Analysis of growth and vitality class of Ulin (Eusideroxylon zwageri T. et B.) on Sempaja Arboretum East Kalimantan

Abstract

The purpose of this study was to determine the growth and vitality class of Ulin stands after the age of 17 years at Sempaja Arboretum, Samarinda East Kalimantan. Collecting data by measuring all species of Ulin which were planted in the arboretum area of 2.5 ha covering diameter/circumference, tree height, and trunk condition in 2020. The growth analysis approach used individual tree increment calculations, while the vitality class and social dynamic assessment were based on the IUFRO classification. The results showed that in the arboretum Sempaja found 82 stems of Ulin which planted as a result of ex-situ conservation activities. The tree’s growth distribution after 17 years was wide both based on the diameter, namely 1.5-11.72 cm, and height, namely 2.4-16.21 m. Based on the mean annual diameter increment (MAId) is 0.09-0.69 cm. yr-1, the height increment (MAIh) is 0.14-0.95 m. yr-1 and volume increment (MAIvol) is 0.00002-0.006 m3.yr-1. The vitality value of Ulin was classified into three classes, meanwhile, the dynamic social was divided into two classes. Based on this assessment, the stand is dominated by trees with average growth and trees requiring maintenance in their development. These results provide input for the need for silvicultural maintenance for the Ulin stand, especially in the management of Sempaja arboretum.