Research progress of forest hydrological effects and integrated forest-water management

To implement the integrated forest-water management based on a deep understanding of the forest-water interrelations for ensuring both water security and ecological security, this paper summarizes the relevant research progress and deficiencies as well as the future research needs.According to the analysis, previous studies focused on the forest hydrological impacts, research about the effects of water on forests is relatively weak, which is the biggest bottleneck to implementing the integrated forest-water management.Although there are long-term observation-based studies of forest effects on runoff, they have only led to a basic understanding, i.e., increasing forest cover will generally reduce annual runoff and the peak flow of small-and medium-sized floods, but the effect on dry-season flow is uncertain (opposite effects of forest logging and natural disturbances), and a big spatio-temporal variation exists in the forest effect on runoff.Thus, it is difficult at present to accurately predict the forest effect on runoff based on the observation results.The main reason is that the forest hydrological effects are the integrated effects of many factors of vegetation, climate, topography and soil on a series of hydrological processes.In the future, attention must be paid to the complexity of forest-water interrelations and the diversity of influencing factors.Therefore, the studies on forest-water interrelations and the integrated forest-water management increasingly rely on the watershed hydrological models.However, the "ecological process" module reflecting the environment-driven variation of vegetation (quantity, distribution, quality) and soil properties should be strengthened for developing real eco-hydrological models and smart decision-making tools for integrated forest-water management.This study is conducive to strengthening the interdisciplinary, multi-scale, and multi-objective research on the integrated forest-water management in the future, and to strengthening the weak links in theory, technology and decision tools, for realizing the high-quality green development featured by the integrated forest-water management.