Inverse Modeling for Spatial Pattern of Temperature Sensitivity (q10) in China

Temperature sensitivity of soil respiration (Q10) is an important parameter on evaluations of feedback intensity between soil carbon efflux and global warming. Although experiments of soil respiration indicate its value has high spatial heterogeneity due to influences of many spatially heterogeneous environmental factors, the coupled climate-carbon cycle models usually assume it a globally invariant constant for its spatial complexity. Therefore, revealing the spatial pattern of Q10 value and incorporating it into coupled climate-cycle models is an urgent scientific problem for reducing uncertainties of projected climate and atmospheric CO2 content. In this study, an inversion analysis method, which combines a process-based terrestrial carbon cycle model (CASA model) with observations of soil organic carbon, was used to retrieve the spatial pattern of Q10 in China at 0.08 by 0.08 degree resolution. The results indicate that the optimal Q10 value for different spatial grid is spatially heterogeneous, which are matched with those derived from soil respiration observations. The mean Q10 values for different soil types range from 1.09 to 2.38. The results indicate that the spatial pattern of Q10 value is related with environmental factors, especially precipitation and top soil organic carbon content. * Corresponding author.