Root architecture and its relation with the growth characteristics of three planted Shorea species (Dipterocarpaceae)

Abstract

Root and its architecture are important for trees to support their growth and development. However, there have been still few reports on tree roots architecture of important tropical forest tree species such as Shorea species. In this study, the differences of root architecture formation and the relation of root architecture and phenotype (growth) characteristics, including Index of Roots Anchoring (IRA) and Index of Roots Binding (IRB) of S. stenoptera, S. palembanica, and S. leprosula in Gunung Walat Education Forest were examined through root growth patterns, root morphology, and root growth variables. The results showed that the root growth patterns and the root morphology of three species were similar, which were classified into Champagnat group model with monopodial typical growth and tended to form orthotrophic branching. The total of root length significantly influenced tree height and trunk volume, while the depth root significantly influenced tree height and the crown diameter. The IRA values of S. stenoptera dan S. palembanica were categorized into medium group, while S. leprosula belonged to high group, suggesting that S. leprosula has a strong root anchorage compared to other two species. The IRB values of three Shorea species were categorized into low group, indicating low root binding ability in soil.