近地表水汽对植被水分补偿及量化研究进展 postprint

Abstract: Near-surface atmospheric water (NSAW) serves as an important hidden water source in arid-zone ecosystems, where its role in mediating water compensation is key to alleviating vegetation water stress amid the increasing frequency of extreme droughts driven by climate change. However, the compensation process, underlying mechanisms, weighting schemes, and quantification methods associated with NSAW and vegetation water remain to be further clarified. Therefore, this paper reviews the research progress on the hydrological processes and functional mechanisms of NSAW, the compensation mechanisms of NSAW for vegetation and soil moisture, and the quantification methods for phase transformation of NSAW. Existing research findings indicate that vegetation can absorb and utilize NSAW water through stomata, cuticles, or specialized structures, and this pathway predominantly governs the process by which vegetation acquires NSAW water. NSAW water is absorbed or liquefied by the soil, indirectly regulating vegetation water content through the hydraulic redistribution (HR) process of the root system and thereby establishing a new moisture balance. Dynamic observations of NSAW, along with high-precision analysis of water sources, have been achieved through the integration of micrometeorological monitoring and stable isotope technology. This approach contributes significantly to the quantification and simulation of phase transformations in the field of NSAW. Nevertheless, reaching a consensus on the quantification of NSAW phase transformation remains challenging owing to the lack of parameters related to the physical properties of materials, particularly thermodynamic parameters. This deficiency results in an absence of data on the efficiency of leaf absorption of gaseous water, as well as a shortage of multiscale coupling models. In conclusion, this review posits that future investigations should focus on achieving breakthroughs in the coupling effects of NSAW and carbon assimilation, the development of collaborative monitoring technologies utilizing multisource data, and the construction of multiscale dynamic models. These advancements are expected to provide a theoretical foundation for the efficient utilization of water resources under arid conditions.