Global climate models predict that many regions may experience changed intensity and frequency of precipitation events in the future, which might make surface soils experience more frequent and/or intense rewetting by rainfall events that occur following dry conditions. Rewetting dry soil (DRW) has long been known to cause a pulse of carbon (C) release (mainly heterotrophic respiration (Rh)). However, how C release respond to changed DRW is uncertain.
Results/Conclusions: Here, we synthesized 446 individual experiments to examine responses of soil C release to moisture under DRW and the underlying mechanisms. Our results showed that DRW significantly increased cumulative Rh (Rh-cum), with a weighted response ratio 0.09 ± 0.04 at global scale. Both biomes level and historical climate region had different response of Rh-cum to DRW. Soil abiotic properties (bulk density and soil texture) were the dominate factors and explained 18.5~69.1% of the spatial variation in response of C release to DRW in this study. To be specific, soil abiotic, combing with substrate and incubation condition of DRW, totally explained 56%, 82%, and 54% for the variation in response of Rh-cum to DRW at global, natural, and cropland ecosystem, respectively. In summary, our study implied that spatial heterogeneity of soil texture should be considered into model to assess the global variation in C pool to DRW, accompanying with future extreme climate event.