Machinery Equals/Not Equals to Productivity 2

Continuing from the previous entry, the Husqvarna 430X takes about 22 hours a day, 7 days a week to mow 3/4 acre. It would mow for about 2 and half hours, then recharge for an hour, then mow for 2 and half hours and charge for an hour, cycling continuously rain or shine. The end result is that the lawn would be more lush and always look manicured, and since the clippings are returned to the soil, little application of fertiliser was required. As compared to, I suppose, a rotary mower used twice a month on the lawn, sweeping away the clippings, and perhaps applying fertiliser afterwards. In the shoes of a landscape worker, I would welcome such a widget that needs little to no "supervision" while I could spend more time and attention on pruning shrubs.

I think it was about 5 years ago that CUGE started a programme to rent machinery out to landscape companies in order to encourage them to use more machines or even purchase some of their own after trying the rentals out. Amongst the mechanical wonders were a backhoe, skid-steer + trench digger combo, wood chipper, and get this - a soil potting machine. I don't think the rental programme lasted for 2 years.

 A backhoe that has to be repositioned after digging was done at one spot.

A skid-steer that required the operator to stand. More suitable to dig trenches (on flat ground), as the brand name suggested.

This photo was taken from an area accessible to the public after the rental programme had closed. A soil potting machine out in the open with a tarp draped over it, which was breaking down due to being exposed to the elements.

Slightly more than a year ago, NParks released S$3 million for the Landscape Productivity Grant (LPG) to contribute towards the purchase of machinery by landscape companies and plant nurseries. The grant subsidised half of the machine price, and the Productivity and Innovation Credit (PIC) scheme subsidised 60% of the other half. The company would pay for the remaining, which is 20% of the machine price. NParks reported that a previous tranche of the LPG saw companies achieving the following improvements to their productivity through mechanisation.
- 77% savings in man-hours as a result of using wood chippers
- 60% savings in man-hours after switching to the use of ride-on mowers
- 50% savings in man-hours using tractor-mounted hedge-trimmers
- 80% savings in man-hours as a result of deploying a wireless remote mower

A tractor-mounted hedge-trimmer being utilised along an expressway. Not seen in this photo was the media posse in front of the tractor.

 One whole lane have to be closed just for this machinery to be used. I have not seen this on the roads myself.

 A similar attachment mounted on an Avant loader chasis. This machine was not used in the park ever again after photo taking.

 A stump grinder that I have not seen after taking this photo on Aug 2013.

Do we still have the same amount of productivity improvements despite of all these machines being put out of action? I think the answer would be resounding. The way these "x0% savings in man-hours" was derived is by demarcating a set amount of work - 1 km of shrubs, 1 acre of lawn, 1 lorryload of branches, etc. - and have the machine tackle the work, and have an appropriate number of human workers carry out the same work. The man-hours put into each set of work would be compared against one another. Outside these trials, landscape works were often back to square one. I heard that a company that owned a remote controlled mower used it rarely. When they have hordes of workers using backpack mowers, it was but a logical development. Of course not all landscape work are deprived of mechanisation. For example, in arboriculture.

Other than lifting workers up into the tree crowns and hauling trunks, apparently the crane could be used to grub out stumps. 

UPDATE

 Saw this stump grinder outside CCK Lot 1 on 3 Feb 2018.

Machinery Equals/Not Equals to Productivity

I was checking out Gebiz as usual in my down time and came across a tender for a "robotic mower", which I thought would be one of these remote controlled mowers featured along with the Landscape Productivity Grant (more on that later). But it turned out to be something less controlled and more automated.

Nah, not this type.

 

So. Refined.

