BEIJING — China's forestry authorities have started the process of reviewing the country's 10 pilot national parks with a view to having their national-park status officially established by the end of 2020.

Launched in 2015, the 10 pilot national parks cover 12 provinces with a total area of 220,000 square km, accounting for 2.3 percent of China's land area, the National Forestry and Grassland Administration said on Aug 14.

They were established largely for the purpose of environmental conservation and to protect endangered species.

Through years of hard work, the pilot parks have made marked progress in ecological protection, the administration said.

For instance, in the Wuyi Mountain pilot park, 6,500 mu (433 hectares) of land has been ecologically restored, while in the Giant Panda pilot national park, nearly 40,000 mu of giant-panda habitat has been restored.

China's next step will be to set clear standards for the construction of national parks, improve management systems and advance legislation to hasten the building of a natural-reserve system with national parks at its heart, the administration said.