Friday, May 2, 2008

ISA HK/China --- Absence of Sammy Au in HK from May 9 - 15, 2008

Dear Station Members,

Please kindly note that the Station Manager Mr. Sammy Au will be absent in HK from May 9 - 15, 2008 inclusive to attend the ISA Asia Pacific Arboricultural Conference in Brisbane, Australia. If there is anything required of him during this period, please either e-mail him at , or try to call him at + 61 - 43 - 252 - 7206 if this number still works in Australia. Please note Brisbane is 2 hours ahead of HK if anyone calls.

Alternatively, you may wish to contact the Station Manager in HK away from the above-mentioned period for any enquiry.

Thank you for your kind attention.

best regards,

Sammy Au
Station Manager
ISA HK/China

Thursday, May 1, 2008

ISA HK/China --- CUGE research online

Dear Station Members,

It is the pleasure of ISA HK/China to inform you that we are now able to access online with CUGE of Singapore to share their research in greenery with their abundant resources. We are indeed grateful to our Singaporean counterparts for providing us this wonderful opportunity to learn about their development which is relevant & guiding for greenery in our territory.

Please kindly follow the link as described below to retrieve the information, & be thankful to CUGE while you are there.

best regards,

Sammy Au
Station Manager

----- Original Message -----
From: Angelia SIA
To: Undisclosed Recipients
Cc: Puay Yok TAN
Sent: Monday, April 28, 2008 5:25 PM
Subject: CUGE Research's Urban Greenery Bibliography Database Now Available Online

(Embedded image moved to file: pic22679.jpg)

Dear Partners,

Thank you for your support to CUGE Research. Since our formation on 1stApril 08, we have received enquiries from some of you. We have also metsome of you to discuss joint research possibilities.It is with pleasure we announce that resources like our newsletters, Xylem and INSIGHT and handbooks like "A Selection of Plants for Green Roofs inSingapore" are now available for downloading at this link, under

Besides publications, we have also implemented an Urban GreeneryBibliography Database, which consolidates some literature which we havecome across in the areas of Urban Landscape Management, Urban Ecology,Forms of Urban Greenery and Socio-Economics research.

We hope you will thisuseful.Thank you.

Best Regards,

Angelia Sia § Manager (CUGE Research)
§ National Parks Board § Tel: +6564717831 § Fax: +65 64723033Privileged/Confidential information may be contained in this message. Ifyou are not the intended recipient, you must not copy, distribute or use itfor any purpose, nor disclose its contents to any other person. Pleasenotify the sender immediately if you receive this in error.Check out our website at

Tuesday, April 29, 2008

ISA HK/China --- Reply to Lo Tung's enquiry on Tree Transplantation

*** Our weekly Station Mail is for the information of Station Members only, but Station Mail has given up copyright & can be freely circulated. For administrative reasons, comments from outsiders are usually not entertained & may be circulated within our system locally & overseas. Please note Station Mail is sometimes given in Blog at , although images are usually not attached due to size. ***

Dear Mr. Lo,

Thank you for your patience for us to draft a reply on your enquiry on Tree Transplantation. Please note that we are giving the reply on technical ground only, without bias nor sentiment, from our professional knowledge as Practising Arborist. ISA HK/China is a research & education organization & we do not become involved with politics. Hence our reply will follow only our guided principles of Integrity, Professionalism, Participation, Fact-finding & Truth-telling, as we always should.

In any recommendation for Tree Transplantation, an Arborist would first study into two major areas: Survival after transplantation & Practicality of the transplanting work.

For Survival consideration, we would review the health & structure of a tree to determine whether it would be worthwhile to carry out the transplant. The guiding principle would be that what good is it to transplant a tree if it would not survive the transplant, or it may pose as a potential hazard to the public after the transplant. An Arborist would have various skills & methods to determine such requirement & it would take several days of lectures to tell you all this, rather than in a simple e-mail reply.

