The Effect of Root Reinforcement Exemplified by Black Alder (Alnus Glutinosa Gaertn.) and Basket Willow (Salix Viminalis) Root Systems – Case Study in Poland

Abstract

Zydroń -Skórski: The effect of root reinforcement exemplified by black alder and basket willow root systems - Abstract. This paper is focused on evaluation of the effect of roots of two species -black alder (Alnus glutinosa Gaerin.) and basket willow (Salix viminalis) on the increase in soil shear strength (root cohesion). The second aim of the paper was to compare the results of calculating root cohesion using the classical Wu/Waldron model and selected fiber bundle models, especially in the context of determining the influence of the criterion of distribution of stresses on calculation results. The research on the studied plant species was conducted on a seven-year plantation of energy crops located in Krakow, Poland, where the test area was modified by covering the natural site by anthropogenic soil. In order to determine the root cohesion site investigations, which included measurements of root area ratio, and laboratory tests, which included determination of root tensile strength, were conducted. The results of root cohesion calculation revealed that the studied species have relatively low values of this parameter. It was also shown that fiber bundle models yield lower values of root cohesion than the classic Wu-Waldron model. Among the fiber bundle models, the lowest values of the investigated parameter were obtained using the deformation model that takes into account the function of probability distribution of root tensile strength.