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2015

Establishing a framework for the recognition of local arboricultural practitioners

Paul Yuen King Chan Technological and Higher Education institute of Hong Kong (THEi)

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Recommended Citation Chan, P. Y. (2015). Establishing a framework for the recognition of local arboricultural practitioners. Yuan Lin: The Journal of the HKILA, 53-59. Retrieved from https://repository.vtc.edu.hk/thei-fac-de-sp/206

This Journal Article is brought to you for free and open access by the Faculty of Design and Environment at VTC Institutional Repository. It has been accepted for inclusion in Staff Publications by an authorized administrator of VTC Institutional Repository. For more information, please contact [email protected]. 香港園境師學會 YUANLIN 園林 The Journal of the HKILA

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得碩園藝

2015 Planting Futures Issue 2015 Superb Fig Ficus subpisocarpa, 筆管榕 (Syn. Ficus superba var. japonica) on the Mui Wo Waterfront, Lantau Island. A self-seeded ‘weed’ that grew naturally out of a crack in the concrete, it is remembered as a bush 25 years ago and was saved from being chopped down by Fabian Pedrazzini of the Green Lantau Association.

It's one of the very few cool, shady spots where you can sit on the waterfront - for free. This solitary tree grew despite, not because of, the efforts of humanity yet repays our ingratitude with a multitude of services. It provides shade for sitting, picnicking, socializing and contemplating. It is a children's climbing frame, a haven for local bird life, and a welcome visual respite from the sad 'architectural' mediocrity that is the Mui Wo bus terminus.

Above all it is a silent teacher. We would all, especially professionals entrusted with designing the future environment, do well to heed its silent lessons! Planting Futures Issue 2015

Yuan Lin is the professional journal of the Hong Kong Institute of Editor Mathew Pryor 彭文輝 Landscape Architects. Consulting Editors Gavin Coates 高嘉雲 It is distributed free to all members and registered practices of Bryan Woo Shing Hin 胡承軒 the Institute, as well as Government offices, libraries, academic bodies, related professional institutes, interest groups and Other Reviewers Michael Thomas 湯米高 members of the local landscape industry. David Morkel 莫景康

Copyright of all the material within the journal is retained by the Graphic design and layouts Bryan Woo Shing Hin 胡承軒 HKILA and the respective author. No part of Yuan Lin, written Maisy Poon Yan Lam 潘昕琳 or pictorial, may be reproduced or published without the prior Monica Chong Ying 莊盈 written permission of the publisher. © 2015. Jasmine Cheung Wing Ka 張詠嘉 May Chan Ka Ying 陳嘉盈 Except otherwise stated, photographs belong to the authors or John Yuen Ho Shun 袁浩信 the editorial team. Acknowledgements The editors would like to acknowledge the kind contributions ISSN No.: 1606-0520 of all the authors.

Publisher Hong Kong Institute of Landscape Architects The publication of the journal is only made possible by the P.O. Box 20561, Johnston Road Post Office, Wan Chai, Hong Kong. many landscape contractors, material suppliers, landscape Tel: 2896 2833, Fax: 2896 3938 practitioners and organizations who have generously taken HKILA Main Website: http://www.hkila.com advertising space in the supplement. The HKILA would like to HKILA Publication Link: http://www.hkila.com/v2/publication.php express its heartfelt gratitude to them for their support. HKILA Email: [email protected] Published and printed in Hong Kong in August 2015. The HKILA Publications Committee would like to thank the staff and students of the Division of Landscape Architecture, Printer e-print HKU, for all their help in putting this issue of Yuan Lin together. Flat A, 1/F., Phase 3 Kwun Tong Industrial Centre, Kwun Tong Road, Kowloon, Hong Kong Tel: 2319 7107, Fax: 2344 2157

Editorial Board Publication Committee of the Hong Kong Institute of Landscape Architects.

All articles in the journal have been peer reviewed. The editors have endeavoured to ensure that the information within the Cover image Jacaranda mimosifolia at Pacific Place 3. Star Street, Wanchai articles is factually correct. The opinions expressed in the articles, (Photo: Barnaby Smith) however, are solely those of the author, and do not represent the Back cover image Jacaranda mimosifolia in flower (Photo: Barnaby Smith) views of the HKILA. Authors take responsibility for ensuring the Supplement cover image New roadside planting at the junction of Jordan Road and Lin accuracy of their work, and that any necessary permissions to use Cheung Road, West Kowloon (Photo: Mathew Pryor) images or other intellectual content, has been obtained from the Supplement back cover image GMP Planting at Star Ferry Pier, Central rights holders. (Photo: Gavin Coates) Contents

11 Editorial

Articles 15 On the symbolism of plants in the context of Hong Kong Yin-Lun Chan

25 Review: The homecoming of the Moon Capital: Landscape symbols and representations in the Tale of Princess Kaguya Winnie Yuen Lai Chan

29 A return to Disney Mathew Pryor

37 A tree preservation ordinance for Hong Kong: An historical note Mathew Pryor

43 A tree for all reasons: Large trees in urban areas Barnaby Smith

49 香港樹木管理的思維缺憾 Tree management shortcomings in Hong Kong 劉興達 | Patrick H.T. Lau

53 Establishing a framework for the recognition of local arboricultural practitioners Paul Y. K. Chan

58 The Tree of Landscape Design Gavin Coates

61 Trials in succession woodland planting at SENT Landfill, Tseung Kwan O Barry Wilson

69 Extreme trees Mathew Pryor and Li Wei

77 Aerial roots of Ficus microcarpa Mathew Pryor and Li Wei

87 An alternative way to green the city: Unplanned vegetation in Hong Kong Gap Chung Wai-kin

93 Amenity and sports turfgrass in Hong Kong Eric Y.T. Lee, PhD

99 Weaving green fabric to a condensed city Greening, Landscape and Tree Management Section, Development Bureau

107 Productive green roofs Mathew Pryor

117 Next issue, public space President's Message

It is my great pleasure to welcome the publication of Yuan Lin 2015, the professional journal of The Hong Kong Institute of Landscape Architects, which serves as a platform for members and related professionals to share experiences, showcase projects and exchange views on matters related to landscape architecture.

This issue of Yuan Lin focuses on planting. The articles presented address the landscape architectural knowledge and technical skills pertaining to the design, implementation and management aspects of planting in a variety of local urban contexts.

I would like to take this opportunity to express my sincere thanks to the authors, Publication Committee, Editorial Team, members and landscape practitioners who have been involved in the production of this issue of the journal. On behalf of the HKILA, I would also like to warmly thank the many landscape material suppliers, contractors and organisations who, through their advertisements, have enabled the journal’s publication. Without all these valuable contributions, Yuan Lin 2015 would not have been realised.

I strongly encourage members to submit articles, reviews, reports and other contributions for the next issue, on the theme of public space, so that we can increase the frequency of publication, and make best use of the journal to promote landscape issues in Hong Kong

Happy reading!

Tak WONG President of HKILA July 2015 Editorial

Planting is one of the fundamental arts and sciences of landscape architecture, and in many ways has come to define and identify the discipline. Landscape architects need to be knowledgeable and skilled in the design, implementation and management of planting, in different contexts and environments.

Trees, shrubs, climbers and grass provide greenery and visual ornament, create environmental comfort through shade and shelter, reduce the ‘heat-island effect’ and diversify ecology of high density urban environments. Plants can also have strong cultural, historic and symbolic meanings and values. There is an increasing body of research to show that urban planting substantially benefits the physical and mental health of city dwellers.

In high rise cities like Hong Kong, intense competition for space creates unique challenges for landscape architects in the establishment and management of planting. In contrast to the natural environment of our country parks, urban plants have to tolerate extreme deprivation just to survive, let alone thrive. Considering the impoverished physical environment that has typically been allowed for trees in our narrow streets, it is little wonder that their average life expectancy is less than 20 years. Landscape architects need to appreciate the inherent artificiality of urban planting and must work closely with property owners, managers, planners, architects and engineers, to ensure the provision of adequate growing space and conditions, and maintenance tailored to achieve the design intent in the long- term. We have a duty to ensure that planting designs emphasise integrated, sustainable, successional vegetation structures, and not focus merely on the immediate, the decorative, and the isolated specimen.

This issue of Yuan Lin has been dedicated to planting. A wonderfully diverse collection of reviews, articles and academic papers, collectively explore the different forms, scales, and contexts of Hong Kong’s urban planting.

A few of the many meanings and values that society can give to plants and planting are discussed in the opening article ‘On the symbolism of plants in the context of Hong Kong’, and specific meanings are explored in the beautiful ‘Landscape symbols and representations in the Tale of Princess Kaguya’.

In ‘A return to Disney’ three practitioners revisit the massive ornamental planting works they helped build for the HK Disneyland Resort, reminiscing on how it was all achieved, and assessing how the planting has fared over the last 10 years. ‘A tree for all reasons’ examines successful examples of greening in the highly contested streets of Wanchai, and highlights the impact that just a small number of individual trees can have on our urban environments. ‘Weaving green fabric to a condensed city’ looks at the many successes of Development Bureau’s ‘Skyrise Greening’ campaign in greening the city’s vertical surfaces and rooftops.

Different forms of planting are explored in several articles. ‘Trials in succession woodland planting at SENT Landfill’ reports on new approaches to establishing sustainable vegetation structures on reclaimed land, while ‘Productive green roofs’ examines the increasing use of roof spaces for the production of vegetable and fruit crops in high rise cities, and suggests that this might be the logical next step in urban farming and green roofs. ‘Alternative way to green the city: Unplanned vegetation in Hong Kong’ is an intriguing student research study that questions the standard approach to planting procurement, and suggests that a small shift in public opinion might lead us to more effectively co-opt nature to green the city on our behalf

Good planting design is based on detailed knowledge of plant growth habits and ecologies. To that end ‘Amenity and sports turfgrass in Hong Kong’ sets out the options for successfully growing lawns: always a challenge in Hong Kong’s unforgiving sub- tropical climate. ‘Aerial roots on Ficus microcarpa’ reports on a research study investigating these remarkable features, typical of one of Hong Kong’s most iconic tree species, and in particular the long-standing question of whether these roots can take up water from the atmosphere around them. Conversely ‘Extreme trees’ investigates how the tolerance of some mature trees to extreme physical damage has resulted in their commodification within the development process in southern China.

Successful urban planting requires good policy and management. The article on a ‘Tree preservation ordinance for Hong Kong’, looks back to the Territory’s early history and provides an interesting footnote to the current discussion about the need for tree protection legislation. By contrast ‘Tree management shortcomings in Hong Kong’ examines some of the policy and management challenges in developing a healthy urban forest in the city today, and ‘Establishing a framework for the recognition for local arboricultural practitioners’ highlights some of the current difficulties faced by the profession in providing quality arboricultural services to the community in Hong Kong.

The centrepiece of the journal is reserved for a beautifully drawn educational illustration of the ‘Tree of Landscape Design’ (Arbor propositum), a planting-orientated, graphic metaphor of the landscape design process. 'During bad times, people On the symbolism of plants in the of South China have context of Hong Kong the tradition of washing Yin-Lun Chan themselves with pomelo As an integral part of our landscape, plants play important functional and aesthetic roles in our everyday life. Plants that appear in our landscape are reflective of the climatic and cultural contexts of where we live, in other words, our leaves. As this tradition goes, identity of place. In the context of Hong Kong, we encounter symbolic imageries of plants from both Eastern and Western contexts. Through a selection of plant symbols and by looking specifically at the ways they are depicted in works of Chinese literature, the worldviews expressed through such metaphorical associations are described. In the citrus fragrance of the so doing, this paper attempts to explore how these plant symbols may be interpreted in a contemporary context. leaves washes away evil and bad luck. Perhaps what is needed for Hong Kong right now is a city-wide wash using this formula.'

Yin-lun Chan

‘China the Flowery Land’, from an old Chinese engraving (Source: Lehner & Lehner 1960: 104)

Yuan Lin 2015 Planting Futures / 15 Introduction Western contexts. Trees and flowers Tamed renditions of natural landscape, Rose aspect is whether a festival is associated and bad. have long been subjects of poem, so to speak. with a public holiday. The choice of Perhaps the most intriguing features literary and poetic imageries, and Rose is one of our favourite florals public holidays can be political, as seen Let us return to roses, which are about any discussion of symbolism in painting. In fact, the artistic lineage of 6) Countryside: Country parks, farmlands symbol of all time. Its flamboyant for example in the replacement of the nowadays perhaps best associated by Hong Kong are the ideas of hybridity, the term ‘landscape’ seems to share (former rice fields), coastal areas redness embodies images of blood and Queen’s Birthday by the First of July at Hong Kongers as associated with St. juxtaposition, and contrast. This myriad common roots as artistic subjects in both (mangroves), uninhabited areas of passion. It has been one of the most the turn of 1997. The other aspect is Valentine’s Day. Outrageously expensive of dichotomies include those of Chinese the East and West. The various Chinese ‘wilderness’. frequently used symbols in literary the workings of capitalism, whether the flowers, the crucial day of profit for / Western, traditional / modern, native translations for the term ‘landscape’ codes. Anecdotally, the author's primary festival can be translated into commercial flower shops, the day for men and / foreign, elitist / popular. This list of can be quite problematic. However, 7) Copies and metaphorical existence: school was of the name 'Rosaryhill' and profit. The danger of commercialised women to make romantic gestures. pairings could be applied to analyse shan-shui （山水）, literally mountain Have you not come across any plastic many mornings would start with the festivals may result in symbols that no Within this commercial phenomenon, all sorts of cultural features of the city, and water, as the term relating to plants lately? Flower trellises for wedding reciting of the Hail Mary, which formed longer contain any cultural or religious the symbolic associations of roses are and a proposal to review the symbolism Chinese landscape painting is a rather ceremonies, fake lawns, landscape part of the Rosary prayers. content. In this case, all cultural coupled with colour and numerology, of plants in Hong Kong based on this straightforward one in relation to the paintings hung on walls – these are the symbols degrade into pure symbols of exemplified in the table below taken line of enquiry promises an interesting European tradition of oil landscape maintenance crews’ favourite! The vibrancy of the rose is symbolic commerce. This is the way they appear from a commercial website where each study. The floral emblem of Hong Kong, painting. Given this background, the of St. Valentine's Day as with other in shopping mall foyers, reflecting pure line is emblazoned with the hyperlink, appearing on coins and flags, is the study of plant symbolism in the context Although Hong Kong may be a fairly festive plants such as Christmas trees consumerism. This means Christmas 'Purchase Romantic Roses!' vividly-coloured flower of the Hong of contemporary Hong Kong might allow built-up city, plants are still major and Halloween pumpkins. Plants and Easter without church, Halloween Kong orchid tree Bauhinia x blakeana. us to get a better glimpse of the identity components of our landscapes. They associated with festivities reflect the without harvest, Ching Ming without And of course, to be consistent with The Hong Kong orchid tree, a hybrid complex inherent in the urban landscape infuse all aspects of our daily lives. As seasonal habits of plants and aspirations ancestors, Winter Solstice/ Thanksgiving capitalist logic, the more expensive it between Bauhinia variegata and of Hong Kong. As such, this paper intends urban dwellers, we seem to be losing of cultures. Hong Kong hosts many without family, Labour Day without gets, the more sincere you are and the Bauhinia purpurea, is a widely planted to provide an updated interpretation of our connections to nature, which is festivals, including both Eastern and the Socialism. One concern about how a more powerful the spell! But to many city sterile hybrid with showy blossoms and some of the traditional plant symbols reflected in our seemingly decreasing Western. This is a reflection of the city’s festival survives is its ability to involve managers, roses are best kept in their brittle branches. Certain wags have been in the contemporary, desacralized and physical contact with living plants. But colonial history, Chinese heritage, and children, so that there is generational ‘safe’ cut-flower and bouquet forms. For heard to wisecrack that these qualities commercialised popular context. I argue this is not quite true, no matter how metropolitan nature. continuity. Only when a festival is urban street plantings, roses grow too do indeed make the Bauhinia a very apt that landscape architects should take on advanced our technology, we still need embraced by children and the younger fast and often appear unkempt. Viewed emblem for Hong Kong. a more active role in incorporating our plants to survive. In fact, we encounter The rise and fall of the popularity of generation can it remain part of an active from a governance perspective, roses cultural attachment to plants into the plants all the time, if not symbolically festivals is a subject of cultural and culture that is continually renewed and represent passion, which requires heavy The striking feature of Hong Kong’s urban design and interpretation of everyday and metaphorically. Now let us revisit folklore studies. It can also be analysed evolving, rather than a dying culture maintenance and must be controlled. environment is its densely packed urban landscapes. some of these plant symbols and for a in the context of contemporary requiring protection and preservation. In setting, a product of capitalist priorities moment indulge in an exercise of over- commerce. There are institutional and this respect, consumerism may be doing and over-the-top commercialisation. Encountering urban plants interpretation. We start with the rose. commercial aspects related to this. One something that is at the same time good Landscapes reflect a place’s ideology and taste. The shiny giant skyscrapers, Let us take a mental inventory of the Colour Meanings multi-lane highways, flyovers and plants we encounter in the contemporary Red Roses: Love & Respect underground tunnels in the city-centre landscape of Hong Kong. Dark Pink Roses: Appreciation & Gratitude of Hong Kong all combine to tell the Light Pink Roses: Admiration & Sympathy story of modernity and efficiency – time 1) Flowers: Including both cut flowers Yellow Roses: Happiness & Friendship is money, and money is king! Amidst this and potted plants. White Roses: Innocence, Purity, To Honor, mechanistic worldview of a city, what is Remembrance the place of plants? 2) Street planting: From the traditional Purple Roses: Enchantment & Enthrallment street trees to the ‘street gardens’ which Orange Roses: Enthusiasm & Captivation Plants are indispensable elements in are becoming more common under considering the city’s feng shui. Urban ‘beautification’ schemes, and those Number Meanings gardens, allées of trees, decorative strange little planters hanging off the 1 Rose – Love at first sight plants – there are indeed many traces railings of heavy trafficked roadsides. 2 Roses – A common love between both parties of plants in contemporary urban lives – 3 Roses – I love you not to mention their processed forms 3) Food: Markets, community gardens, 6 Roses – I devoted to you; I want to be yours such as food, fabric and others. They are nurseries, roof-top farms. 7 Roses – I’m taken with you 9 Roses – Everlasting Love considered a ‘touch of nature’ within the 10 Roses – You are perfect concrete jungle, something that ‘softens’ 4) Other functional uses of plants: The 11 Roses – You're the one that is most important the harshness of built forms, something first one that comes to mind is the in my life ubiquitous bamboo scoffolding used for that relieves us from urban stress. 12 Roses – Be my sweetheart Greening of the city is ‘good’. Planting works on building façades. This category 13 Roses – Secret friend contributes to urban sustainability. would also include all the timber used … Plants filter sound, dust, and produce in building construction, furniture, and 99 Roses – I will love you forever oxygen. Trees are urban lungs. Plants interior decoration. Not to forget paper, 100 Roses – Remaining devoted to you save the world. fabric, and other ‘processed’ forms of 101 Roses – You are my only love plant materials. 108 Roses – Marry me The fact that plants are associated with 365 Roses – Can’t stop thinking about you a broad range of cultural meanings 5) Gardens: Stepping into the scope of Roses (Photo credit: Ziva & Amir, https://www.flickr.com/photos/125619820 999 Roses – Eternal Love have long histories in both Eastern and classic landscape architectural practice. @N03/18185550873/) (Extract from rosemeaning.net)

16 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 17 One of the most important eras for 晉太元中，武陵人，捕魚為業，緣 struggles and leave for the countryside. 而不可褻玩焉。予謂菊，花之隱逸 construction industry in Hong Kong is the 溪行，忘路之遠近；忽逢桃花林， The story of the ‘Peach Blossom Spring’ 者也；牡丹，花之富貴者也；蓮， planning and development of the Rose 夾岸數百步，中無雜樹，芳草鮮 has been suggested as a metaphor for 花之君子者也。噫！菊之愛，陶後 Garden Project in the 1990s involving 美，落英繽紛；漁人甚異之。 Hong Kong, which thanks to its unique 鮮有聞；蓮之愛，同予者何人；牡 the new Chek Lap Kok airport, the Tsing （《桃花源記》陶淵明） political status, avoided much of the 丹之愛，宜乎眾矣。（《愛蓮說》 Ma Bridge, container terminals, and chaos that has characterised the modern 周敦頤） major railway and highway extensions. One year in the Jin dynasty, there history of the Chinese Mainland. As such, Presented as a way to ‘soften’ the tone was a fisherman, who strolled along despite having interacted with foreign There are many admirable flowers of massive infrastructure, and to paint a stream, without noticing how far he cultures for many years, Hong Kong is among land and water plants. The a 'rosy' picture of Hong Kong's future, had gone. Suddenly, he encountered still the foothold of many traditional Jin dynasty scholar Tao Yunming ‘Rose Garden’ conjures quite contrasting a forest of blossoming peach trees, pre-Republic Chinese cultures, having particularly loved chrysanthemum. imageries to the actual massive scale extending a few hundred feet from escaped the ravages of civil war and the Since the Tang dynasty, people have movement of dirt and pouring of the bank. There was not a single other Cultural Revolution. enjoyed peonies. Contrary to popular concrete. But this was quite adept at species within the grove. Smelling preference, I love lotus for its purity describing the bubble economy of the of sweet fragrance, colourful petals But perhaps more important to the even though it rises from mud. I love 1990s. To many, it is remembered as swirled in the breeze. The fisherman common Hongkonger is what peach it for its elegance standing amidst an era of good times, a golden, rosy, became curious. ('The Peach Blossom blossom represents in Chinese fortune- water ripples. It stands upright, its voluptuous era; an era of excess. Spring' by Tao Yunming, translated telling, that of spring, vitality, and good fragrance spreads afar, it deserves by the author) relationships. The peach is thought much respect! I say, chrysanthemum Peach to embody much vitality because it is the hermit of flowers; the peony, The fisherman proceeded along the blossoms before coming into leaf. the wealthy flower; lotus, the most Also in the rose family is the peach. As stream and entered a utopian village that noble of flowers! Alas! There are with the Japanese cherry blossom sakura, had been shielded from the warfare and The Peach, t'ao hua, plays an few who loved chrysanthemum after the Chinese peach blossom is loaded misery of the outside world. The villagers important role in Chinese symbolical Tao. And I guess there is no one who with meaning in traditional symbology. were people who, having escaped art. The blossom, one of the loves the lotus as I do. The Peony is Lotus (Photo credit: Jennifer, https://www.flickr.com/photos/jennifer- In Chinese literature, the peach is the the tyrannical rule of the Qin dynasty, heralds of Spring, favoured season the popular choice. (‘The Love of kecl/4725272095/) classic imagery of an escapist utopia. formed a ‘commune’ in the mystical for weddings, is an emblem of Lotus’ by Chou Tun-i; translated by This came about by the fable told by woods that the protagonist found Matrimony. 2 fortune in relationships, with reference ancients in the Near and Far East since the author) the Jin dynasty poet Tao Yunming, ‘The only once but not when he returned a to peach blossom, arranging furniture the beginning of religious beliefs, Peach Blossom Spring’1. The story starts second time. This escapist attitude is In bookshops or newspaper stands, and wearing particular gemstones. it has an uninterrupted symbolic Compared to the escapist, utopian with a beautiful description of a forest of in fact quite typical of Chinese scholars you can find many feng shui books During Chinese New Year, families carry history of over 5,000 years…The peach, the metaphor of the lotus speaks blossoming peach trees: who get weary of bureaucratic power that teach you how to attract good home soon-to-blossom peach trees eight-petaled lotus, Lien in China, and of an attitude to life that is more worldly. (like Christmas trees) and later have Hasu in Japan, is also the emblem of It speaks to the idea of standing upright young men and women walk around the Past, the Present and the Future, within a corrupted world. Rather than the blossoming tree in circles wishing since buds, blossoms and seed-pods retreating from the world altogether, for good relationships in the upcoming can be seen simultaneously on the the lotus metaphor asks us to stay within year. As the social pressure for men and same plant. The lotus is furthermore society, but maintain our purity, be women to get married continues, this considered the symbol of beauty, honest, and live a righteous life. tradition is likely to endure, especially perfection and purity, because the given the current gender imbalance of beautiful blossom grows clean and Ficus Hong Kong. Fortune tellers and feng untouched by the sullied water of the shui books emphasise the good fortune muddy pools from which it rises.3 No matter what your sense of time is, benefits of peach blossom, perhaps with whether you conceive the image of therapeutic effects. In this respect, plants are often used to a flower as representing the infinite depict preferred lifestyles and images of universe, a flower is just a flower. The Lotus ideal ways of life. Many classical Chinese beauty of flowers stems precisely from literary figures speak of alienation. They the fact that they blossom and they The Prunus flowers are colourful, vibrant write about teachings and metaphors wither; their very essence lies in their blossoms. They are emblematic of of how a person should live virtuously ephemerality. Large trees, on the other energy and youthfulness. On the other amongst chaotic societies and corrupt hand, are to us like elders; there since hand, Confucius and Buddhist wisdom governments. Using the lotus flower as the beginning of time, and their canopies professes a beauty which is more a metaphor, the following piece gives extend way beyond human reach. subdued, quiet, and tranquil. The lotus advice on life, on how to live righteously, One of these, the fig tree is of cultural flower epitomises such characteristics, and to maintain purity even when significance in many cultures. as described in the following excerpt: surrounded by dirt and mud.4 The common fig tree (Ficus carica), One of the most revered plants with 水陸草木之花，可愛者甚蕃。晉陶 native to the Smyrna region in Asia a deep-rooted, religious significance 淵明獨愛菊；自李唐來，世人盛愛 Minor was one of the most widely is the lotus flower, a member 牡丹；予獨愛蓮之出淤泥而不染， revered sacred trees of antiquity. of the tropical water lily family 濯清漣而不妖，中通外直，不蔓不 Among the ancient Hebrews the fig tree was a symbol of peace and Peach blossom (Photo credit: tanakawho, https://www.flickr.com/photos/28481088@N00/8629149917/) (Nymphaeaceae)…Held sacred by the 枝，香遠益清，亭亭靜植，可遠觀

18 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 19 abundance. It was a sacred tree to It has been suggested that the name the early Christians because Jesus of Hong Kong does not mean ‘fragrant desired to eat figs on the way to harbour’, as it is normally translated, Bethany…There are several hundreds but rather ‘incense port’. Apparently of species of fig tree, revered nearly in the Ming dynasty there was a everywhere as the Tree of Life and thriving trade in incense through Knowledge, from Central Africa the village port of Hong Kong on the 'where the natives believe that the south side of the island. The incense spirits of their ancestors live in fig came from plantations of trees which trees, to the Far East where the grew particularly well in this area. 8 Buddhist reveres the pipal, a fig tree, because Gautama found wisdom This tree mentioned by Baker is the under it.' 5 incense tree, Aquilaria chinensis. The incense tree has many uses, but its high Our local fig tree, Ficus microcarpa, is also value stems from its resin which is the called the Chinese banyan or the curtain fragrant element of agarwood. The resin fig. In Kam Tin, there is a famous ficus is formed in response to fungal infection tree that has over the years devoured or external wounding, which can be an entire abandoned village house. For turned into expensive Chinese medicine many Southern Chinese villages, the or an aromatic substance. Agarwood is village tree stands for the well-being of also of religious importance. The burning the entire clan, and the public square of resin-rich agarwood is part of Buddhist under the tree is the centre of the village, and Taoist ceremonies, and it can also be where gatherings and other activities like used to make joss sticks that are used in storytelling and performances are held. the worship of gods:

