SINGAPORE: She was once drawn to animals such as monkeys and insects more than trees, which she thought were “quite boring”.
When she was a biology and tropical forest ecology student, Ow Siew Ngim would take “all the animal modules”. “We can learn a lot more because they move,” she said. “Studying behavioural patterns was so interesting when I was young.”
But trees became a sexier subject over time. “They just speak a different language from animals,” she said. “You need to interpret for yourself, … you need to confirm your inspection based on diagnostic tools and things (like that).
“I like the challenge.”
What made her see trees in a new light was a course conducted by the International Society of Arboriculture (ISA), a non-profit authority on the care of trees.
She went on to become a certified arborist and today is a streetscape and ops tech director at the National Parks Board (NParks). Keeping Singapore’s urban trees in tip-top condition is part of her job.
No longer needing to measure the tree’s girth and height or determine its location, tree doctors hope to cut the time needed for such an inspection by half, said Ow.
NParks’ remote measurements of trees were first done in the Bishan-Ang Mo Kio area in early 2021. But there was no rover at the time — the surveyors had to use trolleys to move the laser scanners and tripods, which weighed tens of kilogrammes.
By the time the project moved to the Botanic Gardens, the compact, industrial-grade electric rover had been added to the mix. By saving them time, it allows the arborists to focus on trees that “really need help”, said Sasi.
An NParks arborist may inspect about 400 to 500 trees in a typical month, and most trees are found to be healthy during first-level visual inspections based on international standards.
Very few trees are referred for second-level inspection, said Ow, without providing figures. (Besides trees with “possible defects”, NParks has also conducted advanced inspections of trees more than four metres in girth since November 2016.)
During advanced inspections, tree doctors will use decay detection instruments. For example, a resistograph drills through the trunk with a needle to measure the wood’s resistance, while a PiCUS sonic tomograph uses sound waves to investigate the tree’s internal condition.
Since the early 2000s, NParks’ tree management has been anchored in a “rigorous regime of inspection and pruning”.
In the beginning, tree doctors used to head off to inspect trees with paper maps in hand, she recalled.
When the first mobile devices came along sometime after 2010, the arborists joked that the gadgets — used mostly for data updates — could double as weapons if they ever needed to defend themselves. Each weighed 1 to 2 kg, Ow estimated.
Today, the mobile devices used by NParks are a fraction of their predecessors’ weight and do much more. They let the tree doctors access details of each tree while in the field and update inspection records in real time.
Read this story in Bahasa Melayu here.