关键词: 边坡, 植被类型, 水土保持, 生态护坡

Abstract: [Objective] The objective of this case was to understand the annual fluctuation of the ecological slope protection capacity in southwest areas.Their characteristics of runoff and sediment yield in rainy seasons during the year 2010 to 2012 were investigated.[Method] Chengyu expressway in Yongchuan region ranging K306+165 to K306+390 was took as the example and foundation.Five vegetations modes,including ecological transitional zone (ornamental arbors+groundcover plants) and slope protection zone (shrubs+herbages),were reconstructed,Their characteristics of runoff and erosion sediment in rainy seasons during the year 2010 to 2012 were investigated in the slope plot experiments.And the difference among the slope rainfall-induced processes of infiltration,runoff generation,erosion and sedimentation were analyzed.[Results] The annual herbaceous plants in the grass-shrub community (i.e.,Vitex negundo+Setaria viridis) (M₅) grew rapidly,which turf-establishment stage was transitory.Its capacity of soil and water conservation was the highest than other modes in the first rainy seasons after turf-establishment (2010).During the rainy seasons in 2011,ecological protection benefit of the grass-shrub communities including perennial herbs were improved apparently,which were especially outstanding in Coronilla varia+Lolium perenne (M₄) and Medicago falcate+Cynodon dactylon (M₃).In third growing season,performance of artificial vegetations M₃ was the most excellent in slope protection by means of developed root system of Bermuda grass,and that of M₄ was the worst.[Conclusion] Ecological protection benefit of artificial vegetations was closely related to their community characteristics.There was positive correlation between the aboveground biomass of vegetations and their capacity of soil and water conservation in initial succession,and did so between root biomass and these capacity in latter succession when there were the same side slope conditions,seed quantity and planting measures.

Key words: side slope, vegetation type, soil and water conservation, ecological slope protection