For Practicality of the transplant, we would usually require to lift a rootball of a size of 10 x trunk diameter to conform to the international requirement in tree transplantation. Therefore, a 2 ft trunk diameter tree would require a rootball of 20 ft in diameter, & so on. On the other hand, you are correct in pointing out that most lorries in HK can not accommodate oversized rootballs. The average width of a HK lorry is usually around 8 ft only. This would mean an acceptable rootball to sit on any lorry would be around 8 ft in diameter, giving the maximum trunk size of a tree to be transplanted to be about 10 inches in diameter. For any tree larger than that, the rootball will have to be cut off, leading to future death or poor growth as seen after many tree transplantation in HK.

Taking the lorry width of 8 ft into consideration, this would also limit the canopy width of any tree to be carried. A tree of 10 inch rootball would usually carry a canopy of natural width well over 20 ft in diameter. This would mean the tree canopy would need to be chopped down to 8 ft in order to fit. Any tree chopped, or better be called 'topped' , would usually lead to future decay at wounds. Decay is a tree is not known internationally to be stopped by chemicals or by cultural treatment. This tree may eventually become a potential hazard to fail in the wind.

Above are the simplified answer to your enquiry from our professional knowledge. Arborists are Tree Doctors & Tree Detectives. We are the specialists in tree care. If you would need more information on this topic, we would recommend you to visit International Society of Arboriculture (ISA at, or to consult any Practising Arborist for a more detailed answer. ISA was set up in 1924, & is the largest & oldest tree care organization in the world. Arborists are also friendly Practitioners & we are always ready to help. You can also find out more about ISA HK/China at in our territory of HK, Macau, Taiwan & China.

Thank you for your enquiry & please do not hesitate to approach us for further questions.

Please kindly note that we are forwarding this message on our Station Mail system for the information & knowledge of our Station Members.

best regards,

Sammy Au
ISA HK/China Station Manager
Practising Arborist, Professional Nurseryman & Landscaper

The ISA Mission - Through research, technology, and education, promote the professional practice of arboriculture and foster a greater public awareness of the benefits of trees. (

----- Original Message -----
From: Lo Tung Lo
To: ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Cc: ; ; ; ;
Sent: Saturday, April 26, 2008 7:10 PM
Subject: 是保育樹木,還是浪費公帑?


這棵樣子奇怪的樹是攝於馬鞍山的一個政府樹木移植接收場,它是眾多受不同建築工程影響而被移植的樹木之一。政府每年耗費大量人力物力去保護受發展影響的樹木,跟據發展局技術指引ETWB TC No. 3/2006規定,負責工程項目的部門必須盡力保護工地上原有的樹木,所有樹木必須被紀錄並由有關的部門對其最終的處理方法(原地保留、移植或砍除)進行審批。政策方向完全正確及對環境負責,但實際運作如何?政府部門如何審批處理受工程影響的樹木?究竟圖中的這棵樹為甚麼這樣奇怪?

圖中的樹是細葉榕(Ficus microcarpa 一般稱為榕樹),未被移植之前是甚麼樣子我們無法肯定,但跟據榕樹正常的生長形態我們其中一個推斷是,原來的樹要比圖中的大得多。移植後主幹已失,剩下來的其實是一條氣根和一節「斷肢」,樹木原來的樣子簡單推斷如下:








跟據發展局技術指引ETWB TC No. 3/2006第17條,任何政府土地上的樹木皆不可以被無故砍伐。發展必須首先考慮原地保留樹木,情況不許可時應考慮移植(除非該樹木的保育價值為低、移植後的存活率低或移植後將無法復原至正常之樹形),最後才考慮砍除。技術指引還清楚表明有關的考慮必須平衡成本及效益。指引內容清晰且合情理,對自然保育越來越關注的市民大眾來說,既為保育把了關,同時亦確保公帑不被浪費。



從圖四中可見,被移植樹木的品種包括本港非常常見的品種,而最令人感詑異的,是當中竟有些是有極高自行散播能力的品種──即等同於野草──典型的例子有血桐(Macaranga tanarius)及台灣相思(Acacia confusa)。另一點必須注意的是,有些外來品種(如台灣相思)本來就是廉價而生長極快的品種(故常大量使用於植林),由幼苗(成本約為港幣10元)起計只要少於十年時間便能成大樹;因此,政府動輒花費上數百倍價錢去移植一棵這樣的樹種是否合理?














