Sunday, May 6, 2018

Hopea sangal - a series of events across 2 years

In Sep 2002, a Hopea sangal re-discovered in Changi, which was significant as it was thought to be extinct in in the Singapore Red Data Book, and the name Changi was thought to have been originated from the tree's common name, Chengal Pasir.

Hopea sangal at Changi.
Photo credit: Tan Beng Chiak

However, the property management company taking care of the area felled the tree without the approval from authorities in November in the same year. The company's manager observed that the tree was struck by lightning and was not doing well, and decided to have the tree removed. Sivasothi who was there to check out the re-discovery was just in time to witness the felled logs from the tree being hauled away.

Hopea sangal stump.
Photo credit: Sivasothi

Logs being hauled away.
Photo credit: Sivasothi

The logs were recovered and artists carved pieces of the wood into sculptures. Some of the sculptures were exhibited at the Singapore Zoo main entrance.


Before the tree was felled, some seeds were collected by Nature Society Singapore's (NSS) members and passed to National Parks Board for propagation. After about two years of being "grown partially in a carbon dioxide enriched chamber", the sapling was more than one metre in height. Some seeds were grown by the NSS and a sapling was handed to the Singpore Zoo.

On 7 Nov 2004, Mr Lee Kuan Yew planted a sapling nurtured by NParks Pasir Panjang Nursery at Henderson Crescent, between Blocks 103 and 104.

Mr Lee planting the Hopea sangal sapling while members of parliament (MP) of the Tanjong Pagar group representation constituency (GRC) and community members look on.
Photo credit: John Yong

Google map showing approximate location of the VIP-planted tree (in red pointer).
Block numbers added by me.
Map credit: Google Maps.

I tried to locate the tree and it was found at a not so prominent spot (pointed by red arrow). 
Photo taken by me on 6 May 2018.

Overall view of the tree - the crown facing the west seemed more lush than the part facing the east, probably due to a block to the east (block 106). Note the surrounding trees that are topped.
Photo taken by me on 6 May 2018.

The tree is leaning to the north, possibly due to the phototropism as there is a block to the south (block 104) and palms (Dypsis lutescens) fighting for crown space. It is also slightly assymmetrical, as the crown is raised higher at the part where it is in contact with the palm leaves.
Photo taken by me on 6 May 2018.

Girdling root to the south of the tree.
Photo taken by me on 6 May 2018.

The plaque reads:
"Tanjong Pagar Town Council
Clean and Green Week 2004
This tree, Hopea sangal was planted by Mr Lee Kuan Yew
Minister Mentor and MP for Tanjong Pagar GRC
on 7 November 2004"
Photo taken by me on 6 May 2018.

Tuesday, May 1, 2018

"Major controversy" - an External Cavity that was not

With reference to "The Curious Incident of the Tembusu Tree that Fell" and the slew of news articles published yesterday.

The Coroner, Mr Marvin Bay referred to the last inspection of the tree on Sep 29, 2016 as a "major controversy" in the case.

In the inspection done on 29 Sep 2016, later revealed to be done by senior manager (also arborist) Thaddaeus Cheng (ISA Certified Arborist, Cert. ID: SG-0621A), found a 1.5m long "cavity". His supervisor, deputy director Elango Velautham, "also inspected the tree as a follow-up to Mr Cheng’s report". He noted that a "flute" was "wrongly perceived" as a cavity at the Coroner's Inquiry on 30 Aug 2017.

However in the news article on 30 Apr 2018, it was written that Elango Velautham explained during the inquiry that upon further inspection, that he found that "it was not an external cavity and that there was no decay", and the arborist used the word "cavity" due to the limitation of the inspection form.

So was it "wrongly perceived", or was it "rightly perceived but written wrongly"? And again, it was not known whether the "wrong perception" was discovered before or after the tree fell.

Also during the inquiry on 30 Aug 2017, the lawyer acting for Angara's family had questioned "the absence of documentary proof showing how the misdiagnosis was determined". Perhaps that statement lead to the Coroner remarking that it would be useful that tree inspections for large and old trees be accompanied by photographs, which "can allow a more cogent analysis of the actual baseline health of the tree".

A flute of an Angsana tree in Clementi.

