Abstract: Hydraulic limitation hypothesis considers that water transport resistance and water potential gradient jointly control the stomatal gas exchange and affect the CO₂ intake, and accordingly, affect the tree height growth. This hypothesis provides a reasonable explanation for the differences of maximum tree height and of height growth patterns in different habits, but has not taken the adapted adjustment of hydraulic architecture and other biological characteristics into account, though the adapted adjustment would drag the increasing water transport resistance to a cetain level. Tree water storage has important biological significance in alleviating the hydraulic limitation of xylem and in controlling the fluctuation of leaf water potential, and is likely the important determinant in stomatal regulation and in the change lattice of water regime. Tree water storage can partially compensate hydraulic limitation. This paper summarized the effects of tree water storage on the hydraulic limitation in the process of tree water use, discussed the possible mechanisms of the compensation of tree water storage for hydraulic limitation and related research methods, and prospected the research directions in future.

Key words: tree water storage, hydraulic conductance, sap flow, whole-tree transpiration, treated water, sewage sludge, emergy, environmental service, waste disposal, sustainability.