水库崩塌特殊地优势植物根力的研究

Study on Root Strength Characteristics of Pioneer Plants in Landslides Scars,Reservoir Watershed

台湾石门水库集水区内地质脆弱且坡度陡峭,2004年"艾利"台风过境后,豪雨冲蚀造成集水区上游800hm2以上的崩塌地。本研究依崩塌地植被调查结果,选取5种优势木本植物进行根系调查,并探讨其对坡面安定功能,另由植株引拔抗力试验与基径、土壤含水量、地上部重等关系,进行回归分析统计,建立根力推估模式,并相互比较。结果显示:引拔抗力(P)与基径(D)的关系最为显著;根力引拔抗力推估式为,山芙蓉:P=5.10D1.49,九芎:P=2.82D1.96,构树:P=11.75D0.74,山盐菁:P=12.56D1.32,山黄麻:P=8.52D1.18,而在固定基径条件下,试验呈现所需拉拔抵抗力大小依序为:山盐菁>九芎>山芙蓉>山黄麻>构树。显示山盐菁、九芎的根系对边坡稳定所提供的水土保持效果较大。

The geology of Shi-Men reservoir watershed is very weak and the slope is very steep. Above 800 hectare landslide after Typhoon Aili pounded Taiwan with strong winds and heavy rains. According to vegetation investigation, we choose live of the most important pioneer plants at landslide scars. We investigate the root distribution and evaluate the slope stability. In order to obtain root strength model from pulling resistance and root tensile strength test that analyze the tests＇ datum by statistical regression. The best estimator for pulling resistance （P） with basal diameter （D） are Taiwan hibiscus ： P=5.10D1.49 ; Subcostate crape myrtle： P=2.82DTM ; Paper mulberry： P=ll. 75D1.74 ; Roxburgh sumac： P= 12.56Dl ; Indiacharcial trema： P= 8.52D1.18. The ability of pulling resistance is Roxburgh sumac 〉 Subeostate crape myrtle 〉 Taiwan hibiscus 〉Indiacharcial trema 〉 Paper mulberry under fixed root diameter condition. Therefore Roxburgh sumac and Subcostate crape myrtle are really obvious about providing slope stability.