We thank Ms Dipa Swaminathan and Mr Arumugam Maniam for their feedback (Protect Singapore's natural green cover; Not much green left after pruning of trees, Sept 17).

The National Parks Board's (NParks) tree management regimen is based on recognised international guidelines for tree care. These are anchored on a rigorous programme of inspections and pruning. Trees are generally inspected once in 12 to 24 months.

Advanced inspections are done on trees which have a girth of more than 4m, as an added precaution.

More intensive inspections are carried out during periods of adverse weather to pick out trees that might need targeted pruning. Checks are also carried out following storms to identify and repair damaged trees.

Trees are also pruned before the onset of the monsoon season to reduce the risk of trees falling during this period.

Our enhanced tree risk management programme has reduced the annual number of tree incidents by about 85 per cent in the last two decades.

Tree incidents these days tend to involve snapped branches.

To improve the general health of our trees, we also carry out cultural treatments, such as mulching to supplement the regular application of fertilisers.

NParks also ensures that its tree care professionals are properly trained and provides training and courses to keep them updated on best practices.

As a City in Nature, we are implementing multitiered planting along our roads that resemble the natural structure of forests. These nature ways will attract butterflies, garden birds and other native biodiversity.

There are 34 nature ways in Singapore, stretching over 130km, and we aim to increase this to 300km by 2030.

Increasing these nature ways will help to mitigate the urban heat island effect and provide a cooler environment, and enhance ecological resilience to the effects of urbanisation and climate change.

Oh Cheow Sheng

Group Director

Streetscape

National Parks Board