Biomass estimation for plantation crops using remote sensing technology

Abstract

Biomass estimation is used to evaluate tree growth, the ability to sequester carbon, and indicate the effectiveness of agricultural management. In-situ methodology is widely used for biomass measurement including the tree height and diameter at the breast height, which result in a high labour cost and is extremely time consuming. The different types of terrains and surrounding conditions within the plantation area could cause challenges for biomass estimation which requires accurate and consistent measurement methods. Even though there are other available applications being used, the unmanned aerial vehicles (UAV) mounted with sensors have progressively attracted the attention of researchers including the industry for the large scale of assessment. UAV enables rapid estimation of biomass over large areas relatively quick, non-destructive, and cost effective. Hence, this review aims to provides a comprehensive overview on the current biomass measurement methods. Recent studies on the biomass prediction across plantations using UAVs with optical, radar, and light detection and ranging (LiDAR), and hyperspectral sensors are also critically reviewed. The techniques used for data processing and analysis are also discussed. The reviewed studies demonstrated that UAV-based approaches achieved biomass estimation with a coefficient of determination (R2) ranging from 0.89 to 0.96, with reported RMSE values of 6.44 t/ha. Therefore, this paper recommends the usage of UAV technology as the effective method in producing significant and reliable results for biomass estimation.