岷江上游杂谷脑河流域河谷断面的土壤孔隙与贮水特征
Characteristics of soil porosity and water storage in valley section of Zagunao River basin in the upper reaches of Min River
-
摘要: 选取岷江上游杂谷脑河流域V 字河谷九子村- 三寨村断面为研究对象,研究河谷断面生态林的土壤容重、土壤孔隙和贮水特征及其异质性。结果显示:土壤容重河谷南侧(1.24 g/cm3)< 河谷北侧(1.47 g/cm3),其中采样表层(0~15 cm)变化幅度大,河谷南侧差值最高达0.27 g/cm3,河谷北侧差值最高达0.015 g/cm3,采样底层(60~75 cm)变化幅度小,且随土层深度和海拔增加而减小;土壤孔隙度河谷南侧(52.51%)>河谷北侧(45.21%),总体高出7.3%,且与土层深度和海拔高度呈负相关;土壤贮水量河谷南侧(380.71 mm)>河谷北侧(332.70 mm),取决于土壤孔隙度,与海拔呈正相关。表明不同坡向土壤贮水能力河谷南侧>河谷北侧。研究结果为杂谷脑河流域生态恢复和退耕还林还草措施的布局选择提供合理建议。Abstract: In this study,the“V” type river valley section formed by Jiuzi village and Sanzhai village of Zagunao River basin in the upper reaches of Min River was selected to study the soil bulk density,soil pore and water storage characteristics and its heterogeneity in the valley cross-section ecological forest. The results showed that soil bulk density in the southern side of river valley was 1.24 g/cm3,less than the value 1.47 g/cm3 in the north side;the variation of surface soil( 0-15 cm) was large,the maximum difference in the southern side was up to 0.27 g/cm3, the maximum difference in the north side was 0.015 g/cm3,while the variation of subsoil( 60-75 cm) was small; the soil bulk density decreased with the soil depth and elevation increasing. Soil porosity in the southern side of river valley was 52.51%,higher by 7.3% than the value 45.21% in the north side;and the soil porosity was negatively correlated with soil depth and altitude. Soil water storage in the southern side of river valley was 380.71 mm,larger than that( 332.70 mm) in the north side;soil water storage depended on soil porosity and was positively correlated with altitude. The results could provide reasonable suggestions for the layout of ecological restoration and conversion of farmland to forest and grassland in the Zagunao River basin.