China will conduct safety management over transgenic organisms and invasive alien species in 2012 to preserve biological diversity, a senior environmental official said on May 22.

As of the end of 2011, a total of 2,640 nature reserves had been established on the mainland, covering 14.9 percent of the country's land area, said Li Ganjie, Vice Minister of Environmental Protection.

"Although rapid progress has been made in the last five years, China is still faced with arduous tasks in this field, including unstable ecological environments and deteriorating ecological functions," Li said.

Satellite monitoring conducted by the Ministry of Environmental Protection last year showed that 80 percent of China's 335 national-level nature reserves are being adversely affected by human activities.

Li reiterated that China will further improve the environmental evaluation system and strengthen supervision on the protection of nature reserves.