Abstract
Plant root system plays an important role in preventing soil erosion and improving slope stability. However, its performance is significantly affected by soil moisture content, and the role of soil moisture in root reinforcement is not fully understood. In this study, the influence of soil moisture on root pullout properties was studied by experiments. Vertical in-situ pullout tests under four different levels of soil matric suction (12 kPa, 18 kPa, 24 kPa, 30 kPa) were carried out on roots of sea buckthorn plants (Hippophae rhamnoides Linn.) which were artificially cultivated for 7 months. Diameter and length of the root system of sea buckthorn were investigated. The results showed that a very significant correlation was observed between root diameter (D) and root length (L) (P<0.01), and root diameter decreased with soil depth. When soil bulk density was constant, peak pullout force (F) and friction coefficient of root-soil interface (μ) decreased with increasing gravimetric soil moisture content in power functions. Soil moisture content significantly affected root pullout resistance because the increase of soil moisture content decreased the friction coefficient between the roots and soil. Root diameter at breakage point (Db) and length of root segment left in soil (Lb) were increased with soil moisture content. In addition, peak pullout force of the roots increased in a power function with root diameter at the soil surface (Do) and in a linear function with total root length (L). The results provided an experimental basis for quantifying the effects of soil moisture content on soil reinforcement by plant roots.
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Abbreviations
- D* :
-
Average root diameter (mm)
- D o :
-
Root diameter at the soil surface (mm)
- D n :
-
Root diameter at the deepest soil depth where root is embedded (mm)
- D b :
-
Root diameter at breakage (mm)
- L :
-
Total root length (mm)
- L b :
-
Root length at breakage (mm)
- F :
-
Peak pullout force (N)
- F Do :
-
Peak pullout force affected by Do (N)
- F L :
-
Peak pullout force affected by total root length (N)
- ΔFDo :
-
Increment of peak pullout force by increase of 0.5 mm in root diameter (N)
- ΔFL :
-
Increment of peak pullout force by increase of 35.7 mm in total root length (N)
- γ s :
-
Soil bulk density (g·cm−3)
- μ :
-
Root-soil interface friction coefficient
References
Abernethy B, Rutherfurd ID (2001) The distribution and strength of riparian tree roots in relation to riverbank reinforcement. Hydrological Processes 15: 63–79. https://doi.org/10.1002/Hyp.152
Alonso EE, Pereira JM, Vaunat J, et al. (2010) A microstructurally based effective stress for unsaturated soils. Géotechnique 60: 913–925. https://doi.org/10.1680/geot.8.P.002
Berrocal A, Baeza J, Rodríguez J, et al. (2004) Effect of tree age on variation of Pinus radiatia D. Don chemical compostition. Journal of the Chilean Chemical Society 49: 251–256 https://doi.org/10.4067/S0717-97072004000300012
Boldrin D, Leung AK, Bengough AG (2017) Root biomechanical properties during establishment of woody perennials. Ecological Engineering 109: 196–206. https://doi.org/10.1016/j.ecoleng.2017.05.002
Docker BB, Hubble TCT (2008) Quantifying root-reinforcement of river bank soils by four Australian tree species. Geomorphology 100: 401–418. https://doi.org/10.1016/j.geomorph.2008.01.009
Dodd IC, Puertolas J, Huber K, et al. (2015) The importance of soil drying and re-wetting in crop phytohormonal and nutritional responses to deficit irrigation. Journal of Experimental Botany 66: 2239–2252. https://doi.org/10.1093/jxb/eru532
Ennos AR (1990) The anchorage of leek seedlings: The effect of root length and soil strength. Annals of Botany 65: 409–416. https://doi.org/10.1093/oxfordjournals.aob.a087951
Fan CC, Su CF (2008) Role of roots in the shear strength of root-reinforced soils with high moisture content. Ecological Engineering 33: 157–166. https://doi.org/10.1016/j.ecoleng.2008.02.013
Genet M, Stokes A, Salin F, et al. (2005) The influence of cellulose content on tensile strength in tree roots. Plant and Soil 278: 1–9. https://doi.org/10.1007/s11104-005-8768-6
Ghestem M, Cao K, Ma W, et al. (2014) A framework for identifying plant species to be used as ‘ecological engineers’ for fixing soil on unstable slopes. PLoS One 9: e95876. https://doi.org/10.1371/journal.pone.0095876
Goodman AM, Ennos AR (1999) The effects of soil bulk density on the morphology and anchorage mechanics of the root systems of sunflower and maize. Annals of Botany 83: 293–302. https://doi.org/10.1006/anbo.1998.0822
Hales TC, Cole-Hawthorne C, Lovell L, et al. (2013) Assessing the accuracy of simple field based root strength measurements. Plant and Soil 372: 553–565. https://doi.org/10.1007/s11104-013-1765-2
Jäger G, Wu Z, Garschhammer K, et al. (2010) Practical screening of purified cellobiohydrolases and endoglucanases with a-cellulose and specification of hydrodynamics. Biotechnology for Biofuels 3: 1–12. https://doi.org/10.1186/1754-6834-3-18
Ji X, Cong X, Dai X, et al. (2018) Studying the mechanical properties of the soil-root interface using the pullout test method. Journal of Mountain Science 15: 882–893. https://doi.org/10.1007/s11629-015-3791-4
Jotisankasa A, Taworn D (2016). Direct shear testing of clayey sand reinforced with live stake. Geotechnical Testing Journal, ASTM 39: 608–623. https://doi.org/10.1520/GTJ20150217.
