ISA HK/China --- Review of Prof. Mattheck's 'Tree Bio-Mechanics' series

*** 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 http://isahkchina.blogspot.com/ , although images are usually not attached due to size. ***

Dear Station Members,

It has been an enormous task for this Station to research into the lecture materials, websites & literature of this equally giant Tree Specialist of Professor Claus Mattheck of Germany. We have spent months actually. Profile of Prof Mattheck is given in the attachment for general information.

Despite some may think Prof Mattheck would behave eccentrically especially in his delivery of lectures (He enjoyed shouting 'Ha !!' to wake up the class), this Station has found his teaching is primarily based on years of observation on the behaviour of trees under various conditions with a lot of experimental work. In his books & lectures, Prof Mattheck has given hundreds of photos showing tree defects & responses under wind loading & this evidence serves to back up his claims. In a way, Prof Mattheck was speaking with details of his research, & its up to the audience to reply otherwise.

The 3 books & website besides the lectures notes of Prof Mattheck that this Station has reviewed are:

1. Stupsi Explains the Tree 3rd edition --- 115 pages (1999)

2. Updated Field Guide for Visual Tree Assessment (VTA) --- 170 pages (2007)

3. The Face of Failure in Nature & Engineering --- 208 pages (2004)

4. http://www.mattheck.de/

Whereas the first two books written in children's language can still be understood in most parts by an experienced Arborist, the 3rd book would definitely require knowledge of Physics & Engineering to apprehend all the equations & mathematics. The written language has been extraordinary in the sense that it was translated from German into English with a heavy European ascent. If anyone in our territory finds Dr. Shigo's Tree Biology with American colloquial English would be difficult enough to read, Prof Mattheck's literature might be even harder. To this Station, reading Dr. Shigo's work was like an uphill battle in every page, whereas for Prof Mattheck's would be for every sentence. There were times that this Station had to go back to Physics & Engineering textbooks to try to figure out the meaning of certain Tree Bio-mechanics terms so described. Arborist without such knowledge may be completely lost in a whirl.

If this Station is asked to compare Dr. Shigo's education with Prof Mattheck's, this Station would reply that Dr.Shigo's work was more on the microscopic side of arboriculture, whereas Prof Mattheck would focus on the macroscopic side. Dr. Shigo would dissect & go deep into the tissue response of a tree after wounding, & Prof Mattheck would focus on the Reaction Wood Development of a tree in wind. This Station felt the work of these two giants complimented each other, & each has filled in the void by the other.

The European attitude of Prof Mattheck in sustaining Mature Trees by constant Crown Reduction to minimize wind loading, would tend to counteract the American attitude of pruning only dead tissues to encourage healthy growth. The two philosophy seems to go in a completely opposite direction, & can anyone say keeping a shortened Mature Tree a crime against humanity while its life can be extended? It may really depend upon how one would take the preference. On the other hand, Prof Mattheck has stood up in Court many times to provide Expert Witness in law cases with his mechanical theories on Tree Failures, & his observation of the development of Fungal Growth in assessing failure time can be educational in our territory. Some of his ideas were completely brand new to many of us indeed.

This Station generally felt that Prof Mattheck's teaching was to incorporate Physics & Engineering into explaining how trees stand & fall. This Station would agree with the proposition of Prof Mattheck in that everything does eventually fail, be it material or organism. It's just that it should not fail prematurely in its designed life, be dead or alive. The ability to predict failure may rest on the knowledge of Failure Mechanics . Since Failure Mechanics are largely studied on objects rather than on living organisms, it may be appropriate that such engineering theories can be borrowed to begin the study on organisms as a start. For living trees, this would mean to combine Tree Biology & Tree Structure for predicting Tree Failures. Prof Mattheck's knowledge seemed to have supplemented the structural side of Tree Physiology in many ways.

Prof Mattheck's education on Tree Mechanics began with forces, vectors, moments, stresses, strains & then progressed to Failure Mechanics, & would even go as far as Mohr-Coulomb's Law of Soil Mechanics. Some may have gone far beyond the domains of our local landscapers & designers. Some would actually take an Engineer to understand what is going on. Yet to carry out Tree Risk Assessment & Tree Failure Analysis to any advanced extent, the knowledge of Bio-mechanics seems inevitable, especially if Expert Witness is to be provided in Court. However, this Station would be bewildered to ask our landscapers & designers to learn Engineering from ground zero to carry out such kind of work, unless we would like to imitate what Singapore has already gone ahead.

There were 5 of our Station Members including the Station Manager attended the 3 day Workshop on Tree Mechanics by Prof Mattheck in August 2007 in Singapore. Pretty much we were all lost during his seminars, because we did not study his information in advance & perhaps thought it could be easily apprehended. We were wrong. Now as this Station has returned to diagnosis this great man's teaching, the knowledge did not seem coming out from nowhere but rather from years of observation & hundreds of experimental research. It is our Station's principles to be fact-finding & truth-telling to be an Arborist in our territory, & Prof Mattheck's information appeared to go along with our belief.

This Station has so far reviewed in our limited capacity of the work of two Arboricultural giants Dr. Alex Shigo on Tree Biology & Prof Claus Mattheck on Tree Mechanics, one being expert on the microscopic side & the other on the macroscopic. Both are necessary to complete our knowledge on Risk Assessment & Failure Analysis. Both are necessary to serve our community with so many Mature Trees nowadays.

Prof Mattheck has expressed the last time he was in Singapore that the Tree Mechanics Workshop there may be his last to tour Asia due to the distance & efforts. May we hope he can change his mind some time in future if we can gather enough money to invite this giant to come over to our territory to share his expertise with us.

May Prof Mattheck live long, healthy & keep shouting 'Ha!!' to us in his lectures.

best regards,

Sammy Au
Station Manager

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. (http://www.isa-arbor.com/)

ISA HK/China --- HK Tree News (Pruning public trees)

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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

It is all familiar that our public frequently complained about the so-called 'incorrect pruning' in our territory. When the attached newspaper cuttings were sent in, this Station decided to respond with an Arborist's viewpoint on events described as such.

In the first set of news, two Bauhinas were pruned for safety reason after branch breakage in strong wind in Ap Lei Chau. Someone wrote in to accuse ' wanton chopping' by a Govt Dept to disturb the greenery development in our city. The second news suggested planting trees in Tsim Sha Tsui created more liability than asset due to Tree Selection.

Before saying anything as such, an Arborist would need to look into the evidence presented for analysis. First, we would need to study the Design & Tree Selection in both cases as a beginning. In the Ap Lei Chau case, the trees selected were Bauhinias which are known not to develop a good Central Leader naturally, but would rather give crooked bends along the stem to branch out in unpredictable manner, which would pose a nightmare for anyone trying to structurally prune. If the Nursery Stocks were not initially selected to have good Central Leader, 60% Live Crown Ratio, Strong Branch Attachment, Balanced Canopy & Taper before installation, even the best pruning operator in the world would have a hard time to correct them back to good Structure & Health afterwards. Poor Nursery Stocks are a bad start & correction will take time & efforts. In reality, some trees may never be able to be pruned back to requirement at all.

Next, we shall need to understand who were doing the pruning? It was said to be the contractor. While it may be easy to teach a contractor to prune at the correct angle from Branch Bark Ridge to Branch Collar in a branch, it would be much harder to teach them what parts to remove & how much to remove. Pruning will lead to responsive growth in a tree. Incorrect pruning will lead to incorrect future growth. To be expert in pruning, the operator will need to understand Tree Biology for tissue response, & also Tree Biomechanics for wind stability. Would it not be too much to ask for a contractor to understand in such details of what they were asked to do? After all, they were only a contractor. It should really be the responsibility of an experienced Arborist to design & supervise the work, & to instruct the contractor on where & how much to cut, & for what objectives.

If an experienced Arborist is to be brought in to design & supervise the pruning, cost will be involved. According to the current Professional Fees Guidelines for CA to provide this kind of supervision for a day, the cost will be HK$6,000.00 each time. Can the tree owner provide this cost? Even if such cost can be provided to employ the right person to carry out the Structural Pruning, there may not be that many qualified Arborists available in our territory to perform the required work at present, because it is rather difficult to teach Crown Thinning, Crown Reduction & Crown Restoration in a classroom. For tall trees, Tree Climbing may also be required to get up inside the canopy to select the branches. Bucket Truck can not penetrate inside tree canopy safely but rather stay on the outside, & usually can not get on top to perform Crown Reduction. Then how many of our CA in HK can climb at present to do this kind of work?

The case in Tsim Sha Tsui followed similar principle of apparently selecting fast growing & wide spreading species without adequate room for future growth, which then led to continuous trimming back to reduce size. This appears to be a classic case of 'tree liability' upon improper Tree Selection in our territory.