發信人:Lo Tung


審計署 署長 鄧國斌先生

康樂文化事務署 署長 周達明先生
康樂文化事務署 康樂事務經理(樹木及園景)香港 張裕生先生
康樂文化事務署 康樂事務經理(樹木及園景)九龍 梁永生先生

漁農自然保理署 署長
漁農自然保理署 高級自然護理主任(南)  何秉皓先生
漁農自然保理署 高級自然護理主任(北) 陳耀強先生
漁農自然保理署 高級自然護理主任(中區) 陳炳光先生

地政總署 署長 譚贛蘭女士
地政總署 地政總署副署長(一般事務)(地政處總部)  梁玉書先生
地政總署 總產業測量師(地政處/總部)  陳永堅先生

路政署 署長 韋志成先生
路政署 高級園境師3  張美馨女士
路政署 高級園境師1  梁錦鴻先生
路政署 高級園境師2  郭德泰先生

建築署 署長 余熾鏗先生
建築署 高級園境師/4 區李婷女士
建築署 高級園境師/2 黃秋雲女士
建築署 高級園境師/3 盧偉思先生


秘書: 馬海櫻女士
委員: 何鍾泰議員、 梁家傑議員
李華明議員、 周梁淑怡議員
涂謹申議員、 陳婉嫻議員
陳智思議員、 陳鑑林議員
單仲偕議員、 黃宜弘議員
曾鈺成議員、 楊孝華議員
劉江華議員、 劉皇發議員 c/o 委員會秘書、
劉健儀議員、 劉慧卿議員
蔡素玉議員、 鄭家富議員
霍震霆議員、 石禮謙議員
李國英議員、 林偉強議員 c/o 委員會秘書、
郭家麒議員、 張學明議員
劉秀成議員、 譚香文議員


長春社 蘇國賢先生
各園境顧問公司 c/o 香港園境師學會

The Standard

Monday, April 28, 2008

ISA HK/China --- ISAAC e-news (Speakers Preview of the 2008 Brisbane ISA Conference)

Dear Station Members,

Underneath is the latest ISA Australia Chapter (ISAAC) e-news given to our region. Inside is a special preview on the Speakers of the May 8 Brisbane ISA Conference at which ISA HK/China will send in a group of no less than 13 participants (8 tree climbers to compete or support at the ATCC, & another 5 persons reported of going to ISA HK/China. No news has been received of which of our Govt Depts is going, although some said they may attend ...).

All ISA Conferences by tradition are serious education & networking known in ISA history of 84 years. In them, the latest research & practices are discussed & information from different regions is exchanged. Arborists are practitioners & talking with fantasy will not please most of them. They want to see things working with objectives attained, & not just talk, talk & talk. This is the attitude that makes Arborists such a distinctive profession accepted in the greenery industry around the world.

The Brisbane Conference will focus on knowledge relevant to our region such as tree inspection, tree pathology, risk assessment & tree failures which our region is aiming to improve. ISA HK/China hopes to bring back updates to educate our professionals so that our trees can become assets to our community rather than liabilities. Further announcement on this may be given later on.

ISA HK/China looks forward to participate & learn hard at the Brisbane Conference in about one week's time.

best regards,

Sammy Au
Station Manager

----- Original Message -----

From: ISAAC E-news


Sent: Sunday, April 27, 2008 4:15 PM

Subject: ISAAC Enews #39 - ISA Asia Pacific Conference - SPEAKER PREVIEW

Visit the ISAAC Website - Now with live tree news from around Australia!If you're not a member of the ISAAC E-news mailing list, you can join it at It's free and you don't have to be a member of ISAAC.

****** ISA Asia Pacific Conference FILLING FAST ******

ISA Asia Pacific Conference - May 9-14, Brisbane, Australia. Interest is strong and more workshops and hotels are booked out. You will regret missing this once-in-a-lifetime opportunity to see this diverse range of speakers. See below for a sample of speaker biographies and abstracts.Register online at the ISAAC Online Shop to avoid disappointment, or go to the ISAAC Website for more details.