Here goes the boring Gebiz details:

INVITATION TO QUOTE FOR THE PURCHASE OF A ROBOTIC MOWER UNIT AND THE OPTION TO PURCHASE SPARE PARTS AND ENGAGE TROUBLE-SHOOTING SERVICES

Quotation No.: NPB000ETQ17000133
Agency: National Parks Board

ITEMS TO RESPOND
1. Robotic mower unit
2. Blade
3. OTHER ITEM OF WORK AND/OR SERVICE NOT INCLUDED IN ITEMS ABOVE BUT WHICH ARE NECESSARY FOR THE FULL AND SATISFACTORY COMPLETION OF THE WORKS.
4. OPTIONAL ITEM - Supply and replacement of Battery, Rechargeable (12 months warranty against manufacturer's defect upon acceptance of item).
5. OPTIONAL ITEM - Supply and replacement of Sealing Strip (for control panel) or equivalent.
6. OPTIONAL ITEM - Supply and replacement of Sealing Strip (for main unit body) or equivalent.
7. OPTIONAL ITEM - Supply and replacement of Wheel Snap Function (for wheel) or equivalent.
8. OPTIONAL ITEM - Supply and replacement of Motor Assy or equivalent (at least 3 months warranty against manufacturer's defect upon acceptance of item).
9. OPTIONAL ITEM - Supply and replacement of Motor Assy Height Motor or equivalent (at least 3 months warranty against manufacturer's defect upon acceptance of item).
10. OPTIONAL ITEM - Supply and replacement of Joystick Kit Rear or equivalent.
11. OPTIONAL ITEM - Supply and replacement of Joystick Kit Rear ( for column kit ) or equivalent.
12. OPTIONAL ITEM - Supply and replacement of Motor Kit Drive Wheel or equivalent (at least 3 months warranty against manufacturer's defect upon acceptance of item).
13. OPTIONAL ITEM - Transportation & on-site inspection/service charge (Per trip).
14. OTHER ITEM OF WORK AND/OR SERVICE NOT INCLUDED IN ITEMS ABOVE BUT WHICH ARE NECESSARY FOR THE FULL AND SATISFACTORY COMPLETION OF THE WORKS.

[Edit: Seemed like items 3 and 14 are repeated. Below are the excerpts of the response of two companies that participated in the ITQ.]

Company A (Awarded)

1. $3980 - HUSQVARNA (SWEDEN) AUTOMOWER - MODEL 430X (PN 967 62 25-03)
GPS Assisted Navigation/ 0.8 Acre Working Area Capacity
2. $71.55 - Husqvarna Automower Blades
3. $1500 - Installation Package includes 2 x complimentary follow-up service/loop wire reset with 3 months from installation
4. $214.50 - Husqvarna Automower 430X Replacement Li-Ion Battery
14. $1105.30 - Additional Automower Ad-Hoc Replacement / Service Parts & Accessories

Company B

1. $7500 - Robotic mower unit
2. $2160 - Blade
3. $4500 - Labour $1500 Wire Laying/ Trenching / Material $4500
4. $850 - Replacement battery
14. $1500 - Labour

The awardee was a lot more competitive in pricing as compared to the latter, and even so they could have profited quite a bit.

This bundle, costing approx SGD 2900, includes an install kit that comes with guide wires (250 metres), which sets the boundary for the robot mower (see below).

 The yellow line around the property represents the guide wires that tells the robot mower not to go past. The dotted lines are its mowing path I suppose.

The guide wires were installed a few inches below ground, so I have no idea why the second tenderer have to go and cost in $1500 for laying it and $4500 in materials (which I guess are the guide wires and staples). Assuming the lawn that this mower was used on was exactly 0.8 acres (3237.5m2), and the guide wires were laid just around the boundary, then only 227.6m of it was needed. The install kit comes with slightly more than that length of guide wires.

No Country for Old (and Young) Trees

Perhaps in view of the incidences of large trees, especially Khaya sp. (African mahogany) falling down and causing loss of lives and damage in property, they have been felled in large numbers. Well except in the case below, that tree has been "halved".

 

Photo on the left mentioned in this post: http://openplants.blogspot.sg/2016/10/pruning-of-trees-for-wind-resistance.html

The Rain tree (Samanea saman... or as the rest of the world know it by Albizia saman) that used to be in that spot used to be as large as the one in the background. I suppose defects on the tree called for it to be removed, and it was replaced by this young Rain tree. But it did not last long, possibly broke in half by strong wind travelling through that "wind tunnel". Its root ball was dug up, and the hole was left uncovered.

