The Yangtze Floodplain: Threats and Restoration

The Yangtze floodplain is a hotspot of biodiversity, but being seriously threatened by various factors, such as habitat loss, alternation of natural flow regimes, overfishing and pollution. Therefore, it is crucial and urgent to restore the floodplain. As a case study, we researched into the effects of river-lake disconnection and restoration strategies. We found that biodiversity of lakes were reduced by 20-50% and the ecosystems were seriously degenerated after disconnection. By establishing the species-area model of fishes, we estimated that the minimum protected area of Yangtze-connected lakes is about 11000 km². It means that at least 5500 km² of disconnected lakes should be reconnected with the Yangtze mainstem for effective conservation of biodiversity. To restore the natural connectivity and hydrological regime, we further studied the migration process of river-lake migratory fishes and estimated water level fluctuation requirements of macrophytes, and hope that the river-lake gates can be soon managed in ecohydrological ways.