摘要：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°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 (ESC), 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°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 (R²=0.44) and intermediate (R²=0.36) moisture conditions, where Q10 increased in the order cropland

关键词：Q10 is correlated with indicators of SOC degradability (pH, C/N, SOC-normalized respiration rate) and is affected by soil moisture.  Environmental soil classes (i.e., a combination of land use, soil group, and texture) serve as widely available proxies for Q10.  The use of ESC and moisture specific Q10 values can improve estimates of soil respiration at the regional scale.

论文方向：[{"id":852,"name":"林学"}]

发表期刊：

数字识别码：10.1002/2017GB005644

是否作者本人： 否