Photo on the left mentioned in this post: http://openplants.blogspot.sg/2017/04/arboriculture-happenings-at-bugis-area.html

 A replacement tree of the replacement tree seen on 23 Oct 2017.

Papers Excerpt - Strength Loss Due To Decay

Journal of Arboriculture 18 (4): July 1992
Determining Strength Loss from Decay by E. Thomas Smiley and Bruce R. Fraedrich

SL% = d^4/D^4 x 100 ;Originally developed by engineers to compare the strength of pipes.
SL% = d^3/D^3 x 100 ;Wagener modified it to take into account the irregularity of  trees.

SL% =     d^3 + R(D^3-d^3) x 100
               -------------------------------
                              D^3
SL = Strength loss
d = Diameter of hollow and/or nonstructurally sound wood
D = Diameter of sound wood
R = Ratio of cavity opening to stem circumference

The R(D^3-d^3) modification was developed by the Bartlett Tree Research Laboratories to account for wood which is "missing" at a cavity opening.

Among trees that broke from internal decay, average strength loss was 33% with a SD of 22% [could be between 11% and 44%].

Severity of decay in the trunk predisposes trees to failure [felling, breaking into half, etc.]. Other factors include crown density, branching structure, leaning, location of decay (e.g., in crotches), site exposure, storm severity, [and might I include inherant wood strength]. A lower threshold (20-25%) may be used for trees that are more predisposed.


Journal of Arboriculture 27(2): March 2001
Comparing Formulae that Assess Strength Loss Due to Decay in Trees by Brian Kane, Dennis Ryan, and David V. Bloniarz 

Gebiz Spiral Watch

Quotation No.: HDB000ETQ17000230 (Housing and Development Board)

QUOTATION FOR ISA CERTIFIED ARBORIST CONSULTANCY SERVICES AT DEMOLITION OF EXISTING PUBLIC HOUSING ESTATES (BATCH 9) AT BLOCKS 30 TO 32 & 34 TO 39, EXISTING SURFACE CARPARK CLAR6 AND ANCILLARY STRUCTURES AT DOVER ROAD

Company A - $29,990
Company B - $5,000 (Awarded)
Company C - $250,000
Company D - $5,000

Lowest bids are 83.3% lesser than second lowest bid.
Highest bid is 50 times (5000%) more than lowest bids.


Quotation No.: HDB000ETQ17000332 (Housing and Development Board)

QUOTATION FOR ISA CERTIFIED ARBORIST FOR CONSULTANCY SERVICES, SURVEYING & RECOMMENDATION FOR NPARKS SUBMISSION FOR THE PROPOSED PUBLIC HOUSING DEVELOPMENT AT CHOA CHU KANG N1C16

Company A - $4,200
Company B - $2,900
Company C - $1,500 (Awarded)

Lowest bid is 64% lesser than highest bid.


Quotation No.: JTC000ETQ17000074 (Jurong Town Corporation)

Provision of Certified Arborist for Tree Species Identification, Value and Risk Assessment Services

Company A - $28,000
Company B - $27.50
Company C - $12,000
Company D - $55,640,000
Company E - $35,000
Company F - $13,800 (Awarded)

 Quantity is 1000 nos... maybe the confusion over the quantity lead to some strange quotes here.
After adjustment, Company B's figure may be $27,500 and Company D's figure may be $55,640. Either way, Company F's figure was the second lowest of all, and was awarded the work. The lowest was Company C.

Resistograph or sometimes known as Resistance Drilling Device

On Jul 2013, two Tembusu trees were observed to be not doing well and to be clear, these tree are not in the Singapore Botanic Garden. The trees have low density of foliage, and the ground within the dripline was compacted, as evidenced by absence of groundcover. Target is the carpark and cars that were parked there, occasional park visitors.

Crown area and trunk of the two Tembusu trees.