The problems with our urban trees appear to be historical. The public also seem to have a lack of understanding of trees. To blame on the maintenance party alone would be like asking Cinderella to dance with an oversized shoe. Would that be fair? On the other hand, if it is the design & tree selection which are causing the problem, there is usually not much that the maintenance party can do to correct it afterwards. Sometimes, a complete renovation may be the only solution. Then the public may outcry for ' tree murder'. Isn't it easy to throw out criticism, but what about finding a workable solution?

Tree Pruning can be compared to human surgery on a person in many ways. No sane person would like his/her body to be operated upon by a meat butcher. Then why should thing happened to our trees ?? Time may be required to train our Arborists to perform quality pruning (with Tree Biology, Tree Biomechanics & perhaps Tree Climbing on real trees), & the road ahead will be long & winding. Maybe an immediate solution is to employ experienced Arborist to design & supervise pruning for certain categories of trees (OVT's, Mature Trees over a certain height/girth, Rare & Endangered Species, Champion Species, etc), & then train up the interested Arborists soonest (Join TCHK?). There appears to be no quick fix on it right away.

Has anybody any better solution?

best regards,

Sammy Au
Station Manager

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. (www.isa-arbor.com)

ISA HK/China --- Inauguration of ' Tree Climbing HK '

攀爬一族 報名申請表 2007年11月8日版本
1 中文姓名： 2 英文姓名：
3 出生日期： 日 月 年 4 最高學歷：
5 工作機構：
6 職位：
7 電郵或傳真：
8 手提電話： 9 辦公室電話：
10 攀樹經驗： 年 / 全無經驗
11 已考獲的樹藝專業資格：
12 身体有否缺陷？
13 閣下有否任何其他補充？
14 填表日期：

免責條款：任何人仕在參與「攀爬一族」及ISA HK/China Station 所舉辦的任何活動之時，均已自我檢查其身心狀況是已經完全符合當次活動的實際要求，才會加入是項活動，並對此條件絶無異議。參于者亦完全同意自負所有活動風險，不會追究舉辦者任何民事或賠償責任。所有參加本族或ISA HK/China Station 活動的人仕均完全明白及同意此「免責條款」後，才自願參加任何活動。
本人同意上述「免責條款」，自願加入「攀爬一族」。本人現將上述表格傳送至 ISA HK/China Station 或 攀爬一族 的egc@netvigator.com 電郵地址，並同意一經傳送，是完全代表本人同意上述「免責條款」，和現行或日後新増的族規族例。

（以下供本族內部記錄使用）
1 是否批准此項申請：
2 不批准此項申請的理由：
2 族號：
3 族類：
3 其他：

ISA HK/China --- Inauguration of ' Tree Climbing HK '

「攀爬一族」的族規族例 2007年11月8日版本

1. 本族有權拒絕任何人仕加入，而無須給與解釋或理由。

2. 為維持本族和諧團結，族長有權無須給予通知或解釋理由，將任何族員驅逐出族，所有族員對此不得異議。

3. 為了本族日後的可持續發展，日後本族可能會因應情況，在得到長老會議的批准後，對族員收取年費，及對舉辦的活動籌募經費，此等費用一經徵收，不會予以退回。

4. 所有族員必須堅持 ISA HK/China Station 所訂下的道德守則，包括誠信、專業、參與社會，找尋事實及道出真相等標準，違反者可能被導致驅逐出族。

5. 所有族員在參加本族活動之時，必須完全遵守導師指示，以免發生危險，違者可能會被馬上終止參與資格及被驅逐出族。

6. 為保持族員的參與本族的熱誠，以下規定各族類人員每年必須參與本族活動的最低次數：
a. 族長、副族長及長老族員：5次
b. 精英族及康體族：3次
c. 修行族：1次

7. 如當族族員未能達到上述第6項的出席次數，可能會被降格至下一族群或被驅逐出族。

8. 周年族員大會(AGM)是本族的最高權力架構，每兩年（暫定）會選出各族群人員(族長除外)。族長只由當屆ISA HK/China Station Manager 担任，無須經選舉產生。

9. 所有族群人員必須堅守自己崗位，族長有權在於任可時間改動族員架構，而無須通過周年大會進行。此舉只是必要時才會採用的緊急措施，以便本族不會發生部落衝突或權力鬥爭。

10. 日後本族可經長老會議商討論後，增添其他族規族例，與本版本同具效力。

ISA HK/China --- Inauguration of ' Tree Climbing HK '

<攀爬一族> 的基本結構 2007年11月8日版本
Basic Structure of Tree Climbing HK ( TCHK )
Chieftain
族長 ( ISA HK/China Station Manager 兼任 )




Chief(s) Tribal Council
副族長 (由選舉產生，人數未定) 長老會議 ( 由長老族員維持 )


Councillors
長老族

Professionals
精英族

Recreationals
康體族

Disciples
修行族

族長 (Chieftain) --- 無投票權，但有最後決定權，只能在零票或相等票才能投票，由當屆ISA HK/China Station Manager擔任。

副族長 (Chief) --- 有投票權，有實權，管理日常事務，必須是ISA考牌官，每2年由族員大會選出 ，任期2年。

長老會議 (Tribal Council) --- 由當屆長老族主持，決定所有會務，任期2年，由每2年的族員大會確定任期。

長老族 (Councillors) --- 成員必須是 CTW 或持有其他國家認可的攀爬修業証書，成員由族長或長老會議過半數長老族員同意後邀請進入，任期2年，由每2年的族員大會確定任期。

精英族 (Professionals) --- 懂職業攀爬，但未考獲上述牌照者，任期不限。

康體族 (Recreationals) --- 只懂康體攀爬者，任期不限。

修行族 (Diciples) --- 所有其他人仕，任期不限。


攀爬一族 — 的其他資料：


宗旨：不論年齡、性別、宗教、種族、學歷 、身體狀況及社會地位，謀其共同發展攀樹活動，由攀爬過程中學習保護樹木及維護生態平衡，從而促進個人身心健康發展。

活動：主要分為康樂攀爬，職業攀爬及相關樹藝知識訓練。

A. 康體攀爬 – 旨在為都市人減壓，發展其體力心智，歡迎任何人仕參加。

B. 職業攀爬 – 磨練樹上工作的各種技巧，例如鋸木、流纜、拯救、鏈鋸使用等等。安全訓練為主要重點，在於“ 預防勝於治 ”成員主為職業攀爬人仕，亦歡迎康體族員加入受訓。

C. 樹藝訓練 – 任何樹木知識和相關護養技術，歡迎任何人仕加入。

裝備： TCHK 歡迎族員自携攀樹器材以作自用。TCHK 亦可提供網上選購方便，本族亦可現場借出族員裝備以供試用，直至本族成功合資購買器材為止。

裝備要求：必須為國際認可的合規格爬樹腰帶、繩索、安全扣、和各類合格器材等等…

免責條款：任何人仕在參與「攀爬一族」及ISA HK/China Station 所舉辦的任何活動之時，均已自我檢查其身心狀況是已經完全符合當次活動的實際要求，才會加入是項活動，並對此條件絶無異議。參于者亦完全同意自負所有活動風險，不會追究舉辦者任何民事或賠償責任。所有參加本族或ISA HK/China Station 活動的人仕均完全明白及同意此「免責條款」後，才自願參加任何活動。

ISA HK/China --- Inauguration of ' Tree Climbing HK '

Dear Station Members & Respected Guests,

Inauguration of TREE CLIMBING HK (TCHK)

Today is another milestone in the development of ISA HK/China Station.

After hard work & careful planning by many, it is the utmost pleasure of ISA HK/China Station to announce that the Tree Climbing HK (TCHK) will be set up as an extension of our Station from today onwards !!

TCHK devotes mainly to Tree Climbing & anything relating to manoeuvring in a tree, be it Recreational & Professional. TCHK will focus on the action part of arboriculture. Yes, it will be on rope & on tree. TCHK will encourage participants to touch trees to love trees, & to enjoy the benefits of trees by physical contact. It will be an experience for those who sit in office all day to come out on a tree to dangle on rope. The climbing will be rehabilitating & refreshing. TCHK is promised to be fun-filled, action packed & very educational.

A major feature of TCHK is that it will communicate in Chinese to fit our public requirement, although English is used in time when necessary. TCHK will follow the Station Mail system of having its own channel to broadcast weekly messages, & it will reply enquiries in Chinese. This is intended to bring TCHK to our public at large & everybody is encouraged to join, be they office personnel to tree care professionals. Just everyone is welcomed.

There is no cost to join TCHK at present & TCHK Membership will be kept alone by the Chieftain who is the Station Manager by appointment. TCHK Membership will not be disclosed publicly just like Station Membership. Our Station Code of Honour of Integrity, Professionalism & Participation with an attitude of fact-finding & truth-telling will equally apply in TCHK. Please refer to the attachments for more information of TCHK which are in Chinese. Please also note TCHK has started up with a firmer structure than our Station which is more knowledge based. Tree Climbing can be dangerous & rules/regulations must be set up for beginners to follow. They are all for good intention because without them, accident may occur.

