ISA HK/China --- HK Tree News (Wanchai and Repulse Bay Tree Failure)

 

Dear Station Members,

 

Attached & below are two recent counts of local Tree Failure worthy for discussion in our Station:

 

 

This incident appeared on the local media may be because the fallen branches damaged a temple where prominent citizens are visiting. Other than that, there did not appear to be any significant value in this Tree Failure case when compared to many other Tree Failures on slope all over HK.

 

What has raised the eyebrow of this Station in this incident would be that this tree was said to be inspected by somebody just 3 months ago before the incident. As trees are developing creatures & they change shape & condition in reaction to the environment, it is very difficult to draw a line to say whether this tree must fail in a certain time. Tree Assessment is always an educational prediction in ISA knowledge so far & ISA HK/China would always recommend a Tree Assessor to possess the basic knwoledge listed in our previous Station Mail (http://isahkchina.blogspot.com/2009/04/isa-hkchina-tree-assessment.html), & not just someone waving credentials. Many Arborists around the world have tried to quantify Tree Assessment but owing to the many factors which can affect the calculation & modeling, not one single method has been adopted by ISA so far to be a universal method for standardization, including the use of Detection Tools for Decay determination (http://isahkchina.blogspot.com/2009/04/isa-hkchina-2009-isa-research-on-tools.html).

 

The Station Manger recently became involved with a similar case of Tree Failure somewhere in Kowloon leading to a law suit for property damages. He has issued a +20 page Expert Witness Report on the incident to comment on responsibilities & liabilities of the opposite side. This just shows that there is always a legal risk involved in carrying out any Tree Assessment if the damages can not be settled between the two parties, & Arborist is frequently the tool to provide independent opinion on the incident.

 

Let's hope it would not be the case for this one.

 

 

This appeared to be a typical case of the client wanting a 'flowering' tree to be grown in his/her compound & expected the tree roots to grow to the centre of the Earth to hold the tree against wind.

 

It can be seen from the photos given that there were hardly any roots adequate for anchorage, yet the tree had developed a full crown above to attract wind. Then when adequate wind pressure exerted on the crown, the tree body simply toppled over like a domino card.

 

In Arboriculture, we always say it is 'Mother Nature makes the Rules, not anybody' for Tree Planting. A tree may be planted there for 'flowering, scent or Instant Effect', but it will be Mother Nature to determine whether this tree is going to last, & would fail it when conditions are met.

 

Would the public be willing to listen to the Arborists gradually?