Another feature that is rather unique The worship of the divinity by the to the landscape of Hong Kong is the lighting and offering of incense presence of retaining wall trees, growing goes back to the remotest times of from within the cracks of stonewalls. Chinese history, and existed more or They are integral to the structure of the less as practiced at the present day, wall and at the same time provide shade or at least in the form of aromatic and comfort to the urban streetscape. substances burnt in honour of the They are perfectly adapted to the hilly gods. We read that in very early topography of Hong Kong Island, an times, the emperors Yao, Shun and example of the integration of natural Yü, offered burnt offerings to the topography, built structures, and Supreme Ruler, Shang-ti, while later Bamboo forest (Photo credit: JFXie, https://www.flickr.com/photos/jfxie/7988632041/) ecology. on as primitive tradition waned or became corrupted, private families between buildings, we often see these Let us for a moment move away from To say this is the home of bamboo, the Depths of a Bamboo Forest’ by Bamboo assumed the right of offering incense matrices created by the structure of this this urban imagery and visit another one is not to say that there are no other Huang Meng-tian, translated by the to their own special gods 9 plant material at close quarters. Baker, of my favourite secondary school texts. plants, but there are very few. On author) Bamboos are grasses. They grow quickly in writing about his first encounter with The following is Huang’s breathtaking the other hand, the sheer amount but maintain structural integrity. Here The smell of agarwood is thought to bamboo scaffolding 6, exclaims: description of the bamboo forest 7: of bamboo gives you the impression Between the hermetic, withdrawn utopia is a basic physics question asked of traverse multiple worlds. Given the that there are no other plants even of the Peach Blossom Spring and the children, ‘Does bamboo or a huge tree cultural significance and commercial How soon one accepts! When I first 說是竹鄉，並不是沒有別的植物， though they are present. Looking self-righteousness of the lotus, bamboo withstand stronger wind?’ As the answer value of its wood and resin, agarwood set foot in Hong Kong one of the 不過實在太少，而竹子之多，給你 across the rolling hills, from the describes an additional dimension goes, although bamboo is much thinner has been referred to as the ‘diamond first marvels that registered with me 的印象似乎是，那裏除了竹，其他 ridges to the hilltop, no, starting from of rural and urban connections. The in girth and easily bends, it can withstand of plants’. This has, however, led it to was bamboo scaffolding. On close 便甚麼植物都不存在了。其實不是 the flat areas it is already all covered narrator describes his visit to a friend much stronger wind precisely because become the target of theft. Over the inspection it could be seen to be held 沒有而是看不到。遠望去一連幾座 in bamboo. Layer after layer. There is living deep inside the bamboo forest, of its flexibility that dissipates the force past few years, many incense trees in together only by short lashings of 山頭，從山麓一直到山頂，不，從 no way to distinguish among culms, and how he admired simple rural life. of the wind. The greatness of bamboo Hong Kong have been illegally felled. reed, and when the workmen moved 平地開始就全鋪著竹，一層又一層 branches, and leaves. You could not To the urban dweller, connections with as a construction material is similarly Sadly, this precious native tree which around on it the flimsy poles creaked 的，不但分不出竹枝、竹幹和竹 even identify the houses, paths, they rural imageries are crucial in maintaining because of this flexibility but at the same has given Hong Kong its name is now an alarmingly. How could it rise so high 葉，連房子、小徑和小橋流水都看 are all covered in a sea of bamboo. a healthy mind. The sight of bamboo in time its ability to withstand longitudinal endangered species. This can perhaps be and remain so strong? Yet, a short 不到，彷彿全被竹的海洋淹沒了。 The wind creates waves across the the urban landscape is perhaps one such compression. a metaphor for the city itself. Many core while later I was showing a newly 當一陣風吹過的時候，竹海上湧著 bamboo sea, the waves press on, one icon that evokes rural imageries in our values of the city are increasingly under arrived friend around, and I walked 暗浪，一浪推著一浪，一直湧到很 after another, to a distance away. It minds. threat. What can be done to reverse Bamboo epitomises the functionality straight past some scaffolding 遠，你很難知道那一片嫩青色和墨 is impossible to tell how deep are the of plants within the urban landscape. these trends? without thinking to comment. It was 綠色的竹海有多深，只是你看竹浪 patches of light and dark green, but by Incense Tree Often it reminds us of our connections only when he stopped to wonder that 的起伏和它的氣勢，就意味著它是 admiring the greatness of the rising to the rural landscape. In the dense I even noticed. (Baker 2011: 169-170) 非常深沉的。（《竹林深處人家》 and falling bamboo waves, you figure The incense tree is closely tied to the urban environment, with little space 黃蒙田） it must be of great depth. (‘Within name of Hong Kong. According to Baker,

20 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 21 Stone wall tree (Photo credit: Jonathan Leung, https://www.flickr.com/photos/jonathan-leung/18918043073/)

Conclusions ease of maintenance. However, our References understanding and connection to 1. Tao. Y. (Unknown) ‘The Peach During bad times, people of South China plants should not be limited to such Blossom Spring’. Onilne at http:// have the tradition of washing themselves technical considerations. They should www.cbooks.org/readbook.asp with pomelo leaves. As this tradition include elements and activities deeply ?job=2&bookID=2&subnameID=45. goes, the citrus fragrance of the leaves embedded in our cultures. We must also 2. Koehn, A. (1952) Chinese Flower Symbolism, washes away evil and bad luck. Perhaps build these connections with agriculture, Monumenta Nipponica 8 (1/2): 121-146. what is needed for Hong Kong right now dietary practices, festivities, religion, is a city-wide wash using this formula. tradition, and superstition. Perhaps the 3. Lehner, E. and Lehner, J. (1960) Folklore and way to overcome escapism is a reversal Symbolism of Flowers, Plants and Trees. New York: Tudor Publishing Company. In the preceding discussion, the Taoist in attitude: rather than be perpetually and Confucian plant metaphors have in retreat, we should let our native plant 4. Chou, T. (Unknown) ‘The Love of Lotus’. illustrated an escapist worldview. The culture re-invade the cityscape. To wage Online at http://www.cbooks.org/readbook. asp?job=2&bookID=2&subnameID=70. peach forest, the lotus, and the bamboo this campaign, we should make use of sea all depict escapist, self-righteous every opportunity to scatter the seeds of 5. Lehner, E. and Lehner, J. (1960) Folklore and approaches to life. In this sense, living landscape into each and every corner of Symbolism of Flowers, Plants and Trees. New in harmony with nature and keeping a our society! York: Tudor Publishing Company. 29. distance from mainstream society appear 6. Baker, H. (2011) Ancestral Images. Hong to be the preferred way to deal with urban Kong: Hong Kong University Press. 169-170 vices. However, in this scheme, human 7. Huang, M. (Unknown) ‘Within the Depths connections to landscape are excluded of a Bamboo Forest’. Online at http://www. from the urban context, and there is no cbooksorg/readbook.asp?job=2&bookID=4& attempt to improve the worrying state of subnamID=152. urban society. To overcome this escapist 8. Baker, H. (2011) Ancestral Images. Hong attitude to life, and to the landscape, Kong: Hong Kong University Press. 349. what is perhaps needed is a way to once again bridge cultural meanings with the Yin-Lun Chan obtained his Master 9. Baker, H. (2011) Ancestral Images. Hong material landscape. Without this cultural Kong: Hong Kong University Press. 348, citing of Landscape Architecture from The Doré (1914) enrichment, the mere act of ‘greening’ University of British Columbia, and is (i.e. the addition of plants) would only now pursuing his PhD in architectural create empty cultural embellishment and landscape history and theory at without any cultural content. The University of Hong Kong. He is the Without doubt, the selection of plants editor of The History of the Landscape in the urban landscape is considered Profession of Hong Kong, 1978-2015: A with regard to their vigour and Collection of Interviews.

22 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 23 'The Tale of Princess Kaguya Review: The homecoming of the is centred on a princess of Moon Capital: Landscape symbols the Capital of the Moon who and representations in The Tale of was sent on Earth by Deva Princess Kaguya as a form of punishment. Winnie Yuen Lai Chan The story is vividly set is a variation on the iconography of the boy miraculously-born out of a lotus in landscape themed flower 化生童子 in Chinese Buddhist art. An old bamboo cutter walks past episodes embedded with the bamboo forest, discovers and adopts her. The Princess spends her humble but carefree years of childhood surrounded early garden symbols and by nature with her adoptive parents, and grows up into human size at a fast pace representations – which are just like a bamboo shoot. Some early scenes in the farm cottage landscape deeply rooted and shared in recall the picturesque Swiss mountain in Takahata’s 1974 TV amine series Heidi, Girl of the Alps (アルプスの少女ハイジ, East Asian culture Arupusu no Shōjo Haiji, 飄零燕). It turns out that the magical bamboo forest has (Japan/China).' more to offer the future princess, and prepares exquisite silk kimono fabric to make clothes and gold nuggets to build Winnie Yuen Lai Chan a palace.

Palatial Landscape and Memory Garden - Spoiler alert - The story is vividly set in landscape themed episodes embedded with early As the palace construction was The Tale of Princess Kaguya (かぐや姫 garden symbols and representations – completed, the family leaves the の物語, Kaguya-hime no Monogatari, which are deeply rooted and shared in countryside and relocates to the capital 平安京 輝耀姬物語) (2013, released in Hong East Asian culture (Japan/China). The city of Heian-kyō (present day Kong cinemas 2014) is an animated film period between the mid-8th to mid-9th Kyoto). They settle into the palace adaption of the 10th-century Japanese centuries marks the Japanese (Heian where the country girl learns to folktale The Tale of the Bamboo Cutter ( 平安時代) reception of Chinese (Tang become an aristocratic woman. The 竹取物語 Taketori Monogatari), directed 唐) culture in all aspects. Pure Land sumptuous palace architecture and by the acclaimed animation master Isao Buddhism 淨土宗 and Taoist landscape courtyard gardens provide settings Takahata 高畑 勲 (b.1935) who co- thought also spread eastward and for the extravagant social life at founded Studio Ghibli along with Hayao became localized. court. The banqueting scenes also Miyazaki 宮崎 駿. This 10th-century Tale draw many references from early of the Bamboo Cutter is the predecessor Bamboo Forest and Pastoral Heian architecture and interiors, of all Japanese courtly literature like the Landscape that are depicted in the painting The Tale of Great Minister Ban classic Tale of Genji (源氏物語, Genji scroll 伴大納言絵詞 1 Monogatari, early 11th-century). It is The bamboo forest is a mythic and ( Ban Dainagon Ekotoba) . centred on the protagonist Princess productive landscape, where the spirits The palace for the Princess is built in 寝殿造 Kaguya (かぐや姫 Kaguya Hime) of The and the bamboo woodcutter meet. the style of Shinden-zukuri Capital of the Moon (月の都 Tsuki-no- The story begins as the little Princess of the aristocratic class of the Heian Miyako) who was sent to Earth by Deva Kaguya (literally ‘luminous radiance’), period. Architectural complexes usually 天人 as a form of punishment. the size of a thumb, is born out of a consisted of buildings and a water garden growing bamboo shoot. Such an image in imitation of the land of Amida Buddha (阿弥陀仏 Amitābha) in Pure Land

Yuan Lin 2015 Planting Futures / 25 Buddhism. The most famous surviving Monoscape Here, the moonscape is also a subject to things, was a term coined by 18th- episode based on the Bamboo Cutter References example of such an arrangement is the evoke emotional attachment, nostalgic century Edo 江戸 commentator as an story. In terms of cinematography, the 1. Collection of Idemitsu Museum of Arts Phoenix Hall in Byōdō-in Temple 平等院 After experiencing the worldly desires mood and a quest for identity. important aesthetic concept in Japanese choices of camera pans and perspective (http://www.idemitsu.co.jp/museum/ 鳳凰堂 (1053), Uji 宇治 in the vicinity of of wealth and fame, growth and loss, culture.3 Such emotion regarding the create a viewing experience similar to collection/introduction/painting/yamatoe/ Kyoto. love and pain, the Princess is drawn Pure Land-scape passing of things is best demonstrated in reading handscroll narratives. Takahata yamatoe01.html)

by the magical power of the Moon on the cherry blossom scene and the legend has referred to emakimono (picture 2. Lothar Ledderose, “The Earthly Paradise: The rural-city dichotomy is highlighted the 15th night of the lunar month and The final procession scene recalls a of Mount Fuji. scroll, 絵巻物) as “the 12th-century Religious Elements in Chinese Landscape here by the vastness of the palace feels the urge to fly back home. This Japanese pictorial genre, the raigō 来 manga”. Two examples of Bamboo Cutter Art,” in Theories of the Arts in China, ed. chambers and the intimacy of the part references the familiar Chinese 迎 of “Amida welcoming the souls of The Buddhist idea of impermanence picture scrolls are in the collections of Susan Bush and Christian Murck (Princeton: Princeton University Press, 1983), pp. 165-83. kitchen garden. The Princess refuses mythology of Mid-Autumn: when the faithful to his Western Paradise”. (mujō, 無常) and the theme of Suwa City Museum 諏訪市博物館 and the rigid rituals only to find pleasure in Chang’e 嫦娥 the Moon Goddess of A depiction of this scene can be found reincarnation as a form of punishment Ryukoku University Library 龍谷大学 3. Mark Schilling, Review of “‘Kaguya-hime no cultivating her own garden. The back Immortality flies to the ‘celestial palaces’ in a wall painting in the Phoenix Hall of for crimes reveal much of Takahata’s 図書館.4 Regarding style, the anime is Monogatari (The Tale of Princess Kaguya)’: yard is used to express her disconnection 天上宮闕 /‘jade towers’ 瓊樓玉宇 of the Byōdō-in or those at the Dunhuang 敦煌 philosophy. The Tale of Princess Kaguya executed with simple, soft brushstrokes Ghibli's Takahata returns triumphant after 14 years” 21st November 2013. (http://www/ from courtly affairs. A similar experience moon, as the 11th-century ci 詞 poet Su caves. The garden platform structure 臺 also marks a beginning and an end for and watercolour to achieve a lightness, japantimes.co.jp/culture/2013/11/21/films/ of wandering in a natural landscape is Shi refers to in the melody of Shui diao serves as a meeting/parting ground for the amine director’s career. Supposed graceful, whimsical yet realistic effect film-reviews/kaguya-hime-no-monogatari- recreated here by looking closely at the ge tou 水調歌頭”. When the lunar deity immortals and men. The Princess leaves to be Takahata’s last movie, it has taken reminiscent of traditional ink landscape the-tale-of-princess-kaguya/#.U-djdCiYXKo) microcosm of the garden that stimulates myth spread to Japan from China during her palace, ascends to the clouds, and is half a century to bring the story to the big painting. 4. Collections of Ryukoku University Library imagination and stirs memories of a the Heian period, the moon was no received by Amida Buddha and celestial screen after he came up with the idea in (http://www.ryukoku.ac.jp/tenjishitsu/ pastoral landscape. longer a taboo image (as in sun worship beings playing musical instruments in his 20s. This thousand-year-old tale is his backnumber/no1/t1/0.html) and Suwa City in Japanese Shito 神道 tradition) but the flower-rain landscape. all-time favorite. His previous work, My Winnie Yuen Lai Chan is a garden Museum (http://www.city.suwa.lg.jp/web/ Paradise Landscape a trouble-free heavenly utopia like the Neighbors the Yamadas (ホーホケキョ historian specialising in Chinese and scm/siryou/siryou_take/index.htm). Peach Blossom Spring, where the Devas The concept of “mono no aware” (物 となりの山田くん, Hōhokekyo Tonari East-Asian landscape and China-West With her extraordinary beauty and enjoy longer lives and fewer desires. の哀れ), literally empathy towards no Yamada-kun, 1999) also has one Encounter of Garden Art. mastery of koto, the young Princess receives proposals from five suitors of high official rank and eventually from the Tenno Emperor 天皇 but she rejects them all. One of the five impossible things that the Princess requests her suitors to acquire is the Jeweled Branch of Hōrai (蓬莱の玉の枝 Hōrai no tama no eda). This legendary treasure can only be obtained from the Taoist immortals’ abodes of Hōrai (Penglai 蓬萊 in Chinese) Island, believed to be located in middle of the Eastern Sea between China and Japan. One suitor eventually brings a fake one he acquired after miraculous efforts and a sea voyage of 500 days from the port of Namba 難波港. Geographical data is precisely written in the story and matches nicely with the Chinese Classic of Mountains and Seas (Shanhaijing 山 海經).

It is interesting to note that the manmade ‘jade branch’ is in a bonsai (tray landscape 盆景) arrangement, a miniaturized representation of Penglai. It is believed that by artificially making a replica, one would have power over the real object.2 However, the magical connotation is conveyed here as something unobtainable. Furthermore, the artificiality of the ‘jade branch’ and other treasures is contrasted with their simpler, natural equivalents: birds, insects, wild animals, grass, trees and flowers–all of which the Princess enjoys.

Phoenix Hall in Byōdō-in Temple, Uji, Japan.

26 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 27 'When the planting works for A return to Disney the Hong Kong Disneyland Mathew Pryor

When the planting works for Hong then planted by TAS, a team of specialist The project changed lives, and the local Resort at Penny’s Bay were Kong Disneyland at Penny’s Bay were soft landscape works contractors horticultural industry. Ten years later, completed in 2005, they were the largest (Tarzan, Asia Landscaping, Shunde three met up again one Saturday morning completed in 2005, they and most high profile that had ever Nurseries), under main contractor China at the Boat House on Inspiration Lake, been undertaken in Hong Kong. The State Construction Engineering with and took a walk to see how the planting were the largest and soft landscape along the entrance roads the help of landscape architects and was doing and to reminisce on ‘what to the Disney Theme Park and Resort, horticulturists from CEDD, EarthAsia and feats were done’ in its creation. around Inspiration Lake, on the screen Maunsell’s site staff team. most high profile that had bunds that encircle the park, and for The planting design was always subject to all the infrastructure facilities and slope David Bloxham much discussion during the construction ever been undertaken in areas, covered more than 110ha. Landscape Construction Manager, period. Concerns were often expressed China State Construction Engineering as to whether the complex ornamental The planting required the manufacture (Hong Kong) Ltd. (2001-2006) design would survive. Hong Kong. The project and placement of some two million changed lives, and the cubic metres of fabricated topsoil, the Eric Lam “What do you make of the planting laying of 110km of subsoil drainage, and Sen. Landscape Architect (Sourcing / design, now that it has had time to the installation of one of the world’s Nurseries), TAS Specialist Landscape mature?” local horticultural industry. largest fully computerized irrigation Subcontractors, (2001-2006) systems. Some 35,000 mature trees David Bloxham headed the main Ten years later, how is the and 5,000,000 shrubs, of more than 660 Mathew Pryor contractor’s landscape team. “The different species, were sourced from Sen. Resident Landscape Architect, planting looks very mature, it’s amazing across SE Asia, Australia and America, Maunsell Consultants Ltd. how much it has grown, and the place is planting doing?' shipped via more than 50ha of temporary (2002-2006) very popular. The grass and shade of the nurseries in Shunde and Dongguan, and trees, it’s a great atmosphere. It always attracts a lot of school groups and bus Mathew Pryor tours. It is rare in Hong Kong to be able to sit out and enjoy the sun by the water”. Inspiration Lake is now considered to be one of HK’s top tourist attractions. When the three old colleagues had arrived that morning there had been only a handful of people, but an hour later the number had swelled to many hundreds.

“I like the lack of intensity, people just walking and enjoying being allowed on the grass.” Mathew Pryor was Senior Resident Landscape Architect in the site staff's office. “Now the trees have grown and created a sense of enclosure and some shade it feels just like a relaxing walk by a lake. I know Disney wanted it to be a botanic garden, but the overall effect is just very green, with big skies. There’s a lot of people just out here with a picnic. The lack of railings and barriers helps.”

Yuan Lin 2015 Planting Futures / 29

Eric Lam worked for TAS, the specialist tonne Ficus rumphii from the former “What do you remember best from Landscape subcontractor, and was Cheoy Lee Shipyard, 1200m across site, the construction?” responsible for sourcing the plant and then back again, became the stuff of material and managing the holding legend on site. Standing under the tree “The berms” said David, and a moment nurseries. “There's a strong atmosphere in its current location in the Arboretum, of silence follows as they each remember along the arrival road. The boulevard the three agree that the vast effort and the two year effort in forming more than effect is very successful. I think my expense seem well worth it. It provides 10km of the 5 - 9m high earth mounds proudest moment was the arrival of the a graceful backdrop to a pair of Chorisia around the theme park. Phoenix canariensis palms, it took so speciosa, the project’s most spectacular much effort to get them all here, then flowering trees. “I remember the topsoil mixing best. get them matched and set out perfectly. The scale of the operation was huge. They were really impressive when they Some of the species have done very That was a big headache. Getting all the were planted, but they have struggled. well. “The Elaeocarpus balansae have different materials: you remember the They don’t look so good now. I don’t grown a lot,” Eric continues, “and the peat from Heilongjiang which turned up think anyone is brave enough to get up Eucalyptus … I can't remember all the on site as a frozen lump, screening all there to cut the pineapple (shape at different species. Some of the unusual that wet CDG from Jordan Valley and all top of the trunk) properly.” Despite the exotics are really doing well, like those the lime and the fertilizers?” intensive maintenance, the palms have …. “ Eric points, but the name has faded declined since they were planted. The from memory. Eventually someone David spent more than a year of his watering of the surrounding ornamental remembers, Filicium decipiens. life sourcing all the component soil shrubs had made the soil too wet, and materials, and then working out how the palms were constantly stressed in “It is sad to see that many of the beautiful to mix to a very specific (29:71) recipe. the first years, which made them more exotics didn’t survive.” Mathew is in “... and all those soil mixing machines susceptible to pests and disease. reflective mood. “I used to love all the that we built, and the stockpiling and fabulous names: Brachychiton rupestris; sending soil samples off to America for “The planting along the roads is too Caryota no; Corypha umbraculifera; testing every other day. I am not sure I ornamental: too difficult to maintain,” Ensete ventricosa; etc. I remember the could do it again”. After trailing a range David adds, “the cost must be very high. heartbreak of losing all the beautiful of mixing methods such as front loaders, Disney maintenance within the theme Rain Trees (Samanea saman), and truck mixers, concrete batching plants park is very effective, they have a well- do you remember that palm species, etc. China State decided to build their developed system. They can make a where all the specimens died suddenly own industrial-scale soil mixing machine. clear distinction between the formal, one night?” (Oncosperma tigilarium). After three unsuccessful attempts they ornamental planting close to the visitors “But then there are a few species that finally built a machine that could mix soil and the mass planting in the background. I thought wouldn’t make it that have at a fast enough rate (6,000m3 / day). A lot of planting on the back side of of the exotic feature species are no are still there but almost invisible now. notes David. “At least the fast growing done OK,” he continues, “the Birds Nest They later built two more to meet the berms, however, which cannot be seen longer obvious.” As the planting has "Joe Lee (TAS Project Manager) went Ficus have created a bit of structure Fern trees (Schizolobium parahybum), production program. by visitors was wasted,” he continues, grown many of the formal characteristics to extraordinary lengths to find them, in the planting. The big Ficus (Ficus the Osmoxylon (O. geelvinkianum), the “many of the trees were planted too and ornamental effects have been lost. eventually tracking down a clump macrophylla) that we spent all that time Yellow Saraca (S. thaipingensis)." “The landslip area up on the hill is still close together, especially on the slopes The intricate patterns in the shrub of them by a Mexican restaurant in sourcing from Australia to plant along bare,” David points out. The slope below the old quarry. There are some planting alongside the roads are no Brisbane. Many of the special plants the Entry Road are good, although it is They have reached the north end of the planting high up on the hills to the perfect specimen trees up there that longer apparent. The planting has a more were bought from private estates." probably just as well that they are not lake and stand and look at a swathe of north was intended to cover obvious could be harvested”. informal feel, but is still impressive and growing as fast as we expected. The Agaves. Many of the 20 different species slip scars. It’s a 30 minute hike by foot effective in creating shade and greening. Mathew points out that the maintenance 3m high cycads we planted outside the of dramatic looking Agaves brought in from the nearest road, although much of Mathew has been amazed at the speed In areas, the planting was probably over- of Lake Island is obviously difficult, “it hotels, are exactly the same as they were from the USA have survived, and some the heavy lifting of materials was done of growth of some of the trees. "Even designed. looks completely overgrown and most of then." are in flower. by helicopter. “I think they abandoned though they were planted as semi-mature the variety has gone from the planting. the attempt to plant that particular area, trees many of the trees seem to have put “I think there were too many trees,” Eric Most of the wetland beds around the Talk of planting brings back some painful “One thing that I did come away from the it was too steep”, Mathew replies. Eric on several metres of growth just in the continues. “I know that Disney wanted edge of the lake have not done well”. It memories. “Good to see the bamboo project with is a greatly expanded plant Chan (Senior Field Officer 2003-2006) last 4-5 years. Trees like the Eucalyptus instant effect, but the density of the appears that only the Lepironia sp. have doing well. They almost killed Joe” says knowledge, and an appreciation of the sent me some post establishment photos spp. have thrived, but many have been planting is a problem now.” The trees survived. David." The soil drainage below the vast range of plants we could be using of the woodland planting a few years lost." Maintenance contractors have have been pruned, but the old colleagues slope on the north side of the lake had in Hong Kong.” Mathew adds. “Some ago. They achieved over 90% success suggested that the high volume of agree that the landscape would clearly “Do you remember all those been so poor that TAS had to replant of the less common local species were rate in the areas they could plant.” irrigation water has discouraged deep benefit from an active thinning program. different species?” the bamboo several times. Some of the a great surprise, such as that Bauhinia rooting, making some of the tree species The balance between immediate impact more sensitive species didn’t survive shrub (Bauhinia galpinii) and the Lipstick “Joe did most of the construction site vulnerable in typhoons. "The screen of and long term maintenance of the Inevitably the talk turns to species. With (Phyllostachys spp.) but those that did Trees (Bixa orelana).” He is happy to see work,” Eric says, “I was based in the trees between the lake and the railway, vegetation is always a challenge. so many, coming from all over the world, are thriving now (Bambusa vulgaris, some of the species that were unusual nurseries preparing the plants. There for example, has been almost completely everyone involved in the planting works B. chungii). The Oil palms (Elaeis at the time have become popular since were huge logistical issues in sourcing blown away." Eric notes that the Phoenix reclinata had their favourites. guineensis) alongside are also struggling. and are now being planted across Hong so many trees and shrubs coming from at the centre of the cascade waterfall There are better memories. “The big Kong: Tibouchina, Xanthestemon, and ten or more different countries around Eric agrees. “The speed at which plants roundabout, which were meant to be “The local species have done well, but transplanted tree is fabulous,” Eric Tabebuia. Another positive impact of the world.” At the height of the project have grown has caused problems. Most the candles in 'Mickey’s Birthday Cake' there seem to be few exotics left,” observes. Moving the 25m wide, 175 the whole project. TAS were operating more than 50 ha

32 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 33 of nurseries in Shunde and Dongguan, detail and maintaining progress, is what wrap the root balls, now everything is with all the trees and shrubs needing to I was most impressed with,” David says. properly wrapped and wired. It takes be sourced, grown on, and transported “They were not very knowledgeable more effort and time but the market is to site to meet a very complex planting about Hong Kong conditions, and I willing to pay for it. We learnt a lot about program. didn’t agree with everything they asked what is not possible. The palms, I don’t us to do, but you couldn’t fault their think we had the expertise in Hong Kong “I vividly remember the trips to Australia determination in getting it done.” The to keep the palms in good condition.” to look for trees, and all the effort to expression ‘done, done, done’ became get them export licenses,” Mathew well known on site. The Disney team Mathew reflects “I think we have a recalls. TAS had a full time operation would never accept any work that was better understanding of what will in New South Wales looking for mature not perfect. It was not finished until it succeed and what won't. Everyone who Ficus macrophylla on farming estates, was ‘done, done, done’. goes to Disney is really impressed with digging them out and then holding the planting. It is a great atmosphere and them in a quarantine nursery for a year “All the work on the soil grading, and fully worth the effort, but it is the simple so that they could pass the Australian setting out those swales,” David recalls, things, rather than complex unusual phytosanitary requirements for export “Disney wouldn’t give up!” The grass stuff that has had the greatest impact. without removing all the soil. swales that encircle the Lake prevent ‘Doing the basic well’ has really been the surface water from the lawn areas take-away message for me.” “Remember Comstock and his ‘fruit running off into the lake and potentially salad’ planting, that didn’t survive?” taking fertilizer with it. Grading them “… and finally, do you ever go to he continues. Disney’s Paul Comstock so that they drained perfectly was an the theme park itself?” (who had conceived most of the planting immense effort of trial and error which designs), had introduced the site team to drove many to the edge. “I learnt a lot David. “No. but I come to the Lake quite a new mixed planting technique, which about sequencing, irrigation and planting often.” involved throwing plants of different works,” he adds, “… and yes, it changed species into a prepared bed and planting the landscape industry in Hong Kong, in Eric. “Yes, I went once after we finished them where they landed. The workers particular, establishing new standards the Penny's Bay contracts, but to check were not impressed, and came back after in moving big trees with big root balls. out the quality of Disney’s plants, he had left, to plant them ‘properly’." Techniques in Hong Kong for lifting trees compared to those we supplied for the on and off trucks, without trunk damage infrastructure works.” “Do you remember the first tree that has improved greatly since Disney, and was planted?" The site had been so now comply with safety requirements. Mathew. “I went once, but I’m too old. exposed in the first couple of years that The workers have moved on to other If I have visitors in town we tend just to when the first tree was planted, all the companies but took their knowledge of head for the lake.” workers flocked to its shade to eat lunch. the ‘Disney’ method with them."

“Did it change the landscape in Eric agrees. “Penny’s Bay lifted standards Hong Kong?” across the industry. There is a much higher expectation on the quality of plant Mathew Pryor is Head of the Division of “Disney were a difficult but highly materials and planting workmanship. Landscape Architecture at the University focused client. I guess their attention to Before nurseries in China wouldn’t even of Hong Kong.

