Explore ways to cut risk of falling trees, branches

About a week ago, I saw a tree branch falling from a height of about 9m.

I heard a soft crackling sound and the rustling of leaves before it fell.

When it hit the ground, the branch, which was about 2.5m, broke into several pieces and scattered around the Park Connector Network (PCN) walking and riding paths. The fallen branch was thin, compared with other branches on the tree, which had a girth of about 2.4m.

Fortunately, nobody was cycling or walking near the area during the incident.

I find that most trees here are planted close to paths.

It is easy for a falling branch to trigger a chain reaction of accidents involving riders on bicycles and personal mobility devices as well as pedestrians. Some paths have been damaged by trees with invasive root systems, and have become hazardous for users.

There are also instances where tree branches stick out into the paths of park users, and some people resort to breaking them off.

With riding allowed on pedestrian paths, the authorities need to allocate more space for trees to grow without encroaching into people's paths.

When planting new trees, it may be better to choose smaller trees that have non-aggressive root systems and do not litter paths with fruits, branches and leaves.

Besides setting up a programme to identify and replace trees that are vulnerable to storms and inclement weather, the authorities should also carry out periodic inspections and regular pruning of trees along major roads or areas with high human traffic.

Although there are steps in place to monitor trees with weak branches, branches on trees in good health have also been known to suddenly break. Drought stress, high winds, storms or heavy rain can cause weak branches to break.

While it is not possible to eliminate the risk of falling trees and branches, the authorities need to consider stepping up the inspection and pruning of mature trees during dry weather spells, and when there are periods of heavy rain.

In some countries, arborists may recommend tree cabling and bracing to reduce stress damage of trees and to help strengthen weak branches.

Will such tree support systems help to reduce the risk of falling trees and branches?

Tan Lay Hoon (Ms)

A version of this article appeared in the print edition of The Straits Times on March 30, 2017, with the headline 'Explore ways to cut risk of falling trees, branches'. Print Edition | Subscribe