Loss of giant banyan shows us that trees don't grow on money

Concrete and incompetence kill natural asset that had been growing for 400 years

PUBLISHED : Monday, 26 August, 2013, 12:00am
UPDATED : Monday, 26 August, 2013, 5:50am

Hong Kong will lose a longtime companion next month as the axe falls on a 400-year-old banyan tree in Kowloon Park.

The tree's felling was ordered by the city's Tree Management Office last week, and although the decision will sadden tree lovers, the Leisure and Cultural Services Department said it was the "most effective risk management measure" to avoid spreading the incurable brown root rot disease.

Independent experts advising the government backed the plan unanimously, but described it as a "painful decision".

Yet there are lessons to be learned from the loss.

Hongkongers may look slack-jawed with amazement when they go overseas and find trees hundreds of years old, even though it is nothing unusual in many places. That's because they are rare in Hong Kong and their numbers are diminishing.

The Kowloon Park banyan tree's canopy has grown to more than 30 metres across since it started out as a sapling next to a village and paddy fields during the Qing dynasty (1644-1911).

It was still growing when the British army took over the area and built the Whitfield Barracks.

The irony is that the tree became threatened only when park development was started at the end of the 1980s.

"A park is supposed to be the best shelter for trees. But it is dying because of the building and poor management of the park," said Jim Chi-yung, a professor of geography at the University of Hong Kong.

The length of a tree's roots is typically three times the width of its canopy, but ignoring the science, the government submerged most of the banyan tree's root system under compacted soil and concrete, reducing its supply of oxygen and nutrients.

The tree's base also became home to construction workers, who inadvertently harmed it by discharging sewage and erecting structures.

Its roots were likely further damaged when a consultant to the Leisure and Cultural Services Department drilled 20 holes in the ground at the tree's base, exposing the much weakened roots to rain and disease.

The tree subsequently lost one-third of its mass and contracted brown root rot.

The disease, which attacks only weak trees, has covered the tree's roots in fungus that has climbed up its branches to six metres above the ground.

The banyan tree's story is just one of many in the city, which lacks a tree protection law and which lost at least one in 10 of its 527 heritage trees between 2004 and August last year.

Despite the opening of the Tree Management Office three years ago, trees are still supervised by more than 10 agencies that are short of resources and trained staff.

The department has long been criticised for being bound in red tape and staffing practices that can mean an employee managing a swimming pool is also responsible for examining a tree's health.

And throwing money at the problem won't make it go away.

"We have learned that money won't help after the damage has been done," said Ken So Kwok-yin of the Conservancy Association.

"We should protect trees from the start," he said.