Some 60% of Taiwan is covered with forest, and the island boasts more than 260 mountains over 3,000 meters tall. The many giant trees that have stood deep in the mountain forests for thousands of years are a precious part of Taiwan’s natural heritage.

Getting close to giant trees

“It’s clear that our giant trees are something that sets Taiwan apart,” says Rebecca Hsu, an assistant ­researcher at the Taiwan Forestry Research Institute. She says bluntly that due to overdevelopment, there are now few countries in the world where primeval forest still survives. Moreover, when such forests are located in undeveloped regions, they are largely inaccessible. It is only in Taiwan, where transportation is convenient and which still has areas of ancient forest, that people can visit them in a trip of only two or three days. For example, two easily accessible trees include the world’s largest camphor tree (Cinnamomum camphora), located in Shenmu Village in Nantou County’s Xinyi Township, and the Lulin Giant Tree, a Taiwan red cypress (Chamae­cyparis formosensis) also located in Shenmu Village next to Provincial Highway 18 (the Alishan Highway). The Forestry Bureau once listed the Lulin Giant Tree as ranking second among Taiwan’s ten largest trees by girth.

The giant trees that Hsu refers to are mainly classified as such by height. In 2016, Hsu and Professor Wang Chi-kuei of the Department of Geomatics at National Cheng Kung University launched the Taiwan Champion Trees—Giant Tree Mapping Project in search of Taiwan’s tallest trees.

In January of 2023, Hsu led a team on a seven-day trek to find a Taiwania tree (Taiwania cryptomerioides) located in the upper reaches of the Da’an River basin and, using a tape measure, determined it to be 84.1 meters tall. This confirmed it to be the tallest known tree in Taiwan and also the tallest in East Asia, and they named it “Heaven Sword of Da’an River.”

Hsu had previously climbed a Douglas fir (Pseudo­tsuga menziesii) in the United States that was between 60 and 70 meters tall. She recalls that the tree looked very old and had many broken branches. “Heaven Sword,” on the other hand, looks extremely healthy.

Taiwania was only discovered by botanists in the early 20th century, and was first formally described by the Japanese scholar Bunzō Hayata. Su Horng-jye, a professor emeritus in the School of Forestry and Resource Conservation at National Taiwan University, believes that Taiwania is a relict species from an earlier geological era. He calls it “the king of conifers.”

In theory, Taiwania trees have relatively few branches, and sparse foliage. Hsu says that viewed from the ground, Heaven Sword looks much the same as other trees. But when you climb it, you discover that each branch is almost as thick as the trunks of other trees. She surmises that this is because of the tree’s location in a valley that shelters it from the wind, and the abundant humidity that also enables epiphytes to flourish on the tree.
 

The ecosystems of giant trees

Hsu has seen the world’s tallest tree, a coast redwood (Sequoia sempervirens) in the US, and says that it is very majestic. “But Taiwan’s giant trees give a very different impression. This is because Taiwan has a more complex ecosystem and there are many kinds of epiphytes and understory plants growing on and around these trees, with a high level of biodiversity.”

Take Heaven Sword for example. When Hsu climbed it she encountered the first branch when she was 50 meters up, and the crown is nearly 34 meters wide. Such a large space gives plenty of room for the growth of epiphytes and for animal activity. “This is the densest crown I have ever seen. The tree is thickly covered by orchids of the species Sunipia andersonii, and included among the ten species of epiphytes growing on it is Phlegmariurus fordii, which is rarely seen on Taiwania.”

According to the Forestry Bureau’s third national survey of forest resources, conducted in 1998, Taiwan’s second-­largest tree by girth (i.e., trunk circumference) was the Lulin Giant Tree, beside Provincial Highway 18. When Hsu climbed it, she recorded 31 species of epiphytic vascular plants in the tree’s crown, including a four-meter-tall Taiwan spruce (Picea morrisonicola), a Taiwan red maple (Acer morrisonense) growing as a bush, and a Taiwan stranvaesia (Photinia niitakayamensis). Together they formed a veritable mid-air garden.

The luck of the draw

Hsu believes that giant trees like these have been able to grow so big and tall because they have “won the lottery.”

Firstly, based on surveys made using airborne ­LiDAR (light detection and ranging), the Forestry Bureau estimates that there are about 900 million trees in Taiwan. Of these, only about one in a million has grown to 70 meters or taller.

Secondly, Hsu conjectures that in terms of tree physiology and ecology, when trees are so tall it should be impossible for sap to rise from the roots all the way to the top, so the forest canopy must rely on moisture absorbed by the leaves. Thus the places in Taiwan where there are many giant trees—including the Da’an River Basin in the Xueshan Mountain Range, the Danda mountain area in Central Taiwan, and the Dagui Lake mountain area in Southern Taiwan—are all located in foggy “cloud forest” areas that are sheltered from high winds and offer abundant moisture, thus providing a favorable environment.