34 / Yuan Lin 2015 Planting Futures 'Whereas great damage is A tree preservation ordinance for done to trees and plantations Hong Kong: An historical note in the neighborhood of Mathew Pryor the respective villages of Calls for an ordinance for the proper protection and management of trees in this Colony; and whereas urban Hong Kong have regularly been made over the last few years1, although there seems little prospect of specific it is frequently difficult or legislation being enacted. It may come as a surprise, therefore, that more than impossible to discover a century ago Hong Kong did enact a Tree Preservation Ordinance. It was the persons who have very brief and narrowly focused, and it is not clear if any prosecutions were ever made under it, but it did sit within committed such damage …' a wider body of legislation that sought to protect natural vegetation, street trees and forestry plantations, and Tree Preservation Ordinance, 4 of 1888 offered harsh punishment for offenders. This article examines the history of tree protection legislation in the early colonial period, both in relation to the growing value of trees to the community, and to the increasing efforts to green the city and the territory. The rationale for legislating for tree protection in this early Historic photograph. ‘Wyndham Street, Central District’ (c. 1905), The University period may give insight to the argument of Hong Kong Library collection over regulation and protection of trees in Hong Kong today. indigenous villagers6 needed timber not and grass for fuel, housebuilding,9 only for house building and fuel, but for and furniture. Timber was imported An early history of the legal quarrying activities. Tall grass was cut from Canton, but was expensive, so protection of trees both for fodder and for constructing any opportunity to acquire it from the mat-shed buildings. These customary surrounding landscape was readily Provision for the protection of trees from practices had resulted in most hill slope taken. destruction first appears in the Hong vegetation being reduced to little more Kong statute book2 in the 1845 Ordinance than sparse grass. Trees only survived The same wording identifying the for the Prevention of Nuisances3. The where they were inaccessible (ravines) wanton cutting of vegetation as a ‘felling, cutting, destroying, or injuring or were growing close to villages and nuisance was inserted into the Ordinance of any standing or growing tree, shrub, had productive value (fruit trees) or to Regulate Chinese Burials, in 1856.10 or underwood, any grass-sod or turf, …‘4 cultural significance (feng shui woods)7. This addressed another common threat is identified as a nuisance carrying the The scant vegetation can be seen in to natural vegetation. Chinese burials penalty of a fine up to $1005. early photographs of the territory (1860 could be elaborate events requiring onwards), and had given rise to Lord wood for both temporary constructions Legislation for the protection of Palmerston’s famous denunciation of and giving rise to the threat of fires from natural trees and vegetation at this Hong Kong as a ‘barren rock’.8 the burning of incense (a threat that very early stage in the city’s history, persists today).11 before government had even started The sudden arrival of tens of thousands planting trees, reflects deep concerns of settlers in the first few years of the Street tree planting started in 1847, along over the destruction of the natural colony greatly exaggerated this demand, Queens Road12, and continued through landscape. Prior to colonisation, with the new colonists needing wood the 1850s and 1860s along most of the

Yuan Lin 2015 Planting Futures / 37 wider thoroughfares of the new city. The a nuisance to being a crime (felony). hard labour, and with or without made desperate pleas to Government to value of trees in greening the city and Protection of trees from wilful theft, solitary confinement, and if a male fund a substantial increase in the number in creating a healthier environment on injury and damage (as opposed to under the age of sixteen years, with of forest guards and greatly increase the the streets became quickly recognised careless destruction) was made explicit or without whipping' severity of punishments for offenders. 30 both by residents and visitors to the in a series of ordinances in 1865 territory.13 relating to property, all with very similar These severe penalties were directly The Legislative Council eventually wording. The provisions of the Larceny comparable to those stated in the responded by enacting a Tree Establishing trees along the city’s Ordinance, 5 of 1865, Clause 23 ‘Stealing ordinance for damaging a bridge, sea- Preservation Ordinance, 4 of 1888. The congested streets was a major tree etc., growing in pleasure ground or wall, or electric telegraph, or for killing law was to protect trees in government challenge. Besides exposure to repeated elsewhere’, and the Malicious Damage cattle or setting fire to a ship, suggesting plantations. It was only four paragraphs typhoons,14 new trees faced threats Ordinance, 6 of 1865 Clauses 16-18 the resolve with which the administration long, but to the point. After the from building works, road alterations15 ‘Injuries to crops, trees and vegetable sought to tackle the problem. introductory statement: and the sheer intensity of activities in productions’, were quickly consolidated narrow corridors. Demand for cheap into the Malicious Injuries to Property Clause 20 relates to the lesser offence ‘Whereas great damage is done timber remained high. Queens Road Ordinance, 8 of 1865. Clause 18, of ‘Destroying trees &c. wheresoever to trees and plantations in the West, for example, was planted in 1855 ‘Destroying trees &c. to the value of growing, to the amount of 24 cents’, neighborhood of the respective but photos of the street corridor in 1860 more than $519 growing in a pleasure where conviction before a police villages of this Colony; and whereas showed that all but one of the trees had ground &c.’ stated: magistrate made an offender liable to it is frequently difficult or impossible been removed.16 In an account of his visit be imprisoned for up to three months to discover the persons who have to Hongkong in 1852,17 Robert Fortune “Whosoever shall unlawfully and for a first offence, six months for a committed such damage …’ made reference to locals stripping lower maliciously cut, break, bark, root up, second offence and two years for a third branches from roadside trees for fuel. or otherwise destroy or damage the offence. Clause 21 has the exact same … the key provision is set out in the The continuous loss and replacement whole or any part of any tree sapling provisions but relates to ‘Destroying any second paragraph: of trees resulted in uneven heights or shrub, or any underwood growing fruit or vegetable production in a garden’ and shapes of trees, as can be seen in in any pleasure ground, garden, defining this to mean ‘… any plant, fruit, ‘Whenever it is proved to the photos along Queen’s Road Central orchard, or avenue, on in any ground or vegetable production growing in satisfaction of the Governor-in- around 1880.18 Tree avenues were only adjoining or belonging to a dwelling any garden, orchard, nursery ground, council, that trees or plantations successfully established along streets in house (in the case the amount of the hothouse, greenhouse or conservatory belonging to the Government in the administrative and military areas of injury done shall exceed the sum of ...‘ Magistrates were able to impose the neighborhood of any village Government Hill (Admiralty) where trees five dollars) shall be guilty of felony, penalties of six months in prison and a in the colony have been felled, could be effectively policed. and being convicted thereof shall fine of up to one hundred dollars for a cut, mutilated, lopped, barked, or be liable, at the discretion of the first offence. Likewise Clause 22 has the otherwise damaged or destroyed, The destruction of natural vegetation Court, to be kept in penal servitude same provisions relating to ‘Destroying and that there is sufficient reason and planted trees became so significant for the term of three years, - or to vegetable productions not growing in to believe that such damage or for the colonial authorities, that in be imprisoned for any term not gardens &c.’ defining these as ‘ ... any Historic photograph. Queen's Road East, Wan Chai 1870s, The University of destruction was committed by the legal terms it was elevated from being exceeding two years, with or without cultivated root or plant used for the food Hong Kong Library Collection inhabitants of the said village or by of man or beast, or for medicine, or for any of them, it shall be lawful for distilling, or for dyeing, or for or in the hills. 22 Numerous practical and political nurseries to raise trees from seed both the Governor-in-Council, by order course of any manufacture, and growing motives have been suggested for the collected from the hill slopes and donated under his hand to levy a special in any land, open or inclosed, not being sudden initiation of a territory wide to Hong Kong by private collectors and rate assessed upon such village to a garden, orchard, or nursery ground ...’ afforestation program. While timber botanical gardens in other colonial an amount sufficient to cover the One month in prison and a maximum fine production was an obvious driver,23 territories in SE Asia. By the end of the damage done …’ of five dollars comprised the punishment there was a growing association of tree century several million seedlings had for a first offence. planting with public hygiene,24 through been planted out in forestry plantations Essentially, the law was just a refinement cooling and purifying the city’s air, and across Hongkong Island and Kowloon.28 of previous legal provisions against The rapid publication of these ordinances visual greening. Hong Kong had been damage to trees in government hint at the state of disorder generally afflicted with infectious disease from A key problem was the lack of staff; with plantations. It was, however, targeted at existing within Hong Kong at the time, the outset,25 and greening of the barren forestry workers dedicated to planting prohibiting the activities of local villagers, and the struggle of the British to exert slopes not only gave settlers hope of work they were not able oversee the and reflected deep suspicions of them authority over the new colony.20 some protection from the subtropical well-being of the planted trees. Theft held by the colonial administration. It sun, but was also symbolic, creating a and destruction of newly planted was enacted in the same year as the The theft and destruction of trees sense of colonial authority through the seedlings was widespread. Villages used ‘European District Restriction Ordinance’ continued, despite the new laws, and the ‘proper’ stewardship of the landscape.26 the recently cleared tree plantation which sought to bar Chinese from police were prompted to issue formal areas29 for foraging and grazing of cattle crowding European settled areas on notices in the 1870s, against theft and The British botanist Charles Ford was and goats. Six forestry guards were the grounds of health, and was in the the collection of wood.21 appointed in 1872 as Superintendent appointed in the early 1880s to protect context of other legislation that sought of the newly established Government the newly planted areas, but these were to exclude locals from areas of precious By the early 1870s tree planting had Gardens, and the Colonial Secretary almost completely ineffectual given the natural resources (e.g. water gathering been undertaken along most of the consolidated responsibility for all tree plantation areas were scattered all over grounds). The identification of ‘the possible street corridors, and attention matters in the territory under him.27 the island from Aberdeen to Kennedy village’ as the transgressor was legally Historic photograph, Pedder Street, Looking South from Praya Central, (1868). by John Thomson, The University of Hong Kong Library Collection turned to the afforestation of the barren Ford established ten large production Town. The Superintendent of Gardens unusual and probably unenforceable.

38 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 39 The use of fines as penalties suggests the during WWII resulted in the consumption improvement and cultural heritage, the References 14. Significant numbers of mature trees were Department, from 1872 onwards were offence was considered a nuisance. It is of nearly all vegetation within the entire threats are also considerably smaller. lost to typhoons. The storm of 23 September published in the Hongkong Government 1874, in particular, caused very sizeable losses Gazette. Common complaints underpinning 1. HKIP Position on Urban Tree Ordinance, CUHK not clear if anyone was ever prosecuted territory. Comprehensive Tree Ordinance HKGG 17 October 1874 under the law, but its very existence calls for tree legislation relate mostly 29. S.E. Hamilton, Watching Over Hong Kong: reflected the competing values of trees Current laws protecting trees and to the application of laws (rather than 2. Historical Laws of Hong Kong Online. HKU 15. Ford, C., Report on Government Gardens and Private Policing 1841‒1941. (Hong Kong: Hong to both locals and colonists. natural vegetation generally follow the the laws themselves) and the need Libraries. Accessed June 2015 from “During the last five or six years a very large Hong Kong Studies Series, 2012) same broad structure as those described for clearer definition of administrative number of trees … have been sacrificed in the Further attempts to introduce legislation above. Wilful damage is covered by responsibilities. With the establishment 3. Ordinance for the Preservation of Good streets to make room for improvements and 30. Westland, A.B., Annual Report of the Botanical against damage to trees in forests and Crimes Ordinance (Cap. 200) and Theft of the Greening Landscape and Tree Order and Cleanliness and the Prevention of alterations in streets and building.” and afforestation Department for 1885, plantations can be found in the Crown Ordinance (Cap. 210) while the lesser Management Section (GLTMS), however, Nuisances within the Colony Ordinance (1 HKGG, 17 April 1886. 16. Historic photographs. ‘The western end of Development Bureau has been able of 1845). Clause 8 ‘Various other nuisances Land Preservation Ordinance, 10 of matter of casual damage is addressed in principally in the nature of trespass or Queen's Road, Victoria, Hong Kong’ and ‘A 31. GLTMS Development Bureau’s ‘Measures 1910 (amended in 1912): which sought terms of a nuisance under the Summary to make significant improvements in damage’ subclause (1.) Street in the Chinese Quarter in Victoria, Hong on Tree Preservation’ sets out the current to prevent injuries to trees upon crown Offences Ordinance (Cap. 228) and the quality of technical guidance and Kong’ (c.1860), Duke of Newcastle’s Collection legislative framework. Crown Land Preservation Ordinance, 6 Ordinance (Cap. 132). The Forests tree matters. Road West, Bird Bridge’ (c.1890), Hong Kong of 1917: which made provision for the and Countryside Ordinance (Cap. 96), 5. In Hong Kong Dollars, although according Public Library. 32. LCQ13: Tree management reply by the better protection of trees on crown land Country Parks Ordinance (Cap. 208), and The history of tree legislation in Hong to the Hong Kong Museum of History silver Secretary for Development, Mr Paul Chan, and other crown property from willful Antiquities and Monuments Ordinance Kong indicates that new laws are sycees and Chinese cash coins were the 17. Robert Fortune, A Journey to the Tea in the Legislative Council (June 3, 2015) to Countries of China Including Sung-Lo and a question by the Hon Leung Che-cheung. typically enacted only in response to main currency at the time. Banks only began damage. The Forest Fires Prevention (Cap. 53) make specific provision for tree issuing Hong Kong dollar banknotes in 1846, the Bohea Hills; with a Short Notice of the Accessed from problems of fire in forest reserves and that we would need to await some new in 1865. 100 dollars was a common amount the Himalaya Mountains: With Map and plantations, and the Plants Ordinance, 11 The enactment of a Tree Ordinance is substantial threat to their existence for summary offences. Casual workman might Illustrations, (London: John Murray, 1852).

to achieve a second Tree Preservation expect to be paid $3 - $5 per month at the of 1920, reiterated previous provisions highly unlikely at this time. Government time. 18. Historic photograph. ‘Queen's Road Central, in seeking general protection of trees believe that existing legislative measures Ordinance. Central District, Hong Kong Island’. (dated shrubs and other plants. The protection for tree protection31 are already 6. Mayers, W.F. and King, C. (1867). The treaty 1880) Hong Kong Public Library, of trees in forested areas was finally comprehensive.32 Our urban and rural ports of China and Japan: A complete guide to the open ports of those countries… Trübner 19. Clause 19 is identical save for the amount condensed in the Forestry Ordinance tree populations are now very much and Co., reported the 1841 British Military exceeding $25 Cap 96, 11 of 1937, which is the fore- larger and in better condition than 130 Census of the pre-colonial population of runner of the legislation in force today. years ago. With the value of trees being Mathew Pryor is Head of the Division of Hongkong Island, as 7,450. 20. Evans, D.M.E., ‘The foundation of Hong Kong: All of this was set aside, just a few years firmly centred on their benefit to local Landscape Architecture at the University a chapter of accidents’, in M. Topley ed., Hong of Hong Kong. 7. Hayes, J. (1984). Hong Kong Island before Kong: The Interaction of Traditions and Life later, when the extreme shortage of fuel ecology, urban greening, environmental 1841. Journal of the Royal Asiatic Society in Towns Hong Kong, (Hong Kong: Hong Kong Hong Kong Branch. 24 105-142 describes the Branch of the Royal Asiatic Society, 1972) landscape before colonization around village 1‒41. areas 21. Police notification, HKGG 1 April 1876 8. Endacott, G.B. (1958) History of Hong Kong. Oxford University Press 22. Richard T. Corlett, ‘Environmental forestry in Hong Kong: 1871–1997’, Forest Ecology and 9. Shop-house construction in the new city Management, 116.1 (1999) pp. 93‒105. depended largely on the Chinese fir, Shelton, B., Karakiewicz, J., & Kvan, Y. (2010). The 23. Humphreys, J.D. (1877). Letter to the Surveyor making of Hong Kong: From vertical to General, dated 1 October 1877 regarding volumetric. London, Routledge p36 planting for timber production in Hongkong. HKGG, 17 November 1877. 10. Ordinance to Regulate Chinese Burials and to Prevent Certain Nuisances within the Colony 24. Harland, W.A., Acting Colonial Surgeon’s of Hongkong, Legislative Council of Hongkong, Report for 1853, HKGG 29 April 1854. Request (Clause.6(i)). (12 of 1856). for more tree planting also made by J.I.Murray, Report of the Colonial Surgeon, 1869, HKGG 11. Chau, K. C., (1994). The Ecology of Fire in Hong 14 May 1870. Kong. (Doctoral thesis, The University of Hong Kong), Hong Kong. 25. Peckham, R. ‘Infective economies: empire, panic and the business of disease’, Journal of 12. Pryor, M. (2015) Street Tree Planting in Hong Imperial and Commonwealth History, 41:2 Kong in the Early Colonial Period (1842‒98). (2013) 211‒37. Journal of the Royal Asiatic Society Hong Kong Branch, 2015. 26. Peckham, R. ‘Hygienic Nature: Afforestation and the greening of colonial Hong Kong’, 13. Both Fryer and Smith note the value of trees Modern Asian Studies 2014: 1‒33. for shade and greening in the new city. 27. A new Tree Planting Department (established Dagenais, F. ‘John Fryer's early years in China. 1873), progressively became the Gardens II: First impressions of Hong Kong and the and Plantations Department (1877) and then Chinese people’’ JHKIBRAS, 30 (1993) 146‒68. Botanical and Afforestation Department Smith, A. (1859). To China and back: being a (1880). diary kept, out and home, (Hong Kong: Hong Kong University Press, 1974 reprint of 1859 28. Detailed annual reports on the activities of original). p29 the Government Gardens and Tree Planting Trees on Queens Road Central (c.1870). The Wellcome Foundation

40 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 41 A tree for all reasons: Large trees in urban areas Barnaby Smith

Introduction Canopy trees in Wan Chai very notable, primarily because they have had sufficient space to mature. It was encouraging to note the contest Perhaps the most important benefit "Our Favourite Old and Valuable of large canopy trees in this climate is The Ficus microcarpa 細葉榕 on the Trees" organised last year by GLTMS1, shade, especially now that the traditional junction of Thomson Road with Johnston promoting public appreciation of trees in shop-house colonnades are all but gone. Road, opposite the Hennessy Road Hong Kong. The cooling effect is remarkable, and Government Primary School, provides it is no coincidence that people put some shade and relief from pollution. Appreciated they may be but many seats under them. Around Wan Chai It has recently been pruned to a high of our urban trees exist in precarious there are several banyans planted in standard and reflects the efforts by circumstances. Footpaths are filled with the late 1980s and early 1990s under LSCD to employ professional local and underground utilities, there are signage the Greening Wan Chai Scheme5. The international arborists to look after these and sight line constraints and, despite scheme was one of the precursors of the invaluable assets. On the opposite side guidelines from HKPSG2, often only new recent Greening Master Plans by CEDD. of the school on Hennessy Road are a developments can provide sufficient These have dramatically enhanced the line of Ficus benjamina 垂葉松 providing space required for large street trees. Wan Chai streetscape for generations much needed shade for several bus The Greening Master Plans (GMP) by to come. Several of these trees are now stops. CEDD have helped push the envelope in optimising urban greening3.

With this in mind, a discussion regarding the value of large urban trees and how best to preserve them is timely. The following examples in Wan Chai are presented for discussion. Perhaps the main observation is the great value that even a single large tree can have in transforming our urban landscapes. None of the following examples are OVTs4.

A mature Ficus microcarpa and a Mangifera indica stand so close they appear Threat to trees from underground Ficus microcarpa at the junction of Thomson Road and Johnston Road to be one large tree on Queensway in front of the Bank of China Building utilities, Queen’s Road East

Yuan Lin 2015 Planting Futures / 43 Nearby Wodyetia bifurcata 狐尾椰 and Garden Road were widened in the 子 palms, planted under the Wanchai 1970’s. His efforts seem to have paid GMP, in the central median of Hennessy off in the retention of two trees, a Ficus Road have created a green corridor. A microcarpa and a Mangifera indica 芒果, handful of palms were retained from barely a metre away from the slip road the existing late 1980s stock, including linking Cotton Tree Drive to Queensway. some Syagrus romanzoffiana 金山葵 The trees subsequently survived the and Archontophoenix alexandrae 假檳 dismantling of Murray House (now 榔. These have increased significantly in Stanley) and the construction of in size and vigour since the concrete the China Bank Building in the late paved surface was broken out under the 1980s. According to pre-1970’s aerial GMP. The new Wodyetia palms can be photographs there were many trees in expected to provide visual amenity for and around the barracks. The benefit decades to come. It is a tribute to CEDD that just two mature trees can provide, and the resilience of the Wodyetia that visually and physically, in ameliorating none of these trees have failed nor been the polluted canyon that is Queensway, damaged by typhoons since they were is remarkable. Khaya senegalensis on Luard Road planted in the late 1980s. planted in 2009. The mature Khaya senegalensis 非洲 but what real cost is this to such an formosana 楓香 has trebled in size Almost opposite the school and slightly 楝 on Luard Road, planted under the international city? over the past few years. It’s especially west is a similar sized Ficus microcarpa, at Greening Wan Chai Scheme in the late encouraging that Swire Properties has the junction of Johnston Road with Wan 1980s, are respectable trees by any Due to the narrow footpaths and busy recently planted an excellent Jacaranda Chai Road. It is a curious fact that this standard, considering that they are only traffic, Queen’s Road East in Wan Chai mimosifolia 藍花楹 at the junction of specimen (623rd tree of the Greening 25 years old. The visual quality of Luard has few street trees. The most obvious Queen’s Road East and Hennessy Road. Wan Chai scheme), was planted by Road has been transformed by these exception being the row of trees in front A seat wall maximizes the benefit of its country singer John Denver in April 1994. excellent specimens. Sadly one failed in of Dominion House just east of Pacific future shady canopy. recent years, and was replaced with a Place 3. Dominion House was designed Further down Johnston Road at the Melaleuca cajuputi subsp. cumingiana with a covered arcade running parallel to Swire Properties also undertook a junction of Luard Road, opposite 白千層. This species, and more recently the footpath which effectively doubles revamp of the shady Dominion Garden Southorn Playground, there is another planted Garcinia subelliptica 福木 the footpath width while providing (with two carefully retained wall trees) Ficus microcarpa (600th tree of the appear to be the new species of choice shade, rain shelter, space for tree and Kwong Ming Street Children’s Wodyetia bifurcata planted in the median of Hennessy Road scheme), this one planted by Governor for street trees in Lockhart Road and planting and protection from traffic, all Playground, in 2012. It complements Chris Patten in 1993. Southorn adjacent congested street locations. in line with HKPSG. What a shame this is similar Wan Chai schemes such as the Playground was laid out in 1934, and They at least provide some greening, if the only building designed in this way. St. James Settlement / Local Community benefits the community not just by not canopy shade. Scheme of Bauhinia Garden at nearby providing for active recreation, but by its The trees planted there are a collection Lun Fat Street (2002). The Jacaranda mature trees along both the Hennessy Understandably maintenance costs of Ficus and Cinnamomum, and at the mimosifolia planted on Star Street at the Road and Johnston Road boundaries. for spreading shade trees are higher, north end a beautiful Liquidambar south west corner of Pacific Place 3 is Three Ficus virens 大葉榕 in the footpath also well worth a look. of Luard Road, just west of Southorn Playground, are particularly impressive. Given the low pedestrian usage, there may be potential to break out more concrete paving and allow these trees vital air and water.

These street trees provide much needed greening in this dense urban environment. It should be noted that they are well maintained by LCSD. People now talk about the financial value of trees. I wonder what is their monetary worth? Their amenity value to thousands of people every day is unquestionable.

Perhaps the most amazing thing about these trees is that they exist at all. According to Gavin Coates, Michael Kirkbride told him of his great efforts to save some of the trees within or around John Denver's Ficus microcarpa at the junction of Johnston Road and Wan Dominion House, Queen's Road East Jacaranda mimosifolia recently Jacaranda mimosifolia planted at the planted at the junction of Queen's south west corner of Pacific Place 3, Murray Barracks when Cotton Tree Drive Chai Road, a long way from any country roads. Road East and Hennessy Road. Star Street

44 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 45 Queen’s Road East runs approximately healthy. It may even be a seedling from along the original coastline and the Hung the one above the temple opposite and Shing Temple was virtually on the beach was almost certainly not planted. in 1841. Hence this was a ship building / mooring / warehousing area (the One should credit LCSD for keeping this memory lives on in street names such “rogue tree” in their SOA and allowing it as Ship Street and Schooner Street) and to thrive. The planting area appears to in a recent seminar, I learnt that Spring have been extended to accommodate its Garden Lane, reclaimed almost opposite, health and growth. Again, it is proof that was a place for wealthy foreigners to one or two mature trees can transform live and had some of Hong Kong’s first the urban landscape and help ameliorate merchant gardens in the late 1840s. In a gloomy corridor. fact Queen's Road East was one of the first streets to be planted in Hong Kong, Focal Points around 1850,6 though the original trees disappeared long ago. Individual trees at focal points can play their part: we know the older urban The age of the Ficus virens just behind the areas of Hong Kong have limited space temple is unknown, but the fact that the for large canopy trees. As a resident, area has been undisturbed has allowed I enjoy and respect the planting of it to mature and provide significant smaller trees in narrow footpaths, greening visible from the road. Hopefully which to be fair, are sometimes more Ficus benjamina next to AIG Tower on the wide footpath of Murray Road, Central the tree will not be damaged by the practicable and appropriate. However, current construction works. it would appear that the value of the Another approach is to provide focal large growing species. References relatively few large canopy trees in trees, either individuals or groups, at Ficus viren 1. Greening, Landscape and Tree Management Similarly, the s almost opposite dense urban areas provide massive junctions or where there are localised We should look for new opportunities Section in Development Bureau, HKSAR in a sitting-out area at the junction of public benefits. There are often idealistic spaces available. to grow large canopy trees. Indeed, the Government. Accessed from Ficus benjamina Street and is best viewed from the north. without wholesale footpath widening Ficus virens at the junction of Queen’s groups are the next to be set aside for large trees. These may 2. Hong Kong Planning Standards and Guidelines The tree is perched on a wall but appears and reduction of vehicular carriageways. Road East and Swatow Street the AIG Tower on Murray Road in Central be limited, but road junctions, sitting (HKPSG) Chapter 4 “Recreation, Open Space which provide much needed shade to out areas, roundabouts and footpaths and Greening” Development Department, pedestrians. Landscape design is a critical with set-backs offer opportunities HKSAR Government. Accessed from positive and critical step for current and It is also encouraging that LCSD has future generations that schemes such as been so positive in trialling different 3. Greening Masterplan (GMP). Civil Engineering the GMPs succeed and associated public tree species in positions where more and Development Department, HKSAR Government. Accessed from community. to thrive. A good example is the Adenanthera microsperma 海紅豆 4. LCSD’s Register of Old and Valuable Trees. Cost or benefit? below the footbridge crossing Hennessy Accessed from < http://www.trees.gov.hk/ en/tree_appreciation/register_old_valuable_ Road. On the west side of the footbridge tree/index.html> Studies have been carried out overseas at Gloucester Road a few Chukrasia and equations devised to place a tabularis 麻楝 are also showing their 5. Greening Wan Chai Scheme, undertaken by monetary value on trees based on the worth. the Wan Chai District Office in the late 1980s environmental services and benefits they and early 1990s. provide. These studies usually indicate Our profession today carries part 6. Pryor, M. (2015). Street tree planting in Hong that the benefits of large canopy trees of the responsibility to ensure that Kong in the early colonial period (1842-1898). far outweigh the maintenance or other our grandchildren can take their Journal of the Royal Asiatic Society Hong Kong costs incurred. Trees are not burdens grandchildren to play in the shade of an Branch. for future generations, they are vital OVT. investment opportunities.

