There was a motion for "Perfecting the tree management system" at this week's Legislative Council meeting and I received many opinions from friends of my professional sector. Some of them complained that the authorities are still cutting down trees casually without replanting them. Others, especially landscape architects, are dissatisfied with the lack of coordination and cooperation between government departments in handling the planning of tree management and greening issues. In response, I moved amendments to the motion to reflect my sector's concerns over the imminent need to formulate a comprehensive tree management and greening policy.

To be fair, the Tree Management Office under the Development Bureau have been making strenuous efforts in carrying out work such as tree preservation and tree risk management in Hong Kong. I am also happy to see that in the guidelines for sustainable building design issued at the beginning of this year, it was stipulated that the minimum percentage of greenery in a site area of 1,000 to 20,000 square meters should be 20 percent. And this has been raised to 30 percent for a site area of more than 20,000 square meters. Furthermore, the greenery should be provided for pedestrian zones, communal podium roofs, flat roofs, main roofs, slopes and retaining structures. However, there are still many other problems that we need to tackle.

At present, there are more than 11 government departments involved in urban tree management-related issues. According to an opinion poll on urban tree management conducted by the Chinese University of Hong Kong in 2009, a majority (about 61 percent) of the public interviewed agreed that enacting a Tree Ordinance would be more effective than relying on the existing guidelines from different departments in the management of urban trees. Furthermore, a large majority (75 percent) believed that a new government department should be established to take charge of urban tree management, whilst another large majority (70 percent) disagreed that Hong Kong has a sufficient number of professionals to manage its urban trees. Dr Eric Lee, who conducted this opinion poll, concluded that a sound sustainable tree management policy should incorporate the following principles:

1. Public safety must always come first.

2. Government and the universities should take the lead in enhancing professional training and public education.

3. An open and fair assessment system must be established to elevate the training and qualification recognition of professionals.

4. The establishment of a database and standardized work procedures to improve the monitoring system.

5. Planting the appropriate species of vegetation at the appropriate locations.

6. Reinforcement of tree maintenance work in accordance with the concept of "spending 30 percent of your effort in planting and 70 percent in maintenance".

7. Keeping a balance between "urban development" and "ecological conservation".

8. While legislation is important, dedication to improving tree management work is even more important.

I agree that now is a good time to consider setting up an independent department to coordinate the work of tree management. I also agree that for those who engage in tree management work, having a sense of commitment is of the utmost importance. Therefore, I think we should facilitate and allow for more members of the public who are passionate about tree conservation to participate in the consultation mechanism.

Since tree coverage alone does not guarantee natural beauty, we must not overlook the need to have strategic planning for the greenery. Besides implementing extensive greening in the vicinity of residential areas and on urban structures, it is necessary to adopt characteristic and thematic landscape design in different districts, so as to avoid the messy and ugly appearance of disorganized mixed planting. Attractive scenic schemes can be created by adopting thematic and strategic planting in a special area or street with a particular species of trees, the flowers of which will add much color to the location. This can help to beautify urban areas, elevate the quality of life for local residents and boost tourism as well as the local economy.

A comprehensive tree management and greening policy should incorporate research in sustainability to support a green economy that is complementary to the development of a green city. Take the research into bamboo as an example. As bamboo accounts for three times more photosynthesis than timber, they absorb more carbon dioxide and release more oxygen into the atmosphere, and they can form carbon sinks that counter the problems of global warming. They also serve as a more sustainable source of natural material because they have a rapid growth rate (harvest within three to five years) and they can be used for a variety of other purposes such as construction, objets d'art, furniture, and kitchenware.

The United Nations declared 2010 as the International Year of Biodiversity to celebrate life on earth and the value of biodiversity in our lives. We must remember that every part of our ecology is interrelated. Apart from trees, grass, flowers and other vegetation, we should also pay attention to the importance of birds, bees and insects within the larger natural ecological cycles. Therefore, we must adopt a holistic and visionary attitude based on sustainability concepts to formulate a sound tree management policy.

The author is a member (Architectural, Surveying and Planning Functional Constituency) of the Legislative Council of the HKSAR, and an honorary professor of architecture at the University of Hong Kong.

(HK Edition 06/18/2011 page3)