Allometric Model of Carbon Sequestration in Coconut (Cocos nucifera L.) Agroforestry System in Indonesia

Abstract Coconut (Cocos nucifera L.) plantations in Indonesia have not yet been recognized as a sector capable of reducing greenhouse gas emissions due to the limited information regarding their potential for significant carbon sequestration, economic value, and sustainability. This comprehensive analysis aims to quantify the carbon sequestration capacity of coconut plantations, advocate their participation in carbon trading mechanisms, and elucidate their potential contribution to Indonesia’s Nationally Determined Contribution. A regression model was developed to assess the incremental growth in diameter and height of trees, utilizing data from multiple age classes and secondary data obtained from the Ministry of Agriculture between 2017 and 2023. The potential carbon sequestration of coconut plantations in Indonesia was estimated using selected biomass allometry models. Significant biomass volume increments were observed between 19 and 58 years. Carbon stocks range from 0.17 to 0.61 t C per mature tree, resulting in a total carbon stock of 75 t C ha⁻¹. Annual carbon sequestration increased by approximately 3%, amounting to 11 million t C from 2017 to 2023. This review underscores the potential role of coconut plantations in Indonesia and globally in carbon sequestration. Our methodology for identifying the growth behavior of a significant coconut variety in Indonesia can be utilized to estimate carbon sequestration for coconut plants at specific ages. It is advantageous to rejuvenate old coconut trees that are more than 58 years old to optimize their development 19 years after planting to unlock the sector’s potential benefits as carbon sequesters, thereby enhancing its economic value.