It should be an urgent priority to impose Barnaby Smith is a Hong Kong based a properly assessed value system in landscape architect with extensive Hong Kong so that tree benefits can experience gained in the HKSAR, PRC and be properly weighed against their Europe. He has recently been involved in costs. Species choice for new trees is the design and implementation of the sometimes influenced by the fact that Greening Master Plans for CEDD and is only the costs are quantified and taken currently supervising the implementation into account and this predicates against of the GMP for New Territories SE. Ficus virens just behind the Hung Shing temple on Queen’s Road East

46 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 47 香港樹木管理的思維缺憾 劉興達

最近發生的連串塌樹事件,特別是彌敦 發展,除了增加不少綠化地帶外,新建道 城市森林學 (Urban Forestry) 一般需要 道栢麗大道的百年榕樹在無風無雨下 路旁都加入綠化,種稙後的樹木大多交 4至5年才能獲得學士或碩士學位。畢 倒塌,令致無辜市民受傷和財物損失,我 由兩個市政事務署或漁農署管理,權責 業後需要從事相關工作若干年,才能獲 們在惋惜痛心之餘,應該從事件中冷靜 比較簡單和清晰。這段期間的發展,綠 得認可,按不同地方和專業團體要求,進 反思,‘冰凍三日,非一日之寒’,尤其 意盎然的新市鎮大大提高市民對舊市 行專業注冊程序,並受到註冊要求的監 是樹木生長問題, 都是多年累積而成, 區的綠化訴求,市政局有見及此,亦成立 管,成為一名問責的專業園林經理,他們 天氣和颱風只是加速問題的表面化,並 了市區綠化委員會去統籌和執行市區 的工作就像物業經理,工程項目經理一 非所有塌樹的主要原因。無論如何,事 的綠化工作。但礙於歷史原因,這些工 樣,統籌負責地區或物業內的所有園境 件獲得政府最高層的關注,特別在發展 作在故有的市政思維上,並未能提升至 和樹木方面的管理工作,運用專業知識 局成立了樹木管理辦事處,相信是香港 專業層面,往往在與專業工務部門商討 和經驗適當引進不同專家組成管理團 有史以來,首次有政策局全面負責綠化 技術問題時,未能為樹木爭取到合適的 隊,例如園藝師;病理;真菌專家,草坪專 和樹木管理政策,是為香港創造‘優質 生長環境,亦未能有效監督建築和工務 家,樹藝師,土壤專家等。全面而宏觀地 環境,優質生活’的重要一步。適當而 工程對樹木的影響。因此,市政局在80 製訂符合當區或物業環境需要的管理 宏觀的綠化規劃和完善的管理,不僅令 年代末期通過在市政事務署內加入專 方針,工作程序,指引,人員培訓, 資源調 香港城市環境優化,美化和宜居宜產,更 業園境師職系,希望將市區綠化工作和 配和監督前線員工,危機處理等重要措 能協助香港成為優質的低碳城市,提高 樹木管理從此提升至專業層面,十分可 施。由於前線樹藝人員是負責執行樹 香港的國際地位和競爭力。因此,正確 惜的是,此項決定遭到部份市政員工反 木護理工作,他們的技術和經驗要求十 的政策思維是達至短中長期目標的重 對而胎死腹中,白白喪失了一次令樹木 分重要,所以,為樹藝人員進行有系統的 要基礎。 管理專業化的契機。回歸以後,兩個市 培訓和行業註冊十分迫切,並提供充足 政局被取消,市政工作交由康樂文化事 的工作和進升機會,才能全面提升樹木 首先,上屆政府在成立樹木辦首份報告 務處和食物環境衛生處兩個政府部門 護理工作的水平。有見及此,香港園境 書中訂立‘人樹共融’政策目標本身 負責。可想而知, 樹木管理更加受到忽 師學會正進行為樹藝從業員進行認證, 在思維上值得商榷,因為提倡和諧共融 視,在缺乏資源和專業支援的情況下,只 為樹藝專業化踏出重要一步。 表示雙方存在茅盾;有爭執,就像政府不 能把管理責任按土地誰屬分界,各自負 斷提倡構建和諧社會一樣。大家要知 責土地界線範圍內的樹木,亦成為最近 另外,樹木辦經常強調上游的綠化規劃 道,樹木在地球的歷史中,在不同的惡劣 被受市民詬病的政出多門和權責不清 工作和下游的樹木檢測和護理程序,而 境環裏不斷發揮頑強的生命力,為各種 的問題。 忽畧了最重要的中游部份,即是如何防 生物提供賴以生存的氧氣和棲息地,維 止其它建築和工務工程進行期間對樹 持生生不息的生態系統。在城市環境 政府一直為現行按部門物業,設施和土 木造成的傷害。有證據顯示,過去大部 中,更默默地為人類淨化空氣,調節氣 地範圍分工辯護,提及斜坡管理亦按同 份倒塌的樹木,根部都受到損害而遭到 候,紓緩生活緊張, 為我們創造一個舒 一方法處理而行之有效。但不要忘記, 真菌或害蟲入侵,根部破損後亦未能接 適的生活環境而作出無償的奉獻。雖 斜坡管理雖由不同部門負責自己範圍 受妥善的處理而染上褐根病。要知道, 然如此,人類並不感恩,從工業革命以 內的斜坡,但工作都是由一批訓練有素, 根部受損很難以‘目視法’檢測,專家 來,在急促的城市化過程中,人類為尋求 經驗豐富的註冊土力工程師負責,他們 亦需要適當儀器配合, 更遑論依賴市民 發展空間,刻意砍伐和傷害樹木之外,更 不單只有專業技能,並受到專業注冊局 監察。因此,為減低這方面的風險,所有 令樹木生長環境惡質化,令樹木容易生 和學會監管,遵守專業守則之外,更要接 工務建築工程合約應當設有樹木主任, 病,脆弱和短壽,這情況在高密度的城市 受持續專業培訓, 終生學習。反觀政 負責為工人灌輸保護樹木意識,提供指 環境中更為嚴重,引發出今天和未來要 府現行的樹藝人員, 學歷和經驗程度參 引並監督工程進行期間不會對鄰近樹 面對的種種環境問題。 差,執業標準模糊, 操守欠缺內外監管 木造成影響;指導善後護理工作。 機制,專業責任不清的情況下,公眾又怎 在香港回歸以前,市區的樹木管理一向 會放心或信服樹木管理工作已做好呢? 最後,希望政府能儘快建立起一支盡職 被視為市政工作的一部份,就像清洗街 盡責的樹木管理專業團隊與市民一起 道,垃圾收集,小販管理等。順理成章 樹木管理從來就是一門十分專業的工 為香港創造真正優質的市區環境。 地,市區的樹木管理就交由兩個市政局 作,特別是在城市環境中的樹木,需要多 負責,並由市政事務署和漁農署執行。 方面的綜合知識,包括城市規劃, 園境 早期的工作多集中在市政公園和郊野 設計,工程,生態,土壤,灌溉,樹木病理,蟲 2008年長沙灣兒童遊樂場塌樹 公園內的樹木,一直到70年代的新市鎮 害,真菌等等的科學。因此,在大學修讀

Yuan Lin 2015 Planting Futures / 49 hoping to elevate urban greening and groups, via established registration middle ground – how to prevent tree management to a professional level. procedures. Becoming a responsible damage to trees during construction However, this was turned down by some landscape manager, their work roles or maintenance of other public works. of the urban services employees and we are just like a property manager or a That was apparent when roots of some missed the opportunity of getting the project manager; coordinating and fallen trees have been seen to have field of tree management specialized. The managing the trees and their landscape been invaded and damaged by fungi or Urban Council was disbanded after Hong zones within a defined site or district. insects. The trees did not receive proper Tree management shortcomings Kong’s reunification with China, urban Using their technical know-how and treatment and this led to them being service works were taken over by the work experience they need to build infected with Brown Root Rot (BRR) Leisure and Cultural Services Department a management team, composed of Disease. We have to understand that in Hong Kong (LCSD) and the Food and Environmental experts and consultants from different damaged roots are difficult to detect Hygiene Department (FEHD). It was clear fields such as gardeners, pathologists, visually, that is why experts also need Patrick H.T. Lau that tree management was going to be a plant disease experts, lawn specialists, proper equipment to do the detection. It low priority. In terms of resources and arborists and soil experts. They need is difficult to just rely on public scrutiny. technical know-how, responsibility for to formulate a comprehensive and In order to reduce risk, all public Recently, there have been a series of the population. However, we are not and country parks, until the development tree management was further divided on macro-management policy in line with construction work contracts should be incidents of mature trees falling over in grateful for this. Humans have damaged of new towns in the 1970s. This the basis of land allocation. Uncertainty the district property or environmental required to have a tree officer who is Hong Kong. Notably a very old banyan trees and deforested lands especially increased the number of green areas, over the division of responsibilities has needs, define work procedures and responsible for imparting awareness of tree unexpectedly collapsed on Nathan since the industrial revolution through along with greenery associated with recently been criticized by the press and guidelines, undertake training, resource trees to workers, providing guidance, Road - Park Lane in good weather rapid urban development. We have newly constructed roads. For the sake public. allocation, supervision of frontline staff, supervising the works to minimise conditions, causing avoidable property degraded the quality of the tree-growing of simplicity, planted trees were mostly and handle crisis management. Because negative impacts on neighboring trees damage and injury of a number of environment, making trees vulnerable to managed by USD or AFCD. Because of the However, the Government has defended front-line arborist staff are responsible during the construction period, and people. Apart from feeling regretful, disease and resulting in them being very successful implementation of green new the current division of responsibilities as for the implementation of tree care undertaking aftercare work. we should also rethink and review the short-lived. This situation is becoming towns, public demands for greening the being equally effective as that of slope work, the requirements of their skills and issue as tree problems are beginning to more serious and pronounced in dense older urban areas increased during that management. We should understand, experience are very important. Therefore Finally, I hope that the Government multiply. These are caused not only by urban areas, which will face increasingly period. Therefore, USD set up an urban although there are different departments systematic training and a comprehensive, will soon establish a comprehensive periodic typhoons and heavy weather. severe environmental problems in the greening committee to coordinate and managing the slopes within their allotted industry-wide form of registration or professional tree management team that In any case, this has caught the attention near future. implement urban greening. However, areas, all necessary works are done by licensing is urgently needed, as well as will create genuine quality in our urban of the Hong Kong Government. The due to historical reasons and traditional well-trained and experienced registered providing ample opportunities for work forest for the people of Hong Kong. TMO (Tree Management Office) was set Before Hong Kong was returned to China, thought, these works were not geotechnical engineers. They not only and promotion in order to enhance the up by the Development Bureau after a urban tree management was seen as undertaken professionally. Frequently, have technical know-how and are level of tree care work. In view of this, similar incident. It is believed that this is part of the municipal services, like street when discussing the technical issues supervised by the Board and professional arborist practitioners are being certified the first time that a bureau was set-up cleaning, refuse collection and hawker with the Public Works Department, institute, but they also comply with by the Hong Kong Institute of Landscape to be responsible for greening and tree management. Urban tree management they neither provided a suitable growth professional codes and receive Architects, to assist this important step Patrick H.T. Lau is a former president management in Hong Kong’s history. was the responsibility of the Urban environment for trees, nor monitored continuous training. On the other hand, forward for the arborist profession. of Hong Kong Institute of Landscape This is considered a significant move in Council, and executed by the Urban the impact of the construction works arborist staff working for government In addition TMO’s emphasis of green Architects and the Chairman of Hong creating a “quality environment, quality Services Department (USD) and the on trees effectively. Therefore, the nowadays are often under-qualified planning on the one hand, and tree Kong caring for trees Association life” in Hong Kong. Appropriate green Agriculture, Fisheries and Conservation Urban Council introduced professional and have little work experience. They defect detection and care procedures on planning and first class management Department (AFCD). Early tree works landscape architects into the Urban have vague standards of practice, are the other, by-passes the most significant not only creates a more livable and high were concentrated in municipal parks Services Department in the late 1980s, Article translated by Audrey Du lacking internal and external monitoring quality city environment, but will also systems for integrity, and have an help Hong Kong become a low-carbon unclear scope of responsibility. How can city, thereby enhancing our international the public be assured or convinced that status and competitiveness. This policy is tree management work is being done an important foundation to achieve both satisfactorily? short and long term goals. Tree management has always required First, the policy objective of “harmony of professionalism, especially in urban trees and people” stated by the previous areas. It requires a wide range of government in the first TMO report general knowledge, including urban is questionable. Promoting harmony planning, landscape design, landscape implies there is dissension between the engineering, ecology, soils, irrigation, two sides, as the government continues tree pathology, insect and fungal control to advocate for a harmonious society. and so on. That is why professional We all know trees have played a major practitioners generally require 4 role in providing oxygen, habitats for to 5 years to get an Urban Forestry wildlife, and maintaining ecosystems Bachelor’s degree or Master’s degree. even in harsh environments for After graduation, they must get relevant centuries. In an urban setting, trees work experience for years before being purify the air, regulate the climate, professionally recognized, based on relieve the tension of life and create the requirements of local professional a comfortable living environment for 2008 - Fallen tree on Cheung Sha Wan Playground exposing its roots Extensive roadworks often threaten the roots and health of a tree

50 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 51 Establishing a framework for the recognition of local arboricultural practitioners Paul Y. K. Chan

HKILA Accredited Arboricultural Regulatory environment a locally recognised registration or Practitioners accreditation system for arborists, they Before the scheme was launched, HKILA welcomed the initiative by HKILA in HKILA launched the Accredited expressed the confusion felt by the establishing an accreditation system for Arboricultural Practitioners (AAP) Industry and employers caused by the local arborists. In their letter to HKILA scheme1 in 2012 to address increasing diverse range of terminologies used in November 2011, DEVB agreed that public concerns over the treatment of for the appointment of tree-related “it is desirable to standardise the use of urban trees and their potential failure positions in government contracts, terminologies and qualifications required causing personal injury and damage to and the inconsistency across different in government contracts of tree-related property. When it was introduced to technical circulars, practice notes jobs.” HKILA members and to the Development and contract provisions, regarding Bureau of the HKSAR Government the qualification required for those Since its establishment, GLTMS has (DEVB) it was made clear that the providing arboricultural services, and maintained and updated its Guidelines scheme was established to meet three their responsibilities. for Tree Risk Assessment.2 As shown main objectives in the local context: in Table 1 to 4, there is a wide range of In a letter sent to DEVB in May 2011, training and qualifications recognised - To formulate regulatory control of HKILA “strongly suggest[ed] Government for the different roles; however, the arboricultural services, to establish and maintain a locally lists contain training and qualifications - To create a knowledge platform for the recognised registration or accreditation that are not comparable in terms of the industry, and system for arborists under the local hours of training, breadth and depth of - To establish a benchmark for employers, context.” Although at the time the topic coverage, assessment method and stakeholders, and the general public. newly established Greening, Landscape, criteria, learning outcomes, and level of and Tree Management Section award under the qualification framework By the end of 2014, the HKILA AAP (GLTMS) under DEVB indicated that the of Hong Kong. Vetting Panel had accredited over 50 Government had no plans to establish local arboricultural practitioners. Those who have been accredited through the scheme are entitled to use the designation HKILA Arb.P. While the development of the scheme has been promising, it is still far from meeting the stated main objectives.

In 2013 DEVB recognised that holders of HKILA Arb.P. were qualified to act as ‘Inspection Officers’ and ‘Endorsement Officers’ in conducting Form 1 tree risk assessments; and that they met the qualification requirements to act as ‘Inspection Officers’ and the training and qualification requirements to act as ‘Endorsement Officers’ for Form 2 tree risk assessments.

Yuan Lin 2015 Planting Futures / 53 (a) have attended and completed the following training courses organised by the TMO:- (a) Have attended and completed the following training courses organised by the TMO:- - Comprehensive Tree Risk Assessment and Management Training Course with assessment; OR - Comprehensive Tree Risk Assessment and Management Training Course with assessment; OR - Refresher Course with assessment; OR - Refresher Course with assessment; OR

(b) have undertaken equivalent departmental training recognised by the TMO; OR (b) Have undertaken equivalent departmental training recognised by the TMO; OR Training (c) have successfully undertaken training programmes recognised by the TMO, such as Tree Risk Assessment Qualification (TRAQ) organised by the (c) Have successfully undertaken training programmes recognised by the TMO, such as TRAQ organised the ISA or Professional Tree Inspection by International Society of Arboriculture (ISA) or Professional Tree Inspection by Lantra Awards; OR Lantra Awards; OR

(d) have valid qualification or certification awarded by recognised institution or industry organisation on arboriculture, such as: Have valid qualification or certification awarded by recognised institution or industry organisation on arboriculture, such as: - Certified Arborist of the ISA, - Certified Arborist of the ISA, - Registered Arborist (Level 3 or above) of Arboriculture Australia, - Registered Arborist (Level 3 or above) of Arboriculture Australia, Training/ Qualification - Technician Member or above of the Arboriculture Association of the United Kingdom, - Technician Member or above of the Arboriculture Association of the United Kingdom, - Accredited Arboricultural Practitioner of the Hong Kong Institute of Landscape Architects, - Accredited Arboricultural Practitioner of the Hong Kong Institute of Landscape Architects, - Professional Diploma Programme in Arboriculture or Tree Risk Assessment and Management of the School of Continuing and Professional - Professional Diploma Programme in Arboriculture or Tree Risk Assessment and Management of the School of Continuing and Professional Studies, Chinese University of Hong Kong (CUSCS), Studies, Chinese University of Hong Kong (CUSCS), - Advanced Diploma in Tree Management and Conservation of the School of Professional and Continuing Education, University of Hong Kong - Advanced Diploma in Tree Management and Conservation of the School of Professional and Continuing Education, University of Hong Kong (HKU SPACE), Qualification (HKU SPACE), - Certificate in Professional Tree Management of the Open University of Hong Kong, - Certificate in Professional Tree Management of the Open University of Hong Kong, - Professional Diploma in Horticulture and Landscape Management of the Technological and Higher Education Institute of Hong Kong (THEi), etc. - Professional Diploma in Horticulture and Landscape Management of the Technological and Higher Education Institute of Hong Kong (THEi), etc.

Have at least 2 years of work experience in tree care and are familiar with tree risk assessment/ management. Have at least 2 years of work experience in tree care and are familiar with tree risk assessment/ management. Work Work Experience Experience

Table 1. Qualification requirements for "Inspection Officer" for Form2 1 Table 3. Qualification requirements for “Inspection Officer” for Form2

(a) Have attended and completed the following training courses organised by the TMO:- (a) Have attended and completed the following training courses organised by the TMO:- - Comprehensive Tree Risk Assessment and Management Training Course with assessment; OR - Comprehensive Tree Risk Assessment and Management Training Course with assessment; OR - Refresher Course with assessment; OR - Refresher Course with assessment; OR - Tree Risk Management Training Course with assessment; OR - Tree Risk Management Training Course with assessment; OR

(b) Have undertaken equivalent departmental training recognised by the TMO; OR (b) Have undertaken equivalent departmental training recognised by the TMO; OR

(c) Have successfully undertaken training programmes recognised by the TMO, such as TRAQ organised the ISA or Professional Tree Inspection by (c) Have successfully undertaken training programmes recognised by the TMO, such as TRAQ organised the ISA or Professional Tree Inspection by Lantra Awards; OR Lantra Awards; OR

(d) Have valid qualification or certification awarded by recognised institution or industry organisation on arboriculture, such as: (d) Have valid qualification or certification awarded by recognised institution or industry organisation on arboriculture, such as: - Certified Arborist of the ISA, - Certified Arborist of the ISA, - Registered Arborist (Level 3 or above) of Arboriculture Australia, - Registered Arborist (Level 3 or above) of Arboriculture Australia, Training/ Qualification Training/ Qualification - Technician Member or above of the Arboriculture Association of the United Kingdom, - Technician Member or above of the Arboriculture Association of the United Kingdom, - Accredited Arboricultural Practitioner of the Hong Kong Institute of Landscape Architects, - Accredited Arboricultural Practitioner of the Hong Kong Institute of Landscape Architects, - Professional Diploma Programme in Arboriculture or Tree Risk Assessment and Management of the School of Continuing and Professional - Professional Diploma Programme in Arboriculture or Tree Risk Assessment and Management of the School of Continuing and Professional Studies, Chinese University of Hong Kong (CUSCS), Studies, Chinese University of Hong Kong (CUSCS), - Advanced Diploma in Tree Management and Conservation of the School of Professional and Continuing Education, University of Hong Kong - Advanced Diploma in Tree Management and Conservation of the School of Professional and Continuing Education, University of Hong Kong (HKU SPACE), (HKU SPACE), - Certificate in Professional Tree Management of the Open University of Hong Kong, - Certificate in Professional Tree Management of the Open University of Hong Kong, - Professional Diploma in Horticulture and Landscape Management of the Technological and Higher Education Institute of Hong Kong (THEi), etc. - Professional Diploma in Horticulture and Landscape Management of the Technological and Higher Education Institute of Hong Kong (THEi), etc.

Table 2. Qualification requirements for “Endorsement Officer” for Form2 1 Table 4. Qualification requirements for “Endorsement Officer” for Form2

After the Robinson Road tragedy in members in the professional groups on The companies listed under the List of the 'Landscaping' category must have at August 2014 in which a falling tree took tree management which are for general Approved Suppliers of Materials and least one “horticulturalist” and one 'tree the life of a pregnant woman, GLTMS reference purposes,” namely: Specialist Contractors for Public Works/ specialist'. The 'horticulturalist' and 'tree made it clear to the public that it is the - List of Approved Suppliers of Materials Landscaping are specialist contractors specialist' can be the same person for responsibility of the property owner to and Specialist Contractors for Public approved for carrying out public works Group 1 contractors, but not for Group maintain trees within private land. This Works / Landscaping4 in one or more of the 50 categories II contractors. Qualifications required for caused widespread anxiety amongst - International Society of Arboriculture, of specialist works. There are two the two positions are shown in Table 5. private property owners over potential Hong Kong Chapter5 classes of Specialist Contractors under liability, and it was suggested by some - The Hong Kong Institute of Landscape the 'Landscaping' category, (Class 1 – Comparing the qualification requirements news media that there was a shortage of Architects, Accredited Arboricultural General Landscape work, and Class 2 between the 'horticulturalist/ tree qualified personnel for tree maintenance. Practitioners (AAP) – Hydroseeding). Both classes contains specialist' for Specialist Contractor In response, and in an attempt to ease two Groups of Specialist Contractors; under the Contractor’s Management public concern over trees within private The service providers/ personnel on the those in Group 1 are eligible to perform Handbook and the 'Inspection Officer/ land, GLTMS posted a new page on three lists, are of very different natures. contracts up to a total value of HK$2.3 Endorsement Officer' for tree risk their website, “Information about tree The first is a list of companies, the second million and those in Group 2 can perform assessment under the TRA Guidelines, maintenance for private properties.”3 is the Hong Kong chapter of a society contracts of any value. According it is possible for a person to be a 'tree The page provides the following lists that based in the United States, and the third to DEVB’s Contractor Management specialist' but not eligible to conduct “contain the qualified service providers/ is an accreditation scheme under HKILA. Handbook,6 Specialist Contractors of individual tree risk assessment whether as

54 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 55 Position Academic/ Professional Qualifications Experience No. required No. required Group I Group II Horticulturalist Obtained a university degree in horticulture or related discipline Three years working 1 1 experience in horticulture OR

Satisfactorily completed a recognized diploma programme in Four years working horticulture or related field equivalent to the standards of Level 3 or experience in horticulture above in the Hong Kong Qualification Framework

OR

Obtained a qualification or certification from a professional institute Five years working or organization of horticulture(h) with standards equivalent to experience in horticulture those of the Certified Horticulturist from the American Society for Horticultural Science or above

Tree Specialist Obtained a university degree in horticulture or related discipline Three years working 1 1 experience in arboriculture OR

Satisfactorily completed a recognized diploma programme in Four years working arboriculture or related field equivalent to the standards of Level 3 or experience in arboriculture above in the Hong Kong Qualification Framework

OR

Obtained a qualification or certification from a professional institute Five years working or organization of arboriculture with standards equivalent to those of experience in arboriculture the Certified Arborist from the International Society of Arboriculture or above

Table 5. Minimum requirements for technical staff for specialist contractor in landscaping category, Class 1: General landscape work, listed under DEVB10 Top heavy - A fallen tree on Paterson Street, Causeway Bay an 'Inspection Officer' or 'Endorsement engaged in constructing or implementing compliance with the relevant clause Conclusion and non-comparable qualifications and References Officer'. The companies are listed for landscaping works to individuals under land lease for private land, that a responsibilities that go with them. carrying out landscape works for public providing mainly arboricultural Registered Landscape Architect (RLA) or 1. HKILA Accredited Arboricultural Practitioners The recent development of mechanisms Scheme http://www.hkila.com/v2/aap.php projects and under the current strong consultancies or supervisory services. competent person should be appointed for tree-related works and tree risk By making reference to established market demand, individual property for assessment of existing trees and assessments, and the newly issued systems for other construction-related 2. Greening, Landscape and Tree Management owners may have difficulty in engaging Adding to the confusion, immediately related services, and that an RLA must technical information do not help activities such as the Mandatory Section, Development Bureau (October 2014), Guidelines for Tree Risk Assessment them for service; while there are many after the three lists, reference is made be appointed for Self-Certification of answer the simple question for the Building Inspection Scheme, Mandatory and Management Arrangement on an Area 7 8 other companies offering arboricultural to PN 7/2007 which states that an Compliance of tree works. However the general public “who is qualified to Window Inspection Scheme, and the Basis and on a Tree Basis, 7th Edition services both to the maintenance units Authorised Person (AP) should be “three lists” have nothing to do with AP do what?” The fundamental issue is Site Supervision Plan system,9 which of the Government or the general public responsible for tree preservation in and RLA. still the absence of a benchmark for clearly set out the required level of 3. Greening, Landscape and Tree Management Section, Development Bureau (January 2015), that are not listed, with their quality employers and the general public. This qualification and experience and the Information about tree maintenance for of service and professional liability was set by HKILA as one of the objectives line of responsibility for each level private properties, http://www.trees.gov.hk/ unassured. of establishing a locally recognised of practitioners, we hope to see the en/tree_care/info_tree_maintenance_pp/ system to arboricultural services. In the Government and professional bodies index.html According to the International Society past three years the industry has not working together in formulating a clearer 4. List of Approved Suppliers of Materials and of Arboriculture Hong Kong Chapter been able to “standardise the use of and more fair system that would facilitate Specialist Contractors for Public Works/ (ISA-HK) website, there are six levels of terminologies and qualifications required quality supervision and implementation Landscaping arboricultural practitioner, established in government contracts of tree-related of horticultural and arboricultural works 5. International Society of Arboriculture Hong through different examinations or jobs”. in Hong Kong. Kong Chapter http://www.isahongkong.com/ assessments. GLTMS has not indicated how each of the credentials and Similar standardisation would be 6. Development Bureau (May 2014), Contractor Management Handbook (Revision B-13) qualifications under the ISA framework equally important to the general Paul Y K Chan in an Assistant Professor align with the typical arboricultural public for non-government projects. and Programme Leader of Bachelor of 7. Lands Administration Office Practice Note No. services required by the general Imagine how confusing it would be for Arts (Hons.) in Landscape Architecture at 7/2007 (PN 7/2007), Lands Department public, such as tree felling proposals, employers or any member of society the Technological and Higher Education 8. Buildings Department (2012), Code of Practice compensatory planting proposals, tree in need of arboricultural services to be Institute of Hong Kong, and a Director of for Mandatory Building Inspection Scheme transplanting, emergency tree felling/ confronted with various terminologies Earthasia Limited. He is Vice-President and Mandatory Window Inspection Scheme pruning reports, etc. Together with the like 'Inspection Officer', 'Endorsement of the HKILA; a council member of Professional Green Building Council, 9. Buildings Department (2010), Code of Practice HKILA AAP scheme and without further Officer', 'Horticulturalist', 'Tree for Site Supervision 2009 elaboration or differentiation, the three Specialist', 'Registered Landscape and a member of the Harbourfront lists contain service provider/ personnel Architect', 'Authorised Person', or Commission, and was a Director of BEAM 10. Annex 35 of Contractor Management ranging from companies primarily 'Certified Arborist', and all the diverse Society (2012-2014). Handbook (Revision B-13), Development Bureau (May 2014)

56 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 57 The Tree of Landscape Design, Arbor propositum | Gavin Coates 設計樹 | 高嘉雲 foliage above. Some are pollinated by the bee of useful criticism (which can also sting, of course!), some fall away as they are reassessed against the design criteria. The remaining flowers develop into the fruit of final proposals in the detailed design ‘The Tree of Design’, admittedly not quite in the same league as its proverbial precursor ‘The Tree of the Knowledge of Good and foliage, maturing into competent contract documentation! Aerial roots may be sent down from the design branches at will to Evil’, is here presented as a metaphor for the landscape design process. One aim is to address the apparent contradiction that seek more knowledge. faces every student and practitioner of the subject, namely that he or she is expected to be ‘creative’, while simultaneously being ‘practical’. Another is to consider how the various components of the design process, from the sublime to the mundane, are Some seeds fall to the ground and germinate as projects, implemented, maintained and managed under the watchful eye of the inter-related. wise old site-supervision owl. The debris of fallen leaves and ‘failed’ design ideas metamorphose into the compost of experience further nourishing the roots of knowledge. So it is that the design process, like the learning process, is not linear but cyclic! Let us take a little arboreal tour. Below the soil surface lies the realm of reality, above it the world of dreams. Our tree is anchored in reality, while its crown reaches up towards the sunlight of dreams and aspirations! The air represents inspiration, art and Things can go wrong. The root of government regulation may become a girdling root that strangles the design process. If the sun humour. The rain of curiosity and research waters the roots of knowledge. As plants convert light energy into chemical energy by of aspiration does not shine, the breeze of inspiration does not blow or the rain of curiosity does not fall, then the tree will be photosynthesis, so our ‘Tree of Design’ can convert dream energy into reality. stunted. The design process may be cut down to the ground in the case of a project being abandoned, but if the soil and root system are healthy, a complete new tree can grow back. The moral of the story? Never stop dreaming. Never stop learning. Never The primary tap-root is enquiry into human interaction with the landscape, with history at its deepest extremity. The two main stop growing. Be the Tree of Design! lateral roots are technical knowledge and site knowledge. These converge at the root collar of observation, corresponding with the survey stage of design development. The trunk is the design analysis stage where the different aspects impacting the design Gavin Coates is a landscape architect and illustrator based in Hong Kong since 1982. Since 2005 he has been involved in the are integrated, leading to the formation of design criteria. The trunk divides into four design-decision branches: Do nothing; design and implementation of the Greening Master Plans for CEDD, and is now a senior lecturer in landscape architecture at The Retain existing site features; Demolish them, and; Formulate new proposals. Various design ideas flower in the sketch design University of Hong Kong. 58 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 59 'The challenges of Trials in succession woodland introducing native species planting at SENT Landfill, and developing a natural Tseung Kwan O succession woodland Barry Wilson structure have been hard to meet due to the exposed site which is critically short of soil water. However, careful woodland management, thinning of plantation species and assisted introduction of native species, should allow for a gradual and continued evolution, whereby the knowledge obtained through planting trials during the operation stage can be fully Site of SENT Landfill and adjacent Tseung Kwan O Industrial Estate Background The landfill is fast approaching capacity Initial planting was undertaken in and typically landscape restoration 1997 on the first fill slopes formed utilised.' There are currently just three operating works would be undertaken at closure. around the base of the site area. landfill sites in Hong Kong following However planting at SENT has been Subsequently, restoration planting has the closure of the thirteen other sites undertaken as an ongoing process ever been undertaken during the planting Barry Wilson between 1975 and 1996. SENT Landfill, since the commencement of progressive season more or less on an annual basis the 3rd landfill site in Tseung Kwan O, restoration. The Restoration Masterplan, as each section of the landfill has been receives about 35% (2012 figure) of the was developed by consultants Urbis Ltd completed. The Restoration Masterplan total waste generated in Hong Kong and prior to letting of the works contract and essentially envisaged the creation of is operated by Green Valley Landfill Ltd, the operator, contracted to manage for three types of native vegetative cover; a subsidiary of the Veolia Environmental a further 30 years following its closure, woodland; scrubland; and grassland, Services Group contracted for the will ensure ongoing maintenance and with the objective of creating a natural design, construction and operation management of the facility. Ultimately system promoting wildlife and nature of the landfill for the Environmental the facility is intended for passive conservation through colonisation and Protection Department of Hong Kong recreational use, with its position natural succession, ultimately achieving SAR Government. abutting the Clearwater Bay Country a climax woodland community. Park making it a potentially valuable public asset.

