The increasing impacts of human activities, such as artificial shoreline construction and the removal of Spartina alterniflora, have significantly altered the ecosystem dynamics of tidal flats. Despite this, few studies to date have focused on the critical role that anthropogenic interventions play in vegetation succession. To address this gap, we combined field observations and remote sensing analysis to investigate the spatial distribution and growth dynamics of salt marshesin Chuandong Port, before and after ditch construction and the removal of Spartina alterniflora. Our results show that ditch construction led to a notable biomass reduction in areas between the ditch and the seawall. In contrast, the biomass of the marsh front initially decreases but gradually recovers to its previous levels over time. Additionally, the removal of Spartina alterniflora significantly influenced the erosion process of tidal flats and alters the composition of vegetation species. These findings underscore the delicate balance between human interventions and coastal ecosystem health, emphasizing the need for sustainable management practices to safeguard both ecological conservation and human interests.