Root rot epidemic covered up, experts say

The government has been accused of covering up the spread of an incurable disease that is killing Hong Kong's heritage trees and of failing to contain the infection, putting many more trees - and potentially human life - at risk.

Brown root rot or tree cancer, confirmed as the cause of historic trees falling in Nathan Road, Tsim, Sha Tsui, before and after Severe Typhoon Vicente, is said to have been officially identified in Kowloon Park in 2007.

The fungus infection has now spread across Hong Kong, but while the government told the public about the removal of individual trees since one fell on a Tsim Sha Tsim bus shelter last month, it has not disclosed the extent of the contagion, specialists say. Tsim Sha Tsui, the site of many historic trees, is the worst-hit area with at least five 'old and valuable' trees having collapsed or been removed in the past few weeks. Other affected areas include Central, Happy Valley, Lei Yue Mun, Diamond Hill and Tung Chung.

The MTR Corporation is also struggling at its nursery in Aberdeen to save two infected trees that were removed to make way for its South Island Line project.

The spread in Tsim Sha Tsui has been traced to the collapse of a third of the branches on an infected banyan in Kowloon Park - which is more than a century old, and dubbed the King of Urban Trees - in 2007.

Failure to remove infected parts and replace contaminated soil is believed to have allowed the fungus to spread by wind to other trees in the park, and to Park Lane Shopping Boulevard and the Observatory, said Lam Tak-chak, who trains arborists for the Vocational Training Council.