---
Some cheem words found in the news articles:

Cadre - a group of trained or otherwise qualified personnel capable of forming, training, or leading an expanded organization, as a religious or political faction, or a skilled work force.
"They hoped to form a cadre of veteran party members."
 Cogent - (of an argument or case) clear, logical, and convincing.
"They put forward cogent arguments for British membership."
Obviate - avoid or prevent (something undesirable).
"A parachute can be used to obviate disaster."
Remiss - lacking care or attention to duty; negligent.
"It would be very remiss of me not to pass on that information."
Wherewithal - the money or other means needed for a particular purpose.
"They lacked the wherewithal to pay."

Coroner's Findings on Tembusu Tree that killed a woman at Singapore Botanic Gardens

Death of woman killed by tree at Botanic Gardens a tragic misadventure, coroner rules

Wong Pei Ting TodayOnline 30 Apr 2018

SINGAPORE — No one, not even experts, could have seen it coming that a Tembusu tree at the Singapore Botanic Gardens would topple and cause the death of a 38-year-old woman in February last year, a coroner said on Monday (April 30).

However, the family of the deceased, Indian national Radhika Angara, are “stricken” with grief by the finding, which ruled her death as a “truly tragic misadventure”.

They still believe it was the “inaction” of the National Parks Board (NParks) that caused the woman to die.

Ms Angara’s sister Aarti Angara, on behalf of her parents and brother-in-law Jerome Rouch-Sirech, said: “Everything we heard over the course of this inquest, suggested to us that the people-in-charge were remiss in their duties to keep the public safe at a Unesco world heritage site.”

Referring to the inquiry, which uncovered that at least 70 per cent of the 270-year-old heritage tree’s core was decayed, she added: “These people have the tools and the wherewithal to prevent this mishap… This could have and should have been prevented. Instead it is my niece and nephew who will have to bear the burden of this disaster, and who will never get to know their mother.”

Ms Radhika Angara, who was regional digital marketing head for Asia-Pacific at MasterCard, is survived by her French husband, Mr Rouch-Sirech, and twins Chloe and Rafa, who are two years old.

She was carrying Rafa in her arms when she was hit by the 40m-tall tree last year on Feb 11. Rafa suffered abrasions on his limbs and contusions on his head, while his mother died of fractured ribs and traumatic asphyxia when she could not breathe after being pinned under the tree.

Mr Rouch-Sirech covered his face with his hands as Coroner Marvin Bay delivered his findings after a four-day inquest that was held over a period of about nine months. He left the courtroom crying.

In a 19-page report, Mr Bay ruled that Mr Thaddeus Cheng, the NParks’ arborist (tree doctor) responsible for the massive tree’s last inspection in September 2016, followed existing protocol. The tree was checked twice a year for the presence of open cavities.

Mr Cheng and his supervisor, Mr Elango Velautham — who also inspected the tree as a follow-up to Mr Cheng’s report — could not have detected the presence of decay unless they performed an advanced inspection, which would require the use of diagnostic tools such as a resistograph and sonic tomographs.

Mr Bay noted that their most significant discovery did not warrant that level of inspection. The men had taken note of a 1.5m long flute that is 30cm at its widest point and 20cm deep at its deepest point, although no decay was found.

The higher-level assessments only kick in if there are reasons to suspect internal decay or any issue that might affect structural integrity.

In this case, Mr Elango, who is the deputy director of Botanic Gardens' Arboriculture and Plant Resource, testified that a massive internal cavity extending a height of 2.9m was only discovered after the tree had uprooted on Feb 11 last year.

Although the cavity was close in distance to the flute structure, it was hidden inside the trunk, he said.

NParks lead arborist Abdul Hamid, along with two other independent arborists — Mr Rick Thomas of ArbourCulture and Mr Derek Yap of Camphora — submitted that the collapse could not have been predicted.

Accepting NPark’s account, Mr Bay said that heavy rainfall and strong winds of 30 to 40km/h in the week leading up to the accident contributed to the tree’s collapse, besides its weak trunk.

“The wind had initiated the process by buffeting the 40m-tall tree (with an asymmetric canopy load), causing considerable swaying. The swaying had transferred these strong imposed forces down the trunk and, in turn, caused the degraded tension roots to fracture,” he said, adding that the tree has a shallow root depth of just 70cm at its maximum.

Explaining how the decay started, Mr Bay said that in the distant past, the roots of the tree were cut to build a path nearby, so they became degraded when they could not propagate further. The cuts also allowed pathogens to be introduced into the tree’s system, causing severe decay in the roots below soil level.

The rot eventually migrated to the trunk itself, leading to massive internal decay.

Two months after the accident, National Development Minister Lawrence Wong said in a parliamentary response that as of November 2016, an enhanced inspection regime involving the use of diagnostic equipment were put in place for large trees that are older than 50 years old.