Yuan Lin 2015 Planting Futures / 61 clear conclusions of one ameliorant over another, however it was apparent that seedling survival rates were severely affected by the extent of amelioration, with no apparent benefit being identified where ameliorants were limited to the immediate rooting zone of the individual (200x200mm) plant pit.

A change in the planting mixes to hardier species was adopted and the Second Year Plant Performance Report demonstrated that the use of leguminous species, in both improving soil structure and showing good survival characteristics, was beneficial. This suggested that more use of Caesalpinaceaetree species could be successful, eg. Bauhinia, Cassia, Delonix and Peltophorum.

The ongoing problems with low 2003 - Restoration Phases 1-4. Phased planting blocks can be clearly identified 2014 - Erosion problems have affected the success of hydroseeding in some areas. Newly planted delicate species in as the landfill grows. soil water content microclimatic growth tubes can be seen with early phase woodland in the background. Whilst continual watering of seedlings Subsequently imported soil material due to the increased shelter from wind 1. Acacia spp. – from A. confusa / A. Current Active Landfill Sites in Hong Kong during establishment may have been from various sources has been used for and sun afforded to them. In particular auriculaeformis / A. mangium the 1500mm deep planting medium. nurse species at the bottom side of a Landfill Location Ha Opened Capacity adequate during the first year of growth, once the establishment period ended Use of CDF was suspended once the block appeared to be redundant. As such 2. Secondary nurse – from Eucalyptus West New Territories Landfill Nim Wan, Tuen Mun 110 1993 61 million m³ and watering was suspended survival construction waste sorting plant was the matrices were amended to attempt citriodora / Casuarina equisetifolia (WENT) became problematic. Only the plantation no longer on the landfill. For the top to provide more and smaller pockets of / Cassia surratensis / C. siamea / 300mm, CDV has been used which is of a sheltered planting areas by increasing Lophostemon confertus / Hibiscus South East New Territories Landfill Tai Chik Sha, Tseung Kwan O 100 1994 43 million m³ species seemed able to cope with the (SENT) water stress on the site and a longer similar nature to that excavated on site. the distribution of nurses through the tiliaceus term approach to soil water content block. North East New Territories Landfill Ta Kwu Ling, North District 61 1995 35 million m³ needed to be addressed if any success Trials in species mix and 3. Tertiary nurse - Albizia lebbeck / (NENT) with growth of non plantation species arrangement The good performance of Albizia lebbeck Calliandra haematocephala / Delonix was to be achieved. in phases 3 and 4 recommended it to regia Early Trials twelve trial blocks were established Over the following years between more extensive use on the landfill whilst to test variations in soil amelioration, The use of water absorbent polymers 1998 and 2003 restoration was carried Aleurities and Gardenia species also 4. Native species A – (aggressive) – The masterplan called for a series of planting spacing and methods. The within the plant pit was considered but out utilising variations of tree species demonstrated acceptable performance. Cinnamomum spp. / Litsea glutinosa planting trials in the initial phases of plant performance was monitored not utilised due to the fact that the major within the planting matrices. Whilst Poor success in establishment was noted / L. monopetala / Ficus microcarpa / F. the restoration, the objective being to over the next 6 years (until 2003) by problem appeared to be the difficulty of the overall greening appeared to be from the following species: benjamina / Celtis sinensis identify at an early stage which plant the Department of Applied Biology and getting roots to leave the extent of the satisfactory, on closer inspection the species and soil media would be most Chemical Technology at The Hong Kong planting pit, and the polymers could not species diversity within the tree groups - Alnus formosana 5. Native species B – (delicate) – Schima effective at promoting growth. With Polytechnic with the Institute for Natural be applied consistently throughout the was still well below that desired. Nurse - Celtis tetranda / Machilus / Schefflera / Castanopsis / approximately 1.5million m3 of soil Resources and Waste Management and top layer. species were expected to make up - Cratoxylum ligustrinum Sapium / Ficus virens required for the landfill it was considered Department of Biology at Hong Kong about 60% of the cover at this stage, - Eucalyptus torrelliana imperative that as much material could Baptist University. The results obtained The conclusion was that a significant however due to the failure of the more - Ficus hispida 6. Protected species – Magnolia be found on site as possible. Small helped influence decision making for the change to the topsoil structure would delicate species they numbered more - Ficus superba grandiflora / Largerstroemia indica / amounts of site stripped topsoil and following planting seasons. be required to promote success in than 90%. In planting Phase 4, Schima, - Gordonia axillaris L. speciosa / Rhododendron simsii / Completely Decomposed Volcanics developing non-plantation species within Castanopsis, Cinnamomum and Machilus - Itea chinensis Ailanthus fordii / Rhodoleia championii / (CDV) were available for re-use however Early Results with Soil Mixtures the restoration. The 1500mm deep in particular, all struggled to survive - Liquidambar formosana Camellia spp. (not C. japonica) early trials looked at the possibilities of planting medium structure was revised even in the sheltered south east area - Litsea rotundifolia utilising Construction and Demolition The early attempts to manufacture to be 300mm CDF covered with 1200mm of the landfill. As a result the balance of - Macaranga tanarius Phased planting currently being Fines (CDF) which would be available a growing medium were based on CDV compacted to 95% MDD. The CDV plantation species was increased from - Mallotus paniculata undertaken has essentially followed the through the duration of the landfill a 1200mm layer of CDF over the material was initially available on site, Phase 6 onwards by adding a second - Phoenix hanceana 6 species block matrix utilising clustered development at an appropriate scale. polyethylene cap layer, with an having been stripped and stockpiled nurse species in order to increase - Pandanus tectorius blocks of 25 plants spaced at 1500mm CDF are principally composed of gravelly ameliorated top layer up to 300mm during site formation. Whilst it was not both the degree of shelter provided - Quercus edithae with some revisions to the species / sandy particles with high pH (9.0) and deep. Ameliorants included horse and in sufficient quantities to last for the and the physical amount of greening. included above. potassium content. Once ameliorated, pig manure, shredded recycled wood duration of the landfill it was considered Those species directly down slope In general it became apparent that a the medium offered good possibilities products and regular horticultural beneficial to utilise the material whilst it from the blocks of fast growing nurse balanced block matrix mix would be of undertaking large scale sustainable products. Survival rates for tree seedlings was available. species were observed to thrive most made up of six species based on the planting. Initiated in April 1997, were variable and it was hard to draw successfully. This was considered to be following :

62 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 63 2010 - Woodland planting about 10 years old. Leucaena has started to invade the light pockets and woodland margins.

2014 - Restoration phase 9. 1500mm planting medium being 2004 - A mixed canopy established. Grass cutting can be 2014 - Restoration phase 9. One year into establishment. Phase 7 planting blocks can bee seen at the rear. graded for future planting phase suspended and the woodland left to develop.

Introduction of microclimatic Early indications are that mortality rates Maintenance issues Conclusion water. However, careful woodland Barry Wilson is a landscape architect, growth tubes do appear lower for plant species planted management, thinning of plantation urbanist and university lecturer. His with MGT’s against those without, Large numbers of invasive Leucaena Continual restoration planting at SENT species and assisted introduction of practice, Barry Wilson Project Initiatives, Following the continued disappointing however the percentage difference leucocephala have become an increasing has ensured that the visual quality of the native species, should allow for a gradual has been tackling urbanization issues in results in establishing native trees within often appears minor for some species, problem on the landfill in recent years, landfill has been significantly improved and continued evolution, whereby the Hong Kong and China for over 20 years. the restoration, a new approach has making it difficult to justify the extra taking a hold on both temporary fill during its operation. Initial tree planting knowledge obtained through planting been considered since the 7th phase of cost. Further trials are looking at specific areas and final restoration slopes. They has now developed into a tall and dense trials during the operation stage can be www.initiatives.com.hk planting (undertaken in 2010) whereby species that might best benefit from the are particularly problematic in areas canopy, giving a positive green image fully utilised. approximately 10% of plants were addition of tubes in combination with of tree planting as they colonise en- around the development and integrating installed with microclimatic growth tubes the use of weed mats as well as critical masse, compete with seedlings for the with the surrounding environment. The (MGTs), as a trial. A detailed review was watering at key times after planting. valuable soil water and crowd out new ecological makeup is similar to that of Project Team carried out in August 2011 to ascertain What has been observed however is plantations. If not continually removed the surrounding plantation woodlands the effect of the tubes and whilst there the clear differentiation in size between at the earliest possible moment their contained within the Country Park areas, Client – Environmental Protection Department were some positive indications for some seedlings, where tubed material is removal becomes increasingly difficult with a variety of invasive flora and fauna Operator – Veolia Environmental Services Group species, the conclusions were hard to consistently larger and more robust in as they become too large to be pulled by having been increasingly identified. draw due to the small sample size. As health. It would also appear that many of hand. Whilst they were initially viewed Landscape Masterplan – Urbis Ltd. such, wider and more stringent trial the delicate species, such as Ilex asprella, positively in their ability to colonise the The challenges of introducing native monitoring has now been established are unable to successfully establish on landfill, their profuse seeding is now a species and developing a natural Independent Consultant – Meinhardt Infrastructure and Environment Ltd. over the last three planting phases the landfill without the assistance of major concern. succession woodland structure have combined with the introduction of weed MGT. been hard to meet due to the exposed Landscape Independent Checker – Barry Wilson Project Initiatives Ltd. mats. site which is critically short of soil

64 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 65 2004 - Weed suppression in planting blocks is essential in the early years of woodland development

Bibliography Research Unit, Chiang Mai University, Thailand. 109–120 1. Carnevale, N.J. & Montagnini, F. 2002. Facilitating regeneration of secondary forests 8. Lai, P.C.C. and Wong, B.S.F. 2005. Effects of with the use of mixed or pure plantations of tree guards and weed mats on establishment indigenous tree species. Forest Ecology and of native tree seedlings: implication for forest Management 163: 217–227. restoration in Hong Kong, China. Restoration Ecology13 (1): 138-143. 2. Chong, S.L. 1999. Restoration of degraded lands in Hong Kong. In M.H. Wong, J.W.C. 9. Lay, C.C., Chan, S.K.F. & Chan, Y.K., 1999. Wong & A.J.M. Baker, eds. Remediation and The utilization of native species in local management of degraded lands. Boca Raton, afforestation programme. Agriculture and London, New York, Washington, DC, Lewis Fisheries Department, the Government of the Publishers. 185–193 Hong Kong SAR. (unpublished)

3. Coomes, D.A. & Grubb, P.J. 1998. Responses 10. Richardson, D.M. 1998. Forestry trees as of juvenile trees to above- and below-ground invasive aliens. Conservation Biology 12(1): competition in nutrient-starved Amazonian 18–26. rain forest. Ecology 79(3): 768–782. 11. Zhuang, X.Y. & Corlett, R.T. 1997. Forest and 4. Corlett, R.T. 1999. Environmental forestry in forest succession in Hong Kong, China. Journal Hong Kong: 1871–1997. Forest Ecology and of Tropical Ecology 14: 857–866. Management 116: 93–105. 12. Zhuang, X.Y. & Corlett, R.T. 2000. Survival and 5. Haggar, J.P., Briscoe, C.B. & Butterfield, R.P. growth of native tree seedlings in secondary 1998. Native species: a resource for the forest of Hong Kong. Journal of Tropical and diversification of forestry production in the Subtropical Botany 8(4): 291–300. (in Chinese lowland humid tropics. Forest Ecology and with an English abstract) Management 106: 195–203.

6. Hau, B.C.H. 1999. The establishment and survival of native trees on degraded hillsides in Hong Kong. (Doctoral thesis), The University of Hong Kong, Hong Kong.

7. Hau, B.C.H. 2000. Promoting native tree species in land rehabilitation in Hong Kong, China. In S. Elliott, J. Kerby, D. Blakesley, K. Hardwick, K. Woods & V. Anusarnsunthorn, eds. Forest restoration for wildlife conservation. International Tropical Timber Organization and The Forest Restoration

66 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 67 Extreme trees Mathew Pryor and Li Wei

The desire for instant landscaping effect in China’s high volume residential development sector has recently generated an extreme form of arboricultural practice. Very mature trees (trunk diameter up to 3000mm dbh) are being extracted from areas of natural vegetation, and having most of their root systems and all of their canopy removed to allow them to be transported to commercial tree nurseries, where they are brought back to life and sold on. The authors visited four commercial nurseries near Guangzhou specializing in this form of extreme transplantation, and three landscaping sites that had used trees from the nurseries, to make detailed observations and to conduct interviews with the operators and site managers to understand the specific operations and techniques employed in handling the trees, and the values associated with this practice. Current scientific literature on the responses of mature trees to transplanting and physical damage gives us some insight into the arboricultural condition of these trees and how they might be able to survive such treatment, and allows us to speculate on how their condition might develop afterwards. This ‘extreme transplantation’ is contrary to all established arboricultural science and practice guidelines for transplanting mature trees. The apparent commodification of our green heritage, also contradicts the principles of environmental preservation and stewardship that Newly arrived Ficus microcarpa underpin the landscape profession. without root ball

Introduction commercial tree nurseries, where they had also been adopted in Hainan, Hunan, are brought back to life and sold on. Guangxi, Jiangxi, and Yunnan provinces. Mature trees have been used in Some trees were taken directly from landscape construction projects for more Extreme transplanting practices forests in Vietnam or Malaysia which than 300 years, to bring an immediate are being cleared for infrastructure and sense of maturity and enclosure to a Four different nurseries specialising development projects, others come from space. It is commonly understood that in extreme transplants in Guangzhou local forests in China, notably where successful transplanting requires as were visited in 2014. Sample trees were vegetation is removed for new road much as possible of the original root measured and their health condition was projects. Across Guangdong, at least system and canopy to be moved intact assessed, and two of the constructed thirteen local species of tree are now in order to minimise water stress, and root balls were partially excavated to being transplanted in this way (Table 1). ensure survival and healthy growth. examine the root condition. Some of the The mechanics of lifting and moving on-going operations involved in moving Bischofia polycarpa 重陽木 trees gets progressively more difficult as the trees were also observed. During the (approx. 30% of the market) tree size increases. Transplanting very visits, interviews were conducted with Ficus microcarpa 榕樹 (approx. 25%) mature trees (>750mm trunk diameter) the nursery owners and site managers Cinnamomum camphora 樟 (approx. 20%) this way can be problematic. to determine the operational and Other 25% is made up of: horticultural processes involved in the Artocarpus nitidus subsp. lingnanensis 桂木 An alternative, extreme form of business. Three landscaping projects Dimocarpus longan 龍眼 Hibiscus tiliaceus 黃槿 transplanting has developed in China which had used trees from these Ficus altissima 高山榕 over the last twenty years, to address nurseries, were also visited and the Ficus benjamina 垂葉榕 some of the operational issues involved. condition of twelve extreme transplants, Ficus virens 黃葛樹 Very mature trees, some with trunk which had been re-planted between Ilex rotunda 鐵冬青 Litchi chinensis 荔枝 diameters in excess of 3000mm (DBH), 2012 and early 2013, were assessed. Podocarpus macrophyllus 羅漢松 are now being transplanted from areas of Sapindus saponaria 無患子 natural vegetation, with most of the root The nursery owners reported that this systems and all of the canopy removed form of transplantation was mostly Table 1. Common species of tree subject to to allow them to be transported easily to practiced in Guangdong Province1 but extreme transplantation

68 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 69 Each of the nurseries visited sold the significant failures and inefficiencies Where possible, trees were harvested sources were transported on flat bed principally Bischofia polycarpa, in the business. (root pruned) in early spring (Feb-Mar), trailers. Total weight of the trees was Ficus microcarpa, and Cinnamomum although the nurseries avoided the approx. 6-12 tonnes. camphora trees. They were bought Demand was, reportedly, high and period around the Ching Ming festival by government agencies for public each nursery had recently expanded its (early April) as the trees did not survive Upon arrival in the nursery, trees were landscaping works and by real operations.3 It was believed that there well if cut at this time.4 Transplanting lifted by crane into an upright position estate developers for residential and were 15 nurseries in the Guangzhou was also undertaken in late summer atop a small pedestal of compacted soil to commercial developments.2 The price area selling only this form of extreme and early autumn (up to the end of elevate it above the surrounding ground, of the trees in the nurseries varied from transplant, while many traditional September) but survival rates tended to avoid the possibility of flooding. After RMB 90,000 to RMB 2,500,000 based on horticultural nurseries also had a few to be lower. Transplantation was not the roots had been unwrapped, a wall size, form and health condition. Ficus extreme transplants in stock. Collectively considered feasible between November was constructed from loose laid bricks in microcarpa, in particular, were prized for it was estimated that there were and January due to the low humidity. a ring immediately around the root ball. their unusual trunk formations. between 1,800 and 2,200 such trees on The wall was inclined inwards slightly for sale in Guangzhou (in 2014). The original sizes of the Bischofia stability. It was backfilled with soil as it Specimens were usually sold within the polycarpa specimens before pruning was constructed. The ultimate height of second or third year after arriving in the Nursery owners claimed the survival were typically 18-25m tall with 0.8- the wall was approx. 0.9-2.2m. Ficus microcarpa nursery, i.e. when they had produced rate for these extreme transplants to be 2.0m trunk diameters: Tree set on bricks before root ball walls constructed around what is left of the roots sufficient new foliage to have a about 95%, although a higher proportion specimens were originally 10-20m tall recognisable tree-like appearance and to of failures were apparent in the nurseries with 0.6-3.5m trunk diameters, and root ball was only watered again when brick wall structure, but those that grew hide the wounds. Some trees, however, and evidence of dieback suggested that Cinnamomum camphora were 18-40m it is seen to be drying out, with the through the wall were cut as the trees had been in the nurseries for four years. the life expectancy of many specimens tall with 0.6-2.3m trunk diameters. intention of promoting deeper rooting. needed to be moved again to their final The comparatively low operational cost would be short. planting locations. compared to potential returns, offset Trees were pruned three months in Micro-spray irrigation systems were advance of moving. The canopy was sometimes installed to apply water to Buds appeared within one to two months cut first to stop all transpiration, before the cut upper surface of the trunk, in an of transplantation for each species. root pruning was undertaken. This was attempt to keep the bark from drying Buds appearing on the lower part of to help avoid severe desiccation and out. This was seldom effective, and the trunk were removed to encourage immediate death. The canopy was often counterproductive. Some nursery bud formation towards the top and twig removed completely with a horizontal owners bound the bark at the top of the elongation in an upward direction (i.e. cut through the trunk and main stems trunk with steel bands to prevent it from avoiding the development of lateral at approx. 9-11m above the ground (to splitting. The trunk was also wetted up to branches). Sprouting was dense from the allow them to be moved by road and sea). three times per day to reduce moisture cut bark tissue around the wounds. Trees Smaller side branches were removed. In loss through the bark and decrease that had been in the nursery for three taller forest specimens where branching surface temperatures. The plastic film years, had regenerated branches up started high up, the tree was truncated wrapping on the trunk was not removed to 75mm diameter and 4.5m in length, to a single massive stem. until new buds had begun to appear. forming a dense, narrow canopy. This shape balanced the need for foliage to The roots were cut very close to the Pruning wounds could be very extensive, make the tree saleable, while facilitating trunk. The root ball ratio for trees with a particularly the top of the trunk.6 Nursery transportation after sale, without further trunk diameter of, say 750mm, might be Intense efforts to re-hydrate a failing owners often covered the surface of substantial pruning. 3:1, for larger trees it tended to 1:1. The Bischofia polycarpa the wound with paint or plastic film to diameter of the root ball did not exceed keep the exposed heartwood dry and to Despite the surface treatment of the The backfill soil was a nutrient poor 2.25m (except where the trunk did so), discourage fungi and insects. Trees were pruning cuts in the nursery, the health pond mud that has been cut into rough and the depth was between 0.6 and 1.5m. also sprayed with fungicide on a regular condition of many of the wounds was cubes (20-45mm) and allowed to dry For Bischofia polycarpa most of the root basis to try and prevent decay. If the bark poor, with notable bark cracking and die and harden. This material was very ball soil was removed (essentially the around a wound died, it was cut back to back and limited evidence of callus tissue dense and broke down very slowly even trees were transplanted bare rooted). live tissue to encourage the growth of being formed. Obvious Areas of decay with repeated wetting. It allowed the The remaining roots had to be wetted callus tissue. were noted on approximately half of the development of fine soil root interaction constantly to avoid desiccation. Ficus Ficus microcarpa specimens. within the root ball while achieving both microcarpa could be transplanted either Nursery owners reported that new good drainage and high water-holding with no soil, or with small soil root balls. roots appeared within one month of Trees were sold on the basis of their capacity. Peanut residue5 was applied to Cinnamomum camphora, required soil transplantation for each species. Brick size, shape and condition. Those in poor the soil surface as a rapidly decomposing root balls. The remaining trunk and root walls of two B. polycarpa specimens health were removed from the nursery. organic fertilizer, every six months. system were wrapped entirely in clear which had been in the nursery for Nursery owners estimated that life plastic to reduce water loss. approx. nine months were dismantled expectancy of the transplants was likely Newly constructed root balls were and the soil carefully removed, to to be only a few years. thoroughly watered to ensure the soil Trees were lifted via padded straps allow the development of roots to be was at field capacity (based on the around the trunk. Trees from overseas observed. Fine new roots (<2mm dia. x The twelve specimens observed in the nursery worker’s judgement), and then were loaded into standard shipping 30-60mm long) could be seen around three ornamental landscaping sites the brick structure was wrapped in containers with a crude wetting system most of the cut ends of old roots. Roots were in full foliage but still had narrow plastic film to keep the moisture in. The Brick walls built to create a new root ball to keep the roots moist. Trees from local were encouraged to develop within the canopies with a mass of small diameter

70 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 71 upright branches. They were all to overcome water stress which results mature tree’s canopy as practical will be initiate and grow new roots.13 After shoot supported with large bamboo tripod from the reduction in water absorbing retained intact. In doing so, the volume growth ceases, root growth is supported stakes. The landscape site managers capacity due to the root pruning needed of the root system moved with the tree by newly produced photosynthate. confirmed that the trees did not receive to facilitate relocation, while continuing should also be maximised. Extreme transplants, which have had all any special horticultural maintenance, to lose water through transpiration. of their foliage removed, have to depend but were simply watered as other trees. Trees do not recover from water stress The Standards suggest a root ball ratio on carbohydrate stored in the trunk to As the trees were seen to be growing until they have regenerated enough new (root ball diameter: trunk diameter) initiate root growth. In mature trees, and in full leaf they were assumed to be fine (<2mm dia.) water absorbing roots for trees >450mm trunk diameter to however, this should be adequate to healthy. to restore water balance.7 be minimum 8:1. Recent research in support root growth, as a much higher Hong Kong has indicated that root ball proportion of total stored carbohydrate No treatment was made of the cut The severity of the water stress suffered volume (as opposed to diameter) is a is in the trunk rather than in the root wounds or preventive measures taken depends on the species. Those that have more relevant measure in this regard as system,14 when compared to small trees. against pests and disease. Despite the highest chance of survival have: it aligns closely with leaf area index (the Further, transplanted trees require much outward appearance of vitality, each of (a) high tolerance of root loss and ability measure of tree canopy), i.e. the water less carbohydrate to produce new roots the trees had sizeable pruning wounds, to initiate and grow new roots in the absorption capacity of the root system than established trees do to generate although these were mostly obscured by soil outside the root ball, and transpiration through the canopy the constant turnover of fine roots. So surrounding foliage and water sprouts. (b) high root : shoot ratio (a measure are in balance. The research studied it is possible for extreme transplants to None of the wounds observed had closed of the physical and physiological examples of mature tree transplanting grow sufficient new fine roots to absorb significantly, and the surface condition balance between root system and and concluded that it could be successful water to support a limited amount of was generally very poor with areas of canopy),8 and at smaller root ball ratios (5:1) if care top growth, based solely on trunk stored bark dieback, incipient decay, and signs (c) high vigour, as this gives the tree was taken in mapping root systems and carbohydrate. of insect attack wounds. greater capacity to change its growth adjusting root ball shapes to match.12 pattern to re-establish internal In the long term, the trees need to Understanding tree responses to balance. Extreme transplantation practices regenerate a significant proportion of extreme transplantation observed in the nurseries, reflect an their original root system to support a Transplanting is most successful understanding of the water balance and full canopy. The limited growth on the when soils are moist and warm, and The extreme approach taken with 9 transplant stress, but adopt an opposite trees observed in the field suggests that these very mature specimens seems transpiration is low. Root pruning strategy to the Standards. The removal of they had yet to do this. to contradict established science and operations should not be undertaken most of the roots (est. >95%) is off-set by technical guidance on transplanting during periods of natural shoot the removal of all foliage. The constant Extreme transplantation, requires other trees. Considering arboricultural elongation. watering of the roots and the trunk significant compromises in the long-term responses to typical transplanting is intended both to reduce water loss health of trees, which may overwhelm operations and physical damage helps American National Standards for Tree through transpiration through the trunk them before they have had a chance us to understand how these trees Care Operations provide guidance on the and maximise water uptake through to re-establish their root and canopy transplanting of mature tree specimens are able to survive this extreme form 10, 11 regenerating fine roots. This raises the systems fully. of transplanting. It also allows us to in the United States. These are based question as to how they can re-grow reflect on the different commercial and on established arboricultural research without a functioning root system or Accepted transplanting practices environmental values that are associated coupled with long practical experience. foliage, and at what cost to the tree. embody the principle of retaining with transplanting mature trees. They emphasise approaches which enough of the branching structure to minimise disruption and damage to the During periods of shoot growth, trees allow the tree to regain a balanced tree, and envisage that as much of the To survive transplantation, a tree has rely on stored carbohydrate energy to form afterwards. In removing all the Tree after one year in the nursery branches, extreme transplantation results in the complete loss of structural This would also emphasise the necessity up to the diameter of the trunk), that form. The dense new foliage observed of thinning. they were not able to compartmentalise at the top of re-planted specimens gave and close them. Indications of extensive the appearance of healthy growth, but Pruning cuts require trees to devote decay were observed in many of the this consisted of a large number of small energy away from growth and towards specimens. diameter water sprouts arising from the wound responses, so Standards ends of truncated stems. The unbalanced recommend minimising cuts. Open Species that are able to survive extreme canopy that is likely to develop from wounds create a route for fungal transplantation can be broadly divided these, and the associated structural infection and pest attack (notably into two groups; those with very active weaknesses, are likely to increase health termites) of the heartwood of the tree.15 growth that allows them to respond problems for the tree in time. Thinning Declining availability of resources in rapidly to changes in growing condition, of water sprouts may help to address mature trees means that they have less and those with dense, decay resistant this, but may further compromise the capacity to respond to damage than wood. appearance. younger specimens,16 and are likely to take longer to recover.17 Larger size The Ficus spp. trees transplanted this The density of the newly formed canopy wounds take proportionately more way are all strangler figs.18 They are fast with respect to the total loss of anchor energy and longer time to close. Wounds growing and can initiate and produce roots may also make extreme transplants on each of the extreme transplants seen new roots rapidly. Aerial root structures Brick wall structure containing the backfill soil Dense pond mud cubes used as an open soil material in more susceptible to failure in typhoons. in the nursery were so wide (dimensions allow them to develop their root system the new root ball

