Root effects on the temperature sensitivity of soil respiration depend on climatic condition and ecosystem type

Root activity may alter the temperature sensitivity (Q(10)) of soil respiration. However, we lack a comprehensive understanding of root effects on Q(10) across different climatic regions and ecosystem types. Here, we conducted a global synthesis of 87 observations of Q(10) values of soil respiration and its components from 40 published studies. We found that roots significantly enhanced Q(10) of soil respiration because root and rhizosphere respiration was more temperature-sensitive than the respiration of root-free soil, especially in cold regions (mean annual temperature < 10 degrees C). Moreover, roots significantly enhanced Q(10) of soil respiration in grassland and cropland but not in forest ecosystems. Overall, our results suggest that the positive effects of roots on Q(10) largely depend on climatic condition and ecosystem type, and are potentially useful for parameterizing and benchmarking biogeochemical and Earth system models.