On Sep 2013, vertical mulching was done to break up the hardpan surface and to pour in used coffee grinds (organic matter) and NPK 15-15-15 (fertiliser).

Making vertical holes.

Overall view of the vertical holes filled with organic matter and fertiliser.

On Oct 2013, the tree on the left was observed to be still low in leaf density but the tree on the right had put out more leaves.

On Jan 2014, the pruning was done by the arboriculture contractor to remove dead branches.

On the same day, I was inspecting the work of the arboriculture contractor and also found that there is a possible cavity below the union of the tree (the tree on the left).

The extent of decay below the union, if any, was needed to be determined in order to ascertain whether the tree is safe. The depression may just be a natural pocket formed by V-shaped point of union. Hence, a request was sent out for quotations from arborists with resistograph or Resistance Drilling Device. The scope of work was of course to have the resistograph work done, first level tree assessment before that, and reports for both. The works were to be carried out at ground level, and three arborists came up with fees of $1800, $1500 and $1100, respectively.

A "Resi" or Resistance Drilling Device that is used to detect cavities in wood, which is a sign of decay. The company that manufactures this particular device, IML, could not use Resistograph to describe its device in some jurisdictions as the term was trademarked by another company, Rinntech.

The resistograph work was done on Feb 2014 and should be done again in 2 years to see if there is spread of the decay, if any.

The Curious Incident of the Tembusu Tree that Fell

On 17 Jul 2017, two independent arborists testified at a Coroner’s Inquiry on the death of Radhika Angara, a mother of two who was killed when a Tembusu tree fell on her at Singapore Botanic Garden.

One of the expert witnesses, Derek Yap, an arborist with Camphora said that the tree had "no visible signs of crack and cavities", based on his inspection after the tree fell and information preceeding the incident. In addition, he said that "about 70 per cent of the tree trunk at its 2m point was decayed". That extent of decay would significantly reduce the structural condition of the tree but the decay could not be observed from the outside of the tree.

A news article was published yesterday with the headline of "NParks disputes arborists’ diagnosis on tembusu tree in fatal incident" (Today Online, 31 Aug 2017).

A National Parks Board (NParks) representative, deputy director Elango Velautham, testified on 30 Aug 2017 that a 1.5m long "cavity" found during an inspection done on Sep 2016 was actually a "flute" (see definition below) This statement raises three points to be noted:
1. The inspection done on Sep 2016 was by NParks officers.
2. One of the independent arborist said that the tree had "no visible signs of crack and cavities" in his testimony on 17 Jul 2017.
3. It was not known whether the misdiagnosis was discovered before or after the tree fell.

Definition of a "flute".

An example of "flutes" - the grooves between buttress roots below the feet of the arborist on the tree. Photo credit: Today Online

The news article suggested that Elango's testimony contrasted with that of the two independent arborists. But could it be that his testimony actually supported the two independent arborists'?

Elango said that NParks arborists have written a statement to note that the flute was "wrongly perceived as a cavity" as a follow-up to the Sep 2016 inspection report. But it was not known whether the misdiagnosis was discovered before or after the tree fell.

The lawyer acting for Angara's family had questioned "the absence of documentary proof showing how the misdiagnosis was determined", as the written statement was not produced in court on 31 Aug 2017. If signs of decay (cavity) was observed from visual tree assessments, both independent arborists "agreed that further tests such as resistograph and ultrasound could be used to detect decay".

Bonus Curious Point

Arborist Derek Yap agreed that the roots might have been cut and leading to possible decay but another arborist, Richard Gordon Thomas from ArborCulture, said it was not clear that root had been cut. However, another news article - "Tembusu tree accident: Botanic Gardens official says there was 'no decay, no cavity'" (Channel NewsAsia, 30 Aug 2017) - mentioned that both arborists "agreed that the tree’s roots were in decay".

Bonus Bonus Curious Points

That same news article mentioned above wrote that Elango described a flute to be a “protruding structure” on a tree’s trunk formed in response to “environmental exertions” to the tree. Could it be that the journalist who wrote that or Elango confuse a flute with buttress roots?

