AGRIVITA Journal of Agricultural Science. 2022. 44(1): 74-81 AGRIVITA Journal of Agricultural Science www.agrivita.ub.ac.id 74 INTRODUCTION Individual stem volume is required for forest management to obtain information on forest mensuration, growth, yield estimation, and forest volume estimation. Methods such as forest inventory measurement have been regularly used to measure height and diameter at breast height for the stand volume. Tree species, stem diameter-at- breast-height (dbh), and tree height are the most common tree parameters assessed in the feld (Luoma et al., 2017). There are two commonly used formulas, Newton’s formula and Smalian’s formula for estimating the volume of trees. If the logs are precisely cylindrical, both formulas can produce similar values (Avery & Burkhart, 1994) . Tree volume equations or allometric models are used to estimate the volume valuable for forest plantations (Mugasha et al., 2016)respectively, this study developed site specifc and general models for estimating total tree volume and aboveground biomass. Specifcally the study developed (i. Currently, this regression model is the most widely used model for estimating tree volume (Giri et al., 2019). Various methods have been used by researchers to estimate the tree or log volume and the log formula can be considered as one of the commonly-used methods (Ahmad et al., 2020). The selection of formulas is based on the reading measurements and the simplicity in calculating log volumes using the formula and the accuracy obtained using the formula (Alemdag, 1978). Based on recent ARTICLE INFO Keywords: Acacia mangium Elevationn Forest plantation Sarawak Tree volume estimation Article History: Received: July 23, 2021 Accepted: September 7, 2021 * ) Corresponding author: E-mail: seca@upm.edu.my ABSTRACT The objective of this study was to examine the efects of four diferent elevations on Acacia mangium volume in Bintulu, Sarawak. A total of 60 felled trees of A. mangium were used to develop a volume equation by measuring the volume at four diferent classes of elevation. The study of stand volume estimation in Malaysian plantations, particularly in Bintulu, is sparse. To get the average cross-sectional area, the volume of each tree in each part of the felled trees was estimated using Smalian’s and Newton’s formulas. Four equations were developed in this study to predict the volume from the diameter and analyze the efect of elevation on tree volume. According to the regression analysis, there was a signifcant relationship between the volume and diameter for each slope steepness. The Very Slope site had the highest volume with an R² value of 0.948 for the model’s ft, which revealed that 94.8% of the data could be evaded. Volume estimation using the regression model can be used to determine and categorize according to its class of elevation, and there is an efect of elevation on standing volume. A. mangium has better growth performance in a very slope area in terms of tree volume compared to diferent elevations. ISSN: 0126-0537 Accredited First Grade by Ministry of Research, Technology and Higher Education of The Republic of Indonesia, Decree No: 30/E/KPT/2018 Cite this as: Selvarajan, P. K., Gandaseca, S., Kudus, K. A., & Wicaksono, K. P. (2022). Elevation efect on Acacia mangium volume estimation. AGRIVITA Journal of Agricultural Science, 44(1), 74-81. http://doi.org/10.17503/agrivita. v44i1.3065 Elevation Effect on Acacia mangium Volume Estimation Prem Kumar Selvarajan 1) , Seca Gandaseca 1,2*) , Kamziah Abd. Kudus 3) and Karuniawan Puji Wicaksono 4) 1) Department of Wood and Fiber Industry, Faculty of Forestry and Environment, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia 2) Institut Ekosains Borneo, Universiti Putra Malaysia Bintulu Sarawak Campus, Malaysia 3) Department of Forestry Science and Biodiversity, Faculty of Forestry and Environment, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia 4) Faculty of Agriculture, Universitas Brawijaya, Malang, East Java, Indonesia