狗牙根群落土壤-根系系统的结构及其抗冲刷与抗侵蚀性能的空间变化

[目的]探讨三峡库区消落带常见的物种狗牙根对库区消落带固土护坡的作用机理。[方法]结合野外调查和室内试验研究,对狗牙根群落根土复合体的结构、根土复合体抗冲刷与抗侵蚀性能及其空间变化进行研究。[结果]狗牙根根系对土壤抗冲性和抗蚀性都有显著的增强效应。随着狗牙根根系生物量的增加,土壤抗冲性和抗蚀性能力也随之增强,且根系生物量与土壤抗冲性和抗蚀性有线性相关性;土壤的抗冲刷与抗侵蚀能力还受消落带海拔梯度的影响,随着海拔梯度的上升,土壤的抗冲刷与抗侵蚀能力逐渐增强,在175m高度达到最大。[结论]由于高度升高,被淹的时间缩短,狗牙根在高海拔地区的生长状况好于低海拔地区。

Spatial Variation of Soil-root System Structure of Cynodon Dactylon Community and Its Capability to Soil Antierodibility and Antiscouribicity

[Objective] To uncovered the mechanism of Cynodon dactylon in slope stabilization.[Methods] We tested the spatial variation of plant growth, antierodibility and antiscouribicity with altitude through field investigation and laboratory experiments.[Results] The roots of C. dactylon had significant effects to enhance the soil antierodibility and antiscouribicity. The antierodibility and antiscouribicity of soil-root system increased significantly with the increase of root biomass, which showed linear regression relationship. The antierodibility and antiscouribicity of soil-root system also was influenced significantly by altitude. It increased with the increasd altitude and showed strongest at the altitude of 175 m, the upper edge of the water-level-fluctuation zone.[Conclusion] The C. dactylon community distributing on the upper parts of the water-level-fluctuation zone is submerged slighter and grow better than those distributing on the low parts.