三峡库区消落带香根草水土保持功能研究

Researches on the Function of Soil and Water Conservation of Vetiveria zizanioides in the Hydro-fluctuation Belt of the Three Gorges Reservoir Area

三峡库区消落带水土流失是制约库区可持续发展的重要生态问题,通过试验小区对库区消落带香根草水土保持效应进行研究,结果表明:1)栽植有香根草的试验小区土壤物理性质要好于裸地,而2 a生香根草试验小区的土壤涵养水源功能要好于1 a生香根草;2)裸地存在严重的水土流失,土壤流失量为0.3383 t,随着植被覆盖的增加,土壤侵蚀深度和土壤侵蚀量都有显著的下降;3)2 a生香根草过滤、沉积土壤流失量0.1986 t;4)香根草具有较强的固土能力,2 a生单株香根草固土量为3.12 kg,其固土量与地下生物量关系可用Y(固土量)=-23.139X2+25.85X-3.1344方程拟合。

Soil and water loss of the hydro-fluctuation belt is an important ecological problem of restricting the sustainable development in the Three Gorges Reservoir Area. Studies were made of the function of soil and water conservation of Vetiveria zizanioides through the method of test plots. The results have shown that： 1 ） the soil physical properties of Vetiveria zizanioides in the test plots are better than those in the bare test plot. The water conservation function of the test plot of two-year-old Vetiveria zizanioides is better than that of the test plot of one-year-old Vetiveria zizanioides. 2） There is a serious soil and water loss in the bare test plot. The soil loss amount reaches 0. 3383 tons. The depth of soil erosion and the amount of soil loss remarkably decline with the increase of vegetation coverage. 3 ） The soil loss amount which is fil- trated and deposited by two-year-old Vetiveria zizanioides is 0. 1986 tons. 4） Vetiveria zizanioides has a strong capacity for soil conservation. A single Vetiveria zizanioides biennial can conserve 3.12 kilograms soil. The relationship between soil conservation and underground biomass is simulated through the equation of Y（soil conservation） = -23. 139X2 ＋25. 85X -3. 1344.