Thirdly, on a geological timescale of thousands or tens of thousands of years, there are other factors that affect tree growth. For instance, Hsu surmises that at the location of the Taoshan ­Giant Tree, a Taiwania 79.1 meters tall, thousands of years ago a landslide formed an area of level ground with deep, rich soil which gave rise to a group of giant trees. Given that these trees, located in a river valley, are vulnerable to landslides caused by heavy rain, and moreover have all been struck by lightning, it is a miracle that they have been able to survive these stark challenges to their existence.

Another example is the Ka’alang Giant Tree, a Taiwania located in the Danda mountain area in Nantou County. It is 82 meters tall, but unusually it has grown in a steep river valley on a slope of 40 degrees where it is difficult even for a person to stand. In order to measure it, in 2022 Hsu built a platform on top of a large fallen cypress tree in the valley. One can imagine how this mighty cypress was toppled by a flow of water unleashed by a torrential rainstorm, whereas the Ka’alang Giant Tree, standing only a few meters away, avoided such a fate, a happenstance that can only be described as lucky in the extreme.

These trees have experienced numerous natural disasters and lightning strikes over the course of time, “so the fact that we can see them now and measure them means that they certainly have ‘won the lottery’!” says Hsu, adding: “The fact that I’ve been able to personally see and visit these magnificent trees means that I’ve won the lottery too!”
 

Hidden groves of giant trees

Giant tree expert Huang Zhaoguo, who has systematically surveyed over 400 giant trees in Taiwan, says that Taiwan’s largest tree by girth, with a circumference of 20.5 meters, is located at the 35 kilometer mark of Daxueshan Forest Road 230. Standing impressively upright, it is known as the “Da’an River Giant Tree,” the “Daxueshan Giant Tree,” or the “Matchless ­Giant Tree.”

After the Jiji Earthquake of September 21, 1999, there was a severe landslide along Forest Road 230, followed by repeated flooding of the area. Huang Zhaoguo was concerned about the Da’an River ­Giant Tree, and invited Chou Yeh-chen, a mountain guide who has surmounted all of Taiwan’s famous “Hundred Peaks” (a select list of mountains over 3,000 meters tall) 16 times, along with mountaineer Huang Yongli, to accompany him on a visit to the tree.

It turned out that there were two newly formed cliffs about two kilometers from the giant tree, and the trio slipped and slid along barren slopes where it was difficult to move forward and even harder to go back. Though Huang Zhaoguo has climbed more than 80 of the Hundred Peaks, he was exhausted. He feared that with any careless move they would plunge down into the 100-­meter-­deep gorge, and if they kept on going they might need to by rescued by helicopter.

At that moment Huang joined his hands together in prayer to the Da’an River Giant Tree and said: “Please let me get over to see you!” To his surprise, he felt a sudden burst of energy, and was able to walk for two more hours until at last the trio arrived at the majestic tree. As they slept that night in a Forestry Bureau storage building, he worried about how they would manage the return journey. The three men, each for himself, all ended up praying to the tree, and somehow the return trip went smoothly. “You tell me, do these trees have special powers?” asks Huang.

Huang Zhaoguo began surveying giant trees more than 20 years ago, and has since spent all of his weekends and holidays in the mountains. In fact, in his working life he was a reporter for the Liberty Times, and at that time his beat happened to be Sanxia, close to Taoyuan’s Fuxing District, where the Hewei group of giant trees is located. He discovered that in addition to the giant tree areas publicized by the Forestry Bureau there were also many hidden giant trees, which inspired his hobby. He divides trees into three categories according to their girth: those with a trunk circumference of six to nine meters, those of ten to 12 meters, and those of more than 12 meters.

To Huang the most beautiful giant tree is the great Taiwan red cypress named “Yaya Qparung” near the Atayal indigenous community of Smangus in Hsinchu County. In his words, it is the “boss” of giant trees. Located in a cloud forest at an elevation of 1,650 meters, it is surrounded by more than 30 red cypresses of various sizes, and appears like a monarch with arms raised, imperiously issuing commands.

“A person’s life and legacy don’t last much more than 100 years, but giant trees remain standing proudly without wavering despite going through countless disasters and changes,” says Huang, adding that when he sees these great trees he often cannot help but spontaneously salute them. For example, Lalashan Tree No. 18, the largest by girth of the giant trees on Mt. Lala in Taoyuan’s Fuxing District, is a fused tree composed of four red cypresses. Although some of the limbs have withered, others are still producing green leaves and shoots as the ancient tree admirably continues its fight for life.

Accessing giant trees

The new policy adopted by the Executive Yuan in 2019 to relax restrictions on public access to mountain forests has not only made it possible for more people to visit the forests, it has also given them the opportunity to seek out giant trees.

Huang Zhaoguo divides the areas where giant trees are located into “general,” “restricted,” and “challenging” depending upon how difficult it is to get to them, and suggests that people should decide which giant tree ecosystems to visit based on their own capabilities.

“Every giant tree is unique, and they are not just randomly accessible—each encounter is a providential meeting.” Such is the invitation extended by tree explorer Rebecca Hsu. The fascinating giant trees on this little island of Taiwan are waiting for us to seek them out.

For more pictures, please click 《Ancient Giants of the Forest—The Island of Magnificent Trees》