TCHK welcomes anybody to join !! TCHK has no distinction in colour or creed, education or wealth. Anyone interested in Tree Climbing & touching trees are welcomed to come in. Tree Lovers are particularly welcomed because this is their chance to talk to their favourite trees.

Please take a moment to study through the attached information of TCHK. Do enquire at 9090 6719 or by e-mail if anyone has any queries & TCHK is always there to help. Employers are kindly requested to pass this information to their Chinese staff for their individual consideration. All Station Members are requested to pass this message to their friends & colleagues for their interest to participate. This message will also be placed on Station Blog.

TCHK looks forward to your participation to climb, protect & preserve our precious trees in our territory, one tree at a time.

Climb safely. Touch trees to love trees.

best regards,

Sammy Au
Station Manager & TCHK Chieftain

致：全世界喜愛攀樹的同志們

熱烈慶祝ISA HK/CHINA STATION 「攀爬一族」的成立

同志們，ISA HK/China Station 籌備已久的「攀爬一族」，現在正式宣告成立！

「攀爬一族」是本會參與社會事務的一部份，是個比本會腦部戰爭更加精彩的一個部份，是喜愛攀樹活動人員不可缺少的一個部份。

攀樹活動是一項有益身心的寧神健體活動，自從其在國外數十年前開展以來，現在全球已有數十萬人參與過各式各樣的康樂攀爬。在參與過程中，當中不乏專業或職業攀爬隊伍，其目的只有一個，就是要愛護樹木及親近樹木。

當今都市人用腦太多，四肢缺少運動，在室內參加運動時又重回「家徒四壁」的感覺，精神緊張未得完全解放，試想起童年時候的攀樹採果，本是返璞歸真的開朗行為，須然當今都市生活已埋葬了此一切。

「攀爬一族」是希望令有興趣人士能夠重拾童真，亦希望透過攀樹活動，令市民更加親近及愛護樹木，是一種以行動來表示保育樹木的行為。

在我們熟悉的城市香港，其實有着不少的爬樹能手，政府部門當中，康文署及漁護署早已有自己的樹木工作隊伍，每天在樹木上工作，至於中華電力公司及嘉道理農場，亦各自有一組爬樹高手，護理其機構內的樹木。

當今現代的爬樹方法，是利用合符國際認可規格的腰帶及攀爬繩扣等工具進行，既有效率、靈活而且又安全。

香港的攀樹隊伍，早在多年前引入西方先進國家的技術及工具，所以現時香港的爬樹技術已有相當高的水平，可惜郤只局限在政府部門及少數私人機構內使用，未能普及推廣。
「攀爬一族」有見及此，自告奮勇成立由志願人士組成的專業及康樂攀爬隊伍，亦憑本會在國際及地區網絡的關係，希望能夠打造出一批符合國際水平的攀樹人員。

「攀爬一族」的主要訓練目標有兩個，一是職業攀爬，二是康樂攀爬。

職業攀爬的主要對象是現職樹木保養行業的人仕及有志投入該行業的人仕，攀爬一族將會定期舉辦訓練課程，並希望每年設定考試，令到本港甚至國內的樹木工作從業員，能夠考獲專業資格，從而提升樹木行業達至國際水平。

康樂攀爬的對象是社會上不同性別，不同年齡及不同階層的人仕，讓他們都有機會學習攀爬，接觸樹木，從而能共享健康及豐盛人生。

「攀爬一族」是一個不設界限，不分種族膚色，不論宗教信仰，不重身體狀況和社會地位的團體，歡迎任何人士參加。參加者只須填回附上的表格電郵至本族指定電郵即可，目前費用全免，直至另行通知為止。

此致

攀爬一族 全体成員敬啟
2007年11月8日
電郵：egc@netvigator.com

ISA HK/China --- Square Rootballs at ETF

*** 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 http://isahkchina.blogspot.com/ , although images are usually not attached due to size. ***

Dear Station Members,

This Station takes on the mission to constantly research on new arbor skills with our limited facilities at disposal. ETF is such a facility for trialling out various techniques & the results are forwarded on Station Mail form time to time for public viewing. The provision of Square Rootballs is now one of them.

Traditional rootballs are round in shape. This is described in many literature as Balled & Burlaped (B & B) trees grown & dug in field. B & B trees are nearly the standard practice for supplying landscaping trees in our territory due to low cost & a tendency of not having Girdling Roots if used fresh & not stored, in favour of Containerized Trees which frequently have developed Girdling Roots. Internationally, the recommended rootball size is about 10 x trunk diameter according to ISA education & also BS 4043, although this practice is not much observed in some of our landscape work especially in transplanting mature trees.

The idea of Square Rootballs at ETF is copied from some western tree nurseries who have been using it for some time silently maybe for commercial reasons. Square Rootballs have the following advantages as compared to traditional round rootballs:

1. More Roots --- For any given diameter, a square will have a bigger area & volume (at the same depth) than a circle, & will therefore contain more roots & soil volume to endure 'Transplant Shock'. More roots retained will favour recovery & enhance growth after transplant.

2. Transport Safety --- A cubic rootball will not roll as easily as a circular rootball in transport. Rolling can damage rootball & lead to foliage chafing & branch breaking in the canopy.

3. Preventing Girdling Roots --- Trees dug with Square Rootball can be stored up to a certain time without the development of Girdling Roots, because the new roots emerged will hit the flat sidewall & be generally deflected at 90 degree in any direction. Traditional round container will guide the roots to turn in circle to form Girdling Roots, which can strangle the tree later by constricting central vessels.

4. Storage Ease --- Square Rootball can generally stand upright on its own unlike conventional round rootball which curves from top down on the side. The side boards in a Square Rootball will perform as a square container for vertical standing.

ETF has sold trees with Square Rootballs to Govt Depts in HK & to customers in China. No adverse comments have been received so far. On the other hand, ETF will be pleased to hear any response with regard to this latest practice for improvement anytime.

HK now is pushing ahead with innovation in arbor development spear-headed by our Station with knowledge gained internationally through ISA contacts. It is this kind of trial & error that the tree care practice in our territory can advance to new height. Quality Nursery Stocks are always the first step to ensure a successful landscape besides a good design. Trees not selected & planted properly are likely to become future liability rather than asset.

This Station would welcome comments on the results of using Square Rootballs against round rootballs for open discussion anytime. Just send in your observation. Thank you.

best regards,

Sammy Au

Station Manager

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. (http://www.isa-arbor.com/)

ISA HK/China --- Sylva Cell introduction

Dear Station Members,

Some of you may be involved in urban design in which finding enough rooting space to grow trees may be a major problem. In situation where heavy traffic by vehicles & pedestrians are major concern, tree planting has to give way to other structures such as pavement & road as priority. This Station has given information on Structural Cells for tree growing in the past but its application can be complex in both tendering & execution.

This Station has recently been advised by Enspec of Australia that they are now introducing a modular structural planting cell called Silva Cell at the following link:

http://deeproot.com/template.php?sec=products&nav=silva&content=sc_app&sub=1&lsel=1

This novelty product is made from polymers & is strong but light enough for tree planting in our urban situation. The link given has excellent description plus video to show the design & specification of the product for which anyone is recommended to look into. It appears that Silva Cell has answered some of our existing challenges in tree installation in our crowded city, although its use has to be experimented with pilot project. If feasible, & if prices can be justified, Silva Cell can be an alternative to planting trees in concrete box planters which may be the current substitution in many of our city areas.

Anyone interested to find out more on Silva Cell is requested to contact the supplier direct for additional information & trial. This Station will be grateful if anyone has tried it out to send us a review for Station broadcast in future.

best regards,

Sammy Au
Station Manager

ISA HK/China --- HK Tree News (Shing Mun River's 'Tree Murder'?'

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Mr. X,

Thank you for your phone call & your direction for us to look into the attached newspaper cutting. We have noticed that you are not our Station Member but are able to gain access to our information for which you are welcomed. We are also accepting your challenge to openly reply your enquiry & to protect your identity which we actually do not know much anyway. On the other hand, we want to assure you that there is no such thing as 'change of wind' of our Station policies upon your knowledge of LCSD staff taking part in our recent Certified Arborist exam. Our values of Integrity, Professionalism & Participation with an attitude of fact-finding & truth-telling have remained constant.

In your request for us to comment on the event of your so-called ' Tree Murder ' at Shing Mun River, our Station is taking up the position of Tree Detective instead of Tree Doctor in the investigation. However, please kindly note that we are commenting with only the given facts & photos in the attachment & we do not have time to study the situation on site. Sending someone out on site for a detailed reporting will involve cost, & the current Professional Fess Guidelines of ISA HK/China would recommend a fee of HK$10,000.00 for an Independent Tree Assessment (ITA) report of this kind for about two trees in a day. Therefore, here you get a limited reply for free, but only with what this Station has seen in the attachment.

