Taiwan’s tallest trees are not easy to find. A team of researchers says it took more than a decade of climbing, mapping and checking false leads to identify the island’s biggest giants, including an 84.1 metre Taiwania fir that now stands as the tallest tree in East Asia.

The account comes from a new Frontiers in Forests and Global Change article by Rebecca Chia-Chun Hsu, Professor Chi-Kuei Wang and Dr Chung-Cheng Lee, who traced their efforts to find, climb and measure Taiwan’s tallest trees.

The researchers wrote that Taiwan is one of the rare places on Earth capable of supporting “giant” trees taller than 80 metres. Since 2014, their group, the “Taiwan tree seekers,” has worked to locate and document them.

In 2023, they found what they called “the reigning champion of the island’s forests,” an 84.1 metre Taiwania fir, or Taiwania cryptomerioides. They wrote that the tree “currently holds the title of the tallest tree in all of East Asia.”

The researchers said the Indigenous Rukai people call these giant firs “The tree that hits the moon”.

Their article links those trees to Taiwan’s geography. The island covers 36,000 square kilometres and has 258 peaks above 3,000 metres, with Mt. Jade reaching 3,952 metres. It is estimated to host 5,000 plant species, with ecosystems ranging from tropical rainforests at sea level to alpine tundra at the highest elevations. About 60 percent of the island remains forested and is home to an estimated 950 million trees.

The researchers wrote that industrial logging from 1912 to 1991 heavily reduced Taiwan’s original primary forests, but steep terrain left some old-growth areas intact because they were too hard to reach.

The formal search began in August 2014, when researchers from the Taiwan Forestry Research Institute launched an expedition into the Cilan conservation area to investigate the “Chilan Three Sisters,” a group of giant Taiwania firs known locally but not scientifically measured.

They found the tallest of the three reached 69.3 metres, with a trunk diameter of nearly 3 metres.

The team later turned to a more remote area near Mt. Benya, close to Great Ghost Lake, a place they said is considered sacred by Indigenous peoples. That trip took four days of hiking to reach the site. The researchers wrote that the expedition showed how hard it was to identify the tallest trees from the ground in dense old-growth forest. On that trip, they climbed a 71.7 metre tree.

To improve the search, they worked with remote sensing experts from National Cheng Kung University and used LiDAR, a 3D scanning method that sends laser pulses from an aircraft to map the height of trees and the shape of the ground.

But the team said Taiwan’s steep terrain created a major problem. Automatic algorithms often overestimated tree height, especially when a tree stood beside a steep cliff. In 2020, the project expanded into a community effort, with hundreds of people in Taiwan reviewing LiDAR profile images to weed out errors.

The researchers wrote that 93 percent of trees had been mismeasured by the automatic algorithm. By the end of 2022, the project had produced the “Taiwan Giant Tree Map,” identifying 941 trees taller than 65 metres.

In January 2023, during the Lunar New Year holiday, the team used that map to target the strongest candidate for the tallest tree title. The expedition involved a 20 kilometre river trace and two days of steep uphill hiking.

They wrote that “Once the climbers reached the crown and dropped a measuring tape from the very top to the ground, the height was revealed to be 84.1 meters.”

The tree was named the “Heaven Sword of the Da’an River” and was recorded as the tallest known tree in Taiwan and East Asia.

By early 2026, the researchers wrote that they had found and climbed 10 Taiwania trees taller than 70 metres, including two above 80 metres.

The mapping work also led them to areas with large concentrations of giant trees. Near Mt. Benya, they found a single hectare of forest containing 11 trees above 65 metres. Near Great Ghost Lake, they reported a “pure forest” of about 30 giant Taiwania firs growing in a dense cluster.

In 2024, the researchers and 15 citizen scientists studied the “Tao Tree” valley, home to Taiwan’s third-tallest tree, to measure how much carbon dioxide the forest stores in its wood. They reported a total carbon density of 1,384.5 megagrams per hectare, not including roots.

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