Evolution Process of Mangrove Forests in Shenzhen Bay and Its Response to Human Activities

Mangrove forests are unique and essential ecosystems which have exhibited pronounced spatiotemporal variations owing to human activities in recent years. By integrating long-term remote sensing data with measured bathymetric data,the current study investigates the evolution process of mangrove forests in Shenzhen Bay in the recent 30 years,and analyzes the impact of human activities on mangrove forests. The results show that the mangrove forests in Shenzhen Bay increased rapidly from 259.6 hm~2 in 1988 to 527.1 hm~2 in 2017. However,significant spatial and temporal variations were found in the area extent change of mangrove forests,of which the mangrove area in the Mai Po reserve steadily increased,accounting for 81.8% of the total mangroves gain. While the area of mangrove forests in the Futian reserve first decreased and then subsequently increased under the impacts of deforestation and reforestation. The implementation of the Shenzhen Bay Reclamation Project favored shoal deposition,which contributed to mangrove forests seaward expansion by providing additional suitable accommodation space. In addition,the morphological adjustments in the Shenzhen Inner Bay caused by altered water and sediment regimes after the implementation of the Shenzhen River Regulation Project have further influence on the mangroves distribution. Correlation analysis showed that the Shenzhen Bay Reclamation Project and Shenzhen River Regulation Project explained 78.4% and 8.5% of total mangroves gain respectively.