LCQ13: Maintenance of trees and flowers

     Following is a question by the Hon Luk Chung-hung and a written reply by the Secretary for Development, Ms Bernadette Linn, in the Legislative Council today (May 22):
     It has been learnt that in recent years, popular plants such as sweet gums, tabebuia chrysantha and cherry blossoms have respectively been planted at Tai Tong Sweet Gum Woods in Tai Lam Country Park, Nam Cheong Park and on the airport island, among other locations, attracting viewing and "checking-in" by members of the public and tourists. On the other hand, there are views that Hong Kong's climate is suitable for the planting of various tree and flower species, and that spectacular scenery of colourful blooms is not only pleasing to the eyes, but can also promote the development of the tourism industry and drive the economy. However, it is learnt that at present, the tree and flower species planted in most districts of Hong Kong are relatively homogeneous and without proper maintenance. In this connection, will the Government inform this Council:
(1) of (i) the number of tree management personnel in various government departments, and (ii) the top 10 major tree or flower species under their management and their numbers;
(2) whether the Tree Management Office of the Development Bureau and/or various tree management departments have formulated new criteria for determining the tree or flower species to be planted;
(3) whether it will consider planting more trees or flowers of different species in more places to create scenic spots with district characteristics; if so, of the locations and species; if not, the reasons for that;
(4) whether it will introduce more new techniques to ensure that trees or flowers stay aesthetically pleasing and healthy; if so, of the details, and how the authorities ensure that the staff of the government departments and/or the contractors concerned can master such techniques; if not, the reasons for that; and
(5) whether it has implemented human resources plans for the arboriculture profession and provided more professional training for tree management personnel in both the public and private sectors, so as to ensure that there will be sufficient arboriculture professionals to cope with the future demand and even facilitate the development of the arboriculture industry?
     The Development Bureau (DEVB) advocates the principle of "Right Plant, Right Place" and seeks to enhance the landscape and tree management arrangements, with a view to developing a sustainable urban landscape and making Hong Kong a more liveable city. In recent years, when choosing plants for landscape design, various government departments have attached much importance to enhancing biodiversity, improving local ecological environments and preparing for climate change. They are also choosing more species with conspicuous flowers to enrich the landscape. My reply to the various parts of the question is as follows:
(1) The number of trees maintained by core tree management departments and the number of their tree management personnel, inclusive of staff of departments and contractors (as at the end of 2023), are tabulated below:
Core tree management department Number of trees (rounded to the nearest 100) Number of tree management personnel (Note 1)
Agriculture, Fisheries and Conservation Department 28 400 (Note 2) 87
Architectural Services Department 143 700 209
Civil Engineering and Development Department 40 500 (Note 3) 128 (Note 3)
Drainage Services Department 16 900 95
Highways Department 580 300 215
Housing Department 87 500 255
Lands Department Not applicable (Note 4) 215
Leisure and Cultural Services Department 542 600 313
Water Supplies Department 149 100 42

Note 1: The figures represent the number of staff involved in day-to-day tree management only. Those temporarily deployed on a need basis and management personnel at the strategic level are not included.
Note 2: The figure represents the number of trees in frequently used areas and facilities in country parks only.
Note 3: The numbers of trees and tree management personnel in infrastructural projects will vary at different project stages.

Note 4: The unallocated and unleased government land (UUGL) is under the jurisdiction of the Lands Department, which is responsible for providing non-routine tree maintenance on UUGL that is not maintained by any designated government departments. The exact number of trees on UUGL is not available due to the large number of trees.

