摘要
[目的]研究消落带适生草本根系解剖结构对单根力学特性的影响,为明确消落带草本根系固土的微观力学机理提供依据。[方法]选取菖蒲(Acorus calamus L.)、狗牙根〔Cynodon dactylon(Linn.)Pers.〕、风车草(Cyperus involucratus Rottb.)、花叶芦竹(Arundo donax‘Versicolor’)4种消落带适生草本为研究对象,使用万能试验机进行单根拉伸试验,使用显微镜及图像分析软件测定根系微观结构,定量分析了根系各显微结构与抗拉特性的关系。[结果](1)根系抗拉力、抗拉强度分别随直径的增大呈幂函数增大、减小,4种草本根系的平均抗拉力以花叶芦竹(13.02 N)最大,菖蒲(5.90 N)最小,花叶芦竹显著大于其他3种草本(p<0.05);抗拉强度以狗牙根(42.79 MPa)最大,花叶芦竹(24.16 MPa)最小,菖蒲和狗牙根极显著大于其他两种草本(p<0.01)。(2)4种草本根系的平均极限延伸率以风车草(36.18%)最大,狗牙根(23.38%)最小,风车草显著大于其余草本(p<0.05);根系弹性模量随直径增大呈幂函数减小,平均弹性模量以狗牙根(195.85 MPa)最大,风车草(72.00 MPa)最小,菖蒲和狗牙根显著大于风车草(p<0.05)。(3)4种草本根系横切面均由表皮、皮层和中柱构成,除花叶芦竹外,基本结构均以皮层厚度最大,中柱鞘厚度最小;除菖蒲外,微观结构组织比量均以皮层面积占比最大,中柱面积占比次之,韧皮部面积占比最小。(4)菖蒲抗拉特性受表皮和髓面积的影响,狗牙根抗拉特性受表皮、木质部和韧皮部面积的影响,花叶芦竹抗拉特性受皮层和髓面积的影响。[结论]4种消落带草本在根系固土能力方面各有优势,菖蒲和风车草根系主要起减缓消落带边坡变形的作用,花叶芦竹根系主要起锚固作用,狗牙根根系既能起较好的锚固作用,也能较好的缓减边坡变形。
[Objective]The aims of this study are to examine the effect of the anatomical structure of herbaceous root systems on the mechanical properties of single roots,and to provide a basis for elucidating the micromechanical mechanism of soil consolidation by herbaceous root systems in water-level-fluctuating zone.[Methods]Four species of water-level-fluctuating zone herbs(Acorus calamus L.;Cynodon dactylon(Linn.)Pers.;Cyperus involucratus Rottb.;Arundo donax‘Versicolor’)were selected as research objects,and the single tensile test and microstructure determination test was carried out.[Results](1)The tensile force and tensile strength of the root system increased and decreased as a power function of diameter,respectively.The average tensile force of the root system of the four species of herbs was the largest in Arundo donax‘Versicolor’(13.02 N),the smallest in Acorus calamus L.(5.90 N),which was significantly larger than the other three species of herbs(p<0.05).The tensile strength was greatest for Cynodon dactylon(Linn.)Pers.(42.79 MPa)and smallest for Arundo donax‘Versicolor’(24.16 MPa),with Acorus calamus L.and Cynodon dactylon(Linn.)Pers.being highly significantly greater than the other two herbs(p<0.01).(2)The average ultimate elongation of the root systems of the four herbs was the largest for Cyperus involucratus Rottb.(36.18%)and the smallest for Cynodon dactylon(Linn.)Pers.(23.38%),which was significantly larger than that of the remaining herbs(p<0.05).The modulus of elasticity of the root system decreased as a power function with increasing diameter,and the average modulus of elasticity was the largest for Cynodon dactylon(Linn.)Pers.(195.85 MPa)and the smallest for Cyperus involucratus Rottb.(72.00 MPa),Acorus calamus L.and Cynodon dactylon(Linn.)Pers.were significantly greater than Cyperus involucratus Rottb.(p<0.05).(3)Except for Arundo donax‘Versicolor’,the basic structure with the cortical thickness was the largest,and the thickness of vascular bundle was the smallest.Except for Acorus c
作者
段继琪
李建兴
王波
杜技能
张立芸
段青松
Duan Jiqi;Li Jianxing;Wang Bo;Du Jineng;Zhang Liyun;Duan Qingsong(College of Resources and Environment,Yunnan Agricultural University,Kunming 650201,China;Power China Kunming Engineering Corporation Limited,Kunming 650051,China;College of Water Resources,Yunnan Agricultural University,Kunming 650201,China;College of Mechanical and Electrical Engineering,Yunnan Agricultural University,Kunming 650201,China)
出处
《水土保持研究》
CSCD
北大核心
2024年第6期130-138,共9页
Research of Soil and Water Conservation
基金
国家自然科学基金“三江并流区水库消落带草本植物根系水下固土机理研究”(42167046)。
关键词
水库消落带
草本植物
抗拉特性
微观结构
water level fluctuation zone
herbaceous plants
tensile characteristics
microstructure
