Factors affecting the shear strength of root-soil complexes from three types of grass hedgerows in a karst area

doi:10.11686/cyxb2020034

Abstract

Abstract:

This research explored the differences in the shear strength of grass hedgerow root-soil complexes from a karst area， and the factors affecting this parameter. Three grass hedgerows， i.e.， Orychophragmus violaceus， Viciavillosa rothvar， and Ophiopogon bodinieri， were established on the upper， middle， and lower slopes of a karst bedding slope in Youyang， Chongqing. The shear strength of the complexes， the basic physical and chemical properties of the soil in the root zone， and the morphological and chemical indexes of the root system in the complexes were measured， and the cohesion and internal friction angle of the complexes were calculated. The main results were as follows： 1） Among the upper/middle slope composites， the O. bodinieri complex showed significantly higher shear strength than the O. violaceus and V. rothvar complexes （P<0.05）， but shear strength did not differ significantly among the three hedgerow complexes from the lower slope. Only the shear strength of the O. bodinieri complex differed significantly among different slope positions （middle slope>upper slope>lower slope）（P<0.05）； 2） The shear strength index was significantly higher for the O. bodinieri and V. rothvar complexes than for the O. violaceus complex. There were differences in the internal friction angle among complexes from the middle slope and in the cohesion of complexes at each position on the slope （P<0.05）. The cohesion and internal friction angle of the O. bodinieri complex and the cohesion of the V. rothvar complex were significantly higher at the middle slope than at the upper and lower slopes （P<0.05）. These parameters of O. violaceus complexes did not differ significantly among the three slopes； 3） Soil organic matter content was positively correlated with the cohesion of V. rothvar and O. bodinieri complexes （correlation coefficients of 0.91 and 0.83， respectively）， but not with the cohesion of O. violaceus complexes. There were significant or extremely significant positive correlations between the cohesion of the three hedgerow complexes and the root morphology index， and the highest correlation coefficient was 0.99. In conclusion， O. bodinieri complexes had the highest shear strength， and the optimal slope location was the middle slope. The shear strength of O. violaceus， V. rothvar， and O. bodinieri hedgerow complexes was mainly affected by cohesion.

Key words: Ophiopogon bodinieri, root system, cohesive force, root surface area, organic matter

Jiao-jiao QIANG, Zhe-hao YAN, Yun CHEN, Bing-hui HE, Han TANG, Xiao-hong LIU. Factors affecting the shear strength of root-soil complexes from three types of grass hedgerows in a karst area[J]. Acta Prataculturae Sinica, 2020, 29(12): 27-37.