Elango added that a Temusu tree is "very slow growing", and decays would "take a very long time to … destabilise a tree". Does he mean to suggest that the spread of decay is in pace with the growth of wood? 

The structural stability of the tree would be impacted if the decay was extensive enough, in spite of the wood strength.

References
1. Tembusu tree that killed woman had no visible signs of decay, Today Online, 18 Jul 2017
2. NParks disputes arborists’ diagnosis on tembusu tree in fatal incident, Today Online, 31 Aug 2017
3. Tembusu tree accident: Botanic Gardens official says there was 'no decay, no cavity', Channel NewsAsia, 30 Aug 2017

A Giant from Thailand - Tamarind Tree Transplanted within Hortpark (2)

As a follow-up on this post: A Giant from Thailand - Tamarind Tree Transplanted within Hortpark, I attempt to examine (albeit using only one sample), whether the "one year to recover for every inch of trunk caliper" rule of thumb holds true for this transplanted Tamarindus indica (Tamarind) at HortPark.

This tree was transplanted to this location on Feb 2010, so by the time girth measurement was taken at the time of writing, it has been about 7.5 years. The girth taken on Feb 2010 was 1.5m, or DBH 0.48m or 18.78 inches. By the rule of thumb, it was estimated that it would take 19 years for the tree to recover from transplantation. However, the girth has increased since then to 1.65m, or DBH 0.525m or 20.67 inches. The increase in trunk caliper in these 7.5 years was 1.89 inches, hence possibly debunking the theory that it would take one year to recover from transplanting for every inch of trunk caliper.

 Bulge in union of codominant branches.

 Fungal fruiting bodies gone, but some fuzzies was still there, indicating that bark was moist.

Myth of Vitamin B-1 that Refuses to Go Away

During the transplanting process at Bangan, Myanmar, the landscape contractor proffered a couple of plant "supplements", which are suppose to help the palms recover better from transplanting. No doubt recommended by his favourite garden centre. I had advised not to use Ferti-Start, which may cause iron toxicity and okay-ed the Bl-Plus, as it contains amino acid.

 Ferti-Start (containing Vitamin B-1 and Chelated Iron)

B1 Plus Super Start (containing Vitamin B-1, Amino Acid and Monopoly Saccharide)

The following is by Linda Chalker-Scott, PhD, who is widely known for her debunking of horticultural myths.

Superthrive and similar claims about products that tout the value of vitamin B-1 and or synthetic auxins as "tonics" that have value when used on a regular basis.

Applying vitamin B-1, or thiamine, to root systems of whole plants does not stimulate root growth. This is a myth that refuses to die, though it has been repeatedly refuted in the scientific literature. To understand why, it helps to think about this in a historical perspective.

Many decades ago the plant growth regulators called auxins were isolated and characterized. Auxins were found to stimulate cell elongation in both root and shoot tissues. Commercial preparations were developed that contained auxin and vitamin B-1 among other ingredients. Research in 1949 found improved root development in plants treated with one of these preparations (Transplantone, which contains both auxin and thiamine), but noted the importance of auxins in this response. Further research throughout the last half of the 20th century investigating the application of auxins to root systems suggested that auxins may stimulate root growth, but that vitamin B-1 on its own does not.

Indole butyric acid (IBA) is one of the most common auxin formulations especially in tissue culture. In cuttings, it has been found to increase the number of roots, to increase rooting percentage, to increase both parameters, or to do neither. IBA has had some success in root regeneration in transplanted trees; it may help redirect resources to the roots by suppressing crown growth.

Naphthylacetic acid (NAA) is also a commonly used auxin and often the active ingredient in commercial preparations. NAA tends to be toxic to seedling root development, as it inhibits primary root growth and enhances lateral root growth. This latter activity may account for NAA’s success in regenerating roots of transplanted and root-pruned trees. Like IBA, NAA apparently suppresses crown growth, which also may redirect resources to the roots.

