CIVIL ENGINEERING DEPARTMENT

1.1 As part of the Environmental Impact Assessment study carried out for the proposed Citybus Headquarters and Bus Maintenance Depot located at Shing Tai Road, Chai Wan, this Tree Survey Report was prepared to identify the baseline conditions of the existing landscape resource and recommend appropriate treatments to the existing trees with the intention to minimize landscape impact.

1.2 The tree survey report includes sections on detailed information on each individual tree inside boundary and consultant’s proposed treatment to individual tree based on established criteria stipulated in WBTC 24/94.

1.3 In order to minimize the landscape impact, comprehensive strategies were proposed to transplant existing trees as outlined in Section 6.2. In addition, compensatory planting proposal was also proposed in Section 7 to mitigate the landscape impact.

2. SURVEY AREA

2.1 The area of site in this tree survey is about 11,327m sq. (approx.) which is bound by Road 20/4, the adjacent site (zone as ”OU”) abutting Road 20/6, Shing Tai Road and another adjacent site (zone as “I” industrial) abutting Shing Tai Road.

3. METHOD OF SURVEY

3.1 This report has covered individual tree species with a trunk diameter larger than 95mm when measured 1000mm above ground level in accordance with Works Branch Technical Circular No. 24/94. Trees are identified with a reference number and marked on the tree survey plan in Appendix A whereas assessment of individual tree is included in Appendix B The photograph of individual tree is included in Appendix C.

4. TREE SURVEY INFORMATION

4.1 Information tabulated in Appendix B includes the following: -

Tree No. : Reference no. of the tree recorded

Botanical Name : Latin name of the tree recorded

Chinese Name : Chinese name of the tree recorded

Height : Full height in meters

Diameter : Trunk diameter in meters as measured at 1.0m from Ground level

Spread : Spread (diameter of canopy) in meters

Health Condition : Relative grading of amenity and arboricultural value from Good to Poor

Where: -

Good - Trees of good form, moderate to large size and in good health;

Fair - Trees of reasonable form, with few or no visible defects or health problems;

Poor - Trees that are of poor form, badly damaged or suffering from decay, dieback or the effects of very heavy vine growth.

Survival Rate The survival rate is based on the following ranges:

After Transplant : High

Medium

Low

Photo No. : The specific photographs of the tree or tree group being identified.

Recommendations : Proposed action for the specified species would fall into two categories:

a) Transplant b) Fell

Transplant - Trees are recommended to be transplanted if they are affected by the site works and are in Good to Fair condition with Medium to High expected survival rate after transplant.

Fell - Trees are recommended to be felled if they are affected by the site works and are in Poor condition or Low expected survival rate after transplant.

Whether any rare species are present, as listed under the “Protection of Endangered Species Ordinance” and “Forestry and Countryside Ordinance (CAP. 96)”, are also noted.

5. TREE SURVEY PHOTOGRAPHS

5.1 There is a total number of 111 trees being surveyed. Photograph of individual tree is included in Appendix C and shall be read in conjunction with the Tree Survey Plan (See Appendix A).

6. TRANSPLANTING AND FELLING PROPOSALS

6.1 Preliminary

Reference shall be made to Appendices for details of transplanting and felling proposal as follows: -

i) refer Appendix A ”Tree Survey Plan ” for location identification

ii) refer Appendix B: “Tree Assessment Schedule” for species identification and recommendations.

iii) refer Appendix C: “Tree Survey Photographs” for photographic identification.

iv) refer Appendix D: “Specification for Tree Felling, Protection, and Transplanting” for specification on any tree operation.

v) refer Appendix E: Architectural information for site information.

6.2 Trees to be Transplanted

13 nos. of trees out of the 111 surveyed trees (of which 23 nos. are outside boundary) within the work area have been identified for transplanting. The recommendation is made primarily on the basis of their locations with respect to the development works. In addition, their current health condition and the anticipated survival rates are also considered. The trees recommended for transplanting are in fair to good health condition with medium to high survival rate after transplanting.

Based on the proposed building layout (see Appendix E), there will be no space for planting after the building is completed. It is therefore recommended to transplant the 13 nos. of trees off site according to the following strategies.

6.2.1 In order to enhance the environmental quality of the area, the feasibility of transplanting T104 (Grevillea robusta), T105 (Bombax malabaricum) and T111 (Bombax malabaricum) to the nearby roundabouts on Road 20/4 (Annex 1) outside Citybus’ proposed depot has been explored. Given that Road 20/4 would only be completed in around July 2002 which could not match the time for transplanting of trees in December 2001, and the roundabouts on this road are quite small with a diameter of about 8 metres, the concerned government departments considered that it was not suitable to transplant the trees at such locations because these roundabouts were delineated by road markings only. Some long vehicles, particularly the container trucks observing the Superpost Centre on Road 20/4, might need to weave into the roundabout to make turnings. From road safety point of view, it is not appropriate to transplant these 3 trees at the roundabouts.

6.2.2 Discussions have been held with DAO of LCSD and Landscape Section of Highways Department on selecting suitable sites to accommodate all the transplanted trees. During the discussion, it was agreed that the trees should be transplanted to a large open space for better establishment and aesthetic reasons.

6.2.3 Effort is also being made through Lands Department to make enquiries from various government departments, including AFCD, etc., for an outlet for the trees.

6.2.4 In case no suitable site can be identified by government departments, it is recommended to transplant the trees to Chai Wan Park (Annex 2) Cape Collinson Chinese Permanent Cemetery (Annex 3), Yee Shing Lane Sitting Out Area (Annex 4) or the proposed Town Park at Aldrich Bay (Annex 5). Visit to the site and discussion with LCSC indicate that this option are feasible, subject to LCSD’s final agreement on the exact location of the transplanted trees.

6.2.5 If the trees cannot be transplanted to their permanent locations immediately due to various reasons, the transplanting contractor shall be required to form a holding nursery for the purpose of nursing the trees exclusively for this project. The maintenance of these trees shall be closely monitored by the landscape consultants until they are successfully transplanted to their permanent locations. The cost for the whole operation up to successful handover of trees to relevant departments shall be borne by the Applicant.

6.3 Trees to be Felled

Due to the site formation and building works, a total number of 75 trees out of the 111 surveyed trees are identified for felling. Their existing health condition is poor and their survival rate after transplanting is low. As none of them are rare species, transplanting of the above trees is not recommended

A copy of the specification for Tree Felling, Protection and Transplanting is enclosed in Appendix D.

7. COMPENSATORY PLANTING PROPOSALS

7.1 The planting proposal (Appendix E) is based on the proposed building layout with the intention to introduce greenery where possible to mitigate the landscape impact and further enhance the quality of the environment.

The existing vegetation mainly consists Ficus trees, as illustrated in the tree survey, a row of Ficus benjamina is therefore proposed to be planted with understorey shrubs. The wall behind the planter will be covered by creepers and vines to form a green backdrop on the street level.

There are planters on the 1^st and 3^rd floor where Ficus benjamina will also be planted. In order to soften the hard edge and introduce more greenery to the building, hanging plants such as Allamanda cathartica and Scindapsus aureus will also be planted to improve the visual quality.

As the quality of streetscape is important to mitigate the landscape and visual impact, it is further recommended that a row of heavy standard Delonix regia should be planted along the proposed footpath along Road 20/4. As the footpath is outside site boundary, approval should be obtained form Highway’s Department.

References

1. Webb, R. (ed.) Tree Planting & Maintenance in Hong Kong, Hong Kong Government Printer, Hong Kong 1991.

2. Dr. S. L. Thrower Hong Kong Trees. The Urban Council Hong Kong 1988.