Price of Tree Climbing Gear

Recently the National Parks Board called a tender for the procurement of tree climbing equipment. Quotation No. NPB000ETQ16000106

The winners and the gear being bought from them are as follows:

Prices are in Singapore Dollars.

Of course, the prices are being set differently from retail price due to the bidders being on a competitive platform, and regular tree climbing hobbyists may not be able to get the same prices. If including climbing ropes, which are not shown here, a beginner climber may be looking to spend $2000-2500 to own a complete tree climbing set.

Climbing Helmet vs Industrial Helmet

Arborists who do climbing would be familiar with the climbing helmet, which mountaineering hobbyists/workers would use as well. Some arborists who are doing just ground-based work took to wearing a climbing helmet maybe because: a. they do not have a "usual" helmet at hand, b. they look more like an arborist with a climbing helmet, or c. they look safety conscious wearing just any helmet.

So should those arborists be wearing a climbing helmet when they are confined to the ground? Let's explore a bit on the climbing helmet first.

Climbing helmet that an arborist was selling through Facebook.

Arborists who does climbing generally adopt the climbing helmet that complies with the BS EN 12492 standard. The tests that the helmet go through are as follow:

• Withstand a 5kg falling mass from 2m height on the top of the helmet.
• Withstand a 5kg falling mass from 0.5m height on the side of the helmet.
• Not break from a sharp 3kg falling mass from 1m height on the top of the helmet.
• Withstand a 500N for on the chin strap.
• Not slip from the wearer's head when a 10kg falling mass is applied on the edge of the helmet.

The general industrial helmet or commonly known as the "safety helmet" generally complies to the EN 397 standard, and the tests they go through, as compared to the EN 12492 climbing helmet are as follows:

• Withstand a 5kg falling mass from 1m height on the top. (fall from 1m shorter)
• Not break from a sharp 3kg falling mass from 1m height on the top. (same)
• Withstand a minimum force of 150N and no more than 250 N on the chin strap.
• (Half of the force applied. This is to ensure that the chin strap holds but the user is not strangled if he gets stuck.)
• Not catch fire after 5 seconds when exposed to a bunsen burner for 10 seconds. (climbing helmet does not have this test)
• No test for falling mass on the side of the helmet.

An industrial helmet with chin strap. A basic model should not cost more than $10.

The main differences are reflected above are that as compared to the climbing helmet, the industrial helmet does not offer protection from impact to the side, and the chin strap breaks with less force applied. I am not a safety expert and cannot offer my opinions on what these variations mean, but as the saying goes, use the right tool for the right job. 


Ask yourself: if not in an environment with falling hazards and not in a construction site, is wearing a helmet necessary?

P.S. Some arborist-looking helmets may look like the real deal and may even try to pass themselves off as one, but they are often of the EN1078 standard, which applies mainly to cyclist helmets.

Secure by Design

Horticulture Week (UK) reported a local police force has suggested design and plant species to help keep the backyard from bunglers.
Article
Video

In Singapore's context, some plants (with the exception of the obvious cactus) that serve the same purpose would include:

Suitable for small spaces

Bougainvillea
Photo credit: Joel Abroad - https://www.flickr.com/photos/40295335@N00

Caesalpinia pulcherrima (Peacock Flower)
Photo credit: kimubert - https://www.flickr.com/photos/treevillage

Duranta erecta or Duranta erecta 'Variegata' (Golden Dew-Drop)
Photo credit: Hildegard Chen - https://www.flickr.com/photos/hildegardtschen

Lasia spinosa (Geli-geli)
Photo credit: Cerlin Ng - https://www.flickr.com/photos/89906643@N06

Pandanus pygmaeus (Dwarf Screwpine)
Photo credit: Ahmad Fuad Morad - https://www.flickr.com/photos/adaduitokla

Suitable for large spaces

Bambusa multiplex or Bambusa vulgaris (Bamboo small or Bamboo large, respectively)
Photo credit: techieoldfox - https://www.flickr.com/photos/techieoldfox

Oncosperma tigillarium (Nibong Palm)
Photo credit: Forest and Kim Starr - https://www.flickr.com/photos/starr-environmental

Licuala spinosa (Mangrove Fan Palm)
Photo credit: author

Zamia furfuracea (Cardboard Palm)
Photo credit: Forest and Kim Starr - https://www.flickr.com/photos/starr-environmental

Feet of the Five Trees

The title above would be the literal translation of "gor zhang chiu kar", the name of the five transplanted trees, or rather that of their predecessors at Esplanade Park. But Nparks went with the milder sounding "under the shade of five trees.

