Forest Loss and Carbon Flux in Southeast Asia: Spatiotemporal Patterns, Ecological Impacts, and Key Determinants

ABSTRACT Southeast Asia's tropical forests play a critical role in global carbon regulation, yet they face accelerating degradation and deforestation. The ecological impacts of forest loss on carbon fluxes and the multidimensional drivers behind forest loss in Southeast Asia remain insufficiently understood. This study aims to quantify forest carbon fluxes, assess the spatiotemporal patterns of forest loss, evaluate the impact of forest loss on carbon fluxes, and identify key drivers across Southeast Asia from 2001 to 2023. We find that the region lost approximately 678,979 km 2 of forest, with Indonesia, Malaysia, and the Greater Mekong Subregion accounting for over 83% of the total loss, concentrated in lowland and swamp forest ecoregions. Carbon fluxes display marked spatial heterogeneity, with Borneo lowland rain forests contributing over 22% of total emissions, while Thailand and the Philippines function as key national sinks. Increasing forest loss was associated with rising emissions, transforming many areas from net carbon sinks into emission sources. Carbon cost indices further reveal significant disparities in emission intensity per unit of forest loss across countries. Using a well‐tuned XGBoost model ( R 2 = 75.62%, RMSE = 0.169) combined with SHAP interpretation, we identified oil palm suitability, human footprint, population density, regulatory level, and road accessibility as key drivers of forest loss. While protected areas do not rank among the top predictors overall, they exert a consistent negative effect on forest loss where they exist. These findings highlight the urgent need for targeted, spatially differentiated conservation and land‐use strategies to mitigate carbon emissions and preserve forest carbon sinks in Southeast Asia.