HU Yang, DENG Yan, JIANG Zhongcheng, et al. Soil Water Characteristics and Its Influence Factors of Different Vegetation Types in Karst Area of Guangxi Zhuang Autonomous Region[J]. Bulletin of Soiland Water Conservation, 2015, 35(5): 22-27.
DOI:
HU Yang, DENG Yan, JIANG Zhongcheng, et al. Soil Water Characteristics and Its Influence Factors of Different Vegetation Types in Karst Area of Guangxi Zhuang Autonomous Region[J]. Bulletin of Soiland Water Conservation, 2015, 35(5): 22-27. DOI: 10.13961/j.cnki.stbctb.2015.05.070.
Soil Water Characteristics and Its Influence Factors of Different Vegetation Types in Karst Area of Guangxi Zhuang Autonomous Region
[Objective] The aim of this study is to investigate the soil water characteristic curve and its influence factors under different vegetation cover in karst area in order to provide the theoretical basis for the quantitative analysis of soil water movement in karst mountain area.[Methods] Based on field survey and laboratory analysis
this paper studied the soil water characteristic curve of four different vegetation type(wasteland
grassland
bushwood and forest-shrub) in typical karst mountains in Guohua
Pinguo
Guangxi Zhuang Autonomous Region.[Results] All the three models including van Genuchten
Brooks-Corey and Gardner fitted the data well
with correlation coefficients were >0.93 and the sum of squared residuals were <0.0005. Among the three models
van Genuchten model was the best fitted model for calculating the soil water characteristic curve. The soil water-holding capacity showed a significant negative relationship with the positive succession of vegetation
saturated water content
non-capillary porosity and particle content
while it showed an extremely significant positive relationship with soil bulk density
clay content
capillary porosity
initial water content and capillary moisture. Under different vegetation types and the same suction
the soil water-holding ability was great at the surface and deep layer soil but poor in the middle layer soil. Under different soil depth and the same suction
the soil water-holding ability in wasteland was the greatest
while it was the poorest in forest-shrub.[Conclusion] Under different soil depth and the same suction
the soil water-holding ability decreases with the positive succession of the vegetation. The dominant factor that influences the soil water characteristic curve in the study area is soil capillary porosity.