Mr Bay called the change a positive step, which “will do much to obviate the risk of a sudden and potentially catastrophic tree failures in the future”.


Tembusu tree accident: Death of woman a 'tragic misadventure', says coroner

Jalelah Abu Baker Channel NewsAsia 30 Apr 2018

The tree's deterioration started in the "distant past" when its roots were cut to make way for a path, Coroner Marvin Bay said.

SINGAPORE:  The death of a 38-year-old woman who was killed by a Tembusu tree which uprooted at the Singapore Botanic Gardens last year was a tragic misadventure.

That was Coroner Marvin Bay’s finding on Monday (Apr 30), two weeks after the conclusion of an inquiry into the death of Indian national Radhika Angara.

Mr Bay noted that there were no external signs or symptoms of an internal decay, a point raised by arborists who had testified during the inquiry. An external void was flagged in 2016 during an inspection, but that turned out not to be damage.

"No other feature was documented about the tree which would have raised the index of suspicion that it was susceptible to imminent collapse," he said.

Strong winds and heavy rain in the days before the tragic incident was a factor in the "final failure" of the tree's roots, said the coroner. The wind had initiated the process by buffeting the tree, causing "considerable" swaying, he added.

This in turn caused the tree's already weakened roots to fracture.

The incident happened on Feb 11, 2017, when Ms Angara was at the UNESCO world heritage site with her husband and now two-year-old twins. She was killed when the 40m-tall tree fell on her. Four others, including her husband and children, were injured.

Ms Angara's husband, French national Jerome Rouch-Sirech, sat with his face in his hands most of the time while the coroner delivered his finding.

Her sister Aarti was also in court. Speaking to reporters on behalf of the family, she said it was inaction by the people in charge that led to the tragedy. It could have been prevented, she added, saying her niece and nephew will now have to "bear the burden of this disaster, and will never get to know their mother".

Breaking down, she said: "Sitting here today, we had to relive the day of the tragedy and what caused her death. That has just been gut-wrenching."

Meanwhile, Mr Rouch-Sirech covered his face and sobbed.

PROGRESSIVE DECAY OF 270-YEAR-OLD TREE

While there were no visible signs of an internal decay, the roots of the 270-year-old heritage tree had in fact deteriorated over time.

In his findings, the coroner pointed to the tree's "distant past" when its roots were cut to build a path nearby. As a result, the roots were unable to spread further and become degraded.

This already "dire" situation was worsened by a severe decay of the roots below soil level.

"This was also associated with the same root cuts that had occurred in the past which had at some point introduced pathogens which had caused progressive decay," said Mr Bay.

The decay eventually migrated to the trunk, causing "massive internal decay" he added.

Protocol that existed at the time was followed, said Mr Bay, but he noted that it would be useful for photographs to be taken during all regular tree inspections for significant trees such as old and large trees, or heritage trees.

"These recorded images would be useful in investigations and inquiries, as an archive of contemporaneously taken photographs of the same tree can allow a more cogent analysis of the actual baseline health of the tree," he said.

This would afford longitudinal tracing and visual examination over years or even decades, he added.

Such decay can currently be uncovered through advanced inspection, he observed. This is done if the arborist conducting checks suspects internal decay or any other issue that might affect structural integrity.

THE LAST INSPECTION IN SEPTEMBER 2016

Mr Bay referred to the last inspection of the tree on Sep 29, 2016 as a "major controversy" in the case. Senior Counsel Chelva Rajah, who represented Ms Angara’s family, had articulated his suspicions about an "external cavity", as documented by an arborist who inspected the tree, and why it had not been addressed before the tree collapsed.

Singapore Botanic Gardens’ deputy director Elango Velautham, the supervisor of arborist Thaddeus Cheng, had explained during the inquiry that the arborist noted a space that "looked unusual" and recorded it as a cavity without decay.

Upon further inspection, Mr Elango found that it was not an external cavity, and that there was no decay. It was in fact a flute, which is a fold in the surface of the tree, and Mr Cheng had used the word "cavity" due to limitations in the form he submitted.

The Tembusu tree that fell was inspected twice a year, as are other large heritage trees, trees in carparks and those in areas where "the occupancy rate is high", Mr Velautham had said during the inquiry, which took place over four days spread out over a period of about nine months.

In response to Channel NewsAsia's queries, the National Parks Board said: "NParks notes the Coroner’s findings that this was a tragic misadventure and will study the Coroner’s report."

Source: CNA/ja/(gs)