72 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 73 from multiple points, bypassing areas of It is not clear if buyers were unaware Acknowledgements damage or decay and taking advantage that the trees might have short life of different ground conditions. This is expectancies, or did not care. From This research work was supported particularly the case for Ficus microcarpa, discussions with nursery owners, it was by Hong Kong Special Administrative which has resulted in it being one of apparent that these trees were bought Region Government, under a General the most commonly transplanted tree solely for immediate, decorative effect. Research Fund of Hong Kong (Grant No. species in Hong Kong, with one of the No concern was expressed that the trees HKU 751612H). highest survival rates.19 may need to be replaced within a few years. Rapid obsolescence has been an Our thanks to the owners and of these In contrast, Bischofia polycarpa and accepted facet of property development extreme tree nurseries for access to Cinnamomum camphora are slower in China for a long time, but is now their trees and for providing information growing trees which are better at beginning to manifest itself in associated on their commercial operations and compartmentalising wounds, and landscaping works. processes. Due to confidentiality have dense heartwood which is more requirements, the names of individual resistant to insect attack and decay. This Secondly, this commodification of parties are not given here. allows them more time to overcome the trees purely for profit, represents a extensive pruning cuts inflicted during despoliation of nature. Setting aside extreme transplanting. Both species any sentimentality, trees of this size appear to initiate shoots and roots must have had significant ecological from cut stems easily. Nursery owners value in their original, natural settings, reported successful cases where B. not to mention any possible cultural, Cut stems quickly succumb to decay, which is often hidden by water sprouts polycarpa trees, with 1500mm diameter heritage or amenity worth. The validity trunks, were cut into multiple trunk of the sources from which the trees were References deciduous trees in temperate climates. Wundbehandlungen an Wurzeln bei Eiche und sections and regenerated effectively as obtained, and the ethics of removing HortTechnology, 15:132-135. Linde. Nachrichtenbl. Deut. Pflanzenschutzd. hard wood cuttings. them, seem highly questionable. 1. Notably in the cities of Guangzhou, 47(2): 28-35. Zhongshan, Zhuhai and Zhanjiang. 10. American National Standards for Tree Care Operations (2012) ANSI A300 (Part 6)- 16. Coley, P., J. Bryant, and F.S. Chapin. 1985. Survival is a relative term in tree Landscape architects undoubtedly 2. Extreme transplants have been used in 2012 Tree, Shrub, and Other Woody Plant Resource availability and plant antiherbivore transplanting. No specimens were come under pressure from their clients landscape schemes in Hong Kong. Management – Standard Practices (Planting defense. Science 230:895-899. observed in either the nursery or in the to use such trees, but as professionals and Transplanting). Tree Care Industry landscape projects that had successfully entrusted with a duty of care for the 3. The total number of trees in stock in 2014 Association Inc. 17. Clark, J.R. and N. Matheny. 1991. Management were 120, 260, 110, and 190 of mature trees. Journal of Arboriculture. closed wounds. In the humid climate, environment, they should view the use 11. Tree transplanting operations in Hong Kong 17:173-183. decay and insects get into wounds of such trees as unacceptable. 4. Period might coincide with the period of often mistakenly refer to arboricultural quickly, and the size of the wounds on natural shoot development, during which standards that have been written for the 18. Strangler figs are epiphytes of the Urostigma these trees were clearly too large for Mathew Pryor is Head, and Li Wei is a root pruning can severely disrupt the internal production of field grown nursery transplants, subgenus of Ficus system of a tree. e.g. American Standard for Nursery Stock the tree to deal with. The effects may Research Assistant, of the Division of ANSI Z60.1 (2014) which covers tree with a 19. Pryor, M. Demystifying Tree Transplanting. be hidden for a time, but there is a Landscape Architecture at the University New top growth, after two years in 5. Peanut residue is a by-product of peanut oil trunk diameter up to 200 mm, and European In proceedings of the International strong suggestion that these wounds of Hong Kong. the nursery extraction process, and has a small carbon- Technical and Quality Standards for Hardy Arboricultural Society Hong Kong Conference start an inevitable process which leads nitrogen ratio. Nursery Stock (2010), which covers trees up 2010, Hong Kong (November 2010). to 190mm trunk diameter. to decline and death within a few years. 6. Trees have great difficulty in effectively In effect, the tree’s adaptation and compartmentalising the wounds from 12. Pryor, M. and Watson, G. (2015) Mature resistance probably keeps them alive substantial heading cuts. Tree Transplanting: Science and Practice. and apparently healthy just long enough (under review by Arboriculture and Urban Forestry journal) for the nursery owners to sell them. 7. Watson, G.W. 1992. Root development after transplanting. In: Neely, D. and Watson, G.W. (eds.). The landscape below ground I: 13. Van den Driessche, R. 1987. Importance of Commodification of Nature Proceedings of an international conference current photosynthate to new root growth on tree root development in urban soils. in planted conifer seedlings. Canadian Journal of Forest Research 17:776-782; Extreme transplants have considerable International Society of Arboriculture. Champaign, Illinois, US. 55-68 Sloan, J.L. and D.F. Jacobs. 2008. Carbon commercial value, so why do landscape translocation patterns associated with new architects find them abhorrent? 8. South, D.B. and R.J. Mitchell. 1999. root proliferation during episodic growth of Determining the “optimum” slash pine transplanted Quercus rubra seedlings. Tree Physiology 28:1121–1126. First, the assumption that the value of seedling size for use with four levels of vegetation management on a flatwoods site the trees is disposable, i.e. used just to in Georgia. U.S.A. Canadian Journal of Forest 14. Kozlowski, T.T. and S.G. Pallardy. 1997. sell a property or give instant effect to Research 29: 039–1046. Physiology of Woody plants (Second Edition). new landscape, suggests that the trees Academic Press, New York, New York, US. 411 pp.; Esparza, G., T.M. Dejong, and are regarded as a commodity rather 9. Harris, J.R., N.L. Bassuk, R.W. Zobel, and T.H. Whitlow. 1995. Root and shoot growth S.A. Weinbaum. 2001. Effects of irrigation than a part of nature. It is sadly ironic periodicity of green ash, scarlet oak, Turkish deprivation during the harvest period on that the value of the trees to buyers lies hazelnut, and tree lilac. Journal of the nonstructural carbohydrate and nitrogen in their mature appearance (which has American Society for Horticultural Science, contents of dormant, mature almond trees. Tree Physiology 21:1081–1086. grown over decades), but due to their 120:211-216; Richardson-Calfee, L.E. and J.R. Harris. 2005. treatment that value is very short-lived. A review of the effects of transplant timing 15. Balder, Von H., D. Dujesiefken, T. Kowol, and Re-planted extreme trees in an ornamental landscaping site in Guangzhou on landscape establishment of field-grown E. Schmitz-Felten. 1995. ZurWirkung von

74 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 75 "Chinese Banyan grows Aerial roots of ‘rapidly with but little care, its Ficus microcarpa foliage is of a glossy green Mathew Pryor and Li Wei colour, and it soon affords an agreeable shade from the fierce rays of the sun, which renders it particularly valuable in a place like Hong-kong’."

Robert Fortune, (1852). A Journey to the Tea Countries of China

Section of flexible aerial root of Ficus microcarpa

This article reports on a study to The distribution and growth of aerial since the beginning of the colonial investigate the nature of aerial roots in roots was observed to be highly variable, period,2 and was used almost exclusively Chinese banyan trees, Ficus microcarpa, but there was a clear link between for this purpose until the 1870s.3 The and the common belief that their growth and high levels of atmospheric botanist Robert Fortune noted, as early presence and growth is associated with humidity. The anatomical structure of as 1852,4 that the Banyan grew ‘rapidly wet atmospheric conditions. the aerial roots suggests that while with but little care, its foliage is of a aerial roots could absorb water under glossy green colour, and it soon affords First, the form and distribution of free- certain conditions, their growth was an agreeable shade from the fierce rays hanging aerial roots on eight selected generated from water drawn from of the sun, which renders it particularly Ficus microcarpa trees growing in a terrestrial roots via trunk and branches, valuable in a place like Hong-kong’. public space in Hong Kong, were mapped and that the association with humid Even the Hongkong Governor, in 1881, on their form and distribution. Secondly conditions was most likely to be due to observed that Banyans turned ‘glaring the extension of selected sample aerial the greater availability of ground water roads to green avenues with the rapidity roots from each tree were measured in such conditions. that would surprise arboriculturists in over twelve months against prevailing Europe’.5 atmospheric humidity. Lastly, section Introduction samples of aerial roots of different It has been valued both for its shade and ages were taken, and the anatomical Chinese Banyan, Ficus microcarpa, is a greenery, and its ability to cope with the structure was observed and compared native of Southern China and has been typhoon winds and the poor growing with that of terrestrial water-absorbing planted as a shade tree throughout environment in dense urban settings. roots to assess the mechanism by which the region for centuries. In Hong Kong, The majority of Hong Kong’s wall trees they might take up water. it has been planted as a roadside tree are F. microcarpa,6 and it is the species

Yuan Lin 2015 Planting Futures / 77 that has been successfully transplanted the trunk or stem first as surface roots, to environmental conditions. Although aerial roots at different developmental most often at mature size within the and after they lignify may fuse with the aerial roots have been observed to stages, and their potential for Territory7. stem, creating highly complex surface absorb water under certain conditions,17 absorbing water from the atmosphere. rooting structures. the mechanism by which they do so has ‘Banyan’ is a generalized term used to not been investigated, and how this From these, an understanding of the refer to Ficus trees of the Urostigma Gill separately defines “clasping” aerial might affect the growth of the aerial root nature of aerial roots and their role in the subgenus of Moraceae, which includes roots that are exposed, but remain has not been assessed. growth of the tree can be formed, which tree species with aerial adventitious appressed to some surface, as seen in may help explain the predominance of roots.8 A number of these grow in Hong the root fan of a wall tree. Aerial roots The objectives of this research study were Chinese banyans in manmade landscapes Kong, e.g. F. microcarpa, F. benjamina, F. can also develop from the callus tissue to understand the role of flexible aerial in Hong Kong. benghalensis, F. elastica, F. macrophylla, around a bark injury which has severed roots in the growth and development of and F. altissima.9 the phloem,15 and have been observed mature Chinese Banyan trees in Hong Materials and methods to bridge over sizeable trunk wounds Kong. Specifically, to investigate: The origin of aerial roots of Ficus trees has (spanning > 500mm), ultimately closing Eight mature Ficus microcarpa trees not been studied in detail. In Southern the wound altogether.16 • the occurrence of aerial roots within were selected for the study by random China, it is widely believed that the the tree, i.e. their number and broad number from a set of 52 trees growing in growth of aerial roots of Chinese Banyan Currently there has been no systematic distribution within the structure of the paved areas in public spaces in Lei King is related to periods of high atmospheric study of the conditions under which tree, Wan, Eastern District. They had all been humidity. Aerial root development flexible aerial roots occur on mature • the development and elongation rate planted at approximately the same time is seasonal with the initiation and Chinese banyan trees, their presence of aerial roots, in relation to and were some 30 years old. The trees elongation of roots starting in spring and distribution within the tree, their environmental conditions, were healthy and vigorous, and growing with the rise in atmospheric temperature growth rates, and how these might relate • the morphological structure of the in identical environmental conditions. and humidity, and continuing until late They ranged from 9.0 to 12.0m in height, autumn when humidity falls again.10 with trunk diameters of 0.24-0.55m From this, it has been assumed that (DBH), and average canopy spread of 9.0- aerial roots are able to absorb water and 13.0m. Landscape maintenance workers nutrients from the atmosphere to sustain reported that free-hanging roots were their growth. However, little research periodically cut (typically twice a year) has been conducted on this point. at approx. 2.0m above the ground, to prevent them from reaching the ground, Gill (1975) notes that adult F. microcarpa and to avoid nuisance to park users. trees produce slender, pendulous (free- hanging) aerial roots, i.e. roots exposed First, the distribution of aerial roots to air for at least of 50% each day and within each tree was mapped. As no free of any support or substrate,11 which methodology for mapping aerial roots under gravity grow downward. There is has previously been established, the a high degree of variability between tree following was devised for this study. specimens in the number of aerial roots The point of origin for each cluster of Typical pattern of aerial roots on a mature Chinese Banyan and their distribution within the canopy, free-hanging aerial roots was identified but no clear indication of what factors and its distance from the centre of the flexible aerial will thicken into a lignified take several years to reach the ground influence this variability. tree was measured. The diameter of the aerial within one to three years. The or come into contact other stems or stem at the point of origin was noted, lignified aerial root has a similar structures. Zimmermann, et al. (1968) From simple field observations, there are together with its position within the appearance to a branch but does not describe the process of lignification three distinct stages in the development cross section of the stem (stems divided bear foliage. of aerial roots in Ficus benjamina,13 of aerial roots. into sectional quarters). The biomass a closely related species. When the of each cluster was calculated as the Aerial roots originate from a single point flexible aerial root reaches soil it initiates 1. Growing tip – 1.5-2.0mm diameter, up product of the aggregate diameter of on a branch or stem, and as they grow and elongates terrestrial roots to absorb to 120mm long, pale yellow, flexible aerial roots within the cluster and their they divide at the tip. Mature roots may water and nutrients. This new terrestrial but brittle, average length (measured at the start of have all three stages present, with a root system forms an anchor, allowing 2. Flexible aerial root – 2.0-5.0mm the study). Results for the percentage of single lignified root giving rise to a cluster the above ground portion of the root diameter, up to 10.0m long, dark total aerial root biomass for the tree by: of many (can be <50 no.) individual to contract and straighten by producing reddish-brown, woody, flexible, (a) distance from the centre of the tree; flexible aerial roots and growing tips. tension wood. Finally, the root enters 3. Lignified aerial root – >5.0mm (can be (b) stem size; and (c) position of point of The cluster is a self-contained system a consolidation phase, thickening to >100mm) woody, light grey, rigid. origin on the stem, are given in Table 1. within which individual flexible aerial become prop stem to support lateral roots can intertwine, but do not fuse branches.14 Prop stems are noticeably In all three stages the longitudinal form Second, the rate of elongation of roots together. straighter than lignified aerial roots that of the root is variable from straight to was measured in relation to atmospheric have not reached the ground. very twisted, although they appear to humidity. Selected sample roots from Roots elongate very rapidly, and have become more twisted with the age. The each tree were tagged, and a reference been observed in a Miami based study to Aerial roots produced from branches growing tip will mature into a flexible point was identified on the root (typically lengthen by up to 10mm per day.12 Aerial immediately around the main trunk or aerial within two to three weeks. The Mature Ficus microcarpa trees growing in a paved publlic space the lowest branching junction). The roots arising in the upper canopy can mature stems, may attach themselves to in Lei King Wan, HK

78 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 79 Aerial root growth Anatomical structure The mature flexible aerial root, in section (Fig. 2), shows many xylem vessels. Aerial roots selected for measurement The new aerial root tip, in section (Fig. Medullary rays cross the xylem. The were all active. They started elongating 1), shows one layer of exodermis cells broad cortex has been sloughed off and in late February and stopped sometime in covering a broad cortex, consisting the parenchymatous pith has become October. Rate of root elongation varied of 9-12 layers of parenchyma cells, lignified. Lenticels are raised. The radial over the course of the year, with April arranged closely. The endodermis is not longitudinal sections through the mature to August being the most active months well defined. The roots have 4-5 xylem aerial root (Figs. 5 and 6), indicate more (Table 2). There was little or no growth groups. A broad parenchymatous pith xylem vessels and some scattered between November and February. In occupies the centre. sclereids. averaged measurements across samples from all eight trees, root elongation was The radial longitudinal section through Discussion greatest in May, with an average monthly the new aerial root tip (Fig. 3), shows increase 244.9mm. Roots extended on three distinct regions: division zone, The distribution of aerial roots was average by 1154.3mm over the year. elongation zone and differentiation zone, highly variable. Some trees had very few as would be expected in a terrestrial root or no aerial roots at all, while immediate Individually the rate of elongation of structure. But the root tip has no root neighbours (in the same environmental flexible aerial roots varied very greatly hairs in the differentiation zone. In the conditions), might have many hundreds. between different roots. One root elongation zone, roots begin secondary Although the trees were of the same might elongate only a few millimeters in growth. In detailed section (Fig. 4), age, their size (reflecting past growth) a month while its immediate neighbor the cork cambium differentiates cork was very different. No relationship length of the root below the reference the densest pattern of aerial roots, had a from the centre. The majority (76.5%) within the same cluster might put on a outwards and phelloderm inwards. The was observed between size of tree and point was measured every week over a biomass of 38.5 ltrs. The radial distance was found on stems between 100 and few hundreds of millimeters of growth. epidermis, as the outmost cell layer, presence of aerial roots. Small trunk period of twelve months. The difference of the point of origin of the roots from 250mm diameter. Only one tree had The maximum elongation of any single could be shed as the tree grows and diameter trees were as likely to have between successive measurements the centre of the tree was categorized roots on a stem >250mm, but only three root (from all samples) in one day was includes many lenticels. Most lenticels aerial roots, (and the same volume of represented the elongation over the time into 1.0m intervals. The tree canopy of the trees had branches of this size. 17.4 mm, (321.8mm in one month on the epidermis are transversely aerial roots) as large trunk diameter interval. Records of the mean weekly spread (expressed as a radius) varied Only a few roots were found on small 1983.4mm across the year) orientated. trees. atmospheric temperature and relative between 4.5m and 6.5m, although diameter stems (0-50mm), although humidity for the period were obtained with the close arrangement of trees, on one tree these accounted for more from the Hong Kong Observatory. canopies tended to be elongated along than 10% of the total. Aerial roots were one axis. Nearly two thirds (62.3%) of predominantly (85.8%) growing from the Lastly, specimens of flexible aerial the aerial root biomass was within 2.0m underside of stems, with only a small roots were collected from two of the of the trunk which broadly reflects the percentage growing from the two sides trees. Samples were taken from both proportion of the branch biomass within of the stem, and very few (1.7%) from the tip and the central portions of the this distance of the trunk. 12.6% of the the top side. aerial roots. These were cut into 10mm aerial root biomass was beyond 4.0m sections and fixed in FAA (Formalin- Acetic Acid - Alcohol) for at least 24 Low High Average hours. Sections were embedded in paraffin after dehydration, then cut Number of aerial root clusters (no.) 1 44 13.7 with 8-10μm on a rotary microtome, Fig. 1. Section of aerial root tip of Ficus Fig. 2. Section of flexible aerial root Fig. 3. Radial longitudinal section of Total aerial root biomass (ltrs) and finally stained with safranin and 0.025 38.5 12.6 microcarpa. X10. 1. Exodermis, 2. of Ficus microcarpa. X10. Cortex has an aerial root tip of Ficus microcarpa, Cortex, 3. Endodermis, 4. Xylem, and been slough off. 1. Xylem vessels 2. (x5). 1. Root cap; 2. Cortex; 3. fast green. The sections were observed Distance from the trunk (m) Proportion of aerial root biomass 5. Broad pith. Medullary ray 3. Pith Xylem; 4. Pith; 5. Division zone; and 6. 0-1.0m 0% 66.0% 37.6% under a light microscope and photos Elongation zone taken with Motic Images Advanced 3.2 1.0-2.0m 21.8% 100.0% 24.7% software. The anatomical structure was 2.0-3.0m 0% 28.8% 15.3% 3.0-4.0m 0% 18.4% 9.9% observed and analyzed to determine the 4.0-5.0m 0% 12.1% 7.5% ability of the different portions of the 5.0-6.0m 0% 8.6% 5.1% aerial roots to absorb water. Stem diameter (mm) Proportion of aerial roots 0-50mm 0% 10.2% 3.8% Results 50-100mm 0% 25.1% 12.4% 100-150mm 7.6% 100.0% 17.6% Distribution of aerial roots 150-200mm 0% 59.8% 28.4% 200-250mm 0% 49.6% 30.5% Amongst the eight trees, the number 250-300mm 0% 19.1% 7.3% of root clusters varied considerably Position on the stem cross section Proportion of aerial roots between the trees (from 1 to 44), with underside 76.9% 95.5% 85.8% Fig. 4. Detailed radial longitudinal Figs. 5 & 6. Detailed radial longitudinal section of a flexible aerial root of Ficus an average of 13.7 clusters per tree. The side 4.5% 19.2% 12.3% section of an aerial root of Ficus microcarpa, (two samples, x10). More xylem vessels exist in mature part of aerial aerial root biomass also varied. The tree top 0% 4.4% 1.7% microcarpa, (x10). 1. Epidermis; 2. root. 1. Xylem vessel; and 2. Sclereids. with just one small cluster measured at Cork; 3. Cork cambium; and 4. just 0.025 ltrs, while the largest tree with Table 1. Distribution and position of aerial roots of Ficus microcarpa Phelloderm

80 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 81 The distribution of aerial root biomass the dry winter months. Rate of growth in roots and fine <2mm water absorbing Species Ficus microcarpa Ficus benghalensis (after Kapil and Rustagi 1966) within the canopy appeared to follow individual roots was inconsistent. Some terrestrial roots of F. benghalensis as the distribution of branch and twig grew steadily throughout the summer, described by Kapil and Rustagi18 (Table Character Aerial root (new) Aerial root (mature) Aerial root (new) Aerial root (mature) Terrestrial biomass within the canopy, with the others would grow quickly then stop. 2). The aerial roots of the two species absorbing root greatest proportion being close to the Averaged maximum daily extensions are fundamentally alike, and both have Root Hair Absent Absent Absent Absent Present trunk. Broadly, the distribution of aerial for the five months June, July, August, distinct pith but lack of root hairs. These Cortex 9-12 cells thick Sloughed off 20-25 cells thick Sloughed off 8-15 cells thick roots around the canopy was even, i.e. Aril, and May ranged between 10.1 and two characteristics make them more Endodermis Poorly defined Poorly defined Poorly defined Poorly defined Better defined roots did not tend to grow just on one 12.4. This is in line with measurements resemblance to stem than terrestrial side. recorded in the Miami study. roots. Kapil and Rustagi also note Xylem strands 4-5 groups Absent Usually 5-7, Absent Usually 3 or 4, that the structure of aerial roots of F. occasionally 10-15 rarely up to 7 Aerial roots were observed to originate With an average annual elongation benghalensis has greater resemblance from all sizes of branch, some as small as of 1154.3mm, the vertical distance to stems. More vessels exist in Pith Distinct and board Lignified Distinct and large Lignified Absent or scanty 25mm diameter. A higher proportion of from the upper canopy to the ground, secondary xylem in F. microcarpa than F. aerial root biomass were growing from equated to several years growth. The benghalensis. Secondary Absent Less of Absent Many fibres, less Few fibres, more vascular parenchyma, of parenchyma, of parenchyma, larger diameter branches, compared to rougher bark of the flexible roots, with tissues many vessels, fewer and smaller numerous and smaller branches, but this was probably raised lenticels, served to prevent them Root hairs, however, are just structures well developed vessels, poorly large vessels, because of their relative age. from fusing together (as was observed in that substantially increase the absorbing medullary rays developed well developed the lignified aerial roots), allowing their surface of the roots, and the absence of medullary rays medullary rays Aerial roots were initiated, very largely, free movement during this time. root hairs would not prevent aerial roots Periderm Well developed Well developed Well developed Well developed Poorly developed from the underside of branches. This from absorbing water. As Esau notes, Lenticels Many Many Many, raised, Many Scanty, scattered is likely to reflect the more humid It was noted that where a root tip hairless epidermal cells are capable of transversely conditions there, compared to the upper stopped growing and had matured into absorbing water.19 oriented side, with rain water naturally draining to a flexible aerial root structure, further the lower side, and it being less exposure growth tended to be initiated through In terrestrial absorbing roots, water Table 3. Characteristics of aerial roots of Ficus microcarpa and Ficus benghalensis to sunlight. The fact that a few roots side shoot rather than extension of the passes from the absorbing cells to the initiated on the sides and upper surfaces existing root i.e. roots divided (ramified) conducting tissues. Esau identifies that in the same way as terrestrial roots. flexible aerial roots of F. microcarpa CO2 intake was reduced but they could of branches suggests that initiation is hence the multiple roots were usually the notable features of this pathway are: might act in a similar way, allowing absorb water like a sponge/activated not related to whether the wood is in found in clusters. Further, it was noted the presence of abundant intercellular In mature aerial roots of F. microcarpa, uptake water and movement to the carbon in at least 75% relative humidity compression or tension. that aerial roots grew by elongation spaces in the cortex but the lack of such existing vessels serve as conduits. Water conducting vessels. conditions. rather than by thickening, possibly to spaces in the vascular cylinder; together is actually drawn up from roots and The pattern of growth in aerial roots enable them to reach the ground as with the presence of a specialized transported to branches and leaves In terrestrial roots of dicotyledonous Conclusion was also highly variable, with some quickly as possible, while minimizing endodermis between the cortex and through vessels. The hanging aerial plants, water usually flows from high roots growing very vigorously alongside demand on energy resources. vascular cylinder. roots can be likened to branches of their soil water potential to low root water The occurrence and distribution of others, in the same conditions, that parent stem. Water moves from branch potential, and is then transported aerial roots in F. microcarpa trees, and were hardly growing at all. Initiation Characteristics and ability to In new aerial root tips of F. microcarpa, to aerial roots through vessels in the up the stem and leaf by evaporation. the initiation and elongation of aerial of new roots and elongation of existing absorb water cells in the cortex and vascular flexible aerial roots. The reverse may occur if the water roots was highly variable. Trees growing roots was clearly related to high levels of cylinder are closely arranged with few potential gradient is reversed.21 Some in identical conditions often had very atmospheric humidity (relative humidity The structural characteristics of aerial intercellular spaces. The endodermis The role of radially orientated ray tissue experiments show the water can flow different aerial rooting patterns. Even in and rainfall). Substantial growth was root tips and flexible aerial roots of F. is also not clearly defined. This would is the uptake of water through the outer into limbs under external pressure very wet conditions, some roots grew, recorded in the wet summer months, microcarpa observed in this study can be suggest that new aerial root tips cannot surface of twigs20. The well-developed through xylem vessel of cut limbs.22,23 others did not. while no growth was observed during compared with root tips, flexible aerial absorb water and conduct it to the xylem rays observed in transection of the The external pressure plays an important role in uptaking water through leaves When aerial roots did grow, it was at Growth rate Relative Rainfall and branches. Aerial roots of other plant times of the year, in environmental (averaged across samples from eight trees) Humidty types such as epiphytic orchids have conditions, and at locations within been shown to be anatomically adapted the canopy and on the originating Maximum daily Monthly total Monthly Monthly total to absorb water.24,25 Epiphytic orchids branch, that were associated with wet (mm) (mm) mean (mm) uptake water and nutrients efficiently atmospheric condition. This supports July 2014 10.1 187.8 80% 260.5 via a multilayered velamen arising from the common belief that their presence August 10.8 201.3 81% 548.2 the epidermis.26,27 But aerial roots of F. and growth is linked to water availability. September 8.0 73.7 77% 140.6 microcarpa do not have such anatomical October 4.1 12.1 71% 109.8 features. From the detailed study of the cellular November 0.3 1.1 78% 31.1 structure of the aerial root tips, however, December 0.0 0.0 67% 44.7 Liu (2011) observed that aerial roots of it was clear that the secondary vascular

January 0.0 0.0 72% 41.7 F. microcarpa have CO2 and water vapor tissues and cells are not closely arranged, February 0.4 1.2 78% 32.0 exchange functions, and concluded that and they do not have structures to March 5.1 38.3 85% 28.4 new aerial roots were active in CO2 intake absorb water. The more mature, flexible 2 April 11.9 196.2 77% 65.4 and H O release, and flexible aerial roots aerial roots were observed to have May 12.4 244.9 85% 513.0 had weak respiration and transpiration structures (lignified surface tissues, activity. Aerial root tips could only many vessels and medullary rays) June 2015 10.5 198.7 80% 291.0 absorb water in very high (almost 100%) that would allow the absorption and Table 2. Observed growth rates of aerial roots relative humidity. In flexible aerial roots, movement of some water, but as Liu28

82 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 83 observed, this only occurred under high References 19. Esau, K. (1953). Plant Anatomy. Chapter 17. levels of atmospheric humidity As roots The root. John Wiley & Sons, INC. 470-529. 1. Liu, Liying, Fu Xiangzhao, Luo zhiqiang, Guo were observed to be growing throughout Xinxiang. (2011). Gas exchange characteristics 20. Katz, C., Oren, R., Schulze, E.-D., & Milburn, J. periods where relative humidity was of aerial root and affecting factors of Ficus (1989). Uptake of water and solutes through relatively low (70-80%), rapid elongation microcarpa (In Chinese). 19(1): 45-50. twigs of Picea abies (L.) Karst. Trees. 3(1): 33- of the root tips is most likely to be 37. 2. Pryor. M (2015) Street tree planting in Hong based on water (and nutrients) drawn Kong in the early colonial period (1842-98), 21. Cook, R., & Papendick, R. (1972). Influence up from terrestrial roots and conducted Journal of the Royal Asiatic Society Hong Kong of water potential of soils and plants on root along branches. The presence of many Branch 2014. disease. Annual review of phytopathology. conducting vessels and well developed 10(1): 349-374. 3. Ford, C. (1872). First annual report on the medullary rays in the cellular structure Government Gardens and Tree Planting 22. Baxter, P., & West, D. (1977). The flow of of flexible aerial roots suggest that their department, HKGG, 1 February 1873. water into fruit trees. II. Water intake through function is the transportation of water Surveyor General's letter to the Acting a cut limb. Annals of Applied Biology. 87(1): rather than its absorption from outside. Colonial Secretary on 'Tree Planting'. HKGG 103-112. 17 November 1877. Chinese Banyan (Ficus microcarpa L.f.), also referred to as F. retusa 23. Granier, A., Anfodillo T., and Breda, N. (1994). The link between the aerial root growth or F. nitida at the time. Axial and radial water flow in the trunks of of Chinese Banyans and wet conditions, oak trees: a quantitative and qualitative therefore, may be associated with their 4. Fortune, R. (1852). A Journey to the Tea analysis. Tree Physiology. 14(12): 1383-1396. Countries of China. John Murray, London ability to take advantage of wet ground 24. Zhang, Z. (1995). Anatomical structure of the conditions, i.e. uptake water through 5. Pope Hennessy, J. ‘The Governor’s Report’ nutritive organs of Dendrobium candidum. their terrestrial roots and move it quickly HKGG 29, April 1881. para 133. J Anhui Agri Univ, 1995, 22(3) : 301- 304. (in within trunk and branch structures, Chinese) 6. Jim, C. Y. (2014). Ecology and conservation rather than an added capacity of of strangler figs in urban wall habitats. Urban 25. Li, M., Su J. L., Wu R. H., et al (2001) absorbing water through the aerial roots Ecosystems, 17(2), 405-426. Anatomical study on the nutritive organs of themselves. Dendrobium candidum. J. Henan Agri Univ, 7. Pryor, M. Demystifying Tree Transplanting. 2001, 35(2) : 126- 129. (in Chinese) In proceedings of the International Arboricultural Society Hong Kong Conference 26. Bowes, B.G. and Mauseth, J.D. (2008). Plant 2010, Hong Kong (November 2010). structure. A colour guide, Second Edition. Manson publishing. 8. Wu, Z. Y., P. H. Raven & D. Y. Hong, eds. (2003). Flora of China. Vol. 5. Science Press, Beijing, 27. Zotz, G., Winkler, U. (2013). Aerial roots and Missouri Botanical Garden Press, St. of epiphytic orchids: the velamen radicum Louis. 37-71. and its role in water and nutrient uptake. Oecologia. 171(3): 733-741. 9. Hong Kong Herbarium , HK Plant Database 28. Liu, Liying, Fu Xiangzhao, Luo zhiqiang, Guo Xinxiang. (2011). Gas exchange characteristics 10. Anecdotal comments from growers and of aerial root and affecting factors of Ficus nurserymen in Guangzhou microcarpa (In Chinese). 19(1): 45-50.