Ted Green:

Ted, a founder member of the Ancient Tree Forum, travels world wide to raise the profile of ancient trees.Ted grew up on the edge of Windsor Great Park, home to some of the finest ancient trees in Europe and many have been special to him from childhood. He is a consultant to the Crown Estates there.Ted has worked on plant pathology at London University. He is a regular writer and broadcaster and campaignstirelessly to make sure that we understand why these trees are special and to encourage anyone who will listen to take action on their behalf.Veteran Tree Management and Conservation or Growing downwards: what can we learn fromancient trees and the natural aging process‘An oak tree grows for 300 years, rests for 300 years and then spends the next 300 years gracefully expiring’. Hence the phrase ‘growing downwards’.Growing downwards was a concept developed by the Ancient Tree Forum, a group of Europe-wide specialists andexperts made up of primarily professional arborists, foresters, historians and conservationists. They are concerned about the continued loss of Europe’s old trees.Studying the way old trees age has provided so many insights into how trees grow naturally to maturity, rest andthen decline. This has led to some methods of management preventing collapse such as retrenchment pruningespecially in the management of 1000s of old pollard trees that remain in the UK and other limited parts of Europe.The essential role of decay fungi in the hollowing process has led to the phrase: ‘the co-evolutionary relationshipbetween trees and fungi’. Words such as disease and fungal attack are now disappearing from the arborist’svocabulary.Recognising the fundamental role of other groups of fungi in tree health and longevity, has led to the management and retention of dead standing and fallen trees and they are now much more common in the landscape.

Ken James :

Ken James is an engineer at the University of Melbourne, Australia and has been investigating tree biomechanics and dynamic wind forces on trees for ten years. He currently is conducting research into tree dynamics and has developed new instruments that can measure the wind loads on trees during storms. He has presented papers at the many international conferences including ISA Conferences in America, Tree biomechanics Conference, Savannah, 2001, European Arboricultural Conferences in Maastricht and Oslo, Australia and New Zealand. He has published several papers on tree biomechanics and is currently developing a dynamic structural model to describe tree movement and loads in high winds. Other research interests include structural loads in tree cables and measurement of internal growth stresses in living trees.Tree BiomechanicsThe mechanical properties of trees is being studied to assess the structural strength and stability under a range of conditions. Understanding the structural properties of trees is fundamental to understanding how trees adapt and survive in their environment. Two methods are used, i.e. statics and dynamics. Static tree pull tests apply forces with ropes to simulate wind loading. Dynamic wind measurements are giving us a different understanding of how trees withstand high winds.Tree dynamics and WindHow trees withstand wind forces is being studied using new instruments that monitor the tree under wind stormconditions. Dynamic analysis is providing information on the forces that impact a tree. This information is being used to assess the stability of trees. Recent wind storms in Melbourne are discussed with some case studies that report on wind loading and the assessment of strength.

Dr David Lonsdale:

Dr David Lonsdale is a consultant, author and educator, specialising in the biology, pathology and mechanicalintegrity of trees. After studying at the universities of Southampton and Manchester, he worked for the BritishForestry Commission for 26 years before going freelance in 2002. His research has involved tree diseases and decay, including the role of latent stress dependent fungi. His many publications include “Principles of Tree Hazard Assessment and Management” (1999). He received the Annual Award of the Arboricultural Association in 1999 and an award for Advancement of Knowledge of Arboriculture from the ISA (UK & Ireland Chapter) in 2001.Tree-related hazards: recognition and assessmentA tendency to fall or to shed parts is the main cause for concern about tree-related hazards from trees. Otherhazards, which will not be mentioned further here, relate to obstruction, poisoning, damage to structures caused by tree growth and subsidence or heave of the ground, related to water uptake by tree roots.Everyone with a responsibility for tree safety should be able to recognise signs that may indicate a potential formechanical failure. Someone with specialist skills and knowledge should, if necessary, inspect such signs in moredetail and assess their significance. Options for conducting general and detailed inspections will be discussed here, with reference to the main signs of potential hazard; these can be summarised as follows:Structural ‘defects’ • Bark inclusions (especially at branch unions)• Cracking/splitting of various kinds• Branch subsidence• Crossing and abrading branchesPotential sites of decay initiation• Wounds from pruning or branch failure• Dysfunctional wood in the centre of the root plates of old trees• Bark wounds, above or below ground• Dead branchesSigns of possible weakness due to decay• Cavities• Dead branches• Exposed, decayed wood• Fruiting of decay fungi (often indicating no more than a need for investigation!)There is much interest in devices for aiding the internal mapping of decay, but these should used only by those with a good understanding of the spatial patterns of decay development, both above and below ground. They should in particular be able to interpret the significance of different types of wounds (e.g. wounds that involve only bark loss or wounds that expose sapwood and/or heartwood or ripewood). They should also understand the tendency for coalescence to occur between decay columns arising from a number of wounds.Structurally weak attachments weakened further by decay• Signs of decay at or near included bark unions• Coppice re-growth on decaying stumps• New growth from positions of previous topping or pollardingSite related information• Soil type and hydrology and hence rooting depth (for the tree species concerned)• Cohesion of soil• Topography (especially regarding steep slopes)Past failure of the tree or of similar trees nearby• Signs of past failure that can be observed during inspection• Types of failure that have been documented (or anecdotally noted by local residents).

