Overlooked and extensive ghost forest formation across the US Atlantic coast

Rising sea levels have driven widespread coastal tree die-off, forming large swaths of ghost forests. While reports of coastal forest loss are accumulating, its true severity and factors determining the underlying mortality risks remain poorly understood. Here, we mapped over 10 million individual dead trees across the US Atlantic region – a sea-level rise hotspot – using deep learning and sub-meter aerial imagery. Our analysis reveals disproportionate and pervasive tree mortality in many previously undocumented ghost forest hotspots, with over 6 million dead trees concentrated in low-lying (< 5 m) forests, primarily driven by salinization rather than flooding alone. Notably, man-made flood obstructions (roads and levees), when present, have reduced forest loss by 44% and 77% respectively in the region. These findings highlight the alarming decline of coastal forests and the need for strategic actions to preserve their critical ecosystem services.