Development has left urban Hong Kong scantily greened with trees compared with other big cities, West and East. There is now a consensus that those we still have are worth preserving. Sadly, we still get reminders that many remain blighted by previous neglect or inadequate care. The latest came on Thursday night, when a 14-metre Chinese banyan tree fell in one of Tsim Sha Tsui's busiest shopping areas, injuring five people. This recalled tragedies at Stanley in 2008 and at Sha Tin in 2010, when falling trees killed a young woman and a cyclist respectively. The Stanley incident, which a coroner's jury said could have been prevented by a more professional inspection system, galvanised the government into action, overseen by the then chief secretary, Henry Tang Ying-yen. This resulted in the establishment of the tree management office, to advise on trees and co-ordinate the efforts of many different departments with fragmented responsibility for them. The tree that fell on Thursday was one of 400-odd deemed 'old and valuable' that are managed by the Leisure and Cultural Services Department, which last checked it on January 30 following earlier treatment for brown root rot. Conservancy Association chief executive Ken So Kwok-yin had helped monitor the tree and says the root rot may have contributed to its collapse. We should wait for a proper investigation before reaching any conclusions. In any case, it doesn't detract from the previous government's efforts to tackle an issue brushed over for decades - balancing environmental and heritage issues with public safety. Inspection resources were beefed up and, in 2010, the then newly established tree management office listed about 2,000 trees considered unhealthy or at risk of disease and in need of special attention. Like any growth industry, however, tree management has experienced teething problems, with a severe shortage of skilled arborists and little practice on the ground. Tree expert Professor Jim Chi-yung has said confusion over qualifications has exposed a deeper problem. Many so-called qualifications were no more than certification from overseas, and underlined the need for a unified standard for the local arborist profession. In practice, government contractors have proliferated, giving rise to reports of inspections by uncertified workers that are signed off by a certified arborist who has not necessarily inspected the tree. There is no question about the environmental, social and economic benefits of trees. Nonetheless, Tang was lampooned as the 'minister for trees' after he was put in charge for a time. We could do with a powerful tree supremo now to instil a stronger ethic of professionalism in the management regime.