Aerial photo taken on Dec. 22, 2018 shows the scenery of the metasequoia forest in Sihong County of Suqian City, east China's Jiangsu Province. (Xinhua/He Jinghua)

Aerial photo taken on Dec. 22, 2018 shows the scenery of the metasequoia forest in Sihong County of Suqian City, east China's Jiangsu Province. (Xinhua/He Jinghua)

Aerial photo taken on Dec. 22, 2018 shows the scenery of the metasequoia forest in Sihong County of Suqian City, east China's Jiangsu Province. (Xinhua/He Jinghua)