One of the five Angsana trees. Average girth of the five: 1.48 m (diameter 0.477 m)

Screengrab from Nparks Youtube showing Raintree being transplanted. Went quite viral.

As explained in this signage, that Raintree was one of the eight being transplanted around Victoria Concert Hall. The Raffles statue was of course wrapped up and protected from possible damage.

One of the eight Raintree at its transplanted pit.

 

Wooden decking installed over the pit.

 Held up by metal struts due to the lean.

Interface between a strut and one of the major branch.

Bravo, even the arboriculture consultant is listed on the "project mainboard".

Rosewood and Teak Timber Harvested Till Near Extinction

Rosewood trees in the Thailand-Cambodia-Laos region and elsewhere, and Burmese Teak are being overly exploited too feed the growing appetite for carved furniture and flooring. In China, an intricately furniture crafted in an antique style could fetch one or two million US dollars.

An alternative flooring material is bamboo. Its as hard as teak but it has no grain pattern (as it is in the grass family) and does not last as long. Teak is the best in decay, insect and termite resistance (check out the longest and oldest teak bridge in Asia - U Bein Bridge in Myanmar). Other alternatives are palms like Coconut and Sugar palm, surprise surprise. The planks (can't really call them timber) from palms appear to have black fibers surrounded by a lighter coloured body. The center of the tree is soft and does not have any vascular bundles. This is contrast to the tropical tree species  where the outer sapwood and heartwood could be both as hard. The wood of these palms are usually harvested after they have passed their time of fruit-bearing of 50-70 years. Both species are not listed in the CITES Appendices or on the IUCN Red List of Threatened Species.

Palm "wood" flooring

Oncosperma tigillarium or Nibong is a candidate to join the two species in alternative flooring material. In addition to being decay-resistant, it is also saltwater, borer and termite resistant. Its current use is in building boats, for poles in kelongs, and the large marine fish traps used in Malaysia and Indonesia. However, even this alternative are being over-harvested, and kelong owners who traditionally use them as piles have to switch to hardwoods, which could cost 6 times more. (Source: https://sites.google.com/site/thehumanitiesempanadas/geography-of-food/kelongs-soon-to-be-an-image-of-the-past)

Nibong palm at Singapore Botanic Gardens, Swan Lake or something

Near the border with Cambodia, Thailand posted their soldiers to patrol the last tracts of old-growth Rosewood trees in nature reserves and post guards to watch over their largest remaining Rosewood tree. (Source: https://eia-international.org/corruption-bloodshed-and-death-the-curse-of-rosewood)

China consumes most of these Rosewood, as there seemed to be a desire among the nouveau-rich to collect such antiques, or rather antique reproductions to show off their wealth. The Rosewood utilised was not only one species - Dalbergia cochinchinensis or Siamese Rosewood pilfered from their southern neighbours - but according to the National Rosewood Standard of China, 33 species in total are considered as Rosewood. One of those species is, surprise again, Pterocarpus indicus or Angsana, a relatively fast-growing tree commonly planted in the Philippines (National tree of Philippines), Malaysia, Singapore, and some say Indonesia. A fungal disease epidemic by fusarium wilt impacted the Angsana population in Singapore in the 1980s and almost wiped them out.

In the early 1990s, the National Parks Board sourced Angsana seeds from the region, grown them, and identified those resistant to the fusarium wilt. Some fruits of their research are exemplified in five fungal wilt-resistant Angsana trees that were nurtured in Bidadari and transplanted to Esplanade Park one year ago. But sometimes, there is still a small number of trees that succumb to the disease.

In conclusion, Angsana is a potential candidate for a Rosewood plantation, as a specimen of 40cm diameter could be grown within 20 years (using the ones in Esplanade as an example), as compared to 40 to 50 years for Siamese or Malagasy Rosewood of 20 cm in diameter.

 A mature roadside Angsana tree

Honourable mentions:

- African Mahogany    Khaya senegalensis
- Kasai    Pometia pinnata
- Wattle Black    Acacia mangium

Pruning of Trees for Wind Resistance

Many town council estates and even National Parks Board managed parks and streetscapes have trees that underwent aggressive pruning by their arboriculture contractors, taking off a lot of minor branches and foliage in the process. This was done in the hopes that the trees would be made safer by reducing the "sail effect", or total surface area of leaves, which could catch wind that are passing through, and apply force onto a tree. An overwhelming force could, amongst many other factors, fell a tree, healthy or otherwise. This line of argument may seen logical but there is no formal scientific study that investigates the removal of minor branches would lead to less strain on trees during a storm.

