A study on the bio-hydro mechanical effects of the tree roots on the Agaclı coal reclaimed – forested land

Abstract

The research area that is in the north of Istanbul (Turkey) and it is a land of open pit coal mining residuals reclaimed and turned to forest in [1988][1989]. The materials that are open pit mine spoils are formed by sandy loam, sandy clay loam, heavy loam and clay (noncalcareous Pliocene I sediments). Pseudoacacia (Robinia pseudoacacia), Maritima Pine (Pinus pinaster) and Stone Pine (Pinus pinea) are planted on these materials. The aims of this research were to determine the strength of the material provided by tree roots and evaluate the performance of the forestation practices at lands especially where open pit coal mining spoil (residual) materials piled up. The research has been performed at two stages. The first one was 'hydro-mechanical effect' concerned about material moisture depletion as a result of transpiration and the second one was 'bio-mechanical effects' due to strength parameters of the roots and their growth pattern within the material. All results were evaluated in relation to tensile strength and displacement curves due to pre and post failure behaviors of materials and root systems. The results showed the increase of the displacement of the material was the significant indicator of the bio-mechanics tensile strength of the material provided by the tree roots. The fast growing type of tree roots have stabilized the material up to a depth for 80-100 cm by covering the coal residual materials within 12 years.

Case study of the Agacli landslide–gully complex during post-coal-mining reclamation and afforestation

“…In order to extract this coal (-40 m), overburden material is used to fill in these regions a lagoon forms over the coal mine, and the water is drained away. The next step is to reach the depth of the coal by removing the dumped overburden (Tokgöz and Izibelli 1995;Tokgöz 2003Tokgöz , 2005. Coal production has currently reached the -40 m level.…”

Deep Phenotyping of Coarse Root Architecture in R. pseudoacacia Reveals That Tree Root System Plasticity Is Confined within Its Architectural Model

“…We chose to study the interaction between dynamic mechanical loading (flexing) and soil geometry (slope) in seedlings of Robinia pseudoacacia L. It has been suggested that this species is useful for reinforcing soil on unstable or eroding slopes [38] , [39] . An experiment was carried out in a greenhouse where seedlings of R. pseudoacacia were grown from seeds in containers at 0° and 45° and their shoots were subjected to multi-directional flexing.…”