‘Cancer trees’ can be saved, Hong Kong experts say as they urge government not to remove those with brown root rot disease
Chinese University expert cites successful cases in Taiwan and Japan in which trees have been spared the chop and nursed back to health
Brown root rot disease, often referred to as “tree cancer”, can be mitigated in its initial stages, and diagnosis does not necessitate immediate felling if the condition is discovered early, according to experts.
Professor Chiu Siu-wai of Chinese University’s School of Life Sciences has criticised the government for what she said was its failure to properly manage and conserve old and valuable trees and opting instead for the easy choice of removal rather than long-term monitoring.
It was revealed last week that 18 out of the 481 trees in the city listed as old and valuable by the Development Bureau had been infected, 16 of which it deemed “irrecoverable” and “more cost effective” to remove to prevent the risk of disease spreading via spores or soil. The numbers were revealed during a meeting of the Expert Panel on Tree Management, which endorsed the removals “in principle”.
“Brown root rot can be treated but it depends on whether you want to or not,” Chiu said, citing examples in Taiwan and Japan. “Unlike in Hong Kong, they don’t wait for a sick tree to reach a terminal stage of rot before confirming brown root rot and scaring the public into believing it must be felled immediately.”
Chiu said antifungal agents could be applied to a tree during the early to middle stages of infection to mitigate structural deterioration and root decay.
Dr Simon Yu Lap-on, a former Leisure and Cultural Services Department tree officer, said there were many scientifically proven ways to preserve such trees. He cited the example of a historic 400-year-old tree preserved in Kowloon Park.