Vitamin B-1 (thiamine) is an important component of tissue culture media, in which isolated plant tissues can be propagated. Its use for stimulating root growth in whole plants is not supported in the literature and one study reported that root growth was greater in the control treatment (water) than with thiamine. Plants in the field manufacture their own source of thiamine and it is therefore unnecessary to add any additional levels. Many fungi and bacteria associated with plant roots also produce thiamine, so it’s likely that healthy soils will contain adequate levels of this vitamin without amendment.

The Bottom Line

• Vitamin B-1, aka thiamine, does not reduce transplant shock or stimulate new root growth on plants outside the laboratory.
• A nitrogen fertilizer is adequate for transplanting landscape plants; avoid use of “transplant fertilizers” that contain phosphate.
• Healthy plants will synthesize their own thiamine supply.
• Healthy soils contain beneficial microbes that synthesize thiamine as well.
• Difficult-to-transplant species may be aided by application of auxin-containing products in addition to nitrogen, but read the label and don’t add unnecessary and potentially harmful chemicals (this includes organics!).
• Adequate soil moisture is crucial for new root growth; be sure to irrigate new transplants frequently and use mulch to reduce evaporation".

Gebiz Spiral Watch

Quotation No.: HDB000ETQ17000211 (Housing and Development Board)

QUOTATION FOR ISA CERTIFIED ARBORIST CONSULTANCY SERVICES AT DEMOLITION OF HDB RESIDENTIAL BLOCKS AT 167 TO 172, MULTI-STOREY CARPARK AND ANCILLARY STRUCTURES AT BOON LAY DRIVE

Company A - $5,250
Company B - $14,515
Company C - $3,750 (Awarded)
Company D - $17,710

Lowest bid is 28% lesser than second lowest bid.
Second lowest bid is 64% lesser than the third lowest bid.
Lowest bid is 78% lesser than highest bid.


Quotation No.: HDB000ETQ17000109 (Housing and Development Board)

QUOTATION FOR ISA CERTIFIED ARBORIST FOR CONSULTANCY SERVICES AT DEMOLITION OF EXISTING PUBLIC HOUSING ESTATES (BATCH 10) AT BLOCKS 246, 247, 248 & 249 AND EXISTING CARPARK A18 AT ANG MO KIO AVENUE 2 & 3

Company A - $17,120
Company B - $6,900
Company C - $3,000 (Awarded)

Lowest bid is 56% lesser than the second lowest bid.


Quotation No.: HDB000ETQ15000677 (Housing and Development Board)

QUOTATION FOR ISA CERTIFIED ARBORIST CONSULTANCY SERVICES AT DEMOLITION OF HDB RESIDENTIAL BLOCKS AT 74 TO 80 COMMONWEALTH DRIVE

Company A - $15,000
Company B - $27,600
Company C - $5,678 (Awarded)

Lowest bid is 62% lesser than the second lowest bid.

Enhancing Post Transplant Success In Palms

At a resort development in Bagan, Myanmar.

Transplanting Borassus flabellifer (Sugar or Toddy Palm) from a farm to the resort for an instant landscape effect. The palms at the farm had their roots burlapped a month beforehand.

The palms would give the reception building in the background a "countryside" look.

Couriered over some rooting hormone (auxin), controlled release fertililser and measuring implements.

 Advised the landscape team there to use one litre bottles to measure out 20 litres or so in a large bucket.

Using my own rooting powder to gauge of the amount to scoop out on the field by the number of tablespoons.

Using a cup with a marking to give a gauge of the amount of fertiliser to be given to each palm on the field.

Workers had no troubles following the instructions.

Mixing some rooting hormone powder in a bucket of water.

Root Cuts

Urban environments often have trees planted in straight rows in order to make the space greener and smooth out its rough edges. And often, that landscape would have to grow by way of road widening, drain improvement, etc., and some trees would have to go. So what would go into the decision of which trees to be removed, and which could be retained?