Leung F, Yan W, Hau B, et al. (2018) Mechanical pull-out capacity and root reinforcement of four native tree and shrub species on ecological rehabilitation of roadside slopes in Hong Kong. Journal of Tropical Forest Science 30: 25–38. https://doi.org/10.26525/jtfs2018.30.1.2538
Leung TYF (2014) Native vegetation as an integrated element in slope upgrading. PhD thesis, the University of Hong Kong, Hong Kong. pp 162–180.
Li Y, Wang Y, Wang Y, et al. (2017) Effects of Vitex negundo root properties on soil resistance caused by pull-out forces at different positions around the stem. Catena 158: 148–160. https://doi.org/10.1016/j.catena.2017.06.019
Mahannopkul K, Jotisankasa A (2019a) Influence of root suction on tensile strength of Chrysopogon zizanioides roots and its implication on bio-slope stabilization. Journal of Mountain Science 16: 275–284. https://doi.org/10.1007/s11629-018-5134-8
Mahannopkul K, Jotisankasa A (2019b) Influences of root concentration and suction on Chrysopogon zizanioides reinforcement of soil. Soils and Foundations 59: 500–516. https://doi.org/10.1016/j.sandf.2018.12.014
Mickovski SB, Bengough AG, Bransby MF, et al. (2007) Material stiffness, branching pattern and soil matric potential affect the pullout resistance of model root systems. European Journal of Soil Science 58: 1471–1481. https://doi.org/10.1111/j.1365-2389.2007.00953.x
Mickovski SB, Hallett PD, Bransby MF, et al. (2009) Mechanical reinforcement of soil by willow roots: Impacts of root properties and root failure mechanism. Soil Science Society of America Journal 73: 1276–1285. https://doi.org/10.2136/sssaj2008.0172
Ng CW, Leung A, Ni J (2019) Plant-soil slope interaction. Boca Raton: CRC Press. p 182. https://doi.org/10.1201/9781351052382
Norris JE (2005) Root reinforcement by hawthorn and oak roots on a highway cut-slope in southern England. Plant and Soil 278: 43–53. https://doi.org/10.1007/s11104-005-1301-0
Pollen N (2007) Temporal and spatial variability in root reinforcement of streambanks: Accounting for soil shear strength and moisture. Catena 69: 197–205. https://doi.org/10.1016/j.catena.2006.05.004
Sanchez-Castillo L, Kosugi K, Masaoka N, et al. (2019) Ecomorphological characteristics of fern species for slope conservation. Journal of Mountain Science 16: 504–515. https://doi.org/10.1007/s11629-018-5106-z
Schwarz M, Cohen D, Or D (2010) Root-soil mechanical interactions during pullout and failure of root bundles. Journal of Geophysical Research 115. https://doi.org/10.1029/2009jf001603
Schwarz M, Cohen D, Or D (2011) Pullout tests of root analogs and natural root bundles in soil: Experiments and modeling. Journal of Geophysical Research: Earth Surface 116. https://doi.org/10.1029/2010jf001753
Stokes A, Atger C, Bengough AG, et al. (2009) Desirable plant root traits for protecting natural and engineered slopes against landslides. Plant and Soil 324: 1–30. https://doi.org/10.1007/s11104-009-0159-y
Turmanina V (1965) On the strength of tree roots. Bulletin of Moscow Society of Naturalists Biological Series 70: 36–45.
Wang X, Hong M, Huang Z, et al. (2019) Biomechanical properties of plant root systems and their ability to stabilize slopes in geohazard-prone regions. Soil and Tillage Research 189: 148–157. https://doi.org/10.1016/j.still.2019.02.003
Wei Y, Wu X, Xia J, et al. (2019) The effect of water content on the shear strength characteristics of granitic soils in South China. Soil and Tillage Research 187: 50–59. https://doi.org/10.1016/j.still.2018.11.013
Xie M (1990) The mechanics mechanism of solid reinforcement by tree root system. Journal of Chinese soil and water conservation 4: 7–14. (In Chinese)
Yang Y, Chen L, Li N, et al. (2016) Effect of root moisture content and diameter on root tensile properties. PLoS One 11: e0151791. https://doi.org/10.1371/journal.pone.0151791
Zhang C, Chen L, Liu X, et al. (2010) Triaxial compression test of soil-root composites to evaluate influence of roots on soil shear strength. Ecological Engineering 36: 19–26. https://doi.org/10.1016/j.ecoleng.2009.09.005
Zhang C, Chen L, Jiang J (2014) Why fine tree roots are stronger than thicker roots: The role of cellulose and lignin in relation to slope stability. Geomorphology 206: 196–202. https://doi.org/10.1016/j.geomorph.2013.09.024
Zhang C, Zhou X, Jiang J, et al. (2019) Root moisture content influence on root tensile tests of herbaceous plants. Catena 172: 140–147. https://doi.org/10.1016/j.catena.2018.08.012
Zhang C, Wang X, Zou X, et al. (2018) Estimation of surface shear strength of undisturbed soils in the eastern part of northern China’s wind erosion area. Soil and Tillage Research 178: 1–10. https://doi.org/10.1016/j.still.2017.12.014
Acknowledgements
This study was supported by the National Natural Science Foundation of China project (No. 31600582), Research Project Supported by Shanxi Scholarship Council of China (2020-054), Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province of China (2017) and Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (2019L0175).
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Zhang, Cb., Liu, Yt., Li, Dr. et al. Influence of soil moisture content on pullout properties of Hippophae rhamnoides Linn. roots. J. Mt. Sci. 17, 2816–2826 (2020). https://doi.org/10.1007/s11629-020-6072-9
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DOI: https://doi.org/10.1007/s11629-020-6072-9