May we first advise you that the Station Manager has done ITA report of this kind on many occasions for various Govt Depts & public in the past. He is also currently acting as an Independent Tree Specialist (ITS) to the HKSAR Govt on several projects & he has produced Expert Witness reports at High Court for tree related disputes. He may be a fair & just person for this kind of reply to you.

In the newspaper cutting so shown, the Besser blocks would impede the flow of water & fertilizer application into the tree roots, but they would not stop them altogether. Water can leak through the gaps between the Besser blocks & reach the roots underneath, or the trees so shown would not be growing with such foliage density. One way to determine whether the roots are developing or not under the Besser blocks is to open them up for a visual inspection. You may wish to apply for permission to do this at the authorities if desperately interested. Facts will convince everybody better.

Trees generally do not require heavy fertilization like shrubs or smaller plants. The Arborist education would recommend an annual application of around 2kg/100 sqm for most trees in a general situation. For trees of inadequate health, we would recommend fixing the problem before fertilizer application, rather than the other way round. This may be contrary to what you may have learned from other sources in the past. Facts will tell you that trees growing in our AFCD country parks do not receive much regular fertilization from human application. Don't these trees perform?

What this Station would see as a challenge would really be that the trees so shown were planted too close to the boundary wall of other planting area which may lead to root cutting on the wall side. This may render wind instability when the trees have matured & there does not appear too much can be done to it. Remember, if a tree is not designed, planted & maintained properly, the tree may become more of a liability rather than an asset. In this theme, the design & quality stocks selection are of primary importance if we want to see an easy maintenance afterwards.

We wish our reply now can assist you to understand how a Professional Arborist would view an event as such. Arborists are practitioners & we tend to look at situation in a practical sense. Please do not mix us up with other disciplines with our due respect to others. However, we have our own professional direction to follow & we prefer to speak with facts.

You are always welcomed to provide feedback, although this Station may not publish it by open Station Mail each time. If you would like to go into this investigation further, this Station would advise you to employ a Certified Arborist to carry out an Independent Tree Assessment with the approval of the concerned authority, although the site work & reporting would cost you.

Thank you for your interest in our communication & we hope this reply will find you well.

best regards,

Sammy Au
Station Manager
ISA HK/China Station ManagerISA Chief Proctor for the HK/China RegionISA Certified Arborist / Certified Tree Climber no. ML-0174AT
Member of Tree Climbers International (TCI) in HK/China RegionInternational Tree Failure Database (ITFD) Coordinator for HK/China
Independent Tree Specialist (ITS) to the HKSAR Govt
Lecturer for Tree Supervision at CITA

ISA HK/China --- Introduction to Wood Decay Fungi (WDF)

*** 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 http://isahkchina.blogspot.com/ , although images are usually not attached due to size. ***

Dear Station Members,

An important part of Arborist's work in practising is Tree Inspection & Risk Assessment. This kind of specialist work would require all training of the Arborist & would demand all skills & knowledge of the practitioner. Not every Certified Arborist (CA) would like to take up the work of Tree Inspection & Risk Assessment due to personal competence & the legal liability involved. CA is held to a higher Duty of Care in Court & putting down the CA no. on an Arborist Report is a legal commitment. Identifying decay in tree is an important part in this kind of work.

Decay in tree is mostly caused by the micro-organisms called Fungi. There are hundreds of thousands kinds of fungi already discovered in the biological world & luckily only a handful would cause decay in living trees, whereas the others would decay dead trees (Saprophytes). In carrying out Tree Inspection in HK/China, Fungal Decay is a common occurrence in a lot of our mature trees.

This Station has taken some time to study & research into the vast topic of Fungal Decay in Trees already. Mycology is the name of the game & it is a huge & complex subject indeed. There are lots of textbooks & websites with good description in Mycology, but most would go beyond the need of an Arborist. Arborist would only need to know primarily the Wood Decay Fungi (WDF) for the work rather than antibiotic fungi, yeasts & parasitic fungi which are not of great relevance to our practice. Therefore in here, we focus on what we want & leave the rest to other experts.

Decay in living trees appeared to be mainly caused by two groups of fungi : the Basidiomycetes (BM) & Ascomycetes (AM). BM is the largest & most common of the WDF, & they are frequently known as Conks & Mushrooms. About 500 of the BM group are responsible for decaying living trees. The AM group is smaller in quantity & only a few significant species have been found to rot living tissues. Both BM & AM are capable to rot dead tissues (Saprophytes) which will lengthen their survival period in a natural environment. By doing so, they have become a threat to living trees & they would inflict wounds caused by natural processes such as sudden temperature change, or through artificial processes such as incorrect pruning.

There appears to be 3 common types of wood decay in living trees:

1. White Rot --- This is said to be the most common type of wood decay & the WDF responsible will first degrade the Lignin & then digest away the cellulose, leaving behind a white or bleached appearance in the decayed wood. White Rot is said to cause less wood strength loss then other rots in the initial stages of decay & Zone Lines would usually appear in the advanced stages of decay.

2. Brown Rot --- Brown Rot is said to be less common than White Rot & is usually found more frequently on conifers than hardwood. However, Brown Rot would decay away cellulose & would leave behind modified lignin, thus giving a brown appearance in the rotted wood. Brown Rot would bring about a significant strength loss even in the initial stage of attack & the wood would become brittle which may fracture easily under tension.

3. Soft Rot --- Soft Rot is primarily caused by AM fungi & the wood attacked would lose significant strength similar to Brown Rot. The Soft Rot & Brown Rot can sometimes be difficult to distinguish by visual means. Microscopic investigation may be necessary to carry out the taxonomy.

Decay in living trees is usually named after the position of occurrence, e.g. root rot, butt rot, sap rot, heart rot, trunk rot, etc. Healthy trees can carry out compartmentalization once the entry of WDF is detected. However, if the tree is in poor health or under stress, the WDF will advance with repeated attacks on the boundaries, sometimes with the help of other pathogens, to spread radially & longitudinally until the cambium is killed. Then the WDF will carry on their living cycles on the dead wood & seek opportunities to attack other living wood. Removal of dead wood alone does not seem to minimize infection, since the spores of the WDF are usually air-borne. Proper cultural practice appears to be more effective in controlling WDF in reality.

Among the hundreds of WDF active in our environment, the 3 most significant culprits in damaging living trees appear to be:

1. Armillaria spp --- Commonly known as Shoe-String root rot or Honey Mushroom. This group of WDF is actually edible, if you can clearly identify them (Warning: Most mushrooms are toxic especially the colourful ones. Do NOT just eat without proper identification.). Armillaria ranks among no. 1 as common in decaying root & lower part of a tree. It attacks & degrades the root system, weakening the infected tree to fall in wind. The fungal threads of Armillaria are said to be bio-luminescent. They tend to glow in darkness, giving them a name of ' foxfire' in wilderness.

2. Ganoderma lucidum --- This is the Wooden Ear that is sold in Chinese medicine shop. This WDF is easy to identify by its varnished mahogany appearance in its annual fruiting body. Nevertheless, this is the no. 2 in common to infect living trees. It occurs near the base of the tree & attack roots. It can kill cambium of roots & decline a tree to create potential failure. However, some experts reckoned the presence of the fruiting bodies alone would not usually be the only reason to suggest removal & other symptoms such as cracks, leaning, etc. would need to accompany the fungal attack. Different experts say different things all the time & the Arborist would need to rely on his/her own experience to judge the situation.

3. Ganoderma applanatum --- This WDF is also known as the Artist's Conk due to its saucer like fruiting body on base of trunk of living trees. It can also be found on dead trees & stumps as Saprophyte. This fungus is no. 3 in common as a WDF for urban trees & its presence would justify immediate removal as a sign of advanced decay. Ganoderma applanatum is a perennial fungus which can live up to 5 years or more, different from the above two WDF which are annual.

Basic understanding of WDF is essential for Tree Inspection, Risk Assessment & especially Tree Failure Analysis. WDF exist in our environment as part of ecology & we can not get rid of them unless we live in a desert. It may also be unwise to eradicate WDF or we shall have fewer agents to clean up our fallen organic matters. It may be really to promote the health & defense of a living tree to withstand WDF as wiser, rather than to constantly spray chemicals to rid them when detected. The emergence of WDF in a living tree is usually secondary to the primary cause of abiotic stresses which are likely to be caused by human intervention most of the time.

WDF should be studied together with Dr. Shigo's Tree Biology for a complete picture of Tree Pathology. Tree Pathology is necessary for Diagnosis & Treatment in writing up certain Arborist Report. Once again, it can be seen that building Arborist knowledge is like knitting a net. The different parts link together & missing knowledge would be like making a broken net ...

