Landscape and Ecological Engineering

, Volume 15, Issue 2, pp 223–230 | Cite as

Influences of plant spacing on root tensile strength of Schefflera arboricola and soil shear strength

  • J. J. NiEmail author
  • A. K. Leung
  • C. W. W. Ng
Short Communication


Mechanical root reinforcement depends not only on root biomechanical properties but also on root biomass. Although it is known that plant spacing can affect root growth, it is not clear how it affects root tensile strength. We interpreted a set of field data to study the effects of spacing of Schefflera arboricola on root area ratio (RAR), root tensile strength and their combined effects on soil shear strength (also termed root cohesion). S. arboricola was transplanted into compacted silty sand at a spacing of 0.5 m, 0.8 m and 1.1 m. After 20 months of growth in the field, the root systems were excavated for root tensile testing and post-test trait measurements. Plant spacing affected the growth and tensile strength of roots. More closely spaced plants had higher RAR but lower root tensile strength, especially for roots 0.5–2 mm in diameter. According to the existing root breakage and fibre bundle models used in this study, which calculate root cohesion as the product of RAR and root tensile strength, the effects of plant spacing on root cohesion were minimal for most soil depths apart from 0.4- to 0.5-m depth.


Vegetation Mechanical contribution Root cohesion Field test Modelling 



The authors acknowledge the National Natural Science Foundation of China for a research grant (no. 51778166). A. K. L. (the second author) acknowledges the award of an EU Marie Curie Career Integration Grant for the BioEPIC slope project.


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Copyright information

© International Consortium of Landscape and Ecological Engineering and Springer Japan KK, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Civil and Environmental EngineeringThe Hong Kong University of Science and TechnologyHong KongChina

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