Investigation on Root Distribution Pattern of Persian Oak and Hawthorn Species in Order to use in Bioengineering Models (Case Study: Boloran Forests, Kohdasht)

Vegetation due to its root system by creating cohesion of soil particles, significantly affects hill slope mechanical properties related to shallow landslides and slope stability. In this regard, the root engineering characteristics of forest species are important. The aim of this study was to investigate the distribution pattern of persian oak and hawthorn in Zagross forests. For this purpose, five trees from both species were randomly selected to study their root distribution. Sampling was performed by using a soil core sampling ring from three horizontal distances and three depths. Root distribution was assessed using the concept of the root area ratio. The results showed that the root area ratio as well as the longitudinal densities of the roots decreases with increasing depth of the soil and increasing the distance from the tree. The maximum root length density was observed in the initial layers and close to the trees. The highest volume density of roots was observed at depths of 0-15 cm. Based on the results of the study, it was found that there was a significant difference between the volume density of root of two persian oak and hawthorn species. Longitudinal and volumetric densities of root in persian oak were higher than hawthorn. In general, the results of this study showed the importance of persian oak in comparison with hawthorn in the field of increasing strength of soil.