NANCHANG, March 11 -- Migratory birds this year chose to overwinter at Poyang Lake in the eastern province of Jiangxi.

Poyang, China's largest freshwater lake, is a seasonal destination for over a million birds. Although most leave for warmer regions like Australia in autumn, around 70,000 birds stayed last winter.

"In recent years, we have seen more migratory birds remain at Poyang," Li Chunru, who leads a bird rescue group near the lake, said. He added that the area now experienced warmer winters and its ecology had improved as a result of environmental protection efforts by the government.

At the end of 2009, the State Council approved construction of the Poyang ecological economic zone, to explore development that followed a balanced path of ecology and economy.

The local government of Jiangxi also introduced measures that helped improve the environment in Poyang, such as the Jiangxi wet land protection regulation and the environmental protection of Poyang Lake ecological economic zone regulation, which were both issued in 2012.

The province no longer only uses gross domestic product (GDP) to evaluate local government performance, and since 2013 has incorporated factors such as emissions and air quality into its assessment system.

Jiangxi provincial authorities said there were further supporting laws, regulations and policies in the pipeline.

Besides Jiangxi, other local governments have released laws and regulations to improve the environment.

The provincial legislature of Hubei in central China passed a regulation banning the practice of slashing and burning crops in February, which will take effect in May.

Burning straw is a major cause of PM 2.5. About 33 million tonnes of straw is burned annually in Hubei.

In Nanping City, in the eastern province of Fujian, 74.75 percent of its land is forested, and its air and water quality are high.

Mayor Lin Baojin said that seven of the city's 10 counties had stopped using GDP as an assessment criterion.

"This does not mean these areas will stop growing economically, as economic development is still key to poverty alleviation. We are just encouraging these counties to pursue high quality and sustainable development."

The city has also been focusing on developing new industries including biomedical, creative and modern logistics.

Registering average annual GDP growth of 45 percent over the past three years, the city's per capita annual income for rural residents has grown by 12 percent over the past two years.

Li lauded Nanping as an example of the success of balanced development."Good natural environment and affluence can be mutually beneficiary," he said.