11. Gill A.M. (1975). Aerial roots: an array of forms and function. In Torrey J.G. and Clarkson D.T. (Ed.), The development and function of roots. Academic press. 237-260.

12. Gill ‘Aerial roots’

13. Zimmermann, M., Wardrop, A., & Tomlinson, P. (1968). Tension wood in aerial roots of Ficus benjamina L. Wood science and technology. 2(2): 95-104.

14. Barlow, P. W. 1986. Adventitious roots of whole plants: their forms, functions, and evolution. Pp.67-110. In: New root formation in plants and cuttings. Springer.

15. Kozlowski, T.T. (1971). Root growth. In Growth and development of trees II. Academic press. 196-250.

16. Author’s unpublished research on sources of damage of trees during transplantation

Mathew Pryor is Head, and Li Wei is a 17. Liu (2011) Research Assistant, of the Division of 18. Kapil, R.N. and Rustagi, P.N. (1966). Anatomy Landscape Architecture, at The University of the aerial and terrestrial roots of Ficus of Hong Kong. benghalensis. Phytomorphology. 16: 382-386. Lignified aerial roots on Ficus elastica, on Lugard Road, The Peak

84 / Yuan Lin 2015 Planting Futures 'There are still many bare An alternative way to areas along the margins of green the city: Unplanned our footpaths and roadsides vegetation in Hong Kong but patches of green can Gap Chung Wai-kin often be seen spontaneously In densely populated Hong Kong, both public and private sectors are carrying popping up in the nooks and out active planting, maintenance and preservation of plants to enhance crannies of the concrete greening in the urban areas. There are still many bare areas along the margins of our footpaths and roadsides jungle. These self-seeded but patches of green can often be seen spontaneously popping up in the plants are an unplanned and nooks and crannies of the concrete jungle. These self-seeded plants are unintentional feature of the an unplanned and unintentional feature of the urban environment. This research project investigates unplanned urban environment. Can the vegetation as an alternative way to green the city where every square inch “unplanned” vegetation be counts. It examines the planning, design intervention and management of self- Pilea microphylla seeded vegetation and its promotion as “planned” to further green a sustainable greening strategy. Can the or even replaced entirely with artificial “unplanned” vegetation be “planned” to plants for ease of maintenance. At the our city?' further green our city? same time, most self-seeded vegetation is regarded as a nuisance and we spend Existing greening in Hong Kong a lot of resources trying to remove these so-called untidy weeds. Self-seeded Greening works in the urban areas of ‘wild’ plants that do survive tend to be Hong Kong currently focus mainly on Gap Chung Wai-kin found in areas where the administrative ornamental planting in gardens, parks, or maintenance authority is unclear with housing estates, roadsides, drainage Pocket park with pots the result that no one is willing to remove reserves and green roofs. Most need them, or where access is difficult such as regular and intensive maintenance way to green the urban areas. In Hong walls above street level or inaccessible to keep them tidy and attractive. Kong 74,100 ha (67%) of the land area highway barriers. Development land is scarce as described is woodland, scrub, grassland and 3 by the HKPSG1 'Developments within wetland, we should take advantage of Opportunities for naturalised and these limited land resources have this natural resource which is constantly self-seeding plants necessarily resulted in a compact urban producing seeds, and let Mother Nature form with limited scope for provision or plant for us. This additional greening In the past five years, Government has preservation of greenery.' Historically option for Hong Kong’s urban area should planted 44.3 million plants in Hong Kong, the limited land supply has resulted be flexible, adaptable and scalable to 75% being shrubs and 10% annuals.2 in extremely high land values and fit the fast changing Hong Kong urban Annuals are usually used for seasonal greening has usually been something environment. Such a greening policy decoration or special events, some of an afterthought compared to the should incorporate a strong (excuse the shrubs struggle in adverse growing architectural and technical priorities pun) grass-roots element, to encourage conditions or are damaged. Only 10% of of development. As a result, greening more citizens to appreciate the value of these plants are trees and of those only often ends up relegated to plant pots self-seeded vegetation. one in ten is planted in the urban areas. or narrow strips in locations which are We need to look for a more sustainable not conducive to healthy plant growth,

Yuan Lin 2015 Planting Futures / 87 Self-seeding plants in Hong Kong heavily trafficked, regularly maintained which are “hazardous to the native and cleaned offer little prospect for plants, reduce the biological diversity, There are many different types of self- successful establishment. Water and affect the ecosystem.”4 seeded plants in our concrete jungle, availability is also critical with some including algae, mosses, ground covers, locations offering more scope for would- Research intention herbs, ferns, climbers, grasses and be invaders thanks to drain blockages, trees, and even succulents. They come regular spillage, overflow or leakage. The overall objectives of the project are in many shapes and sizes, and take to explore how unplanned vegetation advantage of many different urban Value for the City can be employed to connect the city conditions. Their flowers and foliage with surrounding nature and enhance provide colourful highlights in the grey Unplanned, out of control vegetation its ecological diversity. The definition of concrete monotone. Most of these is often considered messy, and blamed greening can be widened to incorporate pioneer and opportunistic plants seed for causing nuisances such as mosquitos this effective and sustainable method and themselves freely. They exploit a variety and bad smells. However, ornamental reduce the financial and environmental of strategies to distribute their seeds and planting areas may well fare just as cost of greening. Why remove all the expand their territory. Most have tiny badly due to design defects, littering, or “weeds”? We should recognize their seeds which can gain a foothold in very poor management and maintenance. In intrinsic value. Highway intervention - Detail Highway intervention small crevices. Self-seeded plants occur fact unplanned greening provides most everywhere in the urban areas and may of the public benefits associated with Strategies to achieve these objectives either invade existing planting areas or ornamental plants, such as improving include promoting the idea of harnessing take advantage of openings in places not air quality, reducing the urban heat- the power of plant naturalization, and intended for planting such as in walls or island effect, moderating soil erosion, explaining the value of small scale footpaths. stabilizing slopes, reducing storm water interventions using ‘wild’ plants. A runoff, etc. They also have additional change of attitude is advocated to Existing planting areas usually have a benefits including easy establishment, appreciate the value of unplanned comparatively rich growing medium rapid growth rates, and high tolerance vegetation, turning it from a nuisance and water supply allowing self-seeded of extremely adverse site conditions, to a resource that can provide another plants to establish easily, especially thereby reducing landscape installation alternative approach to urban greening. where the original planting has aged and maintenance overheads. Annual or failed for some reason. Areas not plants exhibit seasonal changes, and Proposed actions under these strategies designed for plants usually have nooks some wild vegetation is edible or has fall into three categories. First, cultivate and crannies that accumulate litter and medicinal uses. They provide habitats a positive relationship between society organic matter which in turn provides for many insects and birds in the urban and this aspect of ecology by means of nutrients and moisture to seeds and environment, and contribute to the a community-based greening approach spores that find their way into these natural process of soil development, that adopts greening interventions habitats. Besides physical conditions, while providing passive recreation using ‘wild’ plants. Secondly, provide there are other factors affecting the and educational opportunities for the design intervention guidelines and survival rates of unplanned vegetation, community. In fact unplanned vegetation management strategies for Government, so you may find the performance of the serves as an indicator of space that is not landscape architectural professionals, same species varies widely between used for other functions in the urban and the wider community. Thirdly, different districts and environments. The fabric. Some monitoring and control implement demonstration projects to survival of these opportunistic plants is measures are required to deal with show the advantages of self-seeding largely determined by the accessibility problematic species such as Mikania plants and benefits of using them as a and use of the space. Areas that are micrantha and Leucaena leucocephala, greening method.

Alley intervention - Detail

Proposed management in alley Grass growing in paving gaps intervention Alley intervention

88 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 89 Site selection of work based on the agreed outcomes, type of situation, applied according to Cost medium and seeds. In areas that are References engaging the community in preparation the requirements and restrictions. Most not accessible and where user safety In contrast to the traditional top-down and construction wherever safe to do so. of them can be adapted to the existing The cost of self-seeding plant is not affected, zero-maintenance may 1. Planning Department, HKSAR. Hong Kong Planning Standards and Guidelines (HKPSG), city planning process, greening with self- Community involvement in this situation easily with simple modification. interventions are generally lower than be appropriate and the plants allowed 2007, Ch4: 2.1.3 seeding plants should take a more grass- sustainable greening method can This makes the greening process more conventional ornamental planting, to grow wild. This achieves the goals of Development Bureau, HKSAR. roots approach, because local citizens increase local residents’ sense of sustainable. They can be implemented because most of the wild plants can sustainable greening and saves costs. understand more about their own local belonging to their district, and enhance at any scale, on the basis that many be established by seed which is much 2. Planting Records. Accessed from be set up including community groups, that greening becomes more than just something significant! The integrated and more likely to survive in the urban government sectors and professionals, cosmetic. design includes a water retention mat situation. Reduced maintenance Community acceptance is one of the 3. Planning Department, HKSAR. Land Utilization to explain the value of unplanned and reservoir layer which can keep requirements will lower ongoing costs of key issues. School visits and community in Hong Kong 2014, Accessed from community groups can identify locations moist during the dry season. The success widened, more areas can be set aside for public awareness about the value of this which already have significant unplanned Here we have three distinct types of these measures can be assessed by greening, creating jobs for professional kind of planting. Through community 4. Legislative Council HKSAR. LCQ15: 2011. vegetation and suggest locations which of intervention for typical Hong the establishment of wild plants and and technical staff. action, such as green workshops, citizens Proliferation of Mikania micrantha in rural areas and criteria in selecting plant species. they think require additional greening, Kong urban conditions, namely brick their ability to sustain themselves, their can make themselves more familiar with Accessed from possibilities and identify suitable barriers. The interventions are flexible, local ecology. and instigate sustainable community interventions and species. Thirdly, the adaptable, and scalable. They are Systematic management is essential landscapes where they can help to sow task force should establish a schedule flexible with several options for each with regular inspection, localised wild plant seeds and get involved with trimming to ensure user safety, and their ongoing management. removal of invasive species. In any given area, existing self-seeded plants ‘Unplanned vegetation’ is a feasible may be retained because they help and sustainable way to green our urban indicate which areas are appropriate environment and enhance the ecology for further greening, and provide a of the city. Attitudes will change as we living in-built seed bank. Existing poor understand the value of small scale quality ‘ornamental’ plants may be interventions by wild plants. It is said removed from existing planting areas. ‘great oaks from little acorns grow’. Many Where structural considerations permit, small greening interventions of this kind self-seeded plants may be retained can add up to a great transformation of on structures and walls. In alleyways the city! with low pedestrian flow, the paving arrangement can be reviewed, opening up unused areas for planting. Growing medium can be brushed into crevices and sown with common wild plant Gap Chung Wai-kin was an MLA Thesis seeds. Litter can be removed with pick- Student (graduated 2015) at the Division up tongs, avoiding brooms or water- of Landscape Architecture at the jets which easily dislodge growing University of Hong Kong. School children preparing the ground for seeding with wild plant species.

The ground seeded and established Brick paving intervention - Detail

90 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 91 Amenity and sports turfgrass in Hong Kong Eric YT Lee, PhD

Turfgrasses are plants that form a more for the breakthrough, as in the early seldom used. Perennial Ryegrass (Lolium or less contiguous ground cover which 1970s, the Club introduced the then perenne) is used for over-seeding and persists under regular mowing and newly improved hybrid Bermuda grass, hydro-seeding purposes. Weeping Love traffic.1 They were selected through years namely Tifton 419/Tifway and Tifton Grass (Eragrostis curvula), a bundle- of experience and practice. All turfgrass 328/Tifgreen (Cynodon dactylon x C. type grass, is commonly used in hydro- belong to the grass family (Poaceae or transvaalensis cv. Tifway and Tifgreen) seeding for slope protection, because Gramineae). Of the approximately 600 into its golf courses, together with new of its quick germination rate and easy genera and 7,500 species, only a few propagation methods, e.g. stolonization. establishment. dozen are being used as turfgrass and This was a landmark in local turf they are randomly distributed among 8 management history, and a big step Turfgrass species of the 25 genera in the family. Quality forward. The practice has since been of turfgrass is determined by its texture, adopted by many major local institutes Common and Improved Bermuda grass usually the finer the better, tolerance such as the Hong Kong Jockey Club and to wear and tear, quick recovery Hong Kong Cricket Club. Subsequently, Common Bermuda Grass (Cynodon rate and more recently tolerance of many newer turfgrasses were introduced dactylon) though a native grass, has contaminants. In Hong Kong there are into this region, e.g. TifDwarf in the not been widely used for amenity and some 20 native and introduced turfgrass 1980s, TifEagles and several improved sports fields because of its inferior species.2 Prior to the 1970s, only mixed varieties of the Seashore Paspalum characteristics such as coarse texture, grasses were used for amenity and sports grasses at the beginning of the 21st long internodes and poor matting. Seeds turf. Carpet Grass or Big-Leaf Grass century. of Common Bermuda Grass are readily (Axonopus compressus), because it was available in the market and the grass readily available in the wild, became the Of the 20 or so turfgrasses known is specified as a pre-dominant grass predominant and preferred grass species locally, only five are commonly used component for hydro-seeding or erosion for amenity and sports fields. Grassing for amenity, sports and/or erosion control. works were carried out by 'sodmen'. control purposes. They are the common Classification of sods was more or less and the improved Bermuda Grass Seeds of Improved Bermuda grass are done on percentage of the named grass (Cynodon dactylon), Korean Grass now readily available in the market. against the other locally grown grasses. (Zoysia japonica) and Manila Grass (Z. Specifiers should take the initiative to If the sod contained about 70% of Carpet matrella) the two Zoysia Grasses, Carpet use the finer and better varieties in the Grass and 30% of other grasses, such Grass, usually mixed with Tilo Grass, future. Improved Bermuda Grass is also as Tilo Grass (Paspalum conjugatum), and Bahia Grass (Paspalum notatum); referred to as Hybrid Bermuda Grass. Knotgrass (P. distichum) and Wild Oat the other turfgrass species, mainly Merits of these hybrids include better Grass (Chrysopogon aciculatus), the because of their limited availability, are turf character and better response to grass was called '3/7 grass.' Sods were harvested mainly from abandoned fields in the New Territories where they formed natural colonies. After planting, not much follow up maintenance would take place, except initial watering as there was a general myth among the sodmen that grass grown roughly should be nursed roughly.

In Hong Kong as elsewhere, turf management has evolved from a craft to a science in the last four or five decades. View of Yuen Long Town Park from the Pagoda Hong Kong Golf Club should be credited Common Bermuda Grass Hybrid Bermuda Grass - Tifway

Yuan Lin 2015 Planting Futures / 93 cultural practices. Since its introduction of winter and turns green earlier in flowering stalk. Since 'Carpet Grass' Zoysia Grass Seashore Paspalum to Hong Kong in the early 1970s, these Spring than its counterpart. is listed as one of the acceptable improved varieties have been used constituents of hydro-seeding in Hong Korean Grass (Zoysia tenuifolia) is Improved Seashore Paspalum (Paspalum widely in nearly all the local golf courses Seeds labeled as 'Carpet Grass' can be Kong, people often mix this up with the characterized by coarser leaf blades vaginatum), namely Salam, Sea Isle and some sports fields. Quite recently, purchased from seed companies in other Carpet Grass (A. compressus) and and less dense sod. This grass is not Series, Sea Spray, etc. have only been some ultrafine strand selections, e.g. Australia. Grass produced from these use it occasionally in their seed mix. A. commonly used in Hong Kong as its available commercially in Hong Kong TifEagle, have been used on greens of seeds is identified as a different species affinis can be found in small patches availability is limited. for some 10 years. Because of its high golf courses. in the same genus, i.e. Axonopus affinis. in some amenity and sports fields but tolerance to salinity, it can take nearly all This grass is characterized by much it is never considered a good quality Manila Grass (Zoysia matrella) is perhaps kinds of water for irrigation; hence it has When properly maintained, Hybrid narrower, boat-shaped leaves and a turfgrass locally. the most commonly used turfgrass for been considered as an 'environmental' Bermuda Grass stays green throughout much longer, slender and, protruding home lawn, gardens and at times for grass. Quite a few golf courses and the cooler months in Hong Kong. For sports turf as it is readily available in the amenity areas in Hong Kong have used aesthetics and also for increased turf market and the price reasonable. Small this grass in their facilities, e.g. the density, Perennial Ryegrass is commonly Manila Grass sod farms are common in Third Course at Kau Sai Chau Public Golf used for over-seeding dormant Bermuda Shenzhen, Zhuhai and Guangzhou. The Course, SkyCity Golf Course at the Hong Grass fields. price is relative cheap, i.e. about $1 per Kong Airport, and the lawn for the Dr. square foot. Sun Yat Sen Memorial Park. As a new The use of shade-tolerant varieties comer among the turfgrasses, Seashore such as TifGrand and others should Although Zoysia Grass is known for its Paspalum is a tricky grass to maintain due be considered for turf facilities with tolerance of medium traffic, if the wear to a lack of local experience maintaining Manila Grass potential shade issues. and tear exceeds its threshold, damage it, and its compatibility with commonly- is permanent and recovery is very slow. used pesticides. Carpet Grass Zoysia Grass is difficult to maintain as Bahia Grass Although Carpet Grass (Axonopus it requires verti-cutting regularly to spp.) is a preferred grass in nearly all thin out the thatch. Otherwise, the Bahia Grass (Paspalum notatum) is more government tender specifications for grass turns patchy with time. Poorly a pasture grass than a turfgrass as its leaf the construction of sports turf facilities, maintained Zoysia Grass fields are prone is quite wide and the stolons are robust. it does not meet the standards set by to weed infestation. Bahia grass is best for low maintenance national and international authorities, amenity areas such as roadside lawns e.g. numbers of shoots per unit area. In the past, seeds of Zoysia Grass and on fill slopes. The successful change of the Employer's were known to have a very low Requirements (Tender Specification) germination rate. With pre-treatment, Seeds of Bahia Grass are also included from Carpet Grass to Hybrid Bermuda the germination rate of Zoysia Grass in the seed mix for hydro-seeding during grass for hosting the East Asia Games in seeds can be up to 98% and seeds can summer months and is widely used by 2009 serves as an excellent precedent. germinate in about one week. With local contractors. Mainly because of its this improvement, hydro-seeding resistance to drought, Bahia Grass often Although Carpet Grass is best known contractors should consider Zoysia Grass becomes the surviving grass species on for its poor turf quality, coarse texture, seeds in their seed mixes for grassing hydro-seeded sites. (i.e. wide leaf blade), shallow rooting, projects in less fertile or arid sites, e.g. poor wear and tear resistance, and poor Tropical Carpet Grass fill and soft cut slopes. Seashore Paspalum winter colour, as a low maintenance turfgrass, it remains a desirable grass for amenity areas and also for less demanding sports fields.

Based on my observation, in most Carpet Grass based amenity or sports fields, a large percentage of Tilo Grass was found. This is because some of the turfgrass growers cannot distinguish the two in their nursery. The contamination actually originated from the production site. The two types of turfgrass blend in well in the field as both of them share more or less the same turf character, e.g. texture, creeping pattern and growing pattern. They grow harmoniously side by side. Tilo Grass, however, is characterized by a longer greening period: it turns brownish later than Carpet Grass during the onset Tilo Grass Carpet Grass Korean Grass Bahia Grass

94 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 95 Weeping Love Grass

Weeping Love Grass (Eragrostis curvula) is one of the few non-stolon and non- rhizome producing warm-season grasses. It grows in bundles and has never been intended to be used as a turfgrass. Seeds are readily available in the market; this together with its high germination and establishment rate has made it a popular grass species for use in slope control projects. Weeping Love Grass is a bundle-type grass and produces tillers only. It is worth noting that full grown and dry patches of Weeping Love Grass could become fire hazards on remote sites.

Perennial Ryegrass Perennial Ryegrass Centipede Grass As indicated before, uses of Perennial Ryegrass (Lolium perenne) in Hong Kong are restricted to winter over-seeding operations and as a component of the winter seed mix for hydro-seeding. The grass dies completely with the onset of spring.

Other cool-season turfgrass such as Tall Fescue (Festula arundinacea) and Blue Grass (Poa spp.) have been used for over-seeding and hydro-seeding by local Lawn at the Sun Yat Sen Memorial Park hydro-seeding users, and the results were disappointing, e.g. on turf tracks States, Centipede Grass (Eremochloa Conclusions References on race courses and on some local golf ophiuroides) is commonly found in open courses. pastures, roadside and hill slopes in It is clear that there are sufficient turfgrass 1. Turgeon, Alfred J, 2012 – Turfgrass Management, 9th Edition. Prentice Hall Hong Kong (and also in mainland China species available locally to cope with the Other Turfgrass Species and Taiwan). The use of this grass locally demands for various users. Carpet Grass, 2. Lee Yin-tse, 2003 - Turfgrass in Hong Kong, has not been fully explored. Although Hybrid Bermuda Grass, Zoysia Grass and/ Herbarium Leaflet No.15, Agriculture, In contrast to its popularity as a it is listed as a component grass seed or Seashore Paspalum are all suitable for Fisheries and Conservation Department, Hong Kong. native turfgrass in southern United Tall Fescue Wild Oat Grass species, grassing contractors are use in amenity and sports fields. When reluctant to use Centipede Grass seeds managed properly, natural turf facilities due to its high price, (e.g. retail price up can be made sustainable. to US$ 32/lb). Major seed production is restricted to the southern states in USA, the amount produced is small, and is at times affected by weather. Based on my observations, seed production in China (incluing Taiwan and Hong Kong) is low and unpredictable as the majority of spikes produce infertile seeds.

Two other local grasses: Wild Oat Grass (Chrysopogon aciculatus) and Long- Flowered Crabgrass (Digitaria longiflora) are commonly found in old and worn-out sports fields. These two grasses possess Dr. Eric YT Lee is Honarary Senior good turfgrass character but their use Research Fellow of the School of Life has never been fully assessed because Sciences, the Chinese University of Hong of their limited availability in large Kong and President of the Hong Kong quantities for any grassing projects. Institute of Horticultural Science. Weeping Love Grass Blue Grass Long-Flower Digitaria

96 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 97 Given the limitation of space, Weaving green fabric to it seems difficult to achieve a a condensed city sustainable built environment Greening, Landscape and Tree Management Section, Development Bureau by striking a balance General overview of development between development and of urban greening in Hong Kong Hong Kong is well known as a “city of skyscrapers” characterised by its high greenery. By exploring the density, high-rise forms and multi-storey mixed use buildings in the urban areas. untapped spaces offered In addition, extensive infrastructure dominates our urban landscape. As by building roofs and walls, the majority of Hong Kong’s 7 million people are concentrated in around 20% of the land, the city’s highly compact skyrise greenery can be development and scarcity of land pose a great challenge to providing greenery in a positive answer through the city. So, are there opportunities for more weaving green fabric to a greening in our city? In fact, the answer is encouraging - our city can be greened in condensed city at multiple various dimensions. Apart from planting at-grade, we can apply skyrise greenery levels. to high-rise buildings and structures on various planes and surfaces.

Greening, Landscape and Tree Management Section, Skyrise greenery provides us with a wide range of benefits, such as improving Development Bureau aesthetic quality, providing visual relief and psychological comfort, as well as ameliorating the heat island effect, Roof greening at Sha Tin Sewage Treatment Works

Vertical greening on IFC Footbridge Flyover at Junction of Prince Edward Road East and Choi Hung Road

Yuan Lin 2015 Planting Futures / 99 improving air quality through pollution absorption and oxygen generation, and reducing storm water runoff. It is also beneficial ecologically as it promotes biodiversity, creates wildlife habitats and provides links for habitat in the inner urban core. From an economic point of view, it can improve the lifespan of buildings and reduce energy consumption by insulating buildings from the summer heat.

The Government has been taking proactive steps to promote wider use of skyrise greening in the form of green roofs and vertical greening. In the past decade, the number of skyrise greenery projects has been rising, and over 400 government projects have now been constructed with green roofs and/or vertical greening. In addition, the skyrise greening of more than a hundred government projects is being planned or is in progress. There is an increasing trend to apply skyrise greening in commercial and residential developments. Many projects showcase the effective application of skyrise greening technologies with creative designs.

Besides, many schools and non- government organisations (NGOs) have made use of the Environmental and Conservation Fund for constructing green roofs for educational purposes. Over 130 green roofs have been subsidised in the past five years. Some of them were winners in the Skyrise Greenery Awards 2012 organised by the Greening, Landscape Tree Management (GLTM) Section of the Development Bureau. Teaching Hotel Complex, The Hong Kong Polytechnic University Roof garden at Ng Yuk Secondary School

Opportunities and potential areas for greening enhancement

So what kind of landscape works can be called skyrise greenery projects? In a broad sense, skyrise greening encompasses all greening on buildings or structures above ground level, including green roofs and vertical greening. Though not new in Hong Kong, it offers opportunities to optimise space for urban greenery which may take the form of sky gardens, podium gardens, extensive green roofs, edge greenery, green walls and living walls. Recently, skyrise greenery has also added new dimensions for educational and Citywalk 1& 2 Roof garden at Munsang College Primary School Roof garden at Munsang College Primary School therapeutic purposes.