The branches that remains after an aggressive pruning are more vulnerable to failure, as they do not have more branches to act as a buffering shield. Outside limbs can also divert some wind from the center of the tree. Furthermore, trees need leaves to produce food and branches to store it. By have less leaves, the tree produce less food and leads to stress, which could attract pests and diseases. It also contributes to a general decline caused by "starvation". By removing branches, trees divert energy to closing off the wounds instead of growing new wood to stabilise itself.

Tree are known to be "self-stabilising", which means that they could move and add wood in reaction to wind and other forces, in order to resist against said force. After a major portion of a tree crown is removed, the tree would not move when force was applied, and thus could not figure out where to strengthen or put out anchoring roots. This method of tree pruning creates a scene of hustle and bustle, but contributes little to the stability of the trees.

However, other tree pruning methods such as selective crown-reduction, end-weight reduction, crown-lifting and dead-wood removal may be necessary to prevent branch failure. A guaranteed way by which to prevent tree failure is to remove the tree, as it may not be of a suitable size or species for its environment.

The information and ideas in this article were inspired by Greg Lukens, Certified Arborist, Lukens Tree Preservation.

Green Thumbs 2016 Chainsaw Operator

Green Thumbs 2016 on 24 Sep 2016 (Sat)

I was one of the judges for the Chainsaw Operator station. Participants have to carve out a chair using only a chainsaw from a block of hardwood. There were 5 participants - 4 from local companies and one individual, Lam Chor Pau. From the looks of his supporters, he looked to be from the arboriculture community in Hong Kong. Mr. Lam was also the gold prize winner of this category, congratulations on the affirmation of his chainsaw control and safety skills.

An example that the participants have to strive toward.

 Station sign

 Mr. Lam

Participant from Flora Landscape.

 Park manager would have to close one eye on this set-up.

 I would hate for this machine to chase me (in my dreams).

 Singapore Tree Climbing Championship 2016.

Held at the beautiful Bishan-Ang Mo Kio Park River Plains.

Storm-Vulnerable Trees

The Tree Management Programme of the National Parks Board (NParks) describes the inspection of trees "along major roads or  areas with high human activity" at least once every 12 months. Crown reduction  pruning was conducted when necessary. [1]

Furthermore, NParks was on an exercise to remove/replace storm-vulnerable trees and advising other public agencies, such as the Singapore Land Authority (SLA) and Housing and Development Board (HDB), to do the same. The only storm-vulnerable species publicised was the Albizia tree (Falcataria moluccana), which is fast-growing and could easily exceed 20m in height. But its wood is soft and prone to breaking during storms. In addition, they are shallow-rooted and thus susceptible to uprooting. There should be other storm-vulnerable species listed, but unfortunately, they were not shared in the article.

Photo by Shin Min Daily News

Almost 4 years ago (27 Sep 2012), a NSman on in-camp training was crushed by a tree and was subsequently pronounced dead at the hospital he was taken to [2]. The incident took place at the entrance of the Ama Keng Training Area in Lim Chu Kang. If a certified arborist (CA) were to have carried out tree inspection on that tree, the CA could have recommended the removal of the offending tree. Based on the photo, the tree appeared to be an African tulip tree (Spathodea campanulata), detailed further below.

In an "after" photo where SLA selectively removed Albizia trees at Jalan Anak Bukit, (near Bukit Timah Hill), African tulip trees were observed to be left behind and intact. [1] The site of the "after" photo was visited last week and it looked very different due to road expansion works.

 "After" photo after an exercise by SLA to remove Albizia trees. Probably taken in 2012, from NParks website [1].

 Road widening in the target area of storm-vulnerable trees, which include Albizia and African Tulip trees. Photo taken on 11 Sep 2016.

African tulip trees near the edge of the road expansion.

Land Transport Authority (LTA) notice on the road widening.

