Soil water deficit and recovery under different vegetation types on the
Chinese Loess Plateau
Abstract
Characterizing soil water content (SWC) dynamics is a prerequisite for
conducting sustainable vegetation restoration on the Chinese Loess
Plateau. However, quantifying the variations of the SWC in the deep soil
layers remains a challenge because of the different driving factors and
the complexity of surface processes. In this study, SWC in 0–10 m of
artificial forestlands (AF), apple orchard (AO), native forestland (NF),
farmland (maize; FL), and native grassland (NG) were monitored during
2019–2020. The deficit size (DS) and recovery index (RI) were used to
explore the effects of vegetation types on SWC. The results showed that
the SWCs of forestlands were significantly lower than the SWC of native
grassland (12.32%) and tree species significantly affected the SWC. The
monthly DS values in forestlands were negative, while those of FL were
positive. The DS value in 0-10 m and predictive values below 10 m were
negative of forestlands. Thus, tree planting may have consumed soil
water at a depth of > 10 m. During the investigation
period, soil water was restored in 0–1 m with the positive RI values.
In addition, artificial forestlands showed good performance in deep soil
water recovery. Canopy density was the controlling factor for soil water
restoration. Our results demonstrated that the current afforestation
mode used more soil water but was conducive to deep soil water
conservation. Therefore, reasonable adjustments should be made according
to the local soil and water resources for future vegetation selection
and management.