Dr Elizabeth Philip:

Dr Elizabeth Philip is currently a Senior Research Officer with the Forest Research Institute Malaysia (FRIM). During her 17 years tenure here, she has spearheaded about eight research and development projects dealing with arboriculture and forestry issues. Amongst the issues addressed in arboriculture are growth and development of urban trees, abiotic factors affecting tree growth and urban trees in mitigating changing weather and climatic change.She is a certified arborist by the ISA. In improving the arboricutural practices in Malaysia, she has developed aprotocol for monitoring tree vitality and detection tree heath decline.Dr Philip has published more than 25 papers in referred journals and presented more than 100 working papers. In addition, she sits in a number of technical committees as well.Environmental Influence on the Growth and Development of TreesE.Philip and Y.Noor AzlinForest Research Institute Malaysia (FRIM), 52 109 Kepong, Selangor, MalaysiaMan’s fast paced development has brought about secondary problems like increased pollution, degradation of theenvironment and affected human well-being. The call for combating further environmental degradation has been discussed in many international fora and resulted in Conventions like Biological Diversity and United NationFramework on Climate Change Convention and others. The call for more public parks, green space and conservation of biological resources is getting greater attention in light with the changing climatic scenarios.This paper will highlight the different environmental influence on tree growth. The influence of water stress,temporary flooding, and soil compaction on the growth of urban trees will be discussed. In addition, environmental services provided by urban trees in Malaysia would be also be discussed. Amongst the services provided are natural biological air filters to air pollution and therapeutic. In addition, they acts filter to reduce the heat-island effects in urban areas. Besides, it is a good platform for inter-cultural activities while preserving each identity. Man has very strong linkages with nature and is reflected in the daily activities of our forefathers. Cities and towns have been named after plants.Remember to forward this to other tree care professionals that may find this useful.

ISAAC's Internet policy prohibits spam so please only distribute ISAAC E-news to those with a genuine interest.

ISAAC MembershipMembership of ISAAC links you to the professional world of practicing arborists and tree managers in Australia. As a member you get discounted entry to ISAAC events, discounts on books and business insurance, as well as the locally produced newsletter 'The Bark'. Full ISA Members also get the ISA's publications 'Journal of Arboriculture' and 'Arborist News'. Membership supports the continued growth in professionalism of arboriculture in Australia. Now is the time to join. If you already are a member, now is the time to recruit someone else.

You can download a membership form right now -"join online.

If you're looking for great information to pass on to your clients, check out the ISA's new website, Trees Are Good, dedicated to providing tree care information for the general public

Do you have a question or comment? You can send your query online at our If you would like to subscribe or unsubscribe, please see the instructions on our website

Contents of this newsletter are provided for information only and the International Society of Arboriculture, Australia Chapter takes no responsibility for loss or damage resulting from its use. ISA, ISAAC and associated logos are for use by members of the ISA and ISAAC only. (c) 2008 International Society of Arboriculture Australia Chapter Ltd. ABN 77 090 873 644.
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