摘要
黄土丘壑区植被恢复有效阻控了土壤分离过程。为量化该区域土壤分离能力的影响因素,该试验根据植被的分布情况,在纸坊沟流域挑选了8个典型植被样地,采用原状土水槽冲刷法测定了各样地(冲刷流星分别为0.05、0.10、0.15、0.20、0.25和0.30 L/s,径流槽坡度15°)的土壤分离能力,运用随机森林和偏最小二乘法结构模型等方法量化各影响因素与土壤分离能力的响应关系。结果表明:试验区不同样地的根系特征、土壤性质及土壤分离能力具有显著性差异(P<0.05)。土壤分离能力与根长密度、根表面积密度、根体积密度、土壤黏粒、粉粒、砂粒、有机质、全氮、阳离子交换量、表面电势、表面电场、表面电荷密度、比表面积、径流流量、流速、剪切力和水流功率显著相关(P<0.05,P<0.01)。不同影响因素对土壤分离能力变化的贡献率从高到低依次为水力学特性、根系特征、土壤表面电化学性质、土壤基本物理性质、土壤基本化学性质。其中,根长密度、粉粒、阳离子交换量和水流功率是土壤分离能力的主要影响因素,其贡献率均达到了7.5%以上。此外,根系特征和水力学特性对土壤分离的影响路径显著,路径系数分别为-0.57和0.49。此结果有助于加深对黄土丘壑区土壤侵蚀机制的认识,以及黄土高原土壤侵蚀模型的完善。
Vegetation restoration has effectively controlled the soil detachment in the loess hilly gully region.However,the little attention has been received on the influence of the soil surface electrochemical properties on the soil detachment capacity.It is unclear on the interactions and contribution rates of the various influencing factors on the soil detachment capacity.Therefore,this study aims to quantify the influencing factors on the soil detachment capacity in the loess hilly gully region.Eight typical sites were selected with the different dominant species in the Zhifanggou watershed,according to the vegetation distribution.The soil flume scouring method was carried out on the primary trough.The flow rates were set at 0.05,0.10,0.15,0.20,0.25,and 0.30 L/s,with a slope of 15°.The soil detachment capacity of each vegetation site was then measured under different flow rates.Finally,Pearson correlation analysis,random forest,and partial least squares equation were used to quantify the relationships and pathways among the plant roots,soil properties,hydraulics,and soil detachment capacity.The results showed that there were the significant differences in the root parameters,soil properties,and soil detachment capacity among different vegetation sites in the experimental area(P<0.05).The soil detachment capacity of the different vegetation sites was ranged from 19.20 to 315.42 g/(m^(2)·s),due to the variations of the plant roots,soil properties,and hydraulics.Pearson correlation analysis indicated that the soil detachment capacity was significantly negatively correlated with the root length density,root surface area density,and root volume density(P<0.01);There were the significant correlations with the contents of the clay,silt,and sand among the basic soil physical properties,soil organic matter and soil total nitrogen among the basic soil chemical properties,soil cation exchange capacity,soil surface potential,soil surface electric field,soil specific surface area,and soil surface charge density among the soil surface electrochemical properties(P<0.01 or P<0.05);It was also significantly positively correlated with the flow charge,velocity,shear stress,and stream power among the hydraulics(P<0.01).In addition,the random forest analysis presented that the contribution rate of the influencing factors to the variation in soil detachment capacity decreased in the order of hydraulics,root characteristics,soil surface electrochemical properties,basic soil physical properties,and basic soil chemical properties.Among them,the root length density(14.66%),the content of silt(8.09%),soil cation exchange capacity(8.18%),and stream power(7.79%)were the main influencing factors on the soil detachment capacity,whose contribution rates all reached above 7.5%.The partial least squares structural equation showed that there was the significant influence on the pathways of the plant roots and hydraulics on the soil detachment(P<0.05),with the path coefficients of-0.57 and 0.49,respectively.These findings can greatly contribute to the initiation and development of the soil erosion in the loess hilly gully region.The soil erosion can be better predicted in the Loess Plateau.
作者
刘均阳
周正朝
苏雪萌
LIU Junyang;ZHOU Zhengchao;SU Xuemeng(School of Life Sciences,Yan’an University,Yan’an 716000,China;School of Geographical Sciences and Tourism,Shaanxi Normal University,Xi’an 710119,China;College of Humanities,Shaanxi University of Technology,Hanzhong 723001,China)
出处
《农业工程学报》
北大核心
2025年第24期133-141,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(42407478,42277320)
陕西省杰青项目(2023-JC-JQ-27)
陕西省自然科学基础研究计划项目(2024JCYBQN-0314,2024JC-YBQN-0496)
延安大学博士启动项目(YAU202313804)。
关键词
土壤分离
根系
土壤表面电化学性质
黄土丘壑区
soil detachment
plant root
soil surface electrochemical properties
loess hilly and gully region
