Global award for city's 'tree daddy'

An academic who has fought for years to preserve the city's trees has become the first Asian winner of the highest honour in the field of arboriculture.

"I was caught by a surprise … and found out later that it was a group of academics working in the US and Europe who quietly nominated me," said Jim, a member of the government's expert panel on tree management.

Jim has been dubbed the city's "tree daddy" for his unstinting criticism of government and developers, whom he has accused of threatening people's lives with their poor tree maintenance. He is also a keen advocate for a law to protect trees.

The society, which certifies arborists and publishes influential journals, presents the award to one person each year. Since it started in 1975, the prize has only gone to Western researchers.

Jim takes pride in the fact his research has applications in the real world. His areas of study include everything from improving roadside tree management to reducing indoor temperature by greening a building's rooftop.

"I'm not only doing it for research. The very last paragraph of my paper often tells how my research can be applied [in the real world]," he said.

The findings of his research - including more than 300 journal articles in 30 years of study - are often revealing. For example, his latest study last year reversed the traditional belief that a thicker layer of soil for rooftop pitches further cuts temperatures below.

"Our research carried out on a rooftop of a public housing estate in Tseung Kwan O found the opposite, which surprised many in the field. Soil contains water and water carries heat," he said.

He urged the government to follow Germany and Canada, where residents and companies are offered subsidies to plant on the roof. "It not only lowers the flat temperature, it also slows down the discharge of rainwater during thunderstorms."

Born in Hong Kong, Jim, 61, studied at HKU as an undergraduate and earned his PhD at Britain's University of Reading.

After joining the faculty at HKU in the 1980s, he specialised in trees partly because doing so involved only small expenses.

His first lot of research funding amounted to just HK$4,000, about a month's salary. "But I was told that I was given special treatment because the amount was higher than others [got]."

But such is his passion for the subject that he was once mistaken for a peeping Tom, by a policeman who saw him checking trees in a private Kwun Tong garden using a telescope.

He achieved a childhood dream by securing a HK$5 million donation from HSBC to install 14 green pitches on school rooftops and podiums.

"I always wished I could walk, jump and sleep on the grass when I was at school. Now they can do it," he said, adding that his only request was pitches be properly maintained and that the children be able to use them freely.

"Children in Hong Kong are too far from nature … they only learn about nature in class."