黄土高原刺槐林地根系与枯落物对土壤侵蚀的影响  

Effects of Robinia pseudoacacia Litter Cover and Roots on Soil Erosion in the Loess Plateau,China

作　　者：王丹丹 许海超 单志杰[1] 秦伟[1] WANG Dandan;XU Haichao;SHAN Zhijie;QIN Wei(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《水土保持学报》2023年第2期83-89,共7页Journal of Soil and Water Conservation

基　　金：黄河水科学研究联合基金项目(U2243212);国家自然科学基金项目(41877073)。

摘　　要：为探讨自然条件下黄土高原地区刺槐林地枯落物和根系对土壤侵蚀的影响。采用5个坡度(8.7%,17.6%,26.8%,36.4%和46.6%)及3种流量(0.5,1.0,2.0 L/s)分别在有枯落物覆盖、去除枯落物的植被和裸坡样地进行试验,探讨刺槐林地枯落物和根系对土壤侵蚀的影响。结果表明,枯落物和根系对土壤侵蚀有显著影响,当枯落物厚度超过3 cm、根系密度>0.5 kg/m 3时,土壤侵蚀量减小程度趋于稳定。与裸坡相比,刺槐林地土壤侵蚀量减少约55%,且根系和枯落物对土壤侵蚀量减少的贡献率分别为66%和34%。此外,枯落物与根系可降低土壤可蚀性,增加土壤剪切力,进而增强土壤的抗蚀能力。与裸坡相比,有枯落物覆盖和去除枯落物覆盖的植被样地土壤可蚀性分别降低80%和66%,土壤剪切力分别提高285%和237%。研究结果为揭示森林植被的土壤侵蚀机制提供新的思路,对改善黄土高原的植被建设具有一定的指导意义。In this study,the effects of Robinia pseudoacacia litter cover and roots on soil erosion was explored in the Loess Plateau.Five slope gradients(8.7%,17.6%,26.8%,36.4%and 46.6%)and three flow discharges(0.5,1.0 and 2.0 L/s)in vegetation covered with litter removal and bare slope plots,respectively,were used to investigated the effects of Robinia pseudoacacia litter cover and roots on soil erosion.The results indicated that litter cover and roots had significant effect on soil erosion,the reduction degree of soil erosion tended to be stable when the litter thickness was more than 3 cm and the root density was more than 0.5 kg/m 3.Soil erosion amount of Robinia pseudoacacia was reduced by about 55%compared with the bare slope,and the contribution rate of litter cover and roots to soil erosion amount reduction was 66%and 34%,respectively.Moreover,the combination of litter cover and roots can reduce soil erodibility and increase soil critical shear stress,and consequently strengthen soil resistance capacity to erosion.Compared with the bare slope,soil erodibility was decreased by 80%and 66%,and soil critical shear stress was increased by 285%and 237%,respectively,in the plots with and without litter cover.These results provide a new idea for revealing the soil erosion mechanism of forest vegetation and have certain guiding significance for improving vegetation construction in the Loess Plateau.

关 键 词：土壤侵蚀 枯落物 根系 土壤可蚀性 临界剪切力 

分 类 号：S157.1[农业科学—土壤学]