Surgeons of the canopy

Tree-climbing arborist techniques are a relatively new method of trimming branches in Taiwan, with only five people certified by the International Society of Arboriculture

By Han Cheung  /  Staff reporter

Wed, Nov 08, 2017 - Page 13

Professional arborist Weng Heng-bin (翁恆斌) doesn’t like trimming trees.

But his job can be crucial — in last month’s case, it was to prevent Formosan black bears from climbing out of their enclosures at the Taipei Zoo. Weng says that if the trees have to be cut, they might as well be done by someone who cares about them and understands their physiology.

“Of course the trees suffer damage when you trim them,” he says. “So before we cut a branch, we have to properly consider the impact on the tree and try our best to minimize the damage. We also try to cut in places where the tree can recover more quickly.”

Video by Sofia Kuan

Weng’s business, Climbing Tree (攀樹趣), boasts a formidable team: He and Maverick Du (杜裕昌) are among five people in Taiwan to receive professional certification from the International Society of Arboriculture, while Sylvia Hsu (許芢涵) is this year’s national female tree climbing champion.

Weng Heng-bin feels at ease among the trees at the Formosan black bear enclosure at the Taipei Zoo.

Photo: Han Cheung

Unlike traditional arborists who operate from ladders and cranes, the trio use a rope and harness system to get up close and personal with the trees, navigating even the highest branches with ease.

Maverick Du makes his way up a branch using a harness and rope system.

Photo: Han Cheung

“Cranes aren’t able to enter the black bear enclosure,” Du says. “So in this case, our skills are vital, otherwise the trimming is limited to what can be reached via ladder. With our climbing skills, we can pretty much get to anywhere we want on the tree to find the ideal spot to cut.”

Weng Heng-bin saws off a branch at the Formosan black bear enclosure at the Taipei Zoo.

Photo: Han Cheung

Other applications of their services include helping researchers collect data and samples, building tree houses and hosting recreational tree climbing sessions — which is becoming a popular activity.


Luo Hsuan-yi (羅諠憶), who oversees the zoo’s Formosan animal area, says that previously the black bear enclosure’s trees were trimmed using the ladder method where all branches were trimmed to about the same length.

“The benefits of this method is that it guarantees that the animals don’t get out, and also we won’t need to trim again for a long while,” she says. “But the trees suffer more damage, and it looks less natural. That’s why we wanted to try something different.”

She likes what she sees, though she is a bit wary that by not cutting all the branches, the bears could still escape if they grow long enough — although the arborists say they do take future growth into consideration.

Du, Weng and Hsu all started out as recreational climbers, but became so engrossed in their hobby that they eventually made it their career. Weng encourages people to try tree climbing, as it provides a new perspective and appreciation for trees.

“I hope that people can feel how strong the trees are and start thinking about how to protect them,” he says. “Then they might start wondering why the tree in front of their house has been trimmed in a certain way.”

Weng rates the Formosan black bear job a four out of 10 in terms of difficulty.

“This is a warm up for our next task at the Formosan macaque area,” Du says. “Those trees are larger and taller, and there’s a pond underneath. We can’t let the branches fall into the water, so we have to secure them by rigging.”

Weng says one of the toughest tasks he ever undertook was having to venture out onto a lone branch that hung over a traditional house.

“I had to sit on the branch and cut the end off while preventing it from falling on the roof. I had to keep my balance, withstand the branch jerking from the cut while grabbing the end. I could have easily fallen off.”


As a relatively new trimming method in Taiwan, the business has its challenges.

“People either don’t know about it or believe that it’s too dangerous,” Du says. “We actually charge about the same as the traditional method, but people have this misconception that since we don’t bust out the large cranes and heavy equipment, we should not be charging this much.”

But more institutions are starting to take notice. Three employees of the Taipei City Government’s Parks and Street Lights Office were also in the black bear enclosure, helping out with various tasks. Wu Bing-hsuan (吳秉軒) says that they’ve been training with Climbing Tree since July and just purchased their equipment for their own projects.

“Our supervisor has allowed us to try this method in our parks in Neihu,” he says. “The certificate requires one-and-a-half years of climbing experience, and we are working toward that goal.”

Wu says one reason so few people have the certificate is that until this year, it entailed two trips to Hong Kong. Du says the general success rate is between 30 and 40 percent, and many people don’t have the resources to make that many trips.

But next month, the Taiwan Arboriculture Society will host local exams for the first time — with Weng and Du as examiners. Wu says by the time he is eligible for the exam, there will be many more certificate holders in Taiwan.

Weng and Du also have their personal goals: Weng has his sights set on scaling the major “sacred trees” of Taiwan, while Du wants to climb as many different species of trees as possible.

“Each species is a different experience — from physiology to growth status to what you can see up there and the general atmosphere,” he says.