Figures/Tables 6

References 23

1	Fabio C N， Romain D， Fritz S， et al. Bedrock bedding， 1andsliding and erosional budgets in the Central European Alps. Terra Nova， 2015， 27（5）： 370-378.
2	Li X K， He C X， Jiang Z C. Method and principles of ecological rehabilitation and reconstruction in fragile karst ecosystem. Carsologica Sinica， 2003， 22（1）： 12-17.
	李先琨，何成新，蒋忠诚. 岩溶脆弱生态区生态恢复、重建的原理与方法. 中国岩溶， 2003， 22（1）： 12-17.
3	Aerts R， Maes W， November E， et al. Surface runoff and seed trapping efficiency of shrubs in a regenerating semiarid woodland in northern Ethiopia. Catena， 2006， 65： 61-70.
4	Endo T， Tsuruta T. The effect of tree roots upon the shearing strength of soil //Forestry and forest products research institute. annual report of the hokkaido branch， forest place experimental station. Sapporo， Japan： Forestry and Forest Products Research Institute， 1969.
5	Bischetti G B， Chiaradia E A， Simonato T， et al. Root strength and root area ratio of forest species in Lombardy （Northern Italy）. Plant and Soil， 2005， 278（1/2）： 11-22.
6	Mao Z， Yang M， Bourrier F， et al. Evaluation of root reinforcement models using numerical modelling approaches. Plant and Soil， 2014， 381（1/2）： 249-270.
7	Bourrier F， Kneib F， Chareyre B， et al. Discretemodeling of granular soils reinforcement by plant roots. Ecological Engineering， 2013， 61（Part C）： 646-657.
8	Liu C Y， Hu X S， Dou Z N， et al. Shear strength tests of the root soil composite system of alpine grassland vegetation at different stages of degradation and the determination of thresholds in the Yellow River source region. Acta Prataculturae Sinica， 2017， 26（9）： 14-26.
	刘昌义，胡夏嵩，窦增宁，等. 黄河源区高寒草地植被根-土复合体抗剪强度试验及退化程度阈值确定. 草业学报， 2017， 26（9）： 14-26.
9	Qi Z X， Yu D M， Liu Y B， et al. Experimental research on factors affecting shear strength of halophyte root-soil composite systems in cold and arid environments. Journal of Engineering Geology， 2017， 25（6）： 1438-1448.
	祁兆鑫，余冬梅，刘亚斌，等. 寒旱环境盐生植物根-土复合体抗剪强度影响因素试验研究. 工程地质学报， 2017， 25（6）： 1438-1448.
10	Li J， Wang X， Jia H X， et al. Ecological restoration with shrub roots for slope reinforcement in a shallow landslide-prone region. Acta Ecologica Sinica， 2019， 39（14）： 5117-5126．
	李佳，汪霞，贾海霞，等. 浅层滑坡多发区典型灌木根系对边坡土体抗剪强度的影响. 生态学报， 2019， 39（14）： 5117-5126.
11	Wang Y， Du F， Zhou M， et al. Research on shear strength of root soil composite in a forest and grass standing site in northern shaanxi. Research of soil ang Water Conservation， 2018， 25（2）： 213-219.
	王月，杜峰，周敏，等. 陕北林草混交根土复合体抗剪强度研究. 水土保持研究， 2018， 25（2）： 213-219.
12	Zhou T， Chen Y， Wang R Z， et al. Root characteristics of Cynodon dactylis and Trifolium repens and their effect on shear performance of purple soilin barren hillside. Acta Prataculturae Sinica， 2019， 28（3）： 63-73.
	周涛，谌芸，王润泽，等. 种草和施用聚丙烯酰胺对荒坡紫色土抗剪和抗蚀性能的影响研究. 草业学报， 2019， 28（3）： 62-73.
13	Li T， Wang R Z， Chen Y， et al. Effects of polyacrylamide and grass root system on shear strength and physical properties of purple soil on barren slopes. Acta Prataculturae Sinica， 2018， 27（2）： 69-78.
	李铁，王润泽，谌芸，等. PAM和草类根系对荒坡紫色土物理性质与抗剪性能的影响. 草业学报， 2018， 27（2）： 69-78.
14	Tang H， Chen Y， Liu X H， et al. Study on the mechanic features of root and root-soil matrix of Dolichos lablab L.hedgerows on the slopes of the karst area. Acta Ecologica Sinica， 2019， 39（16）： 6114-6125．
	唐菡，谌芸，刘枭宏，等. 喀斯特坡地拉巴豆地埂篱根及根-土复合体力学特性. 生态学报， 2019， 39（16）： 6114-6125.
15	Zhang Q Y， Tang L X， Pan L， et al. Study on the tensile and shear properties of shrubs and the applicability of model WU in karst area. Journal of Yangtze River Scientific Research Institute， .
	张乔艳，唐丽霞，潘露，等. 喀斯特区灌木抗拉抗剪特性及WU模型适用性研究. 长江科学院院报， .
16	Wang R Z， Chen Y， Li T， et al. Root distribution characteristics of Vetiveria zizanioides and Digitaria sanguinalis and their effects on the anti erodibility of purple soil in slopelands. Acta Prataculturae Sinica， 2017， 26（7）： 45-54.
	王润泽，谌芸，李铁，等. 香根草和马唐的根系特征及对坡地紫色土抗侵蚀性的影响. 草业学报， 2017， 26（7）： 45-54.
17	Institute of Soil Physics， Nanjing Soil Research Institute， Chinese Academy of Sciences. Physical properties of Soil. Beijing： Beijing Science Press， 1978.
	中国科学院南京土壤研究所土壤物理研究室. 土壤物理性质测定法. 北京：北京科学出版社， 1978.
18	Li H S. Experimental principle and techniques for plant physiology and biochemistry. Beijing： Higher Education Press， 2000.
	李合生. 植物生理生化实验原理和技术. 北京：高等教育出版社， 2000.
19	Liu Y B， Hu X S， Yu D M， et al. Root distribution characteristics of combination of herbs and shrubs in loess area of Xining basin and its effect on enhancing soil shear strength. Journal of Engineering Geology， 2020， 28（3）： 471-481.
	刘亚斌，胡夏嵩，余冬梅，等. 西宁盆地黄土区草本和灌木组合根系分布特征及其增强土体抗剪强度效应. 工程地质学报， 2020， 28（3）： 471-481.
20	Wang G， Zhou T Y， Wei J. Experimental study on shear resistance of herb root soil complex in purple soil and yellow soil. Soil and Water Conservation in China， 2019（4）： 34-37， 69.
	王耕，周腾禹，韦杰. 紫色土和黄壤草本根土复合体抗剪性能试验研究. 中国水土保持， 2019（4）： 34-37， 69.
21	Cheng H， Zhao J M， Cai G T， et al. Experimental study of increment in shear strength of soil with roots of tall fescue plants. Journal of Nanchang Institute of Technology， 2018， 37（1）： 1-8.
	程洪，赵建民，蔡高堂，等. 高羊茅根系增强土壤黏聚力的试验研究. 南昌工程学院学报， 2018， 37（1）： 1-8.
22	Andreoli A， Bischetti G B， Chiaradia E， et al. The roots of river restoration： Role of vegetation recover in bed stabilization. Iahr World Congress， 2017.
23	Wu Y R， Liu J， Zhang X， et al. Relationship between anti-shear characteristics of root and its responses to their chemical components for three shrubs. Journal of Arid Land Resources and Environment， 2019， 33（4）： 129-133.
	武艺儒，刘静，张欣，等. 3种灌木直根抗剪特性及其与化学组分的关系. 干旱区资源与环境， 2019， 33（4）： 129-133.

