Mangrove aboveground biomass estimation using UAV imagery and a constructed height model in Budeng–Perancak, Bali, Indonesia
Mohammad Basyuni, Alfian Mubaraq, Rizka Amelia, Anindya Wirasatriya, Sigit Bayhu Iryanthony, Bejo Slamet, Shofiyah S. Al Mustaniroh, Novia Arinda Pradisty, Frida Sidik, Rizki Hanintyo, Elham Sumarga, Siti Halimah Larekeng, Severino G. Salmo, Tadashi Kajita, Hayssam M. Ali, Anjar Dimara Sakti, Virni Budi Arifanti
Abstract
Mangrove forests store higher amounts of organic carbon than other forest types. Despite advancements in remote sensing , accurate mapping of mangrove biomass remains a challenge due to ecosystem complexity and varying forest structures. Although traditional in-situ methodologies have been widely used for carbon stock assessments , numerous studies have demonstrated the effectiveness of remote sensing techniques, including unmanned aerial vehicles (UAVs) for mapping mangrove biomass over larger areas. These techniques are combined with allometric equations and UAV photogrammetry to improve accuracy. This study aimed to spatially estimate aboveground biomass (AGB) in various ecosystems by integrating high-resolution digital surface models and digital terrain models (DTMs) with Lorey's height measurements. Moreover, this study utilized UAV imagery and in-situ measurements to enhance the accuracy of the carbon assessments. The integration of Lorey height into our methodology is essential, as Lorey height, which is the average height of unevenly aged forest stands, is a valuable parameter for mangrove ecosystem management . Accordingly, the correlation between UAV-derived canopy height and field measurements will be improved, resulting in more reliable AGB data in mangrove ecosystems. This study has been conducted in Budeng–Perancak, Bali, Indonesia, including restored mangroves, undisturbed mangroves, Nypa , and ponds. The UAV imagery acquisition is supported by a series of in-situ measurements to obtain field data on the forest structure (for canopy surface model [CSM] cross-validation). The AGB across the mangrove land cover types in Budeng–Perancak ranged from 2 Mg ha −1 to 480 Mg ha −1 (mean: 240 Mg ha −1 ), with the highest average total AGB in natural mangroves (239 Mg ha −1 ), followed by restored mangroves (232 Mg ha −1 ), indicating a successful restoration effort at Budeng–Perancak. UAVs enable detailed data collection at small spatial scales to map mangroves and obtain precise spatial information on mangrove ecosystems. This finding can improve the accuracy of greenhouse gas inventory and carbon storage estimates.