Dangers sprouting in the city
2014.11.18

City dwellers love trees, probably because there are so few of them in the concrete jungle they live in. But does the attention and effort we put into maintaining trees match our affection for them?

CITY living comes with many conveniences but also many downsides, including having to endure toxic air as well as noise and light pollution. That is why we put parks in city centres, and plant trees on roadsides. The lawns, flowers and trees give us a feeling of being back in nature.

Apart from their aesthetic value, trees also improve air quality. But we seldom spare a thought for them until something bad happens.

Avoidable tragedies?

TREES can cause havoc from time to time. Just look at the fallen branches that are strewn all over our roads and cause traffic problems after a typhoon. Sometimes, heavy branches or even an entire tree could fall without warning, causing injuries or even fatalities.

The most recent incident was particularly tragic as the 37-year-old victim was pregnant. She was walking along Robinson Road in Mid-Levels when a 15-metre-tall tree fell on her. She died whilst her baby was delivered afterwards and survived. Are these accidents inevitable, or have we been failing to properly maintain the health of our trees?

Wrong tree in the wrong place

LACK of proper care is one cause of tree problems. Another one is that some kinds of trees are just not suitable for Hong Kong. In the words of tree expert Sammy Au Wing-sum, “It’s not the right tree for the right place.”

Au, president of the China Arborist Association, noted half of the 1,500 different kinds of trees in Hong Kong are indigenous to the South China region, while the other half were introduced from other places. Non-indigenous species of trees could alter local ecology, he said, and might not adapt well to the hot and wet conditions here.

Failure in maintenance

A UNIVERSITY professor said that parts of the Indian oak in the Robinson Road incident had broken several times before and had apparently not received proper care. Part of the soil over the roots was covered by concrete, and the trunk had turned black, a sign of serious fungal infection.

Even if the tree was healthy, it could have still fallen because it was not planted in a suitable location. That kind of tree could grow over 10 metres tall in just a few years and needed a location with deeper soil.

A host of problems

AU also pointed out many other tree maintenance problems in Hong Kong. Almost all trees that line the side of the roads have the expansion of their root system hindered by concrete road surfaces. There is also a general lack of head room for the foliage to spread and grow. Some trees were seen growing into overhead shop signs or street lights; trees in the countryside have their branches sticking out and are often knocked off by passing double-decker buses.

Regular pruning is required to keep a tree healthy, Au said, but the job was often entrusted to unqualified workers, resulting in problems such as over-pruning.

Comprehensive efforts needed

CLEARLY, the way we have been treating our trees leaves much to be desired. A comprehensive and coordinated system of tree management is required as a permanent solution.

These should include stepping up maintenance of trees in public places and making it compulsory for private property owners to inspect and maintain trees regularly, with corresponding technical support and law enforcement. There should also be public education on the importance of keeping our trees healthy.