The effect of Persian oak species (Quercus persica) in soil reinforcement (Case Study: Tabarok, Bazaft basin)

Document Type : Research Paper

Authors

Abstract

Vegetation enhances the soil resistance against instability and erosion through increasing the soil cohesion. The main effect of vegetation in stability improvement is soil reinforcement by roots. The amount of reinforcement depends on distribution and strength of roots. The aim of this study was to assess the quantity of these two parameters of Persian oak roots and also comparing the tensile strength and reinforcement effect of roots in winter and summer seasons. Damage survey method was used to assess the distribution of roots. The diameters of all roots in trenches were measured by a digital caliper. Some root specimens were randomly selected from five tree samples and their tensile strengths were measured using a standard Instron. The range of root diameter and corresponding force and tensile strength were 0.1-5.5 mm, 1.3-411.3 N and 0.93-1217.39 MPa, respectively. Maximum and minimum root densities were in 0-10 and 50 cm soil horizons. The maximum reinforcement effect was belong to winter and 0-10 cm horizon. Minimum and maximum reinforcement effects for winter season were 0.0001 and 3.37 and 0.0004 and 2.87 MPa for summer.

Keywords


[1]. Bischetti, G.B., Chiaradia, E.A., Simonato, T., Speziali, B., Vitali, B., Vullo, P., and Zocco, A. )2005(. Root strength and root area ratio of forest species in Lombardy (Northern Italy). Plant and Soil, 278: 11-22.
[2]. Waldron, L.J. )1977(. The shear resistance of root-permeated homogeneous and stratified soil. Soil Science Society of America Journal, 41(5): 843-849.
[3]. Waldron, L.J., and Dakessian, S. )1981(. Soil reinforcement by roots: calculation of increased soil shear resistance from root properties. Soil Science, 132: 427-435.
[4]. Greenway, D.R. )1987(. Vegetation and slope stability. In Slope Stability: geotechnical engineering and geomorphology. Editors. Anderson, M.G., and Richards, K.S. John Wiley and Sons Inc, Hoboken, New Jersey. p 187-230.
[5]. Schmidt, K.M., Roering, J.J., Stock, J.D., Dietrich, W.E., Montgomery, D.R., and Schaub, T. )2001(. The variability of root cohesion as an influence on shallow landslide susceptibility in the Oregon Coast Range. Canadian Geotechnical Journal, 38(5): 995-1024.
[6]. Chiatante, D., Schippa, S., Di Iorio, A., and Sarnataro, M. )2003(. The influence of steep slope on root system development. Journal of Plant Growth Regulation, 21: 247-260.
[7]. Dupuy, L., Faurcaud, T., and Stokes, A. )2005(. A numerical investigation into the influence of soil type and root architecture on tree anchorage. Plant and Soil, 278: 119-134.
[8]. Di Iorio, A., Lasserre, B., Petrozzi, L., Scippa, G.S., and Chiatante, D. )2008(. Adaptive longitudinal growth of first-order roots of woody species (Spartium juncerum) to slope and different soil condition-upward growth of surface roots. Environmental and Experimental Botany, 63: 207-215.
[9]. Wu, T.H., McKinnell, W.P., and Swanston, D.N. )1979(. Strength of tree roots and landslides on Prince of Wales Island. Alaska. Canadian Geotechnical Journal, 16(1): 19-33.
[10]. Stokes, A. )2002(. Biomechanics of tree root anchorage. In: Waisel, Y., Eshel, A., and Kafkafi, U. Editors. Plant roots: The hidden half. New York, Marcel Dekker, Inc. pp 175-186.
[11]. Vergani, C., Chiaradia, E.A., and Bischetti, G.B. )2012(. Variability in the tensile resistance of roots in Alpine forest tree species. Ecological Engineering, 46: 43-56.
[12]. Watson, A.J., and Marden, M. )2004(. Live root-wood tensile strengths of some common New Zealand indigenous and plantation tree species. New Zealand Journal of Forestry Science, 34(3): 344-353.
[13]. Norris, j. )2005(. Root reinforcement by hawthorn and oak roots on a highway cut-slope in Southern England. In Eco-and Ground Bio-Engineering: The Use of Vegetation to Improve Slope Stability, Springer Netherlands, pp. 61-71.
[14]. Abernethy, B., and Rutherfurd, I.D. )2001(. The distribution and strength of riparian tree roots in relation to riverbank reinforcement. Hydrological Process, 15: 63-79.
[15]. Morgan, R.P., and Rickson, R.J. (2003) Slope Stabilization and Erosion Control: A Bioengineering Approach: Taylor and Francis, UK.
[16]. Tosi, M. )2007(. Root tensile strength relationships and their slope stability implications of three shrub species in the Northern Apennines (Italy). Geomorphology, 87: 268-283.
[17]. Abdi, E., Majnounian, B., Rahimi, H., Zobeiri, M., and Habibi Bibalani, G.H. )2010(. Investigation of Biotechnical Properties of Parottia persica in Order to Use in Bioengineering (Case Study: Patom district of Kheyrud Forest). Journal of Natural Environment, Iranian Journal of Natural Resources, 63(1): 53-62.
[18]. Majnounian, B., Abdi, E., Foshat, M., and Soofi Mariv, H. (2014).
Determining Biomechanical Properties of Poplar (Populus nigra) for Soil Bioengineering Purposes.
Journal of Forest and Wood Products, 67(1): 13-19.
[19]. Karrenberg, S., Blaser, S., Kollmann, J., Speck, T., and Edwards, P.J. )2003(. Root anchorage of saplings and cuttings of woody pioneer species in a riparian environment. Functional Ecology, 17: 170-177.