There are nine tree species identified as being invasive in Singapore. A common attribute of these invasive tree species is that as compared with non-invasive species, they have only 54% of the mean wood density. It should be noted that other than Falcataria moluccana and some outlying individuals of Cecropia pachystachya, "no attempt has been made to control the other species." [3]

The following are four of the invasive tree species that could be considered "storm-vulnerable", which could be removed from roadsides, forest edges, parks and high-traffic areas:

a. Acacia auriculiformis (Ear-leaf acacia)
It could grow in nutrient poor soil as it has nitrogen-fixing bacteria associated with its roots. Fast-growing and drops a lot of leaves. Roots grow shallow, spreading and densely matted, which makes it suitable to stabilise eroding land.

b. Cecropia pachystachya (syn. Cecropia peltata) (Trumpet tree)
In Singapore, this tree is viewed as a weed and is short-lived [4]. It has hollow stems, which is inhabitaed by ants.

c. Falcataria moluccana (Moluccan albizia)
Perhaps the fastest-growing tree in the world [4]. Like the Acacia, it is capable of fixing nitrogen from the air. Considered a weed and hazard due to its soft, brittle wood, and shallow roots.

d. Spathodea campanulata (African tulip tree)
Similar to the Albizia tree, the wood of the African tulip tree is soft, tends to become hollow, and drops their branches over time. The roots grow shallow and is more likely to uproot during storms.

Table 1. Invasive tree species in Singapore with their common names
Acacia auriculiformis    Ear-leaf acacia
Cecropia pachystachya    Trumpet tree
Falcataria moluccana    Moluccan albizia
Leucaena leucocephala    Lead tree
Manihot carthaginensis    Ceara rubber tree
Muntingia calabura    Jamaican cherry tree
Piper aduncum    Spiked pepper
Spathodea campanulata    African tulip tree

Table 2. Potentially invasive tree species (not necessarily storm-vulnerable) identified in the paper [3]
Hevea brasiliensis    Para rubber tree
Andira inermis    Brown heart tree
Ptychosperma macarthurii    Macarthur palm
Elaeis guineensis    Oil palm
Ficus religiosa    Bodhi tree

Reference:
1. National Parks Board Tree Management Programme (https://www.nparks.gov.sg/news/2013/1/nparks-tree-management-programme), 1 Jan 2013, Last updated on 20 Nov 2014,
2. Jalelah Abu Baker and Lim Yan Liang, NSman's death: Tree was checked in April, Asiaone (http://news.asiaone.com/News/Latest+News/Singapore/Story/A1Story20120929-374484.html), 29 Sep 2012
3. Nghiem, L. T. P., Tan, H. T. W. and Corlett, R. T. 2015. Invasive trees in Singapore: are they a threat to native forests? Tropical Conservation Science Vol.8 (1): 201-214
4. Tee et. al., Trees of Our Garden City, 2nd ed, 2009

The man behind the design of Seiwaen (Singapore's Japanese Garden)

Kinsaku Nakane on the left with his son Shiro on the right.

Seiwaen opened on 16 Feb 1973, the largest Japanese garden outside of Japan at that time. The garden was built on a man-made island in the middle of Jurong Lake, adjacent to Yu Hwa Yuan (Chinese Garden). Designed by Professor Kinsaku Nakane, Japan's leading landscape designer, the garden took four years to complete. Originally part of a swamp, the Chinese and Japanese Gardens are two of three man-made islands at Jurong  (the third one being Jurong Country Club... which is more of like an extension rather than an island).

This large strolling garden was constructed according to the gardening techniques that prevailed from the Muromachi Period (1392 - 1568) to the Momoyama Period (1568 - 1615). The architecture was based on post-war style.

Funding came from Singapore and Japanese governments as well as the local Japanese organisations at the cost of $3 million. The garden symbolises the peace and prosperity between Singapore and Japan. Notable landmarks are the 4 metres (13-foot) tall Kasuga stone lantern that overlooks a lake and Torii gates at the "guesthouse" building.

The garden was closed since 2001 and in 2003, after a review, closed for renovations and reopened on 15 July 2007. As part of the effort to re-invent itself, large amount of earth was brought in to terra-form the land; artificial hills were created.

Nakane passed away at the age of 77 on 1 March 1995 in Kyoto. Apart from designing gardens in Japan, China and in the West, he was the President of the Osaka University of Fine Arts and Nakane Garden Research, which is still in operation today with his son Shiro at the helm. [URL: http://www.lares.dti.ne.jp/~nakane/index.html]

The Tenshinen ('Garden of the Heart of Heaven") at the I.M. Pei West Wing, Museum of Fine Arts, Boston, USA, which was completed in 1987 was his most prominent work. Reminiscent of the gardens in the shogun estates of the Edo period (1603-1867), the Tenshinen incorporates symbolic details of the New England landscape (rocky coastline and deep forests) over which Nakane flew in a helicopter when he was formulating his garden plan. The Japanese garden at Jimmy Carter Library and Conference Center in Atlanta, Georgia, was also designed by him.

The Tenshinen was re-opened on April 2015 after a year-long effort to restore the garden, and documented by the Nippon Television Network Corporation. In the course of the renewal, new plants, paving, irrigation, drainage, lighting, and granite gravel were installed.

