Abstract:Partitioning the autotrophic and heterotrophic components of soil respiration is essential for assessing underground flow of carbon and energy and balance of terrestrial ecosystem. Currently, there is a new issue focusing on partitioning the root-derived CO2 efflux from soil (frequently termed rhizosphere respiration) into actual root respiration (respiration by autotrophs) and rhizomicrobial respiration (respiration by heterotrophs). Although the two components of soil respiration are crucial in determining carbon and energy balances of plants and soils, there is also a big gap among researchers in whether to partition the two components or not. The disagreement concentrates on how to understand the respiration of root and rhizomicrobes and the feasibility of partitioning the two components. The obtained results are often different because of differences in methods, research purposes and experiment scales. Moreover, the limitation of experiment technology also intensifies the disagreement. With the change of global climate, carbon allocation and flow in underground ecosystem will change potentially, and the changes of carbon flow and microbes in the rhizosphere will affect profoundly soil carbon storage and trace gases emission. Therefore, partitioning the respiration of the actual root and the rhizomicrobes will be a key research issue in the future.