This Station works hard to develop Arborist knowledge for our Station Members in our territory all the time. This Station also appears to be the only entity in our territory providing such knowledge locally. Knowledge is what we need if we want to improve our Tree Care practice. This Station has to work hard.

More useful research will appear later when this Station has run over them one by one ...

best regards,

Sammy Au
Station Manager

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. (http://www.isa-arbor.com/)

ISA HK/China --- China Tree News (Expensive Flowering Trees & How to produce trees with Girdling Roots)

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

Attached are two recent Tree News from China:

1. Expensive ' Flowering' Mature Trees on high demand

As said before, China is an Old Dragon & the Old Dragon has its own standard of beauty.

It was said that the topped Lagerstroemia of approx 200 mm trunk diameter & 3.5 m tall grown in an 14 inch pot as shown in the attached picture, could fetch between 10,000 to 100,000 RMB in the China market. It was also reported that these topped trees were in high demand & customers flocked in to check stocks everyday.

What would be the hypothesis behind for the popularity of these apparently damaged trees grown in tiny pots among the China customers, which would be regarded as wastes in Western markets? The only probable explanation might be that they have a few flowers dangling in the canopy. Lagerstroemias are great survivors & can be grown from cuttings. Trees of these sizes after topping could survive, but were likely to develop cankers & cavities everywhere in the tree body. Growing them in tiny pots would also lead to the development of Girdling Roots.

Research has shown that while the canopy develops to an extensive mass above ground & the roots are girdling (circling) below ground, the tree could lose stability in the wind, or the vascular tissues at root collar could be strangled by the Girdling Roots to restrict flow of water & nutrients. When tree falls, it may pose hazard to people & property down below. Words will not prevent a tree from falling.

If these topped trees were planted in city parks or even in a backyard, they may never develop good structure & health. There is no way to stop the decay except by compartmentalization to take over. Yet compartmentalization in Mature Trees is usually very very slow.

So, these 'expensive' trees were sold for a lot of money in China. HK may be smarter than that, do we?

2. How to produce trees with Girdling Roots

Our brothers & sisters up north have apparently adopted this ' Double Containers' production system from pot plant production (maybe also Plug technology in Greenhouse) in the West. They would probably think that producing trees & disposable pot plants in horticulture would belong to the same category.

In the tree production so shown, Girdling roots are likely to develop in just a few months after containerization. When roots have reached the side of the container, they have nowhere to go but to circle around the container wall to become ' root bound ' to form Girdling Roots. Research has shown that once Girdling Roots have developed, they will have a tendency to stay that way even when severed in future. There seems to be no satisfactory method to completely eliminate Girdling Roots so far in tree production, once they have formed.

In pot plant production, shrubs or annuals are produced ' root bound' for maximum root absorption of water & nutrients, & to minimize transplant shock. Shrubs & annuals are smaller plants grown for scent & colour. Their falling hazard is low & their damaging strength is usually insignificant. Has anyone heard a person got killed or a car became crushed by a falling Azalea or Camellia?

However, when it comes to massive structure like trees & palms, the falling hazard is an entirely different story. Trees are something that would develop a big crown even with Girdling Roots. Top heavy trees with a restricted root system can be a great danger in wind. It would be like an office chair with spreading legs of just a few inches long. Would this chair remain standing if sat upon ? Then why should we use trees with Girdling Roots?

It is apparent that trees with Girdling Roots should not be used in landscape, because they can kill or damage when they grow big. Liability in using trees with Girdling Roots can easily be proved in Court since the exposed root system would give the evidence. The tree owner or relevant parties may be held liable for Negligence.

Horticulture & Arboriculture may belong to the same category for our brothers & sisters up north. Let's wish them good luck to their people, their properties & their trees.

Next time in a storm in China, would anyone like to stand under those trees with Girdling Roots, even if you have nowhere else to stand ....??

best regards,

Sammy Au
Station Manager

ISA HK/China --- Review of Dr. Shigo's Tree Biology series

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

Arboriculture is an advancing profession & becoming a Certified Arborist (CA) is only the beginning of serious learning. Countless knowledge of arboriculture is confronting CA & modern Tree Biology is one very important subject for any CA to master. CA without good knowledge of Tree Biology is like a doctor not knowing well the human body. Can this CA go very far?

When it comes to modern Tree Biology, any CA would give respect to the name of Dr. Alex Shigo. It seems to be this giant who woke up the world on looking at trees with a totally new concept & Dr. Shigo practically has revolutionized Tree Pathology upon his research. His influence on arboriculture is profound & inviting. Without his research, maybe many Arborists would still carry on the old way of Flush Pruning, Wound Dressing & Topping the trees.

Dr. Alex Shigo, respected by many Arborists as the 'Founder of Modern Arboriculture', has published hundreds of research paper & several books on Tree Biology, Tree Pathology & Tree Anatomy. Most of them are not available in our part of the world for unknown reason. In order to discover his knowledge, this Station has spent some months to study through his published education as follows:

1. A New Tree Biology with Dictionary --- 636 pages for the book + 144 pages for the dictionary

2. Tree Pruning --- 192 pages

3. Modern Arboriculture --- 440 pages

4. Tree Anatomy --- 104 pages

5. Dr. Shigo's website (http://home.ccil.org/~treeman/shigo/index.html) & research papers

It is impossible to give a detailed account of the information contained above in a simple Station Mail. Our Station Members are encouraged to purchase Dr. Shigo's books & to browse through his website to understand the very useful information contained within.

The Station Manager has studied for years on Horticulture & Landscape Design to facilitate his work in nursery production & landscaping. But when he came to study Dr. Shigo's series, they turned out to be another world of knowledge that he had never seen or heard before. Dr. Shigo's Tree Biology is a unique vision of its own & appears to be rather different to conventional teaching. In fact, some of his research would be regarded as a challenge to conventional wisdom in the biology domains.

Dr. Shigo was the Chief Scientist of the US Forest Service from 1959 to 1985 to study the Discolorization & Decay in Forest Trees. In his work, he had found repeated patterns of tree responses deviated from conventional knowledge of wounding & pathogen development. He discovered that trees belong to a Generating System & are great Compartmentalizers to fight decay. He had carried out many research to prove his thinking.

Dr. Shigo challenged the wisdom of conventional Tree Biology in studying under microscope for dead cross sections of tree parts instead of longitudinal dissections of living trees which would give accounts on boundaries of defence & compartmentalization in fighting pathogen invasion. Dr. Shigo has taken the pain to dissect over 15,000 trees with chainsaws to study living & dead trees for his analysis. It may appear to be difficult to repeat Dr. Shigo's work today by dissecting so many trees anywhere in the world. We seem to be running out of trees nowadays.

Dr. Shigo looked at a tree as part of an ecological system & would incorporate tree with the organisms living on or around it together with the environment interacting with it. Whereas conventional Tree Biology would tend to focus on tree parts & the physiological functions of each part, Dr. Shigo would combine all the living parts into a system & call it Symplast. He studied the energy transfer of Symplast in performing its daily functions such as growth, maintenance, storage & defense, & viewed the tree as an energy pump where energy reserves are moved & converted in accordance with the requirement of the tree to respond to the outside environment. He had looked at tree from an angle where hardly anybody had done the same before.

Most CA in HK would probably know Dr. Shigo through the theory of Compartmentalization of Decay in Trees (CODIT) which is a tested subject in the exam. CODIT has become perhaps a distinction between the study of arboriculture with horticulture in major when it comes to Tree Biology. However, CODIT is really a simplified model & Dr. Shigo's literature would go into details of Reaction Zone & Barrier Zone in microscopic anatomy. Chemistry would come into play & anti-microbial compounds at cell level would be discussed. The knowledge would go far beyond the CA exam requirement.

Another point in Dr. Shigo's research suggested that CODIT are strongly affected by genetics. He tested Flush Cuts (forbidden by ISA education mostly) on trees of strong CODIT & found decay development well contained in some trees. On trees of same species & same size in the same lot, other trees would perform poorly, suggesting that trees are like animals with grading & fitness. The higher grade would be the winner of survival & the lower grade would perish by natural selection. His comment on our current forestry practice of harvesting only higher grade timer would leave behind community of poor grade to survive, which may lead to the downgrading of performance of our forest in future. By this theory, Dr. Shigo criticized our current nursery practice of ensuring high percentage success in seed germination & seedling production, to bring trees of poor genetic into our urban environment which would lead to maintenance aggravation.

