LAUSR

The natural flow regimes of rivers have been threatened by climate change and increased human activities, which could consequently affect their heath and integrity. Forest disturbance and climate variability are two of the most critical drivers affecting hydrological processes in forested watersheds. Despite an increased understanding of the relationship between climate change and flow regimes, few investigations have been conducted on how forest disturbance influences flow regimes. Moreover, existing researches have not accounted for the effects of climate variability on flow regimes when assessing the effects of forest disturbance. In the present study, the paired watersheds approach, which can account for temporal and spatial variations of climate, was applied to a typical small forested watershed ( < 100 km ) in northern Daxing′anling to investigate the effects of forest disturbance on flow regimes. The results showed that low⁃flow regimes were more sensitive than high⁃flow regimes to forest disturbance. Even though the area of forest disturbance was only 6.74% of the total watershed area (Laogouhe watershed), the average magnitude (0.47 mm) of low flows was lower by 26.58% and the average variability (0.39) of low flows was higher by 36.77% than those of low flows (0.60 mm and 0.28, respectively) in the control watershed (Xiaobeigou watershed). Besides, the differences in low flow magnitude and variability between the paired watersheds were statistically significant (P<0.01). In contrast, the magnitude, duration, and variability of high