ISA HK/China --- 2009 Research in 'Managing Trees in Construction' Part 1

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Dear Station Members,

Attached is the latest research from ISA on 'Managing Trees in Construction' which is an all relevant topic in our territory & has caused adequate friction between various factions of our society with Govt & Private Developers when it comes to Tree Preservation on site.

The article has clearly pointed out that not every tree is worth saving in a construction site & priorities must be given to preserve only those trees which can become an asset instead of a liability after the development. It has also pointed out that an experienced Arborist well versed in the science of Tree Preservation, should be appointed to be part of the team from the design stage onward all the way to development completion, to ensure the right trees are to be retained, protected & maintained properly throughout. We wonder how often this process is being observed in our development at present.

Trees appeared to be preserved out of sentimental value for many a times in our territory, & we have frequently seen over-mature trees topped like Lamp Posts for fitting onto lorry transport for relocation, usually without question being asked how they would perform in future after the transplantation. In line with current Tree Preservation Policies in HK, any plant with a DBH over 95mm at 1.3m above ground would be classified as a 'Tree' regardless of species, & therefore certain sized bananas, bamboos & palms have all been relocated in this rigid manner without much consideration to the value of retention, & sometimes relying on the contractor's skills to survive this species upon transplant. Many curses have been reported to ISA HK/China from our Contractor Staton Members for this practice.

The 'Compensatory Planting' in HK is also currently set at a 1 : 1 ratio without much regard to whether the size of the planting area upon completion could really hold up the 'Compensated' planting for healthy & sustainable growth. All these practices do not appear to be in line with international trends but appeared to be acceptable to our general public. Heavy funds have also been devoted maybe in vain in this manner to retain trees of questionable nature without public scepticism & in the name of Greenery Protection. It is known to ISA HK/China that China landscapers at present would not do the same in their Tree Retention Policies, nevermind our good neighbour Singapore.

If HK would discard the pigeon-hole housing environment for our residents from the 1970's to the healthy & comfortable density at present, would our Govt & Developers do the same for our tree planting? Or is it the more the better for our trees as a comparison to advanced nations, disrespecting the need for above-ground & underground development of a tree? Are our public funds justified to save common bananas, bamboos & palms, or trees with low survival rate with poor wind-resisting structure only for possible future removal or replacement in a storm? Are we really taking our tree planting seriously to compare with advanced nation, or even China?

It appears that we may have a lot of questions for ourselves in our process of Greenery Protection.

Meanwhile, enjoy the attached research.

best regards,

Sammy Au
Station Manager

"Trees are good for the community. Trees need care like human beings. Arborists are the Tree Care Professionals."