Adaptive seasonal management after eradicating invasive Spartina: A nature-based approach

China has a US$325 million program (2022–2025) to eradicate invasive saltmarsh cord grass, Spartina alterniflora, which threatens coastal biodiversity. This study explores post-eradication restoration approaches and their compatibility with Nature-based Solutions (NbS). Tracking marsh recovery at the Dongtan Nature Reserve (DNR) with remote sensing, we ask: do two management approaches - water level regulation (WLR) and vegetation management (VM) - operate synergistically or in trade-off to improve bird habitat and restore native plants? Recovery was monitored using 225 Sentinel-1A SAR images (2018-2023) and 92 Sentinel-2A datasets (2017-2023). We found water distribution stabilised in WLR areas since 2020. kNDVI observations showed mowed areas had 20% faster vegetation growth than uncut zones. Spatial correlation analyses revealed synergistic interactions between WLR and VM across 90% of the reserve, with trade-offs limited to minor areas. Even in zones inundated approximately half the time (49.1% of the reserve), where seasonal hydrological variability poses challenges, both strategies jointly achieved the restoration goals. The results show that adaptive seasonal management can simultaneously support vegetation recovery and bird habitat optimization, demonstrating strong compatibility with NbS principles of adaptive management. The DNR case provides a successful model for S. alterniflora eradication projects elsewhere.