Li Zhanshu, China's top legislator, has called for intensified supervision over the country's red lines for ecological conservation as China makes continuous progress in ecological remediation.

The chairman of the National People's Congress Standing Committee made the remarks on Tuesday while reporting to an ongoing session of the committee.

Since the 18th National Congress of the Communist Party of China in late 2012, China afforested 64 million hectares of land, about one-fourth of the total area afforested around the world during the same period, he said.

He noted continuous growth of the country's forest coverage rate and forest stock volume, which makes China the country with the largest growth in its forest resources.

Over 300 rare and endangered wild animals and plants saw their population stabilize or increase, he continued.

However, he also noted a series of problems national legislators found in their research tours to different regions.

Some illegal projects related to industry, mining, tourism, breeding and property development are still being found in national-level natural reserves, he said, adding some local governments change the scope of protected areas to make way for development.

"The country still needs to further strengthen supervision over the ecological red lines," he said.

The term "red line" is often used in China to describe boundaries that cannot be crossed.

He said ecosystem degradation still occurs in some areas due to a lack of plans for ecological conservation and remediation in natural resource exploitation.

Almost half of typical violations exposed in the second round of central environmental inspection are related to illegal mining, he said.