The Temperature Sensitivity (Q10) of Soil Respiration: Controlling Factors and Spatial Prediction at Regional Scale Based on Environmental Soil Classes
The Temperature Sensitivity (Q10) of Soil Respiration: Controlling Factors and Spatial Prediction at Regional Scale Based on Environmental Soil Classes
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DOI：
10.1002/2017gb005644
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发表时间：
2018-02-01
影响因子：
5.2
通讯作者：
Amelung, W.
中科院分区：
文献类型：
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作者：
Meyer, N.;Welp, G.;Amelung, W.
异养土壤呼吸的温度敏感性是模拟碳动态的关键，但它是可变的。然而，目前，大多数模型采用温度每升高10摄氏度土壤呼吸增加1.5或2.0的固定值（Q10）。在这里，我们确定了Q10在区域尺度（鲁尔流域，德国/比利时/荷兰）的变化。我们将研究集水区划分为环境土壤类（ESC），我们将其定义为土地利用，聚合土壤组和质地的独特组合。我们从每个ESC（108个样品）中取了9个土壤样品，并在4个土壤湿度水平和5个温度（5-25摄氏度）下培养它们。我们假设，Q10的变化是由土壤有机碳（SOC）的降解性和土壤水分和ESC可以被用作一个广泛可用的代理Q10，由于SOC降解性的差异。测得的Q10值范围为1.2至2.8，并与SOC降解性指标（例如，r = -0.52）。土壤水分对Q10的影响是可变的：Q10在农田中随着水分的增加而增加，而在森林中则减少。ESC在干旱（R-2 = 0.44）和中等（R-2 = 0.36）水分条件下捕获了Q10变异性的重要部分，其中Q10以农田的顺序增加
The temperature sensitivity of heterotrophic soil respiration is crucial for modeling carbon dynamics but it is variable. Presently, however, most models employ a fixed value of 1.5 or 2.0 for the increase of soil respiration per 10 degrees C increase in temperature (Q10). Here we identified the variability of Q10 at a regional scale (Rur catchment, Germany/Belgium/Netherlands). We divided the study catchment into environmental soil classes (ESCs), which we define as unique combinations of land use, aggregated soil groups, and texture. We took nine soil samples from each ESC (108 samples) and incubated them at four soil moisture levels and five temperatures (5-25 degrees C). We hypothesized that Q10 variability is controlled by soil organic carbon (SOC) degradability and soil moisture and that ESC can be used as a widely available proxy for Q10, owing to differences in SOC degradability. Measured Q10 values ranged from 1.2 to 2.8 and were correlated with indicators of SOC degradability (e.g., pH, r = -0.52). The effect of soil moisture on Q10 was variable: Q10 increased with moisture in croplands but decreased in forests. The ESC captured significant parts of Q10 variability under dry (R-2 = 0.44) and intermediate (R-2 = 0.36) moisture conditions, where Q10 increased in the order cropland