An 83.4-meter-tall evergreen fir in Zayul county of the Tibet autonomous region. [Photo provided to chinadaily.com.cn] 

Chinese scientists updated the height of a giant tree in Zayul county of the Tibet autonomous region on Sunday — 83.4 meters. Recognized as China's tallest tree, it was measured at 83.2 meters in May, according to the Institute of Botany of the Chinese Academy of Science.

The latest measurement was performed in August jointly by scientists and surveyors from the institute, the Shanghai Chenshan Botanical Garden, the China Environmental Protection Foundation, Wild China Film and the forestry and grassland bureau of Tibet's Zayul county.

With a diameter of 207 centimeters and around 380 years old, the tree is called Abies ernestii var. salouenensis, a type of evergreen fir.

The giant tree was discovered by Guo Ke, a researcher from the institute in May, as part of China's second comprehensive scientific expedition to the Qinghai-Tibet Plateau.

Wang Zi, a member of the scientific research team and a doctoral student at the Institute of Botany of the Chinese Academy of Science, collects plant material from the giant tree in Zayul county in the Tibet autonomous region. [Photo provided to chinadaily.com.cn]

Guo's team discovered multiple trees in May that could potentially measure over 75 meters. A tree was measured at 83.2 meters by researchers, displacing a Taiwan cedar (Taiwania flousiana) measuring 72 meters tall in China's Yunnan province, a 76.8-meter Bhutan pine in Tibet's Metog county and a Taiwania cryptomerioides on the island of Taiwan, which stands at about 81 meters.

"In August, surveyors made a scientific expedition to Zayul again to carry out a more professional survey for the giant tree and regional biodiversity. By integrating measurement methods such as manual tree climbing and unmanned aerial vehicles, the new height of the tree was measured at 83.4 meters," said Wang Zi, a researcher and PhD student at the Institute of Botany.

Zayul county is located in the mountain valley area of the transitional zone between the Himalayas and the Hengduan Mountains, with an average elevation of 2,800 meters. Its climate is unique, complex and diverse, with abundant annual precipitation, a mild climate and moderate sunshine, Wang said.

The Zayul River — a tributary the Yarlung Zangbo River — and the Nujiang River in Zayul county have primal forests, which are home to the giant trees, Wang said.

"The climbing-tree survey and investigation reflect that the tree hosts more than 50 species of plants, including climbing plants, creepers, parasitic plants and other types, showing a unique and rich biodiversity on this tree and in surrounding areas," Wang said.

Pyrrosia drakeana, a plant found on the 83.4-meter evergreen fir in the Tibet autonomous region. [Photo provided to chinadaily.com.cn]

Liu Tuanxi, an explorer and a technical guide for the expedition, and his team members climbed to the top part of the tree to complete the survey.

It took three people almost eight hours to reach to the treetop. The climbing was mainly completed by means of ropes, without nailing the giant tree. All equipment was collected and taken away without causing any damage to the tree, Liu Tuanxi was quoted as saying in an interview by Beijing Youth Daily.

"While almost reaching the top of the tree, I worried the tree would break by wind as it was as tall as a 28-story building. I gradually calmed down and was amazed by the gorgeous beauty and mighty nature," he said.

"After I became more relaxed near the top of the tree, I took a nap up there."

Smilax myrtillus, a plant found on the 83.4-meter evergreen fir in Zayul county of the Tibet autonomous region. [Photo provided to chinadaily.com.cn]

Rhodobryum giganteum, a plant found on the 83.4-meter evergreen fir in Zayul county of the Tibet autonomous region. [Photo provided to chinadaily.com.cn]