In reviewing Dr. Shigo's literature, this Station has found Dr. Shigo's education is not easy to read or understand at all. For us here in HK who are used to British education, Dr. Shigo' writing in colloquial North American world be almost uphill battle in every page. For those whose English is not international enough may find it almost impossible to apprehend Dr. Shigo's literature. Also, Dr. Shigo's education is really meant for the understanding of researchers & practitioners. Anyone without sound background in Biology may find it hard to even proceed. Our AFCD Station Members are recommended to study Dr. Shigo's series because they may be relevant to their work especially in Tree Pathology, although the information can also be applied to Urban Trees which tend to be planted as individuals rather than in groups in a much more hostile environment.

If Dr. Shigo's work is so difficult to understand, some may ask then why bother ?

It is because Dr. Shigo's research is required for Arborist service such as Tree Selection, Tree Installation, Tree Inspection, Risk Assessment, Pruning, Diagnosis & Treatment, Tree Protection during Construction, Cabling & Bracing, & writing up Legal Consultation. In the important field of Tree Assessment, Arborists would need to understand how cracks are formed, how decay would advance, whether mushrooms would topple a tree immediately or later, how rapid is wound closure, how cavities may affect wind stability, how topping could be corrected, how to inspect Cabling & Bracing wound, etc.& etc. Many information in the series can be used for writing up Arborist Report & used as Court reference in Legal Consultation. Arborists need to be fact-finding & truth-telling, & we can not comment with our personal opinion without facts & research. Dr. Shigo's work would provide this support.

Dr. Shigo emphasized on ' Trees must be touched to be understood.' For those who do not touch trees & try to understand his work, it would be as tasty as chewing leather shoes. Dr. Shigo also said ' Education starts when you doubt something. Education occurs when you resolve your doubts.' When the CODIT model was brought up in 1985, there was skepticism all around the world. Conventional biologists felt challenged & would not accept Dr. Shigo's finding. Many biologists in Asia today still have not come to acknowledge Dr. Shigo's research & carry on the old thinking. Treating trees to a lot of scholars are still to be like treating humans or animals. Trees do not appear to be well understood by our public from viewing comments in the media. We have a long way to go indeed.

This Station would recommend the able & serious to try to study through the research of Dr. Shigo to improve themselves. Some of his books can be obtained on ISA website while some of his research can be downloaded from the internet.

The Station Manager would be pleased to offer any help, no matter how limited or ignorant, on any problem that anybody might encounter on understanding Dr. Shigo's education series. Please do enquire when needed.

best regards,

Sammy Au
Station Manager

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. (www.isa-arbor.com)

ISA HK/China --- HK Tree News (Greening Open Drainage Channels)

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

Below is a recent set of news regarding greening Open Drainage Channels (ODC) in the old sectors of our city to rid foul smell & provide landscape area for improving the quality of life of nearby residents:

http://hk.news.yahoo.com/071013/60/2hibf.html

In contemplating about the whole idea, this Station has reservation on just covering the ODC with concrete deck & then try to 'green' the deck, because:

1. There may be more hard surface created which will absorb heat from the sun, than before the construction.

2. If there is going to be extra soft work on deck to cover the created hard surfaces, the soil weight will require a thicker deck at higher cost, & the soft work will lead to heavy maintenance especially from vandalism in the older part of our city. Tree planting would generally require around 0.6 - 1m thick of soil for healthy growth & wind stability for the future mature trees. If planting only dwarf trees, shrubs & groundcovers, the landscape may appear insignificant & immature to show the world, & to justify all the expenses incurred.

3. The temperature of the deck will be the same as ambient temperature. The roots of all plants will be hot in summer & cold in winter. The Buffer Zone of ground temperature can not be provided for anything growing on a concrete deck. This applies to roof planting as well.

Above are just some major points of concern in the greening matter, besides the consideration for storm water collection & sediment removal inside the covered channel.

A possible solution to derive the objective of eradicating smell with landscape provision under low cost, might be the installation of Flood Gate at the estuary of the ODC to convert the ODC into a flowing river implemented with ornamental fishes. At times of low flow, Flood Gate can be raised to increase water level. The slow flowing water can be stirred by circulation pumps & oxygen pumps for sustaining water life so that smell can be reduced to minimum. This is how fish farm is operated in many parts of the world. Water plants can also be installed to add colours & to sustain water creatures. A balanced ecological system will be created in place. Landscape can then be installed on both sides of the converted ODC, with trees, to form a natural setting. In times of storm, Flood Gate can be opened to direct water exit, although some fishes may be lost...

The Station Manager has seen this idea in action in Osaka years ago & illegal angling was happening along the converted channel because it was so attractive. The same idea is also being used everywhere in Holland for navigation & irrigation, although it is to keep water out from the ocean, instead of getting it out from land.

Flood Gate is an option besides decking the ODC which is expensive, time consuming & rather disturbing to the public during construction. Besides, decking may not be as environmentally friendly & may become another Heat Island if not carefully designed with landscape. On the other hand, using Flood Gate would depend upon other factors including pollution control into ODC & also flow rate. Stagnant polluted water will be hard to purify by biological means. Further studies by more parties will be needed to justify its use. Once which system is decided, the landscape can compliment it as it should.

We wonder which system will be chosen at the end & based on what ground ... ?

best regards,

Sammy Au
Station Manager

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. (www.isa-arbor.com)

ISA HK/China --- Review of LAO PN 7/2007 Tree Preservation in Private Develpment

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

This Station has recently received a copy of the latest Lands Administration Office (LAO) Practice Note (PN) no. 7/2007 on the latest policy in Tree Preservation in Private Projects, & has taken a quick review of its contents for the interest of our Station Members.

This Station has found the PN 7/2007 is perhaps the best & most updated among all PN's so far issued with regard to Tree Preservation for Private Projects in our territory. It is written in administrative English meant for the understanding of professionals. Lesser laymen may find it hard to fully appreciate the contents & the intention. This PN can be downloaded at http://sc.info.gov.hk/gb/www.landsd.gov.hk/en/legco/lpn.htm but patience may be required to await speed which may appear rather slow at times.

Measures are taken very seriously & clearly in this latest PN for Tree Preservation not previously adopted for Private Projects. This PN has laid out procedures & methods to go about the planning & execution with regard to tree affairs on private development down to efficiency not detected in previous PN before. This PN appears to be written with deep consultation with Arboricultural Professionals in its many international practice recommended, which has made this PN an advancement in saving our precious trees in private development indeed.

There are major points deserving the attention of our Station Members in this PN:

a. Self-Certification of Compliance (SCC) --- Instead of requiring an official inspection by Lands Dept (LandsD) for the Certificate of Compliance (CC) on the Compensatory Planting upon the completion of the private project, this PN gives suggestion that the lot owner can now appoint a Registered Landscape Architect (RLA) to submit a SCC to certify that the Tree Works have been implemented in accordance with the approved application. On the other hand, LandsD reserves the right to randomly inspect the SCC & may challenge the opposite if found. This will save valuable time & administration for both the lot owner & the Govt, but place a heavier liability on the RLA for the inspection.

b. Competent Person (CP) Status --- In para 15 of the PN & in para 2b of the Appendix II, the position of a Competent Person is brought in to be recognized alongside the RLA for works such as Tree Survey, Tree Works Supervision & Tree Assessment. The definition of CP is that of any person who possesses a professional or vocational qualification in horticulture, arboriculture &/or tree care, & he/she also has minimum 1 year of closely related post-qualification local experience. This Station interprets that any experienced Certified Arborist (CA) with good knowledge & social standing will be qualified to enter this rank of CP to carry out the required work, although the final decision rests upon the Govt. CA appears to indirectly obtain an official status in our Govt system this time.

c. Requirement of Proper Arboricultural Practice --- In Appendix II 'Guidance Notes on Preparing Submission to LandsD' for Tree Survey Plans, Tree assessment & Other Advisory Notes for Good Practice in Tree Care, etc., international arbor practice is quoted for recommendation to determine Tree Retention, Tree Transplantation, Tree Planting & Pruning. Furthermore, Transit Nursery is no longer required, Topping is prohibited, & Pruning Guidelines are given to imitate international practice. This is an excellent improvement indeed ! Yes, this PN is going to adopt international practice & ISA begins with an 'I'. If experienced CA's are not qualified to work to such requirements, please kindly tell us who then...

This good PN has indirectly brought in the service of Arborists for design & supervision in Tree Survey, Tree Assessment, Tree Transplantation & Tree Pruning, which are all specialist training of experienced CA. We very much feel the status of CA in HK is gradually receiving recognition by our Govt & public day by day. This rapid development in our local arboriculture is unprecedented in the landscape history in HK & this Station is truly grateful for the wisdom of our Govt. On the other hand, this Station will continue to supervise our Arborists to serve well our community as a duty, & to upgrade the quality of living of our loving city with better trees.

