The renovated "Bird International Airport" allows birds to settle down with confidence

Before governance

After governance

The picture shows the comparison before and after the management of the Spartina alterniflora distribution area in Shandong Yellow River Delta National Nature Reserve.

(Photo provided by Dongying City Ocean Development and Fisheries Bureau, Shandong Province)

□ Science Times reporter Hu Lijuan

Under the blue sky and white clouds, the vast wetland stretches as far as the eye can see. On both sides of the criss-crossing roads, reeds and rushes swaying gently in the wind can be seen everywhere. Flocks of birds such as wild geese, swans, cormorants, egrets, etc., some stop to forage, some play on the water, and some dance in the air. The surrounding scenery sets off an interesting scene, making it an ideal home for wild birds.

On November 28, the reporter came to the Yellow River Delta National Nature Reserve in Shandong Province. The beautiful and harmonious scenes he saw along the way were amazing. It is hard to imagine that a few years ago, this place was still a "green desert". Due to the rampant growth of the invasive alien species Spartina alterniflora, it has brought serious threats to biodiversity and ecological security.

48.3% of coastal salt marshes are occupied

Spartina alterniflora, which protects beaches and embankments, promotes siltation and land reclamation, and slows down the erosion of my country's coastline, has been praised by many as the "protector of beaches". Since it was introduced to my country in the late 1970s, it has grown wildly and spread all over the coastal mudflats, relying on its developed root system, strong salt and flood tolerance, making the coastline look green, but it has been invaded by these small grasses.

Especially in recent years, experts have discovered through analysis of remote sensing data that 48.3% of my country's coastal salt marshes have been occupied by Spartina alterniflora, covering an area of ​​about 600 square kilometers.

Not only that, the invasion of Spartina alterniflora will also cause competitive exclusion to native species. By quickly occupying ecological niches, it will cause a decline in the biomass and biodiversity of native species, destroy the ecological balance, and lead to the suffocation and death of many organisms such as shellfish, crabs, algae, and fish.

From being praised as a "green guardian" in the early days of its introduction, Spartina alterniflora has been transformed into a "green desert" that destroys the ecology. It has been listed in the list of the world's 100 most harmful invasive alien species published by the International Union for Conservation of Nature.

Legislative prevention and control, the clearance rate in the control area exceeds 99%

Standing at the site of Kendong 12, which was once an oil production platform in the Kendong block of Shengli Oilfield, Zhou Licheng, head of the Scientific Research Center of the Yellow River Delta National Nature Reserve, pointed to the mechanized tillage boats under construction in front of him and told reporters: "In 2021, more than 130,000 mu of tidal flats in the Yellow River Delta were invaded by Spartina alterniflora, and the living space of local salt marsh vegetation, Suaeda salsa and seagrass beds was largely occupied. The tidal gullies where freshwater and seawater meet were blocked, benthic organisms decreased rapidly, and birds lost a lot of space to live and forage."

As one of the cities in my country that started the whole-region control of Spartina alterniflora earlier, Dongying City included Spartina alterniflora into the first municipal ecological protection and restoration regulations in China, using the power of the rule of law to prevent and control Spartina alterniflora and protect the ecological environment. In addition, Dongying City has also joined forces with the Yantai Institute of Coastal Research, Chinese Academy of Sciences, to carry out scientific and technological research and efficient prevention and control.

"Dongying has implemented the experimental project of Spartina alterniflora control for three consecutive years, exploring and forming control models such as mowing + flooding and mowing + tillage." Yang Guoqiang, secretary of the Dongying Municipal Party Committee, told reporters that through targeted treatment and systematic treatment measures, as of now, a total of 11,000 hectares of Spartina alterniflora have been controlled, the removal rate in the controlled areas has reached more than 99%, the number of benthic organisms has increased by nearly 30%, and the species and number of birds at the mouth of the Yellow River have increased significantly.

Today, Kendong 12 has become the main base for the protection zone to control Spartina alterniflora. As a member of the expert team, Xie Baohua, an associate researcher at the Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, who has been conducting scientific research on the invasion mechanism and control technology of Spartina alterniflora for a long time, has deep feelings about it.

"There are two ways of reproduction for Spartina alterniflora. Sexual reproduction of seeds plays a leading role when Spartina alterniflora invades new areas, while asexual reproduction of underground rhizomes is the main way of reproduction for maintaining the population." Xie Baohua said that through continuous research and experiments on physical and chemical technologies for the control of Spartina alterniflora, a key technology system for the control of Spartina alterniflora suitable for different tidal flat habitats has been formed. This technology system has been successfully applied in Shandong, Tianjin, Fujian and other places, with a promotion and application area of ​​more than 150,000 mu, and the control effect is good.

Build housing projects to help birds settle down

In early winter, the Yellow River Delta National Nature Reserve welcomes a large number of migratory birds for wintering. An increasing number of rare species have also settled here, and the Oriental White Stork is one of them.

As a national first-class protected bird, the Oriental White Stork is an endangered species in the world and is also the city bird of Dongying. They like to build nests in high places and forage for food and live in wetlands.

"The choice of birds is a strong proof of the good ecological environment." Xie Tian, ​​an associate professor at Beijing Normal University, said that the control of Spartina alterniflora has made room for the recovery of some local species, such as reeds and Suaeda salsa. "Combined with the restoration of wetlands, an obvious feature is the increase in bird species."

The reporter saw several tall poles and bowl-shaped bird nests on both sides of the road in the reserve. Zhou Licheng said that this is the home of the Oriental White Stork. The reserve has built more than 130 such artificial breeding nests, and AI recognition probes are installed on the top of the nests, which can not only monitor the living habits of birds and count their numbers in real time, but also protect their safety around the clock.

76 kilometers of blocked tidal channels were dredged, more than 50,000 mu of saltwort were restored, and 1,500 mu of seagrass beds were repaired... In recent years, with the implementation of ecological dams, water system connections, bird breeding islands, plant ecological islands, fish habitats and other ecological protection projects in the reserve, the former bare land and saline-alkali beaches have been transformed into large wetlands with lush aquatic plants and rich biodiversity. The ecological beauty with dancing water birds and wild fun is blooming again.