Soil Hydrological Function And Storage Potential Of Typical Vegetation In The Pailugou Watershed Of The Qilian Mountains

Qilian Mountain is an important ecological area in northwestern China.It has strong water conservation and hydrological functions and is a necessary guarantee for the sustainable development of ecological civilization in the northwest region.In this paper,the determination of soil physical properties under different altitude gradients in the Pailugou watershed of the Qilian Mountains was conducted to explore the laws of soil physical properties under different vegetation types,the laws of hydrological function,and the assessment of soil water resources storage potential,in order to provide a drainage basin for Qilian Mountains.Different vegetation types provide the theoretical basis for the use of soil water resources at different altitudes.By analyzing the physical properties,hydrological function and soil water storage potential of Picea crassifolia forest,alpine shrubbery and sunny slope grassland at different altitudes,the results show that:?1?The soil bulk density of Picea crassifolia forest in the study area ranged from0.38 to 0.87 g·cm^-3,and the average soil bulk density was 0.58 g·cm^-3.The average soil bulk density at each elevation from small to large was 2700m<3300m<3100m<3200m<2800m<2900m<3000m.The soil bulk density of shrubs ranged from 0.38 to0.62g·cm^-3,and the average soil bulk density was 0.53g·cm^-3.The order of average soil bulk density at various elevations was:3500m<3400m<3600m<3700m;the soil bulk density was changed on sunny slopes.The range is 0.85¹.21g·cm^-3.The average soil bulk density is 1.05g·cm^-3.The order of average soil bulk density at each elevation is:3000m<2900m<2800m<2700m.The results of differences in bulk density showed that the soil of the Picea crassifolia forest and the alpine shrubbery soil in the 0-40cm soil layer were significantly different from those in the sunny grassland soil?P<0.05?,and the differences between the Picea crassifolia forest and the alpine shrubbery forest not significant?P>0.05?.?2?With the increase of soil depth,the total porosity of Picea crassifolia forest and alpine shrubbery forests gradually decreases,and the grasslands on sunny slopes gradually increase.The soil total porosity of Picea crassifolia forests and alpine shrubbery soils and sunny slope grasslands There were significant differences among soils?P<0.05?;the variation ranges of total porosity,non-capillary porosity,and capillary porosity of Picea crassifolia forest in the study area were 65.24⁸1.41%,10.24²8.68%,and 41.98⁶5.23%,respectively;The total soil porosity in the Picea crassifolia forests shows a pattern of increasing first and then decreasing with altitude.The ranges of total porosity,capillary porosity,and non-capillary porosity of shrubs were 73.49-81.41%,46.72-64.64%,and 13.18-28.33%,respectively;the total soil porosity of shrubs generally increased with elevation.After reducing the law.The ranges of total porosity,non-capillary porosity,and capillary porosity in sunny slopes were 54.10-65.99%,6.94-13.53%,and 42.81-54.55%,respectively;the total soil porosity on sunny slopes increased with increasing altitude.According to the law,the porosity of soil capillary increases with increasing altitude.?3?With the increase of soil depth,the maximum water holding capacity,capillary water holding capacity,and field water holding capacity of Picea crassifolia forests and shrubs have gradually decreased,and sunny slopes gradually increase.Overall,the soil of shrublands Hydrological function is the most powerful,followed by Picea crassifolia Forest and the worst on sunny slopes.The range of soil water holding capacity,capillary water holding capacity,and maximum water holding capacity of the soil of Picea crassifolia forest were from 45.57 to 85.27%,75.93 to167.93%,and 76.09 to 188.54%,respectively.The soil water holding capacity in the field generally increases first and then decreases with the increase of altitude;the capillary water holding capacity of the soil increases with the increase of altitude and then increases first and then decreases;the maximum soil water holding capacity increases with the altitude.The first increase and then decrease the law.The order of soil total water storage at each elevation is:2700m<2800m<3300m<3100m<3200m<2900m<3000m.The maximum soil water holding capacity,capillary water holding capacity,and field water holding capacity in the shrubs ranged from 104.26 to174.86%,80.62 to 143.93%,and 56.30 to 84.80%,respectively.At the altitude of3400m³500m,the rainfall peaks.The maximum water holding capacity of soil and water conditions is significantly higher than other elevations.The maximum soil water holding capacity,capillary water holding capacity,and field water holding capacity of sunny slope grassland ranges from 46.12 to 75.09%,37.29 to 54.97%,and36.29 to 49.73%,respectively.The maximum soil water holding capacity increases with increasing altitude,and the capillary water holding capacity increases.The water holding capacity of field and the field increased first and then decreased with the increase of altitude.The total water storage capacity of the shrubbery was generally a“fluctuating”pattern with the increase of altitude.?4?The storage and storage potential of soil water resources of Picea crassifolia forests,shrubbery forests and sunny slopes in the study area ranged from 13.57 to39.05%,17.89 to 37.64%,and 11.29 to 24.01%,respectively.The average soil water resources of typical vegetation in the study area increased.The storage potential of the alpine shrub?29.46%?>the Picea crassifolia forest?24.33%?>sunny slope?16.62%?,the maximum values??are found in the surface soil.Soil water storage and storage potential of Picea crassifolia forest and alpine shrub in 0-40cm soil layer decreased with increasing soil depth.There was no significant difference in soil water storage potential between Picea crassifolia forest and alpine shrubbery in 10-20 cm soil layer?P>0.05?,but there was a significant difference between them?P<0.05?.There was a significant difference among the three vegetation types in the potential for increasing the storage of soil water resources?P<0.05?.