Single Oil Palm Tree Detection and Its Potential Expansion in Honduras

Honduras is among the ten largest palm oil producers in the world. Accurately detecting the current plantation status and oil palm distribution is crucial to optimize the planting layout. However, current information on single oil palm trees in Honduras is scarce. Here we used submeter-resolution RGB satellite images in 2022 to detect the spatial distribution and single oil palm tree in Honduras with the four-direction gradient difference, single-tree feature extraction, and double-ring detection methods. In the accuracy validation zones, the recall, precision, and F1-score metrics for the spatial distribution of oil palm were 86.50%, 86.57%, and 86.53%, respectively; counting accuracy for single oil palm trees was 86.75%; and localization accuracy was approximately 6 m. We estimated 0.25 million hectares (ha) of oil palm plantation area in Honduras, corresponding to 28.27 million trees and an average density of 113 trees/ha. Furthermore, we categorized planted land into highly or moderately suitable zones for future expansion. Among the 0.25 million ha of potentially available land, the highly and moderately suitable zones represented 10,501 ha and 242,120 ha, respectively, with the potential to carry approximately 28.55 million oil palms. For future oil palm expansion, priority should be given to highly suitable zones. This study not only characterized the distribution and single oil palm properties in Honduras but also suggested potentially suitable zones for future plantation expansion, thereby providing important methodological references and data support to assess the impact of oil palm planting on the ecological environment and socioeconomic aspects at the country scale.