Forum: Not all native tree species are suitable in urban settings
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We thank Osman V.P. Mohamed for his letter “Bring back native Singaporean hardwoods for sturdier canopy” (June 18).
As part of efforts to transform Singapore into a City in Nature, the National Parks Board (NParks) uses a wide range of tree species – native and non-native – in our planting palette for parks, streetscapes and park connectors.
Not all native species are suitable in urban settings, which tend to be windier, drier and hotter than original forest conditions.
Species are selected for specific growing conditions and purposes, including the provision of shade, visual relief, supporting biodiversity, and strengthening ecological connectivity across green spaces.
For example, native flowering trees such as Yellow Cow Wood (Cratoxylum cochinchinense) and Sparrows’ Mango (Buchanania arborescens) provide food and habitats for fauna like birds and butterflies. Native species mentioned by the writer, such as Tembusu (Cyrtophyllum fragrans) and Seraya (Rubroshorea curtisii), continue to be used in our landscape, and the Common Rhu (Casuarina equisetifolia) is found naturally in our coastal areas.
Non-native species like the Rain Tree (Samanea saman) and Trumpet Tree (Tabebuia rosea) are planted for their broad canopies to maximise shade. The endangered River Tristania (Tristaniopsis whiteana) has distinctive peeling bark that transitions from whitish grey to coppery brown, contributing to a space’s visual character.
We are also naturalising more of our landscapes through natural designs and planting schemes that recreate the look and feel of Singapore’s forests. At some sites, including slopes along expressways, habitat areas in parks, and nature ways, vegetation is allowed to grow more naturally with selective interventions. Nature ways are planted with native trees and plants to mimic forests’ multi-tiered structure. Native species like Kasai (Pometia pinnata) and Mempat (Cratoxylum formosum) are planted along streetscapes around the Central Catchment Nature Reserve to facilitate habitat and ecological connectivity.
Where necessary, NParks progressively removes species more susceptible to disease or at higher risk of failure, such as Senegal Mahogany (Khaya senegalensis) and Sea Apple (Syzygium grande), replacing them with hardier species like Sea Gutta (Planchonella obovata) and Shore Laurel (Neolitsea cassia), which are more suited to Singapore’s weather and urban conditions. Drought-tolerant species like Common Sterculia (Sterculia parviflora) are selected for areas with less rainfall.
Given climate change, more frequent and intense weather events may bring higher wind speeds, greater rainfall variability, and greater risks of tree incidents. We will continue regular inspections and maintenance, like tree pruning, to mitigate these risks.
Oh Cheow Sheng
Group Director, Streetscape
National Parks Board
