Workers plant Mangrove trees at Sanjiang mangrove provincial wetland park in Haikou, south China's Hainan Province, March 23, 2020. (Xinhua/Yang Guanyu)

Aerial photo taken on March 23, 2020 shows workers planting mangrove trees at Sanjiang mangrove wetland park in Haikou, south China's Hainan Province. (Xinhua/Yang Guanyu)

A worker plants mangrove trees at Sanjiang mangrove wetland park in Haikou, south China's Hainan Province, March 23, 2020. (Xinhua/Yang Guanyu)

Workers plant Mangrove trees at Sanjiang mangrove provincial wetland park in Haikou, south China's Hainan Province, March 23, 2020. (Xinhua/Yang Guanyu)