Photo taken on Sept. 15, 2013 shows a lake of the Arxan national forest park, in the Greater Hinggan Mountain, north China's Inner Mongolia Autonomous Region. As China's largest state-onwned forest reserve, the Greater Hinggan Mountain in Inner Mongolia features 940,000 hektares of primitive forest. (Xinhua/Zou Jianpu)

Tourists review photos on a camera at the Arxan national forest park, in the Greater Hinggan Mountain, north China's Inner Mongolia Autonomous Region, Sept. 15, 2013. As China's largest state-onwned forest reserve, the Greater Hinggan Mountain in Inner Mongolia features 940,000 hektares of primitive forest. (Xinhua/Zou Jianpu)

Photo taken on Sept. 15, 2013 shows the fall scenery of the Arxan national forest park, in the Greater Hinggan Mountain, north China's Inner Mongolia Autonomous Region. As China's largest state-onwned forest reserve, the Greater Hinggan Mountain in Inner Mongolia features 940,000 hektares of primitive forest. (Xinhua/Zou Jianpu)

Photo taken on Sept. 15, 2013 shows the fall scenery of the Arxan national forest park, in the Greater Hinggan Mountain, north China's Inner Mongolia Autonomous Region. As China's largest state-onwned forest reserve, the Greater Hinggan Mountain in Inner Mongolia features 940,000 hektares of primitive forest. (Xinhua/Zou Jianpu)

Photographers take photos of the scenery of the Greater Hinggan Mountain at the Arxan national forest park in north China's Inner Mongolia Autonomous Region, Sept. 15, 2013. As China's largest state-onwned forest reserve, the Greater Hinggan Mountain in Inner Mongolia features 940,000 hektares of primitive forest. (Xinhua/Zou Jianpu)

Photo taken on Sept. 15, 2013 shows a canyon of the Arxan national forest park, in the Greater Hinggan Mountain, north China's Inner Mongolia Autonomous Region. As China's largest state-onwned forest reserve, the Greater Hinggan Mountain in Inner Mongolia features 940,000 hektares of primitive forest. (Xinhua/Zou Jianpu)