呼吸最低温度（T-min，描述土壤微生物呼吸的温度适应）。在4℃至28℃之间确定了瞬时土壤微生物呼吸。平方根模型可以很好地计算土壤微生物呼吸的温度。拟合每种土壤的温度对土壤微生物呼吸的影响，所有土壤的 R-2 均高于 0.98。 T-min 范围为 -8.1 摄氏度至 -0.1 摄氏度，并随着 MAT 的增加而线性增加 (R-2 = 0.68)。当同时考虑多个其他驱动因素（平均年降水量、土壤 pH 值和碳质量）时，MAT 主要调节 T-min 变化；一项独立实验表明，碳的有效性对 T-min 没有显着影响。利用 T-min 和 MAT 之间的关系，可以估计 MAT 增加后的土壤微生物呼吸，从而导致呼吸随着 MAT 的减少而相对增加。因此，土壤微生物呼吸反应适应 MAT 中的长期温度差异。我们建议 T-min = -5 + 0.2 x MAT，即 MAT 每升高 1 摄氏度，估计呼吸的 T-min 就会增加约 0.2 摄氏度，可用作将土壤微生物呼吸的温度适应纳入模型预测的第一近似值。我们的结果可用于预测不同变暖水平以及不同 MAT 的广泛地理尺度下土壤微生物呼吸对温度的响应的未来变化。
Warming is expected to stimulate soil microbial respiration triggering a positive soil carbon-climate feedback loop while a consensus remains elusive regarding the magnitude of this feedback. This is partly due to our limited understanding of the temperature-adaptive response of soil microbial respiration, especially over broad climatic scales. We used the square root (Ratkowsky) model to calculate the minimum temperature for soil microbial respiration (T-min, which describes the temperature adaptation of soil microbial respiration) of 298 soil samples from alpine grasslands on the Tibetan Plateau and forest ecosystems across China with a mean annual temperature (MAT) range from -6 degrees C to +25 degrees C. The instantaneous soil microbial respiration was determined between 4 degrees C and 28 degrees C. The square root model could well fit the temperature effect on soil microbial respiration for each individual soil, with R-2 higher than 0.98 for all soils. T-min ranged from -8.1 degrees C to -0.1 degrees C and increased linearly with increasing MAT (R-2 = 0.68). MAT dominantly regulated T-min variation when accounting simultaneously for multiple other drivers (mean annual precipitation, soil pH and carbon quality); an independent experiment showed that carbon availability had no significant effect on T-min. Using the relationship between T-min and MAT, soil microbial respiration after an increased MAT could be estimated, resulting in a relative increase in respiration with decreasing MAT. Thus, soil microbial respiration responses are adapted to long-term temperature differences in MAT. We suggest that T-min = -5 + 0.2 x MAT, that is, every 1 degrees C rise in MAT is estimated to increase T-min of respiration by approximately 0.2 degrees C, could be used as a first approximation to incorporate temperature adaptation of soil microbial respiration in model predictions. Our results can be used to predict future changes in the response of soil microbial respiration to temperature over different levels of warming and across broad geographic scales with different MAT.