In Toowoomba, Queensland, Australia, the Ju Raku En is a Japanese garden designed by Nakane with construction starting on 1983 and opened in April 1989. The 4.5 hectare garden is jointly own by University of Southern Queensland and the Toowoomba City Council, and is Australia's largest Japanese garden. It is located at the northern side of the campus.

Sources:
1. Elizabeth Ten Grotenhuis, The Journal of Garden History, pp. 231-232, 30 Apr 2012)
2. Museum of Fine Arts, Boston, http://www.mfa.org/collections/featured-galleries/japanese-garden-tenshin-en

Trees of Our Garden City: A Guide to the Common Trees of Singapore

Publisher: National Parks Board, Singapore
First published: 2001, Second ed: 2009
Authors: Tee Swee Ping et al. (see more below)
Pages: 210 pages
Showcasing 132 trees and 18 palms species

Chapter Headings:
Foreword
Introduction
Chapter 1 - Our Garden City Story
Chapter 2 - Tree and Palm Species
Chapter 3 - Tree Biology
Chapter 4 - Tree Care (Tree Planting, Tree Planting Distance, Tree Inspection, Tree Pruning, Pests and Diseases of Trees, Conservation of Urban Trees)
Chapter 5 - Growing Trees in Rooftop Gardens
Chapter 6 - Trees and the Environment
Glossary
Bibliography
Index (by Botanical names, by Common names, by Chinese names)
Acknowledgements

Editorial Committee:
Tee Swee Ping
Yong Wei Kwong
Ms Jerrie Ng Sy Chi
Ms Germaine Ong Zi Ming

Writers & Contributors:
Dr Chin See Chung, Dr Tan Puay Yok, Dr Benito Tan, Dr Nura binte Abdul Karim, Dr Lim-Ho Chee Len, Dr Lena Chan, Dr Fong Yok King, Ang Chee Wee, Ali Ibrahim, Abdul Hamid bin Mohd, Chan Chun Leong, Derek Chan Yeow Kwang, Low Yong Kwee, Eric Ong Yongquan, Hassan Ibrahim, Ms Kalthom Abdul Latif, Lahiru Suranga Wijedasa, Lee Jia Hwa, Lim Choon Boon, Ms Lily Chen Mei Jun, Lua Hock Keong, Muhamad Shahrizal Sihab, R Mathichandran, Ms Patricia Yap Siew Yen, S K Ganesan, Simon Longman, Sim Eng Koon, Tan Chin Peng, Ms Thereis Choo Yi Siang, Toh Chin Heng, Voon Chin Seng, Ms Lee Pin Pin, Ms Germaine Ong Zi Ming, Ms Mitina Tan, Ms Melanie Wee Mei Choo, Ms Chan Yang Sun, Yong Wei Kwong, Ms Jerrie Ng Sy Chi, Tee Swee Ping.

Photos Credits:
Chan Chun Leong, Lee Jia Hwa, Ms Patricia Yap Siew Yen, Lin Yangchen, Paul Leong, Ms Lily Chen Mei Jun, Choy Heng Wah, Gary Chua Liat Seng, Benjamin Lee Yi-Hann, Mervin Quah, Ms Eleanor Soh, S K Ganesan, Wong Tuan Wah, Dr Yam Tim Ying, Tee Swee Ping.

Tree Conservation Area (TCA)

Tree Conservation Areas have mature trees that enhance the environment with their lush greenery and shade. It was established in Singapore to control careless felling of those trees.

Protected trees are defined as:

• More than 1m girth (or 0.31m diameter)
• Heritage trees and roads (could be outside TCA)
• Within vacant land

Trees could be protected whether on State and privately owned land. They cannot be felled without approval from National Parks Board (NParks).

Failure to do so:

• Compensation (when case taken to court; determined by prosecution. between $76,000 and $50,000 based on past cases) and fine of not more than $50,000, or
• Composition fine of $2,000 for each tree felled [1]

A Certified Arborist report may be needed to accompany the request to NParks.
Depending on tree species, size and condition, a basic assessment report costs $150-$600 per tree.

To check if your land is on TCA and for reports to accompany your submission, contact a Certified Arborist (not from NParks) from this list:
http://www.cuge.com.sg/Listing-of-Certified-Arborists


Reference:
1. http://wildsingaporenews.blogspot.hk/2009/07/house-owner-fined-6000-for-cutting-down.html
2. https://www.nparks.gov.sg/gardens-parks-and-nature/tree-conservation-areas

 TCA 1

TCA 2