In order not to have our younger CA's getting it over their heads with the current good news, this Station wishes to emphasize that the CA credential is really regarded internationally as a threshold to push open the gate of Professional Arboriculture. The road ahead is long & winding, & the CA must not stop at just collecting the credential. Many practical skills in Pruning, Tree Climbing, Tree Inspection, Risk Assessment, Diagnosis & Treatment, Legal Consultation & many others, are not tested in the CA credential at present. Upon the application of skills on site for any arbor service, all knowledge will be required & CA is liable to a higher Duty of Care in Court. Getting the CA is really a start & not an end. CA must be forever learning & this Station will try its best to provide.

For our younger CA's, it is also important to note that CA & CTW in ISA HK/China Station are required to comply with the principles of Integrity, Professionalism & Participation with an attitude of fact-finding & truth-telling. By maintaining these values, the CA profession will be respected in our community for a long time.

In the realistic situation in HK for landscape project submission, it may be true that the RLA firms would be stronger in documentation & drawing (including AutoCAD) provision, whereas the practising CA's tend more to be more working individuals well versed in site work. The two professions should really come to support each other in both paper & practical work to match the requirements of this latest PN for the benefit of the clients. Both should be winners & competition should not exist. This has been proven in the work of the Station Manager in past for Govt & Private Projects alongside with major landscape consultancy firms for difficult tree matters. With an open attitude of cooperation & mutual objective, no obstacle is too strong to overcome.

This Station will urge our Station Members to positively study the contents of this very useful PN if you are working in the relevant field. You may also wish to contact the Govt Depts for further explanation with regard to any enquiry in the contents of this PN.

best regards,

Sammy Au
Station Manager

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. (www.isa-arbor.com)

ISA HK/China --- Oct 7 Concurrent Training Sessions at ETF

Dear Station Members,

This Station wishes to thank the participants of the Oct 7 Trip to ETF for making the gathering such a hugh success. Despite the heat of 35C in the shade, everybody was finding it enjoyable & very educational indeed. Some have seen how nursery trees grown to international standard for the first time, & the tutorship on Plant ID & Pruning was excellent. The strong sunshine added enthusiasm to the learning & everyone has found the sessions well worthwhile for the journey so made.

We particularly wish to thank the Tutors Mr. KM Li & Mr. Tong Ng for their excellent Plant ID & Natural Target Pruning training. Mr. Li & Mr. Ng also refused to waive their share of payment of the trip & insisted to pay the RMB 180 person for transport, meal & drink like everybody. Such kind of selfless devotion will set an example in our Station history for bringing in fresh air to the landscape industry & gentlemen of this quality ought to deserve a round of applause form all of us. Thank you, our respectful Tutors...

Please kindly find attached the bunch of photos taken by this Station & sent in by Station Members for the footprints of the Oct 7 Trip. Please keep the one you want & share them with friends & family for the memorable occasion.

Upon the success of the Oct 7 trip, this Station is planning for other educational sessions at ETF such as Chainsaw Uses, Crown Restoration Pruning after Topping, Structural Pruning for Landscaping Trees after DLP, Tree Biology & Pathology, Tree Anatomy, Intermediate Tree Climbing, Basic Rigging, Tree Risk Identification, Fundamental Tree Inspection, Diagnosis & Treatment, etc. Now with help of volunteer Tutors, the above training have become possible instead of having just the Station Manger to do it all alone in the past. Our thanks to our wonderful Tutors indeed.

If any Station Member would like to offer any Arbor Training of above or beyond, you are most welcomed to contact this Station for arrangement anytime. We shall review & gather them into concurrent sessions to be run in HK or ETF as appropriate.

In view of the popular demand for Professional & Recreational Tree Climbing among our Station Members & public, this Station is planning to open up a Climber's Corner (CC) for anybody interested to join, hopefully within a month's time. The CC will communicate mainly in Chinese to facilitate understanding by our Chinese Channel Station Members who tend to be mostly Tree Climbers. There will be a separate class of Station Membership for CC & by tradition, Station Membership in CC is never to be disclosed publicly & will be kept alone by the Station Manager for privacy. However, the contributors for the CC will likely be experienced Tree Climbers & anybody is welcomed to contribute. The Station Manager's job is to distribute the CC Station Mail & may not have time to write on it. The CC Station Mail will be placed on Station Blog together with the usual English Station Mail for anybody's viewing.

Now for something to be celebrated. It is the pleasure of this Station to announce that our Station Membership has already reached over the 410 no. mark by Oct 1, 2007. We are also growing strong with weekly application to join this Station from all sectors of our society. The ratio of 70% Degree Holders & 60% Master Degree is still maintaining & we have more landscape architects in our Station than any other greenery institute in HK at present. We should also be by now the biggest & the most inclusive greenery organization in HK if we count in the complimentary Station Membership besides the official Station Membership of over 410 no. We have indeed proven yet another HK Miracle with no funding, no proper structure & no venue. All we have are knowledge, principles & enthusiasm, with ISA backing us behind all the way.

This Station wishes to thank all of you very much for your continuous support to develop proper arboriculture in our territory. ISA HK/China Station looks forward to grow successfully with our society to provide a better quality of living, with dedication, professionalism & integrity, one tree at a time.

best regards,

Sammy Au
Station Manager

ISA's Mission - Through research, technology, and education, promote the professional practice of arboriculture and foster a greater public awareness of the benefits of trees. (http://www.isa-arbor.com/)

ISA HK/China --- HK Tree news (Tree failure to nearly kill & tree labels)

*** 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 http://isahkchina.blogspot.com/ , although images are usually not attached due to size. ***

Dear Station Members,

Attached are two sets of recent Tree News in HK drawing our attention:

1. Tree Failure to nearly kill

According to the media report, an Aleurites moluccana of approx. 12m x 0.4m dia. was waving & suddenly fell to hit a passing taxi, crushing the front part of the car & poking through the front seat with failed branches. Luckily no one was sitting in the front passenger seat. The taxi driver & the lady passenger at the back both escaped a narrow kill. Should the angle of fall deviated by a little to the side or back, either the driver or the passenger would be hit right in the head, potentially causing serious injury or even death ...

It was reported that the failed tree had mushroom growth on the root collar & the failure appeared to be a structural defect with wind loading.

An interesting point to note in this incident is that the failed tree appeared to be in good health with sound foliage from the photo shown. A lot of our local Tree Inspectors, be they landscapers or others, would usually determine the health & condition of a tree just by looking at the foliage. It does not seem to be common to hear anyone commenting on branch attachment, lattice geometry, wind loading & pest problems with potential to fail. It would be regarded that any tree with good foliage, the tree would be healthy & safe. By Arborist standards, having good foliage alone does not mean the tree is safe in wind. In fact, it is usually quite the opposite because the bigger the crown, the higher is the liability for wind loading on that tree.

The crown of a tree is similar to the sail of a boat. If the crown is full but the branch attachments are weak, it would be like a sailing rig with weak connections. In wind, weaker connections would fail. However, our conventional practice appears to be that a Tree Inspector would only look at a tree for foliage density & colour. Structure & Wind Loading would not be emphasized or may even be missed out. Trees are massive structures with a potential to kill if failed, & trees are not pot plants or tomatoes. We can not judge the safety of a tree by horticultural standards alone. It is sad that Tree Failures in our urban settings are usually named an Act of God. Inadequate Risk Management would be rarely mentioned.

This unfortunate incident is likely to initiate insurance claim & may even bring Law suit from the victim's side. After all, they have had a traumatic experience never to be expected. If Arborist is involved in acting as an Expert Witness for any side in Court, quite likely the incident would be proven not an Act of God. Records & documentation would be investigated & the liabilities would be ascertained by the lawyers. Arborist would only provide technical support.

Would anyone be interested to take up the case?

2. Tree Labels in Tai Po

Someone wrote to the media complaining Tree Labels were incorrectly tagged for some public trees in Tai Po. The relevant Govt Dept have instructed the contractor responsible to rectify the placement & this Station does not see any major threat in messing up a few tree tags by accident indeed. HK has a culture of complaint & insignificant incident as such would be blown to distortion at times.

However, what is raising the attention of this Station for this event is really the design of the tree tags. They appeared to be sheets of printer paper inserted inside transparent plastic bags with the opening on top to collect rain or irrigation water. If water would get inside the bag, the paper is likely to dissolve & mosquito breeding is likely to happen.

Would it not be better if laminated label is to be used instead ? Laminated labels are equally cheap & available, & can be replaced with ease just as good as the existing one.

Just a casual thought ...

best regards,

Sammy Au
Station Manager

ISA HK/China --- Pruning Guidelines of ETWB Feb 07

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

This Station received a useful Pruning Guidelines so printed under with 'ETWB Feb 2007' in the attachment from a Station Member (not a Civil Servant !). This Station has reviewed the contents & found nothing of a confidential nature harmful to anybody, & would anticipate this kind of information may be included into the landscape specifications later for Govt contracts.

