Conservationists draw up list of historic sites threatened by development Tree conservationists have called on the public to join a 'flash mob' on Sunday to highlight the urgent need to protect trees growing from cracks on historic stone walls. Flash mobs, increasingly common around the world, involve organised groups of people suddenly materialising in public places, performing a scripted activity, and then dispersing as suddenly as they appeared. The conservationists hope such action will increase awareness of the growing risk of trees being bulldozed along with the walls for transport or property developments. The Conservancy Association has identified 11 historic walls with trees on them they say are unique to the city. The sites are: Forbes Street, Kennedy Town; Hollywood Road near the former police quarters; Bonham Road near Centre Street; Rose Lane, western Mid-Levels; Stubbs Road near Kennedy Road; junction of Bonham Road and High Street; Hospital Road near Bonham Road; Robinson Road, Mid-Levels; Kowloon Park; St Stephen Lane, western Mid-Levels; and Ship Street, Wan Chai. None of the walls fall under any specific protection but some of the trees on isolated sites are now being listed in the Old Trees Registry based on age and size. The group will submit the list to the Antiquities and Monument Office (AMO) in the hope that the authority can include these sites in their protection plans. The Conservancy Association complained that neither the existing monument laws nor the Old Trees Registry kept by the government are sufficient to protect them, and that they fall under the fragmented responsibility of various departments. 'We can no longer tolerate such a fragmented approach and watch these public assets disappear silently in the tide of development,' said Lister Cheung Lai-ping, chief executive of the association. Ms Cheung said the ideal solution was a comprehensive tree-protection ordinance. The government, however, has said such a law is unnecessary. A spokeswoman for the AMO yesterday said old stone walls could only be protected if their historical value was confirmed and that the vegetation on them was irrelevant in their consideration. But she said the AMO, which primarily deals with historic buildings, was now considering compiling a more complete and up-to-date record of historic stone walls in the city. The flash mob action will take place at 11am on Sunday in Forbes Street, Kennedy Town, where about 20 trees grow on a historic stone wall. The site was almost removed as part of an urban renewal project years ago and is under a new threat by the proposed development of the Island Line rail extension to Western and Kennedy Town.