草类 Types of grass	种植方式 Method of placement	篱带规格 Hedgerow specification		播种（移栽）密度 Seeding (transplanting) density	移栽时情况 Status of transplanting	出苗/成活率 Emergence (survival) rate (%)	播种（移栽）时间Seeding (transplanting) time	采样时间Sampling time
草类 Types of grass	种植方式 Method of placement	长Length (m)	宽Width (cm)	播种（移栽）密度 Seeding (transplanting) density	移栽时情况 Status of transplanting	出苗/成活率 Emergence (survival) rate (%)	播种（移栽）时间Seeding (transplanting) time	采样时间Sampling time
二月兰 O. violaceus	撒播Broadcast sowing	200	20	0.003 kg·m^-2	-	≈66	2018-10	2019-01
光叶苕子 V. rothvar	撒播Broadcast sowing	200	20	0.004 kg·m^-2	-	≈75	2018-10	2019-01
沿阶草 O. bodinieri	移栽Transplant	200	30	4行，每株间距约10 cm。 Four rows, about 10 cm each.	株高约为5 cm，地径约0.8 cm，冠幅约为7 cm。 The plant height is about 5 cm, the ground diameter is about 0.8 cm, the crown width about 7 cm.	≈90	2018-07	2019-01

草类 Types of grass	种植方式 Method of placement	篱带规格 Hedgerow specification		播种（移栽）密度 Seeding (transplanting) density	移栽时情况 Status of transplanting	出苗/成活率 Emergence (survival) rate (%)	播种（移栽）时间Seeding (transplanting) time	采样时间Sampling time
草类 Types of grass	种植方式 Method of placement	长Length (m)	宽Width (cm)	播种（移栽）密度 Seeding (transplanting) density	移栽时情况 Status of transplanting	出苗/成活率 Emergence (survival) rate (%)	播种（移栽）时间Seeding (transplanting) time	采样时间Sampling time
二月兰 O. violaceus	撒播Broadcast sowing	200	20	0.003 kg·m^-2	-	≈66	2018-10	2019-01
光叶苕子 V. rothvar	撒播Broadcast sowing	200	20	0.004 kg·m^-2	-	≈75	2018-10	2019-01
沿阶草 O. bodinieri	移栽Transplant	200	30	4行，每株间距约10 cm。 Four rows, about 10 cm each.	株高约为5 cm，地径约0.8 cm，冠幅约为7 cm。 The plant height is about 5 cm, the ground diameter is about 0.8 cm, the crown width about 7 cm.	≈90	2018-07	2019-01

草类 Types of grass	坡位 Slope position	根长 Root length （cm）	根表面积 Root surface area（cm²）	根体积 Root volume（cm³）	纤维素 Cellulose (%)	半纤维素 Hemicellulose （%）	木质素 Lignin (%)	木纤比 Wood fiber ratio
二月兰 O.violaceus	上坡Up	208.59±83.62Aa	28.67±4.98Ab	0.46±0.10Ab	0.27±0.03Bc	0.55±0.07Aa	0.17±0.01Aa	0.65±0.07Aa
	中坡Mid	304.95±81.32Ab	40.84±12.09Ab	0.49±0.44Ab	0.37±0.02Aa	0.34±0.06Ba	0.15±0.01Ab	0.40±0.02Ba
	下坡Down	297.86±82.54Aa	42.05±12.73Ab	0.32±0.04Ab	0.37±0.04Aab	0.28±0.01Ba	0.16±0.01Aa	0.39±0.09Ba
光叶苕子 V. rothvar	上坡Up	274.84±87.67Ba	38.76±14.43Ab	0.32±0.05Bb	0.34±0.04Ab	0.45±0.03Ab	0.16±0.01Ba	0.47±0.04Ab
	中坡Mid	680.99±79.51Aa	55.91±15.61Ab	0.46±0.03Ab	0.44±0.06Aa	0.38±0.04Ba	0.21±0.01Aa	0.48±0.08Aa
	下坡Down	369.79±63.91Ba	42.06±6.00Ab	0.40±0.04Ab	0.42±0.05Aa	0.42±0.03ABa	0.18±0.01Ba	0.42±0.03Aa
沿阶草 O.bodinieri	上坡Up	276.47±75.01Aa	65.95±3.36Ba	1.25±0.67Ba	0.43±0.02Aa	0.41±0.03Ab	0.18±0.03Aa	0.41±0.08Ab
	中坡Mid	439.23±120.49Ab	94.97±5.69Aa	2.33±0.40Aa	0.44±0.21Aa	0.36±0.13Aa	0.18±0.04Aab	0.46±0.18Aa
	下坡Down	261.22±114.52Aa	74.19±9.15Ba	1.49±0.21ABa	0.23±0.11Ab	0.28±0.18Aa	0.18±0.04Aa	0.93±0.51Aa

