| چکیده انگلیسی مقاله |
Precipitation is the most important water resource in arid and semi-arid regions of China. The redistribution of precipitation among atmospheric water, soil water and groundwater are related to the ecological security of semi-arid regions. The study took widely replanted Pinus sylvestris var. mongolica (PSM) in Mu Us Sandy Land (MUSL) as research object and monitored precipitation, soil moisture, sap flow, deep soil recharge (DSR). Results show that the reconstruction process of PSM in MUSL has changed the distribution of precipitation. Precipitation is intercepted in shallow soil, then evapotranspiration increases, DSR significantly decrease, up to 466.94 mm of precipitation return to the atmosphere through evapotranspiration in 2016. Vegetation increases SWS capacity, with maximum water storages in PSM plot and bare sandy land (BSL) being 260 mm and 197 mm per unit horizontal area, respectively. DSR has decreased from 54% of precipitation to 0.2% of precipitation. Infiltration rate is affected by PSM and soil temperature, infiltration rate in the BSL plot was 11 times of that in the PSM plot from August to September in an annual base. The SWS in shallow soil decreases 16 mm and 7.58 mm per unit horizontal area in 2017 and 2019, respectively. PSM annual sap flow is maintained at a relatively constant level of 153.98 mm.yr-1. This study helps understand the role of precipitation-induced groundwater recharge in the process of vegetation reconstruction in semi-arid regions and why PSM forest degradation. It is necessary to reduce PSM density to allow adaptation to extreme drought in the future. |