     According to the data collated from the core tree management departments, the ten most common tree species (in descending order) are Taiwan Acacia (Acacia confusa), Paper-bark Tree (Melaleuca cajuputi), Chinese Banyan (Ficus microcarpa), Elephant's Ear (Macaranga tanarius), Chinese Fan-palm (Livistona chinensis), Queen Crape Myrtle (Lagerstroemia speciosa), Chinese Hackberry (Celtis sinensis), Horsetail Tree (Casuarina equisetifolia), Candlenut Tree (Aleurites moluccana) and Camphor Tree (Cinnamomum camphora), with about 270 000 trees in total. Government departments have been planting more plants with special features in recent years, such as Yellow Pui (Tabebuia chrysantha), Rosy Trumpet Tree (Tabebuia rosea), Sweet Viburnum (Viburnum odoratissimum), Golden Penda (Xanthostemon chrysanthus) and Scarlet Sterculia (Sterculia lanceolata) planted in urban areas, as well as Sweet Gum (Liquidambar formosana), Schima (Schima superba) and Hong Kong Gordonia (Polyspora axillaris) planted in rural areas.
(2) and (3) The "Right Plant, Right Place" principle advocated by the DEVB encompasses considerations such as availability of planting space; adaptability, characteristics and matching of species; as well as compatibility with landscape designs and the environs. The DEVB encourages the tree management departments and the industry to plant the right plants which can suit the environment and attain the designed functions while allowing them to grow healthily in a sustainable manner. To this end, the DEVB published in 2018 the "Street Tree Selection Guide", which was subsequently updated in 2023, to provide information on 80 tree species for reference by various departments and the industry, thereby encouraging higher diversity of urban tree species.
     With reference to district characteristics, we have formulated Greening Master Plans for every district, which provide recommendations on thematic planting, including the planting of trees with conspicuous flowers. In addition, we encourage tree management departments and works departments to consider planting more plants with conspicuous flowers at suitable locations in new projects and within existing green spaces.
     At present, more plants with conspicuous flowers have been planted in various districts, such as the cherry blossoms in On King Street Park near Shek Mun in Sha Tin, Tai Po Waterfront Park and Hong Kong Velodrome Park in Tseung Kwan O; the Tabebuia trees of different colours in Nam Cheong Park and Tin Shui Wai Park; the Flame of the Forest (Delonix regia) in Tuen Mun Park and along the riverside of the Kwong Fuk Bridge in Tai Po; as well as the Hong Kong Orchid Tree (Bauhinia blakeana) in Kowloon Tsai Park. In 2023, the Government announced the launching of the "Shining City Project" to carry out urban beautification work along the Shing Mun River and the Yuen Long Nullah. Such work includes the planting of trees with conspicuous flowers, such as Camel's Foot Tree (Bauhinia variegata), Yellow Pui (Tabebuia chrysantha) and cherry blossoms along both sides of the Shing Mun River, and the planting of Beautiful Bougainvillea (Bougainvillea spectabilis) and other shrubs with conspicuous flowers along both sides of the Yuen Long Nullah.
(4) To promote healthy growth of plants, the DEVB promulgated a technical circular that requires new at-grade road projects to reserve sufficient growing space for roadside greening. In addition, the DEVB formulated the "Guidelines on Soil Improvement" and the "Guidelines on Soil Volume for Urban Trees", which provide strategies and methods for soil improvement and set out design standards for soil volume and soil depth for newly planted trees.
     The adoption of applicable technology in tree management provides useful aids in monitoring the health and structure of trees and tracking their changes and anomalies. In view of this, the DEVB has been proactively identifying emerging know-how to enhance tree management, co-operating with local institutions in trying out potential technology through research and pilot projects, and sharing the relevant progress and experience with tree management departments. Major technologies currently in use or on trial include tree tilt sensors, root detection systems with tomographic scanning, remote sensing multispectral imaging and 3D LiDAR sketching. The outcomes of the relevant research and pilot projects will be disseminated through guidelines or sharing sessions as appropriate, thereby enabling staff of relevant government departments and contractors to master the technologies.
(5) The Government has long been concerned about the manpower situation of the industry, and has been allocating resources to the training of tree management personnel. In mid-2020, the DEVB launched the $200 million Urban Forestry Support Fund to attract more entrants to the arboriculture and horticulture industry, so as to meet the demand for manpower and uplift the professional standards of practitioners. With support of the Fund, various new initiatives have been rolled out, including the Study Sponsorship Scheme which provides sponsorships and scholarships to encourage more people to undertake arboriculture, tree management and arboriculture-related programmes. Training allowances are also provided for arboriculture and tree management graduates through the Trainee Programme to help them receive structured on-the-job training to acquire actual work experience, with training periods lasting from 18 months to three years. The Government also launched the Registration Scheme for Tree Management Personnel in December 2020, which encourages all eligible in-service arboriculture practitioners to register on a voluntary basis in order to uplift the standard of arboriculture practitioners. As at end-2023, over 870 practitioners have registered under the scheme. Moreover, the DEVB provides staff of government departments with over 5 000 training places annually, covering various areas of tree management which include professional training.
Ends/Wednesday, May 22, 2024
Issued at HKT 15:58