草类 Types of grass	坡位 Slope position	根长 Root length （cm）	根表面积 Root surface area（cm²）	根体积 Root volume（cm³）	纤维素 Cellulose (%)	半纤维素 Hemicellulose （%）	木质素 Lignin (%)	木纤比 Wood fiber ratio
二月兰 O.violaceus	上坡Up	208.59±83.62Aa	28.67±4.98Ab	0.46±0.10Ab	0.27±0.03Bc	0.55±0.07Aa	0.17±0.01Aa	0.65±0.07Aa
	中坡Mid	304.95±81.32Ab	40.84±12.09Ab	0.49±0.44Ab	0.37±0.02Aa	0.34±0.06Ba	0.15±0.01Ab	0.40±0.02Ba
	下坡Down	297.86±82.54Aa	42.05±12.73Ab	0.32±0.04Ab	0.37±0.04Aab	0.28±0.01Ba	0.16±0.01Aa	0.39±0.09Ba
光叶苕子 V. rothvar	上坡Up	274.84±87.67Ba	38.76±14.43Ab	0.32±0.05Bb	0.34±0.04Ab	0.45±0.03Ab	0.16±0.01Ba	0.47±0.04Ab
	中坡Mid	680.99±79.51Aa	55.91±15.61Ab	0.46±0.03Ab	0.44±0.06Aa	0.38±0.04Ba	0.21±0.01Aa	0.48±0.08Aa
	下坡Down	369.79±63.91Ba	42.06±6.00Ab	0.40±0.04Ab	0.42±0.05Aa	0.42±0.03ABa	0.18±0.01Ba	0.42±0.03Aa
沿阶草 O.bodinieri	上坡Up	276.47±75.01Aa	65.95±3.36Ba	1.25±0.67Ba	0.43±0.02Aa	0.41±0.03Ab	0.18±0.03Aa	0.41±0.08Ab
	中坡Mid	439.23±120.49Ab	94.97±5.69Aa	2.33±0.40Aa	0.44±0.21Aa	0.36±0.13Aa	0.18±0.04Aab	0.46±0.18Aa
	下坡Down	261.22±114.52Aa	74.19±9.15Ba	1.49±0.21ABa	0.23±0.11Ab	0.28±0.18Aa	0.18±0.04Aa	0.93±0.51Aa

抗剪指标 Shear index	草类 Types of grass	自然含水率 Natural moisture content	土壤容重 Soil bulk density	毛管孔隙度 Capillary porosity	有机质 Organic matter	根长 Root length	根表面积 Root surface area	根体积 Root volume	纤维素 Cellulose	半纤维素 Hemicellulose	木质素 Lignin
黏聚力 Cohesive strength	二月兰O.violaceus	0.07	-0.52	-0.31	0.32	0.92^**	0.82^**	0.18	0.47	-0.52	-0.36
	光叶苕子V. rothvar	-0.19	0.09	-0.54	0.91^**	0.99^**	0.80^*	0.66	0.72^*	-0.56	0.86^**
	沿阶草O.bodinieri	-0.05	-0.07	0.02	0.83^**	0.85^**	0.94^**	0.85^**	0.11	-0.24	0.11
内摩擦角 Internal friction angle	二月兰O.violaceus	-0.18	0.20	-0.22	0.46	0.39	0.16	0.30	0.13	-0.46	-0.44
	光叶苕子V. rothvar	0.48	-0.23	0.57	-0.34	-0.57	-0.79^*	-0.05	-0.44	0.20	-0.25
	沿阶草O.bodinieri	-0.60	-0.03	-0.56	0.56	0.52	0.31	0.38	0.77^*	0.36	0.04
平均抗剪强度 Average shear strength	二月兰O.violaceus	-0.23	0.48	-0.08	0.52	0.06	-0.07	0.38	0.04	-0.23	-0.33
	光叶苕子V. rothvar	0.46	-0.20	0.31	0.28	0.06	-0.40	0.45	-0.02	-0.22	0.36
	沿阶草O.bodinieri	-0.63	0.09	-0.57	0.64	0.56	0.47	0.61	0.69^*	0.27	0.13