Taking steps to root out falling trees

NParks says it ensures potentially dangerous trees are removed, makes regular checks
Feng Zengkun Straits Times 25 Dec 11;

With the monsoon season well under way, the authorities are taking steps to make sure falling trees do not harm pedestrians or cars.

Last month, a large tree fell across Clementi Road during a thunderstorm, blocking two lanes of traffic.

A reader who wrote to the press felt the mishap might have been due to housing estate improvements that removed part of the tree's roots.

When asked by The Sunday Times, town councils including the Holland-Bukit Panjang and Ang Mo Kio councils declined to comment on specific measures to ensure that trees are unaffected by estate improvement work, but said their officers trim branches of trees to increase their stability.

Thunderstorms, they added, can snap branches and cause trees to fall, no matter how well they are maintained.

The National Parks Board (NParks), which manages roadside trees, said it takes steps to ensure that potentially dangerous trees are removed.

Plans for roadworks and other projects have to be approved by the agency, it said.

If the work cuts into the major roots of trees, the contractor has to either alter the plans or remove the trees. It then has to pay for the same number of trees to be planted elsewhere to maintain the country's greenery.

NParks said it conducts regular checks to make sure roadside trees will not fall during heavy rain.

Its officers remove dead and diseased branches, and trim overgrown crowns to prevent falling deadwood from harming pedestrians and cars.

In extreme cases, where the tree has cavities or decay that may cause it to topple, the entire tree is removed. These weak spots may be caused by disease or lightning strikes. The trees are replaced with hardy species that thrive in urban areas, and are tailored to the land conditions.

In estates with narrow tree planting strips, for example, medium- sized trees such as the Pouteria obovata and Xanthostemon chrysanthus are used.

Along major roads, trees are also given a 2m-wide space for their roots to spread.

According to the latest NParks figures, the number of tree falls has declined from 3,100 in 2000 to about 1,000 in 2009.