Advances in soil moisture-carbon-microbe coupling on the Loess Plateau, China

Soil organic carbon, soil water and microbial community changed asynchronously under vegetation restoration on the Loess Plateau. Soil microbial community was the carrier of various life activities and mediated carbon-water coupling process. By the process of oxidation and reduction reaction, the soil microbial community played a key role in regulating water/carbon coupling. Although numerous studies have been studied soil organic carbon and water content induced by vegetation restoration, due to the variability and complexity of the association between soil microbial activity and community structure, the study of soil microbial community mediated water-carbon coupling has largely unknown. So far, the couplings among soil water, carbon and microbial community after vegetation restoration on the Loess Plateau still lacks overall integration. Most of studies only assumed that each biochemical process was relatively independent, which made our cognition of the couplings of water, carbon and microbial had great limitations. In this review, the vegetation restoration process and soil organic carbon change on the Loess Plateau were reviewed, and the responses of soil organic carbon and microbial community to precipitation patterns were summarized based on the existing theories and evidence. Finally, by integrating key ecological processes such as atmospheric, vegetation, soil and microbial interfaces, a soil water-carbon-microbial coupling framework was constructed and integrated into ORCHIDEE（ecosystem carbon model） and HYDRUS-2D（hydrological process model）. Based on stable carbon and water isotope technology and DNA probe technology, the coupling model of soil water-carbon-microorganism on the Loess Plateau was preliminarily constructed, which would help to cope with global extreme climate change and realize the sustainable development of the Loess Plateau.