100 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 101 quality in master planning, in which the Play and learn elements of skyrise greenery are skillfully incorporated into the building design for In 2010, with the support of the the enjoyment of the public,” according Environment and Conservation Fund, to comments from the jury. Munsang College Primary School converted its rooftop into a beautiful Built on four main themes: openness; roof garden – a green lawn where enjoyment; sustainability; and students can relax, walk, chat, play togetherness, the project was completed and paint. The school received a Silver in 2011 to house the Central Government Award in the Skyrise Greenery Awards Offices. A 'Land Always Green' concept is 2012 in recognition of its efforts and reflected in the natural lush landscape commitment to greening. of the 1.27ha Tamar Park, a landscaped roof providing a public open space, Not only does the roof garden help developed as an integral part of the to absorb heat by 2°C to 3°C and save Tamar Development Project. This 'urban energy, it also provides students with Munsang College Primary School lung' is a welcome green space amidst a relaxing environment for outdoor Landscape Plan and perspective drawing of Kai Tak Development (Source: Kai Tak Office) the conglomeration of skyscrapers in our educational activities such as student central business development area. exchange programmes and a food waste The leading role of the Hong Kong planting practices in the upstream recycling scheme. Through planting Government in greening the city and proper vegetation maintenance in Another exemplary open space is the a variety of flowers, herbs, seasonal the downstream, with due emphasis Kai Tak Cruise Terminal Park which is fruits and vegetables in the roof garden, The greening policy aims to bring about on protection of public safety as a nestled on the roof of the iconic new Kai students have acquired the skills to sow, noticeable improvements in urban priority consideration. The Section also Tak Cruise Terminal Building. The park irrigate and weed the land. They observe greenery, to enhance existing greened spearheads the promotion of skyrise occupies an area of 23,000 m2 which is the growth of plants and gain a better areas and create quality greening greening through organising seminars, currently the largest green roof in Hong understanding of plants while teachers opportunities. To achieve these workshops, project visits, facilitating Kong. It features a spacious central lawn, provide guidance. Students can “eat, targets, technical circulars, guidelines exchange among practitioners, a dedicated viewing platform, a peaceful play and learn” by experiencing organic and standards for skyrise greenery and professional institutions, and water garden, an eye-catching fountain farming in the roof garden. provisions have been promulgated. encouraging research studies to plaza and it is a unique space to enjoy For government building projects, a enhance the knowledge of new greening the open air and magnificent harbour minimum 30 % of greenery coverage technologies and their application view with stunning cityscapes. Munsang College Primary School for site areas over 20,000 m2, and a of skyrise greenery. Some recently minimum 20% greenery coverage for completed or on-going research studies site areas between 1,000 m2 and 20,000 such as 'Study of Climbing Plant Species The book ‘Skyrise Awards 2012’ and m2, has to be achieved. Similarly, site for Application of Vertical Greening 'Pictorial Guide to Plant Resources for greenery coverage requirements have in Drainage Services Department's Skyrise Greenery in Hong Kong' can be been incorporated as prerequisites for Facilities', 'Green Roofs: Green Roof downloaded at www.greening.gov.hk. granting Gross Floor Area concessions Guidelines, Water Quality and Peak in building plan submissions to promote Runoffs' and the bilingual 'Pictorial publication of the book ‘Skyrise Awards sustainable green building design in the Guide to Plant Resources for Skyrise 2012’, and has successfully raised public private sector. For example, the Kai Tak Greenery in Hong Kong' can be found at awareness of skyrise greenery and Development has greening ratios of an the Greening website . from the public for the development of parameter for both public and private quality skyrise greenery in Hong Kong. sites and minimum 20% of total roof These measures provide an open cross- area. discipline platform for the trade and Skyrise greenery in various Tamar Park Tamar Park Tamar Park industry to share valuable professional dimensions in Hong Kong The Government also encourages and practical experience so as to lower integrating skyrise greening in the early the technical barriers in the application We are glad to see not only the increase planning and feasibility stages so that of new greening techniques. in quantity but also a wider scope in adequate structural loading capacity, adoption of skyrise greenery in various planting space, irrigation and drainage In 2012, we organised the Skyrise projects in Hong Kong. The following systems are duly incorporated for Greenery Awards to promote skyrise are some exemplary skyrise greenery successful implementation. greening as an integral part of the projects showcasing creative designs. project to achieve quality landscape The GLTM Section of Development in the built environment and fostering Open spaces for the community Bureau promotes a holistic greening public appreciation of exemplary approach embracing adequate space skyrise greenery projects. The launch Tamar Development, the Silver Award allocation for new planting, proper of the Awards scheme, included a winner in the 'Government Projects' selection of planting species as well series of activities and publicity: award category of the Skyrise Greenery Award as quality landscape design and ceremony/ seminar; roving exhibition; 2012, "demonstrates outstanding Kai Tak Cruise Terminal Park Kai Tak Cruise Terminal Park

102 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 103 Therapeutic garden Skyrise Greenery Award 2012, Drainage skyrise greenery can be a positive step Services Department has been focusing forward, weaving green fabric through a The North Lantau Hospital features on enhancing greening in its other condensed city at multiple levels. a roof garden with various greening facilities, for example the Kowloon elements, such as an extensive City Pumping Station. In order to bring We see that there are still substantial green roof, vertical greening and a aesthetic and environmental benefits bare roofs and walls yet to be exploited. rain garden. The rehabilitation roof to the surrounding residents, the site This living green fabric in the form of garden is also designed with a patient- coverage of greenery of the project skyrise greenery can transform our focused approach with therapeutic and reached an impressive level of nearly dense building mass to a green oasis. restorative healing effects with features 60%. In addition, the project is a such as the horticultural therapy area, showcase of green infrastructure where Article by the Greening, Landscape and colour therapy columns, tactile walls the pitched green roof, rain garden Tree Management Section, Development etc., to stimulate the full range of senses and terrace planters make rain water Bureau. – memory, hearing, touch, smell and harvesting possible. taste – as necessary supplements to the visual experience. Conclusion

Green infrastructure Given the limitation of space, it seems to be difficult to achieve a sustainable With the successful experience in built environment by striking a balance applying vertical greening and green between development and greenery. roofs of the Shatin Sewage Treatment By exploring the untapped spaces Works, a Silver Award winner of the offered by building roofs and walls,

North Lantau Hospital (Source: Architectural Service Department)

Kowloon City Pumping Station (Source: Drainage Service Department) North Lantau Hospital

104 / Yuan Lin 2015 Planting Futures Productive green roofs Mathew Pryor

As with many high density cities, Hong - Improving building sound insulation building coverage is now mandated for Kong’s thousands of grey roof spaces - Providing visual greening within the new building projects in Hong Kong5 constitute a significant proportion of city and has become a central component of the built area, and represent a severely - Ameliorating some effects of storm green building certification systems.6 For underutilised asset. water, and landscape architects, green roofs have - Increasing biodiversity and urban created exciting new sites for landscape A ‘green roof’ is a roof that is covered wildlife in the city and new technical challenges with growing medium and vegetation in dealing with plants in extreme planted over a waterproofing Since 2011, Development Bureau’s conditions. membrane, typically with some form of ‘Skyrise Greening’ campaign1 has root barrier, drainage layer and irrigation promoted the benefits of greening at Practical issues system to support it. Green roofs have height in Hong Kong, and has resulted been incorporated into new buildings in more than 400 green roofs2 being In practice, however, problems can and retrofitted to existing buildings since established in urban areas. These have occur on green roofs when the long term the 1960s and have been shown through mostly been retrofitted to school and health of the vegetation is compromised numerous scientific studies to offer a infrastructural buildings, for example to the point where it cannot perform its wide range of potential environmental the award winning Shatin Sewage functions properly. Common symptoms benefits and contributions to a Treatment Works3. The ‘Be our Greening of failure include: poor plant health / sustainable urban lifestyle. Depending Partner campaign’4 has brought support loss of vigour; plant death; growth / on the type of green roof (extensive from commercial and community predominance of weeds and invasive / intensive) and location, these might organizations for this initiative. plants; soil waterlogging, and soil include: desiccation. These typically result from Green roofs have rapidly become a key one or more of the following: - Improving thermal performance and ‘green development’ tool in the urban building energy conservation expansion and renewal of the city. • Poor drainage - Improving urban air quality Following the lead of countries such as • Over watering - Reducing urban heat island effect Singapore, Germany and France, green • Inadequate irrigation

Brooklyn Grange commercial organic farm, New York

Yuan Lin 2015 Planting Futures / 107 • Soil nutrient deficiencies • Misuse - unplanned active use • Use of unsuitable species • Insects and pathogens (virus, bacteria, fungi)

It is unsurprising that in a recent study of 42 green roof systems in Hong Kong (that had been established for more than 2 years)7 more than 40% of owners / managers reported significant long- term problems in the performance of their green roof system, and in a small number of cases the green roof had failed outright. Problems appear more prevalent in intensive green roof systems, with thinner soil layers. Green roofs with a greater depth of soil were generally more resilient.

From the study survey, there appear to be a number of underlying causes of green roof under-performance.

• Green roofs are artificial constructions dependent on precise irrigation and effective drainage systems. Small problems or deficiencies in either, can rapidly lead to systemic failure. The vegetation is not self-sustaining and does not function as an urban ecological habitat. Plants are growing in very Rooftop farm growing vegetables, corn, lotus and rice, Liuzhou (Photo: Xinhua) marginal conditions, and are constantly under stress. The very thin drainage the need for: constant monitoring of to maintenance is reactive (act only when We need to move beyond the long-term, a green roof system (indeed, Productive green roofs layers have no capacity for storage, plant and soil health; regular checking problems occur), or the maintenance ornamental planting of exotic species any non-self-sustaining vegetation) and under intense summer monsoon of drainage layers; undertaking very team is encouraged to minimise effort (in bold geometric patterns). These has to be planned, designed and The environmental benefits of rooftop rains the soil above can easily become regular soil aeration; and the continual and expense, then the green roof is likely mono-specific blocks have no ecological managed as a fully integrated part of farms (growing crops for food) have waterlogged. Conversely, the very thin adjustment of watering regimes, all of to fail in time. Up on the roof, planting value and are not resilient. If they fail, the natural environment and centred been found to be broadly similar to layers of soil used to support growth, which are vital to long-term success. can be ‘out of sight and out of mind’, and they do so comprehensively. We need around a resident community that those of more conventional (intensive) leave plants vulnerable to rapid drying Even an understanding of the need for becomes just another building façade to investigate the use of combinations has a vested interest in its on-going green roofs, namely: out in the winter months. The number active re-planting, and improvement of material. Even where there is oversight of native species that have a chance of maintenance, care and development. one killer of plants in Hong Kong is too soil nutrition was largely absent. Further, of rooftop vegetation, it is usually from developing into a sustained ecological Our management of green roofs should - Reduction in solar heat gain, and much water, the number two killer the design of many green roofs is reliant a distance where plant health problems habitat, or the use of particular species recognise that the vegetation, like all positive impact on building insulation 10 is not enough water. Hong Kong’s on proprietary systems (irrigation, may not be obvious. Only where an that can actively engage the community landscapes, has seasonal and life-cycle and urban heat island effect11 aggressive climate poses big challenges drainage, soil materials, etc.), which tend individual or community feels a sense of in their care and maintenance e.g. patterns, and will naturally evolve and - Energy conservation, improved to green roof systems.8 This problem to be inflexible and difficult to adjust, so ownership in a green roof, will it receive productive crop species. adapt to environmental conditions. We thermal performance is compounded by active use. Even may not be resilient in the long-term. the careful and proactive stewardship it need sensitive, proactive maintenance - Biodiversity and wildlife seemingly lightweight activities such We need to recognise that the value of needs. The use of unitary systems, which are of the vegetation (and attendant water, - Improvement in urban air quality as pedestrian walking can be sufficient a green roof is dependent on it being more flexible and adaptable to complex soil and fauna), that help it grow and - Noise and sound insulation to result in significant compaction maintained in a specific way. Typically There is still much to be learnt in the roof shapes, and the consideration develop over time. - Urban greening12 of soil layers, and a decline in plant they are not conceived as self-sustaining design and management of green roof of partial systems, (i.e. not blanket - Buffering stormwater run-off performance. Access to some green vegetation systems, based on native systems, in particular mechanisms for coverage), would allow for greater Where they are safely accessible, and can roofs has been restricted by managers to flora and fauna. In many respects green monitoring their health, identifying depths of soil (up to 250mm) so that a be designed for active use, green roofs In addition, rooftop farms can have avoid such problems. roof systems are far closer to carpet incipient problems, and taking timely wider variety of plants can be used and can have considerable community and significant social / community benefits13, bedding than urban ecological habitats.9 action to address them. Beyond the existing species choices can be grown in public health benefits (‘soft benefits') and have the potential to help address • Green roofs have very specific technical refinements which will come less marginal conditions. in the form of social / community the rapidly growing issue of food security maintenance requirements which are • Ownership has been identified as a from the continued practice of building interaction, recreation, and interaction for urban areas13 and help to reduce more intense than standard horticultural key factor in green roof success. Where and operating green roofs, there are Different operational models that with nature (salutogenic environments). their ecological foot print.14 maintenance that might be appropriate there is no clear definition of who is other ways we can improve our approach encourage and facilitate active use for ground level planting. Many responsible for maintenance (i.e. it is to greening roofs across the city. and positive ownership, should be Rooftop farm projects have been managers were completely unaware of ‘someone else’s issue’), or the approach considered. To be successful in the initiated in many high density cities

108 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 109 across the world, in the last ten years. Table 1: Rooftop farms in Hong Kong Brooklyn Grange commercial organic farm, and the Eagle Street Farm Commercial Buildings (6) - Spring Workshop, Wong Chuk Hang Rd 2014 Greenpoint, in New York City are the - Mission Green Top, Kowloon Bay 2009 - Fresh & Green's Balcony, Fo Tan 2014 best known, but fine examples can be - IPC Foodlab Farm, Fanling 2012 - Art Garden 818, Kwai Chung 2014 found as far afield as Johannesburg and - Hysan Building Rooftop Farm, CWB 2013 - Crystal Group Rooftop Farm, Kwun Tong 2014 Bangkok. Even in China rooftop farms - Bank of America Tower Rooftop, Central 2014 - King's Centre, North Point 2014 Institutional Buildings (20) are becoming popular with notable - Rooftop Republic x Green Monday, 2015 - HKU Rooftop Farm: Run Me Shaw 2012- examples of people growing vegetables, Nan Fung Tower, Central Building, Simon KY Lee Hall, Pokfulam 2014 corn, lotus and even rice on rooftops in - CUHK: Library, Shaw College, Teaching 2012- Nanhai and Liuzhou. Residential Buildings (9) Complex, Wu Yee Sun College, Lee Woo 2014 - Kam On Court Parking Building, Shatin 2009 Sing College, Shatin - Yau Ma Tei Gardener Rooftop Farm 2011 - Tai Yuen Estate Market Rooftop, Tai Po 2012 In Hong Kong, some 45 of the 400 green - Au Young Family Rooftop Farm, 2011 - HKCEC Sky Garden, Wanchai 2012 roofs that have been established, are Chai Wan - Australian International School, 2012 productive rooftop farms, growing - SLOW Experience, Wan Chai 2011 Kowloon Tong - The Pawn Restaurant Rooftop, Wan Chai 2011 - HKICC Lee Shau Kee School of Creativity, 2013 vegetables and fruit (Table 1). These have - Stella So's Rooftop Farm, Cha Kwo Ling 2012 Kowloon City all been built on grey roofs (rather than as - Time to Grow x Gardens & co. Urban 2012 - Chinese Young Men's Christian Assc’n 2013 part of a new building development), or Farm, Sheungwan Center, Kwai Chung are conversions of existing green roofs. - 11/F Sham Shui Po, Sham Shui Po 2013 - JCCAC rooftop farm, Shek Kip Mei 2013 Time2Grow’s rooftop farm on 39/F of Bank of America Tower, - Very MK Rooftop Farm, Mong Kok 2014 - CityU GROW Rooftop Farm, Kowloon Tong 2014 2 Central (Photo: Time2Grow) They range in size from 25 to 1,000m , - CCC Tam Lee Lai Fun Memorial Secondary 2013 and the largest can actively engage up to Industrial Buildings (10) School, Tuen Mun 50 gardeners. They are operated either - HK Honey/HK Farm Creative Industry's 2010 - Madam Lau Kam Lung Secondary School, 2014 by the building owner or by a community podium, Ngau Tau Kok Lam Tei - City Farm - Taikoo, Quarry Bay 2010 - Kowloon City Baptist Church Hay Nien 2014 enterprise group. Demand in many of - Project GROW, Ma Tau Chung 2011 Primary School, Ma On Shan these rooftop farms outstrips supply, - Fun n Farm, Kwun Tong 2012 - Lui Ming Choi Primary School, Tsing Yi 2014 with long waiting lists. The motivations - City Farm - Kwun Tong, Kwun Tong 2012 - Tan Siu Lin Primary School, Olympic 2014 given by owners and users for setting up - City Farm - Tsuen Wan West 2013 - Feeding HK Causeway Bay, Causeway Bay 2014 a productive rooftop farm include: Source: Division of Landscape Architecture HKU Review of green roof performance in Hong Kong - Social / community enterprise e.g. (2014) City Farm, Taikoo - Corporate sustainability e.g. Bank of America Tower, Central - Educational e.g. Australian International School (HK) - Family e.g. Very MK, Mong Kok - Restaurant e.g. The Pawn, Wan Chai - Charitable causes e.g. Feeding Hong Kong at Confucius Hall Secondary AIS(HK) Edible Rooftop Community Project at the Australian Very MK rooftop farm, Mong Kok (Photo: Very MK) School, Causeway Bay International School (HK), Kowloon Tong,(pictured above) is an example of an owner-led project. The school renovated approx. 25m2 of its ailing green roof into a productive garden, The HKU Rooftop Farming project with the aim of getting students interested in gardening, on the Runme Shaw Building HKU raising awareness of food production and healthy living. Main Campus (built by the Division of Managed by the AISHK Edible Roof Club, the garden is Landscape Architecture and Time2Grow) funded by club subscription. Set up involved rehabilitating is an example of a community enterprise existing planting beds (various sizes, 0.4 - 6.5m2) and adding project, and is the basis of a new book new planters, soil materials and gardening equipment. on rooftop farming in Hong Kong, Students of various ages look after the plants once or twice which is intended to help individuals a week after school while the main responsibilities lie on a and community groups create and run teacher who manages the garden and ensures essential tasks are undertaken. On weekends and school holidays productive gardens on their building City Farm, Taikoo is an example of a Private Commercial Enterprise project. It 2 the tasks are undertaken by building maintenance staff. roofs.15 was established on 900m of grey roof space in the ZungFu Industrial building in Taikoo (with subsequent projects in Kwun Tong and Tsuen Wan). The farm The garden is seasonal with a growing schedule designed is run on rented roof space as a commercial (for-profit) venture. Individuals to ensure key planting and harvesting activities happen Any comparison of on-line images of or small groups of local residents interested in urban farming for fresh food within term time. The garden has a modest output due to traditional green roofs and those of production, health or therapeutic benefits, social interaction and recreation, its small-scale operation. Participating students get to keep productive rooftop farms reveals one can rent up to 10 moveable planters (900x600mm) on a monthly basis. Each what they harvest as an encouragement. In terms of raising startling difference: people. Where planter can produce up to 10-15kg produce per year. City Farm advocates awareness, and providing a rewarding educational and green roofs are seen as decorative green living for city people and the health benefits of “Eat Fresh, Eat Local”. social experience for students it is highly successful. What planting patterns, rooftop farms are The company provides organic soil in planters, planting materials and tools, was planned as an extra-curricular activity has become a teaching tool for students to learn about food and plant life clearly shown as centres of vibrant social for growing vegetables. Staff manage the garden and provide daily watering Feeding Hong Kong rooftop farm at Confucius Hall cycle. It is also a popular venue for other staff and student communities. services. City Farm runs 8-week learn-and-practice gardening skills courses, as Secondary School, Causeway Bay (Photo: Feeding Hong well as workshops on different urban gardening subjects. activities. Kong)

110 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 111 8. The same ‘thin layer growing media’ problem 19. Hydroponic and aquaponics technologies are that beset many of the vegetation systems already in operation in Hong Kong, such as VF applied to concrete slope surfaces in HK in Innovations Sustainable Farming and the last few years, and more recently some of Aquaponics.com.hk the green wall / vertical green projects. 20. Banerjee, C., & Adenaeuer, L. (2013). Up, Up 9. Tan, P. Y. and Sia, A. (eds.), (2008). A Selection and Away! The Economics of Vertical Farming. of Plants for Green Roofs in Singapore, Journal of Agricultural Studies, 40-40 Platt, Second Edition, Centre for Urban Greenery P. (2007). Vertical Farming: An Interview and Ecology, National Parks Board, Singapore. with Dickson Despommier regarding on the future projection of vertical farming. 10. There is a general misconception that as long as vegetation is green, it is heathy. 21. Arai, J., & Ozaroff, E. Use of hydroponics technology to address growing problems in 11. Delor, M. (2011). Mini-project report urban environments.; Le Blond, J. (2012). summary Current state of Building-Integrated Rooftop Fish Farms to Feed Germany’s Agriculture, its energy benefits and Sprawling Urban Population’. The Guardian. comparison with green roofs. 22. Cerón-Palma, I., Sanyé-Mengual, E., Oliver- 12. Quesnel, A., Foss, J., & Danielsson, N. (2011). Solà, J., Montero, J. I., & Rieradevall, Solutions from above: Using rooftop J. (2012). Barriers and opportunities regarding Agriculture to move Cities towards the implementation of rooftop eco. Sustainability (Doctoral dissertation, Thesis greenhouses (RTEG) in Mediterranean cities School of Engineering, Karlskrona, Sweden) of Europe. Journal of Urban Technology, 19(4), 87-103 13. Specht, K., Siebert, R., Hartmann, I., Freisinger, U. B., Sawicka, M., Werner, A., 23. Yeang, K. (2011). Eco Skyscrapers (Vol. 2). & Dierich, A. (2014). Urban agriculture of the Images Publishing future: an overview of sustainability aspects of food production in and on buildings. 24. ‘Buildings that grow food’, Accessed June Agriculture and Human Values, 31(1), 33-51 2015 from

14. Drumm, R., & Ridgeway, O. H. Singapore: 25. Thomaier, S., Specht, K., Henckel, D., Dierich, Growing Up.An article describing the food A.,Siebert, R., Freisinger, U. B., & Sawicka, problem of Singapore, then introduce rooftop M.(2014). Farming in and on urban buildings: The HKU Rooftop Farming project, Runme Shaw Building HKU Main Campus, was set up in 2012 as a two year research Jack Ng’s vertical farm in Singapore farming (hydroponics) as a solution. Present practice and specific novelties of Zero-Acreage Farming (ZFarming). Renew project by the Division of Landscape Architecture, investigating the differences in environmental and technical growing uses a rotating structure to gain 15. Pryor, M. Edible roof: productive rooftop Agr Food Syst (Online First). doi, 10(1017), conditions between the city’s rooftops and those at a ground level. The farm was designed and constructed by enough sunlight to grow salad farming in a high density city. Due for S1742170514000143 undergraduate students as part of their Landscape Practicum class. The work was funded by HKU knowledge exchange vegetables (Photo: Amusing Planet) publication Oct. 2015. Hong Kong, MCCM and teaching development grants. The farm was initially 110m2, and comprised some 90 planters (typically 600x400mm), Creations. 26. Wilson, G. (2002). Can urban rooftop growing a variety of vegetable crops. The farm is now managed by the student-led HKU Rooftop Farming team. With the Mathew Pryor is Head of the Division of microfarms be profitable. Urban Agriculture 2 16. Nowak, M. (2004). Urban agriculture on the Magazine (7) August, 22-24. help of Time2Grow (Rooftop Republic), it has now been expanded to more than 400m and has a community of some Landscape Architecture at the University 40 active gardeners, all organized via their Facebook page. Farm produce is communally shared, or donated to the on- rooftop (Doctoral dissertation, Cornell). of Hong Kong. campus vegetarian restaurant, or given to the Feeding Hong Kong food distribution charity. (Photo: HKU Rooftop Farm) Accessed June 2015 from Hui, S. C. (2011). Green roof urban farming for 28. Mackay, C. Modifying the Green Roof for 20 buildings in high-density urban cities. In Downunder. Commercial production on farming infrastructure , sometimes Following the lead from a number of References rooftops in combination with aquaponic / recent studies in the USA,32 the Division Hainan China World Green Roof Conference 21 2011 (pp. 1-9). 29. Whittinghill, L. J., Rowe, D. B., & Cregg, B. hydroponic structures, or more of Landscape Architecture, HKU, has 1. Skyrise Greening campaign< http://www. Sanyé-Mengual, E., Cerón-Palma, I., Oliver- M. (2013). Evaluation of vegetable production The potential for commercial-scale conventional structures such as glass just embarked on a new research greening.gov.hk/en/new_trend/benefit_of_ Solà, J., Montero, J. I., & Rieradevall, J. (2015). on extensive green roofs. Agroecology and food production on urban buildings houses22 or wind / shade structures. initiative to map potential rooftop green skyrise.html> Integrating Horticulture into Cities: A Guide Sustainable Food Systems, 37(4), 465-484 is starting to be explored.16 Workable space in Hong Kong and to develop a forAssessing the Implementation Potential of 2. Hui, S. C. Green Roof /wall Research Database. Rooftop 30. Quesnel, 2011 techniques and approaches have already At a more speculative level there are any mechanism for evaluating the potential Department of Mechanical Engineering, HKU, Greenhouses (RTGs) in Industrial andLogistics been demonstrated,17 and predictions number of bold architectural proposals for commercial farming on rooftops in 1-25. Reaching Worcester Roofs. Study assessing rooftop production are beginning growing crops.23 The ‘agri-tecture’ cost and revenue for rooftop greenhouse and 3. HKILA Design Awards 2012. In Yuan Lin 2011- 17. Germain, A., Gregoire, B., Hautecoeur, I., water systems. 18 24 to be made. Studies suggest that if movement gives new definition to the Rooftop production is unlikely ever to be 12: 80-93 Ayalon, R., & Bergeron, A. (2008). Guide to access and logistics can be resolved, concept of a ‘green’ building, but issues commercially competitive with ground setting up your own edible rooftop garden. 32. Berger, D. (2013). A GIS Suitability Analysis of the roof spaces of large-scale industrial of access and seasonality of processes level food production due to the cost of 4. Greening, Landscape and Tree Management Alternatives and the rooftop garden project. The Potential for Rooftop Agriculture in New Section, Development Bureau. buildings and housing estates can be have yet to be addressed. installing soil, water, infrastructure, and EcoDesign Resource Society, 2013. The York City (Doctoral dissertation, Columbia Urban Farming Guidebook 2013: Planning University). activated for the production of high the added costs of operation at height. 5. Buildings Dept. 2011. APP 152 Practice Note for the Business of Growing Food in BCs Stoudt, A. E. (2015). Redefining urban value crops grown using hydroponic and Research is starting into various aspects Revenues, however, may offset the cost for Authorized Persons, Registered Structural Towns & Cities. EDRS, Vancouver, Canada. food systems to identify optimal rooftop aquaponics practices,19 making a positive of vertical farming, including: species of green roof maintenance, and active Engineers and Registered Geotechnical Philips, A., 2013. Designing Urban Agriculture: community garden locations: a site suitability 25 Engineers ‘Sustainable Building Design A Complete Guide to the Planning, analysis in Seattle, Washington (Doctoral contribution to the city’s food security growth performance / yield; scale use would bring positive stewardship to Guidelines’ HKSAR Government 26 Design, Construction, Maintenance, and dissertation, USC). and reducing its ecological footprint. of operation; necessary building their management, thereby increasing Management of Edible Landscapes, Wiley, modifications;27 the level of infrastructure the chances of long term success. 6. Hong Kong Green Building Council, BEAM Plus Hoboken, New Jersey. Most commercial productive required to establish and maintain;28 We need to re-evaluate our current 29 7. Division of Landscape Architecture HKU, 18. Donald, W. W. T. (2011). CTBUH Technical rooftop farm operations that have different types of planter; the effects approach to ‘green buildings’, and see if Review of green roof performance in Hong 30 Paper. Case studies of the rooftop farms in been developed to date have been of climate on rooftop growth; and we might make more effective use of our Kong (2014) Singapore. based on some form of vertical operational costs.31 roof spaces as a way of greening the city.

112 / Yuan Lin 2015 Planting Futures Yuan Lin 2015 Planting Futures / 113

Next issue, public space

Yuan Lin is intended to recognize the work of landscape architects and to develop a discourse on issues relevant to the Landscape profession within Hong Kong.

The next issue will address issues of public space in Hong Kong, and explore how the nature and meaning of pubic space has developed, and is evolving, in Hong Kong, China, and other related territories and what impact that has had on landscape practice. For instance this might include issues relating to: changes in the form and volume of pedestrian movement and the occupation of space in the city; the design and management of public space; the internalisation and commercialisation of public space; new definitions of ‘public’ and collective ownership, etc.

HKILA members and related professionals are invited to submit contributions for the next issue to the Publications Committee, Hong Kong Institute of Landscape Architects. P.O. Box 20561, Johnston Road Post Office, Wan Chai, Hong Kong, (publications@ hkila.com)

Contributions should be topical, concise, factual, informative, critical, and not promotional. They may take the form of:

• Articles - opinion pieces containing views / reasoned arguments, • Reviews - assessments of published books, completed projects, technical details, data, processes, etc., • Academic papers - scholarly articles reporting on formal qualitative or quantitative academic research, • Graphic illustrations or photographic images with accompanying descriptions.

Written contributions should be between 1500-6000 words. They will be reviewed by the editorial team and invited reviewers. All pieces should be written in English using a professional or academic style. References and citations should be used where possible to position the piece with respect to established knowledge within the Landscape discipline. The piece should relate to Hong Kong, where possible, with references to other territories where appropriate.