Tree Maintenance The tragic incident concerning a tree felling case in Shatin on a cycling track on 14 June inspires me to write this short article. A 15-metre high yellow poinciana was snapped off and collapsed onto the track in Yuen Chau Kok and seized the life of a cyclist after being sent to the hospital for critical treatment for two days. A similar incident indeed happened in Stanley on 2008 whence a university student was also killed by a fallen coral tree. On March 2009, the HKSAR Chief Secretary for Administration led a Task Force comprising officials from relevant bureaus and departments examined a range of issues in connection with proper tree management. Previously, the government has adopted a so-call "integrated approach" in assigning duties and responsibilities to individual department for maintaining and preserving trees and vegetations. Hence, Agricultural, Fisheries and Conservation Department would take care of trees in country park, Leisure and Cultural Services Department would look after trees in leisure parks and gardens, whereas Works Departments would be responsible for trees planted on slopes which were under their maintenance responsibilities. Following the recommendation of the "Report of the Task Force on Tree Management" published in June 2009, a "Tree Management Office" had been set up under Development Bureau as central coordination to ensure more effective implementation of the "integrated approach". Whilst public trees will be taken care of by our surveyor counterparts of the new Tree Management Office, other private sector professional property and facility management surveyors should not neglect the importance of tree maintenance inside private developments. Both tree incidents, as reported by journalists, were suspected of suffering internal decay of trunk. Such decay may be caused by fungal or disease attack which might not have been easily detected visually, at least in the initial stage of deterioration. However, there may be symptoms to help identification of the potential decay, such as dried tree branches, dieback twigs; presence of wood cavity and swollen parts that necessitates a further detailed investigation. The Development Bureau published a "Pictorial Guide for Tree Maintenance to Reduce Tree Risk" in May 2010 which provides useful information for tree maintenance practitioners to signal early symptoms so that consequential actions can be derived for improvement. A full version of the pictorial guide can be downloaded from the Bureau's website. It draws our attention to five key factors of tree inspection and maintenance. Five key factors 1. General Condition Identify any leaning tree with horizontal cracks in tension side and/or buckling bark on the compression side of trunk, associated with soil cracks in soil surface. Extra support may need to be provided to prevent further leaning or, if the problem is irrecoverable, the tree may need to be removed entirely. 2. Crown Condition Identify any dieback twigs on tree crown. Proper pruning may need to be carried out to remove the dead twigs. 3. Branch Condition Identify any dead, cracked or dried out tree branches. Proper pruning may need to be carried out to remove the irrecoverable branches. 4. Trunk Condition Identify any V-shaped crotch with cracks or split. Similar defects identification shall be investigated for codominant stems at a weak union. Wood decay and cavity at the trunk is also an early symptom of possible tree failure. Extra support may need to be provided to prevent further cracks, splits, or enlargement of cavity and if the problem becomes irrecoverable, the tree may need to be removed entirely. 5. Root Condition Identify any severely cut or damaged roots, e.g. by improper excavation, and any fungal fruiting body growth on roots. In case such defects were revealed, further investigation and continuous monitoring may need to be carried out to observe any risk of irrecoverable tree failure. One of the common tree maintenance problems is improper pruning. Poor pruning may further shorten the life of a tree if it was already sick or deteriorating. However, there is currently no statutory requirement of a competent worker to perform such tree pruning work. Surveyor may resort to the service of a certified arborist if in doubt. The Development Bureau also published a guideline on pruning as a general reference. Assessment plan As a general guide for surveyors who may be involved in tree maintenance, it is recommended that a risk assessment and management programme could be carried out. The following procedures may be useful as part of your assessment plan. 1. To carry out visual inspection in order to identify any obvious tree decay and to observe any localized situation that may cause damage to trees. 2. To assess any possible risk of tree failure and the level of consequential damages if failure did occur. 3. To determine any immediate treatment, such as extra support, is required to reduce risk to occupants and public. High hazard situation shall be immediately rectified, such as removing failure tree or to suspend excavation work. 4. To consider any further investigation, testing or opening up for inspection is required in order to ascertain tree condition, especially the covered roots or potential internal tree trunk decay. 5. To carry out continuous monitoring of the tree condition if an early symptom of decay or failure is observed. This is an essential procedure in case excavation work is being carried out in the vicinity of a tree. Temporary protection may need to be provided to ensure trees are not affected by such construction works. 6.To carry out proper pruning of dieback twigs or damaged branches by a competent worker. A property and facility management surveyor may resort to the service of a professional landscape contractor who appoints full-time certified arborist as advisor. 7. To reserve sufficient fund on the management account for performing regular tree maintenance. 8. To provide training to in-house maintenance staff, who will be responsible for inspection and pruning of trees, on knowledge of proper tree care. The training course offered by professional education institutions and lectured by certified arborist can be a useful source of providing such training. 9. To provide appropriate tools and equipment for maintenance staff especially personal protective facilities to ensure work safety.