Construction activities such as demolishing, building, excavation and heavy vehicles traversing the site would damage and cut roots, which diminishes tree health and/or structural stability.

When roots must be cut, they should be cut as far away from the trunk as possible to reduce impact to tree health. If the root space is permanently lost as a result of lowering the grade or construction of a structure, then the portion of root system cannot be replaced, and stress and stability issues may not be overcome.

Before any works, it is a good idea to locate roots by hand digging or excavation using compressed air tool. A new technology, ground-penetrating radar (GPR) can be used to detect roots as deep as 0.9 m and with a diameter as small as 1 cm. However, the size of roots cannot be determined, two roots close together cannot be distinguished, and the soil type is ideally in sandy soil. Resolution and depth of detection is reduced with soil with high water and clay content, which is the case in Singapore's soil.

In nature, root injuries are common and roots have evolved to have strong compartmentalisation. Just as flush-cutting branches is no longer an acceptable practice, pruning a root to its point of origin should not cut into the parent root. And preferably beyond sinker roots, and several smaller cuts instead of one large-diameter cut. Tools that are not sharp enough to cut roots such as excavators are used, they would result in torn and crushed. Such damaged roots should be pruned with a clean cut instead of being left as they are.

Trenching in a linear manner at a distance from the trunk that is less than three times the trunk diameter (or DBH x 0.5 x 5 from the center of trunk) can reduce stability. Adventitious roots may be formed by trees with root loss and are able to provide them with water and nutrients to maintain green foliage. However, those roots are too small to support the weight of the tree and may result in tree failure in wind conditions. Tree support systems and tree removal are possible remedies.

More research is needed to determine and recommended specific practices on the factors that affect decay development after root pruning: root diameter, distance from the trunk and presence of heartwood on the cut surface.

A Giant from Thailand - Tamarind Tree Transplanted within Hortpark

Tamarindus indica (Tamarind) somewhere in the middle of Hortpark, which was transplanted from the entrance of Hortpark.

Tamarind Road in Yishun is named after this tree. The fruit is known locally as "assam".

The area immediately around the trunk was sunken, as compared to the outer ring of the compost circle. This is possibly due to the root ball of the tree sinking, as it was transplanted when it was already a large tree.

Fungal fruiting bodies a.k.a. mushrooms observed at the root flare of the tree, presumably exacerbated by the compost that is piled around it.

Before being transplanted to the middle of Hortpark. Compare this root flare with the one above, the buttress roots were more apparent. Photo taken approximately 7 years ago (Feb 2010).

Somehow in the trenching process the rootball was raised, and the root flare was covered. Hence, resulting in the tree being planted at grade or lower than grade, even though it was thought to be planted higher than grade by using the top of the rootball as a guide.

 

Tamarindus indica (Tamarind) was located at the carpark entrance of Hortpark at Hyderabad Road. This tree was first brought in from Thailand. At the time when it was being transplanted to the middle of Hortpark, it had been there for 2 years (since 2008). Girth was 1.5m (DBH 0.48m or 18.78 inches) and height just under 10m.

The tree after its second transplanting.

Generally, this species has low chances of success when transplanted, which is in stark contrast to the other species in the same family (Leguminosae). It was being transplanted without trenching beforehand, and waiting a few weeks to encourage new fine roots*, and that would further lower transplant success. Trenching more than 10 weeks before moving the tree may reduce the advantage of root pruning, as regenerated roots will quickly grow outside of the rootball.

A rule of thumb was that transplanted trees would take one year to recover for every inch in diameter. Recovery was defined as being able to resume growth in girth, not just putting out new foliage. The tree would need, in "theory" (again, rule of thumb), almost 19 years to recover, based on a DBH of 18.78 inches. Hence, the tree would need 12 more years from today in order to increase in girth. That is, if it manages to overcome a possible basal decay as indicated by the fungal fruiting bodies.

*Fine roots refers to roots (0.05 - 2.0mm dia.) that are colonised by mycorrhizae, and both of them are responsible for the entry of water and nutrients into the plant from the soil.