scholarly journals Soil water deficit and recovery under different vegetation types on the Chinese Loess Plateau

Author(s):  
Mingshuang Shen ◽  
Yang Yu ◽  
Shouhong Zhang ◽  
Ruoxiu Sun ◽  
Zhengle Shi ◽  
...  

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.

2012 ◽  
Vol 9 (10) ◽  
pp. 12029-12060 ◽  
Author(s):  
Y. Q. Wang ◽  
M. A. Shao ◽  
Z. P. Liu ◽  
C. C. Zhang

Abstract. Negative water balance in soil can lead to soil desiccation and subsequent the formation of a dried soil layer (DSL). Essential progress on DSL temporal change has been hampered by difficulty in collecting deep soil water samples (i.e. > 1000 cm), which are necessary to quantify the real extent of DSL. We collected soil samples up to a depth of 1800 cm and investigated the evolution of soil water content (SWC) and DSL under three vegetation types (C. korshinskii, R. pseudoacacia, apple) in three zones (Ansai, Luochuan, and Changwu) of the Chinese Loess Plateau. As plant growth age increased, SWC, available soil water (ASW), SWC within DSL (DSL-SWC), and quantity of water deficit for DSL (DSL-QWD) showed similar change trends of decreasing at first and then increasing, whereas DSL thickness (DSLT) showed an increasing trend over time. A turning point in soil water change was found for the three vegetation types. In Changwu zone, the turning point, both in and out of DSL, was corresponded to the 17-year-old apple orchard. The period from 9 to 17 yr was vital to maintain the buffering function of deep soil water pool and to avoid the deterioration of soil desiccation because the highest mean decline velocity of ASW and the maximum mean forming velocity of DSLT were 165 mm yr−1 and 168 cm yr−1, respectively. Significant correlations were found between DSLT and growth age and root depth, and between DSL-QWD and root depth, whereas mean DSL-SWC had no significant correlation with either growth year or root depth. Soil water condition was highly dependent on the growth year of the plants. This information provides pertinent reference for water resource management in the Chinese Loess Plateau and possibly in other water-limited regions in the world.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong-wang Zhang ◽  
Kai-bo Wang ◽  
Jun Wang ◽  
Changhai Liu ◽  
Zhou-ping Shangguan

AbstractChanges in land use type can lead to variations in soil water characteristics. The objective of this study was to identify the responses of soil water holding capacity (SWHC) and soil water availability (SWA) to land use type (grassland, shrubland and forestland). The soil water characteristic curve describes the relationship between gravimetric water content and soil suction. We measured the soil water characteristic parameters representing SWHC and SWA, which we derived from soil water characteristic curves, in the 0–50 cm soil layer at sites representing three land use types in the Ziwuling forest region, located in the central part of the Loess Plateau, China. Our results showed that the SWHC was higher at the woodland site than the grassland and shrubland, and there was no significant difference between the latter two sites, the trend of SWA was similar to the SWHC. From grassland to woodland, the soil physical properties in the 0–50 cm soil layer partially improved, BD was significantly higher at the grassland site than at the shrubland and woodland sites, the clay and silt contents decreased significantly from grassland to shrubland to woodland and sand content showed the opposite pattern, the soil porosity was higher in the shrubland and woodland than that in the grassland, the soil physical properties across the 0–50 cm soil layer improved. Soil texture, porosity and bulk density were the key factors affecting SWHC and SWA. The results of this study provide insight into the effects of vegetation restoration on local hydrological resources and can inform soil water management and land use planning on the Chinese Loess Plateau.


CATENA ◽  
2017 ◽  
Vol 150 ◽  
pp. 71-78 ◽  
Author(s):  
Yali Zhao ◽  
Yunqiang Wang ◽  
Li Wang ◽  
Zihuan Fu ◽  
Xiaoyan Zhang ◽  
...  

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