Taiwan surveys document East Asia’s tallest known tree and dense old-growth fir stands
A research team surveying remote forests in Taiwan has documented an 84.1-metre Taiwania fir, reported as the tallest known tree in East Asia. Using airborne LiDAR, field expeditions and citizen review of map profiles, the project mapped 941 trees above 65 metres and identified dense old-growth stands. A separate valley survey reported very high forest carbon density, although its estimate excluded root systems.
The story
Researchers working in Taiwan’s remote mountain forests reported a series of results from a long-running search for exceptionally tall Taiwania firs (Taiwania cryptomerioides). The central finding is an 84.1-metre tree, tape-measured after climbers reached its crown in January 2023. The team identifies it as the tallest known tree in Taiwan and East Asia and calls it the Heaven Sword of the Da'an River. The project began organized field work in 2014 and later paired expeditions with airborne LiDAR, which uses returning laser pulses to model terrain and estimate tree heights. In Taiwan’s steep landscapes, however, automated readings often mistook topographic changes for tall trees. The source says citizen scientists began reviewing LiDAR profiles in 2020, helping researchers reject false candidates; the automated system had incorrectly measured 93% of the trees it flagged. By the end of 2022, the Taiwan Giant Tree Map listed 941 trees taller than 65 metres. Surveys also located concentrations of large trees near Mt. Benya, including one hectare with 11 trees above 65 metres and a separate cluster of roughly 30 giant Taiwania firs. In a 2024 study of the Tao Tree valley, researchers estimated carbon density at 1,384.5 Mg/ha, excluding roots.
Why it matters
Tall trees and old-growth stands are difficult to assess in Taiwan because rugged terrain limits ground access and can mislead remote measurements. The combined workflow gives researchers a way to prioritize field visits while retaining direct, climber-based height checks for the strongest candidates. It also turns scattered discoveries into a map of individual trees and clusters, which is more useful for ecological study than isolated reports. The Tao Tree valley estimate adds evidence that at least one surveyed giant-forest site holds a large amount of carbon in above-ground forest components, though it should not be generalized to all forests or treated as a full carbon inventory.
Evidence and context
Taiwan’s terrain ranges from humid lowland rainforest to alpine tundra, and the source estimates that about 60% of the island remains forested. It also reports that industrial logging between 1912 and 1991 removed much original primary forest, while steep and inaccessible areas retained some old-growth stands. The search illustrates how airborne LiDAR can narrow surveys across difficult landscapes, but it also shows that automated height estimates need human checking where cliffs and abrupt elevation changes distort results. The resulting map offers a documented starting point for locating exceptionally tall trees and dense stands rather than relying only on ground reports.
Limits and unknowns
The findings do not establish the condition, protection status, or long-term survival prospects of every mapped tree or stand. Tree-height detection was especially uncertain in Taiwan’s rugged terrain: the source says an automated system incorrectly measured 93% of its identified candidates, requiring citizen reviewers and field expeditions to filter results. The reported carbon-density estimate for the Tao Tree valley also excluded massive root systems, so it is not a complete accounting of all carbon stored there. The source does not provide comparable carbon measurements for every giant-forest site.
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Story timeline
Organized search begins
Researchers from the Taiwan Forestry Research Institute began an organized expedition in the Cilan conservation area to survey the Chilan Three Sisters.
Citizen review added
The project expanded citizen review of LiDAR profiles to help remove false giant-tree candidates.
Map completed
The Taiwan Giant Tree Map documented 941 individual trees taller than 65 metres.
Tallest tree measured
Climbers tape-measured the Heaven Sword of the Da'an River at 84.1 metres.
Taiwan surveys document East Asia’s tallest known tree and dense old-growth fir stands
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Highlights
- Tallest Taiwania fir measured at 84.1 metres
- Mapping tall trees with LiDAR and citizen review
- Clusters of giant Taiwania firs near Mt. Benya
- High carbon density found in Tao Tree valley
Transcript
Scientists documented an 84.1-metre Taiwania fir, the tallest known tree in East Asia, in 2023.
Using airborne LiDAR and citizen scientists, the team mapped 941 trees taller than 65 metres.
Dense old-growth stands were found near Mt. Benya, with clusters of giant Taiwania firs.
A study in Tao Tree valley estimated high forest carbon density, highlighting ecological value.
This mapping approach helps prioritize field visits and supports better ecological understanding.