he migration of birds is a natural wonder, demonstrating the resilience and remarkable mechanisms of life in the face of environmental challenges. Each year, millions of birds embark on journeys spanning thousands of kilometers, traveling from their breeding grounds to distant wintering destinations and back again. This incredible process is a testament to life's marvel on Earth.

Wetlands and coastal ecosystems play a crucial role in facilitating this migration. Yancheng, located in the eastern part of China's Jiangsu Province, holds a pivotal position on the East Asia-Australasia migratory bird route. Its extensive wetland ecosystems and favorable geographical location make it a core hub for bird migration. This article explores the vital role of Yancheng Wetlands in bird migration conservation and the outcomes of wetland ecosystem restoration projects, emphasizing the significance of wetland conservation in maintaining ecological balance and safeguarding endangered bird species.

I. Significance of Yancheng Wetlands for Migratory Birds

Yancheng boasts 582 kilometers of coastline and covers 769,700 hectares of wetlands, making it the largest and best-preserved coastal wetland area along the western Pacific coast and the edge of the Asian continent. Yancheng Wetlands National Nature Reserve was established in 1983 and was upgraded to a national-level reserve in 1992. It was also included in UNESCO's "Man and the Biosphere Program" in the same year. The significance of these wetlands for migratory birds is exceptional.

Resting and Refueling Point: Yancheng occupies a central and critical location along the East Asia-Australasia migratory bird route, with the world's largest intertidal wetland area and the most extensive radiating sand ridge system. Its unique geographic position and healthy wetland ecology make it a vital area for millions of migratory birds to rest, molt, and overwinter every year.

Refueling Station: The wetlands harbor abundant benthic organisms, plants, and insects, serving as a rich food source for migratory birds. Research has identified 39 species of benthic organisms, 35 fish species, 11 shrimp species, and 11 crab species in the Tiaozini wetland, making it a true "feasting ground" for birds.

Breeding Ground for Migratory Birds: Some migratory bird species choose to breed their offspring in Yancheng Wetlands, where they find suitable breeding environments, including wetland vegetation and secure nesting sites.

II. Challenges in Wetland Conservation

The core areas of the reserve face challenges such as the invasion of Spartina alterniflora and elevated land surfaces due to tidal deposits. The old seawalls impede the influx of inland freshwater, leading to a relative decrease in natural swamps, partial aridification, reduced wetland biodiversity, and a lack of food resources for waterbirds. Consequently, the ecosystem is gradually deteriorating.

The freshwater wetlands in the core area of the reserve primarily consist of large areas of reed habitats, characterized by high reed density, while shallow water marshes and mudflats are relatively small. This situation cannot meet the overwintering needs of birds like the red-crowned crane.

Between the reserve's southern core area and the seawall road, there are approximately 100-meter-wide aquaculture ponds used as buffers. These human-made disturbances and water pollution from aquaculture ponds have had a significant impact on the healthy development of the ecosystem.

III. Wetland Ecological Restoration Measures

Zoning for Ecological Restoration: Different areas within the wetlands are designated for specific ecological functions to meet the needs of different bird species, including the red-crowned crane and flamingo.

Rehabilitation of Ecological Water Systems: Clearing and optimizing water systems are essential to ensure the normal water circulation of the wetland ecosystem and improve fish habitats.

Diversifying Ecological Environments: Increasing the areas of shallow water marshes and mudflats to meet the diverse requirements of various bird species, particularly red-crowned cranes.

Establishing Ecological Buffer Zones: The creation of ecological buffer zones aims to reduce human disturbances and promote the recovery of the wetland ecosystem.

Controlling the Growth of Spartina Alterniflora: Measures are implemented to control the growth of Spartina alterniflora and minimize its harm to the wetlands.

IV. Wetland Restoration Effects

Gradual Increase in Bird Numbers in Restoration Areas: The wintering populations of birds in the central experimental zone and core zone of the reserve have shown an increasing trend. The number of bird species increased from 25 to 38, and the bird population rose from 33,316 to 41,163. Particularly, the wetland restoration and reconstruction area witnessed a significant increase in bird populations, from 3,173 in the winter of 2016 to 14,747 in the winter of 2018. In 2018, Yancheng Wetlands experienced a surge in bird species diversity, with a 40% increase compared to previous years, reaching a historical peak. These trends indicate the wetlands' effectiveness in becoming an ideal habitat for birds. Bird numbers continued to grow by 15% in 2019 and 25% in 2020, underscoring the positive impact of conservation efforts.

Protection of Two Well-Known Rare Bird Species:

Red-crowned Crane: The red-crowned crane is a nationally protected first-class animal in China and a symbolic bird of Yancheng Wetlands. These cranes breed in wetlands in East Asia and Russia and migrate south to overwinter in Yancheng, covering a month-long journey. They then spend almost five months in Yancheng tidal flats. As a result, Yancheng's coastal tidal flats are often referred to as the "second home" for red-crowned cranes.

Flamingo Protection: Wetland restoration projects have also contributed to the protection of flamingos. With the creation of diverse ecological environments, flamingo nesting sites have increased in the restoration areas, leading to a gradual rise in their numbers. Since 2012, from the discovery of the first flamingo by photographer Li Dongming in the restoration area, 11 flamingos have been found in Tiaozini Wetland. This demonstrates the appeal of diversified ecological environments for flamingos, providing them with more breeding opportunities.

Other Ecological Benefits: Furthermore, the wetland ecological restoration projects have offered more habitat for other wildlife, helping to maintain the health of the ecosystem.

V. Conclusion

Bird migration is a natural marvel, and wetlands serve as the crucial stage for this spectacular phenomenon. Yancheng's wetlands and tidal flats, with their rich biodiversity, abundant habitats, and unique geographical location, are invaluable sanctuaries for migratory birds. Through wetland ecological restoration projects, Yancheng has not only protected rare bird species such as the red-crowned crane and flamingo but also provided additional habitat to sustain ecological balance and promote the health of the ecosystem. In the face of increasing global environmental challenges, the importance of wetlands becomes even more evident. Let us continue to work diligently to protect this beautiful and precious natural environment, enhancing the splendor of birds and the miracles of nature.

References:

(1) "Global Coastal Forum - Case Collection of Natural Education and Ecological Restoration in the China Yellow (Bohai) Sea Region." (2) "World Heritage Wetlands: China's Yancheng," Yancheng Wetlands and World Natural Heritage Conservation Management Center. (3) "Biodiversity Becomes the Best Example of Wetland Conservation in China's Coastal Cities."