The contents of the Guidelines are similar to the knowledge of ISA education on pruning, except they are much simplified for some reasons. In fact, if a Certified Arborist (CA) would look closely at the Guidelines, he/she may find some of the information is taking a similar approach with the book "An Illustrated Guide to Pruning, 2nd edition --- E Gilman" which tends to be a standard text of CA to study day-to-day pruning work. However, the Guidelines have also remained traditional terminologies like Formative Pruning, Crown Lifting, Cleaning, etc. & missed out on Crown Restoration & Mature Tree Pruning which are both vital & relevant to our Topping problem & OVT maintenance in our city.

Another issue that this Pruning Guidelines did not mention specifically is the pruning techniques for Decurrent (without a Central Leader) Trees which have been commonly grown for flowering in the past in HK. A lot of these Decurrent Trees have by now reached maturity & many of them can not be pruned in the same manner as Excurrent (with a Central Leader) Trees. Examples of Decurrent Trees would include the common Ficuses, Bauhinias, Delonix & Lagerstroemias which are common in our city. The species of Delonix regia (Flame tree) would grow fast & tall, & would usually fail without much warning.

To a lot of experienced CA & Tree Farmers, pruning is a vast & complex subject to master. Some say it would take a year to learn proper pruning & a lifetime to perfect. The Station Manager himself goes to ETF every weekend to care for his 20,000 trees & the majority of the time would be spent on Structural Pruning. In nursery production, borer attack is a common pest problem which would kill off the Central Leader of a tree like Topping. Crown Restoration is necessary to re-build the Central Leader or the tree can not be sold.

In a lot of Tree Inspection & Risk Assessment, the recommendation in the Arborist Report would include mitigation measure like Corrective Pruning. This kind of recommendation must be given very carefully because once cut at the wrong places, the tree may suffer by offsetting wind balance or nutrition uptake ability, & the cut parts can not be re-attached by any means.

This Station rarely gives instruction on the subject of Pruning in Station Mail, because we worry that someone may read the information & decide he/she would know it all. Pruning is a 3-dimensional practice & every tree has a different geometry. What is shown on books is usually 2-dimensional only & branch structure is usually not given in details. The Station Manager has always found before pruning is to be discussed, subjects like Tree Biology, Biomechanics & Nursery Standards should first be consulted to understand where to cut & how much to cut. The Arborist should first ask him/herself some questions before carrying out any pruning: Why should I prune, where & & how much to prune. There are times for safety reason or others, healthy tissues may be cut off seemingly absurd to laymen, e.g. Directional Pruning in High Voltage Transmission Lines. Those cuts are particularly hard to accept.

Tree Pruning can not ignore the use of Chainsaws. Chainsaw use involves primarily safety, cutting technique & maintenance. Knowledge in arboriculture is usually knitted together like a net. Any part missing will be like a broken net.

The Oct 7 Trip to ETF will be a good time to learn proper pruning on real trees by experienced tutors. There are still about 10 vacancies available at present & may be going fast once this Station Mail is out. If anyone wants to learn pruning on a real 3-D tree, why not come along to see it in action with tuition, rather than pondering it in theory from a 2-D book or computer?

Oct 7 invites you.

best regards,

Sammy Au
Station Manager

ISA HK/China --- HK Tree News (Moving 850 trees for a Bicycle Track in Yuen Long)

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

Attached is a recent set of local news describing some tree disturbance in the Yuen Long area for the proposal to build a Bicycle Track. Some 850 no. of trees would need to be removed or transplanted owing to the construction. Some District Board members were raising concern with removing trees & would opt for transplantation. The general sentiment may be that by transplanting the affected trees, they would be saved from destruction.

Form an Arborist's point of view, trying to save trees not worth saving would cost time, money & efforts for a political exercise which may run into potential tree failures at the end. If those trees were growing in poor structure & health, or if those trees can not be transplanted with proper management (rootball, transport & future growing space), the transplanted trees would become more of a liability rather than an asset after all the time & effort spent. Have we not seen this happening many times in the past all over HK ? Do we call those topped trees after transplantation a proper 'Tree Preservation' ?

In an assessment of this kind, Arborists should be involved, be them from the Govt Dept or private consultancy. The landscape consultant could carry out the initial tree survey with their better facilities in documentation & CAD, but the Arborist should review in details of those trees recommended for retention, transplantation & removal with their better knowledge in Tree Care. The Arborist should study & recommend which trees to keep, move or fell with their professional judgment with justification to be reflected in an Arborist Report.

Certified Arborist (CA) in ISA HK/China will need to abide the Code of Honour of Integrity, Professionalism & Participation with an attitude of fact-finding & truth-telling in their work. Any breach of these in any way may lead to serious discipline by ISA HK/China, besides the CA involved may find him/herself liable to civil action in Court. Arborist Report is no flirting indeed.

At the District Board level, the Arborist can represent the Govt to explain the required tree movement to the politicians with facts & professional knowledge. Arborist has to speak out with facts & truth, not point of view. Aesthetic or species is usually a secondary consideration when safety is an issue. After all, what's good is it to have a 'good looking' tree, if it would fail to hit someone at the end? If the politicians do not like what is being told, then it will be ' Mother Nature makes the rules, not anybody ' to them. Arborist can not compromise facts & truth with politics. The politicians will have to bear the legal & moral responsibilities of tree failures in future if they do not listen, nobody else.

So, that's how a good Arborist would tackle a job like this. In HK today, we do not have an Arboricultural Office in our Govt like in western countries to handle all our tree affairs. It appears to be the administrators talking to the politicians on tree affairs most of the time. Would they do the same in a medical situation ?

HK may change for the better in handling our tree affairs eventually ...

best regards,

Sammy Au
Station Manager

ISA HK/China --- China Tree News (Saving Dying Trees in Beijing & IPM China 2007)

*** 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 http://isahkchina.blogspot.com , although images are usually not attached due to size. ***

Dear Station Members,

Attached are two sets of recent Tree News from China :

1. Research to save dying Mature Trees in Beijing

It was reported that following heavy urbanization in Beijing, the health & growth of Mature Trees in the City have been seriously threatened. According to statistic, in the year 2005 alone, around 10, 000 no. of Mature Trees in Beijing have died. In the year 2006, in the famous Tian An Man Square, over 200 no. of Mature Pines also died off.

In view of such deteriorating situation for the Mature Tree planting in Beijing, the Beijing Institute of Landscape has begun their research on the decline of Mature Trees. It is said that their research will focus on environmental science, plant physiology, plant aging biology & plant protection. It is reported that such research will fill the vacuum in the studies of Mature Trees in the capital city of China.

In reality, this will be an excellent opportunity to sell ISA to Beijing in the eyes of this Station. However, this would mean sending someone knowledgeable enough in arboriculture, language, diplomacy & culture to stay in contact with Beijing, preferable up there to drink & party with them whenever on call. Beijing has also a tradition of protectionism & anyone outside Beijing can be considered as a foreigner. We also need to be careful about the true intention behind this message, whether the event was really aiming for fund rising only to save a Dept. In China after 1949, any outside influence would be labelled ' foreign intervention' if not welcomed or desired, & our brothers & sisters would not tell us on the face. Once shut away & black listed, it may require extra effort at senior level in the Govt to break the ice. We just have to play it their way to be invited rather.

China the Old Dragon is certainly not as easy to enter as some may think without better understanding of this land of 1.3 billion, under a socialist Govt running an apparently capitalistic economy.

2. IPM China 2007

Once again, this national event hosted by seniorities in the Chinese Govt appears to be a suitable spot for this Station to participate for promoting ISA & arboriculture over there. This event is held close to HK, just 50 miles away to our west. Language does not appear to be a problem & there are lots of Chinese landscapers attending this gathering. The cost for a 9 sqm booth is only USD 625 for a period of 3 days & logistics are available conveniently for participants.

However, on further enquiring about the event, it does not appear to have a seminar session in this important national gathering !! The participants are there only to sell their products in their own booth for passing customers. No education session or discussion will be available. It will be everyone for himself in the event. This IPM show appears to adopt the traditional China Market Place style of heckling & bargaining, & not really meant for promoting education or research.

The Station Manager has also enquired what if a Tree Climbing Demonstration can be arranged by us? Would IPM China consider to promote it? The answer is a definite 'yes', but we have to bring in our own tree. We also have to remove the tree after the show immediately at our own cost. The place for the demonstration will need to be arranged at an additional cost to us ...

Therefore, at such an important greenery show at national level in China, no education or demonstration session is made available to the participants. We can only sit there to wait for passing customers to enquire about ISA & tree care, & they are likely to ask us for brochures & catalogues for their future pirating. Hardly any of them will understand English & they would be most interested in prices rather than knowledge. To a lot of them, it is money that makes the world go round ...

Would this be the kind of Trade Show that we are prepared to go in at present?

best regards,

Sammy Au
Station Manager