Singapore has built a global reputation as a leafy “city in nature”, but the tropical city-state must incorporate more native plant species into its green infrastructure to strengthen climate resilience and lower costs, a prominent botanist has said.
The country relies heavily on imported ornamental plants to green its buildings and public spaces, but should invest more in indigenous species that are better adapted to extreme heat and disease while supporting richer biodiversity, said Professor Veera Sekaran of the National University of Singapore (NUS).
Speaking at an event assessing the cooling effectiveness of a miniature forest planted outside a shopping mall, Sekaran, director of NUS’s regenerative agritech centre, said Singapore’s Building and Construction Authority (BCA) should incentivise developers to use more native greenery by strengthening its Green Mark certification scheme.
Currently, the scheme awards one point to developers that use species from Southeast Asia in at least 50 per cent of their greenery mix, and another point for creating wild landscapes covering 10 per cent of a site. Sekaran said more weight should be given to the use of native plants.
The Green Mark system assesses a building’s environmental sustainability through a points-based framework across categories including climate resilience, health and wellbeing, and carbon.
Veera Sekaran speaking at an event to assess the cooling potential of microforests on Friday 20 March. Image: Robin Hicks / Eco-Business
Sekaran added that decisions about the role of nature in shaping Singapore’s construction industry should not be left solely to engineers. He called for ecologists to be more involved in designing the Green Mark framework.
In a statement to Eco-Business, BCA said native plants are already recognised within the scheme for their “superior resilience and lower maintenance needs”.
The agency added that Green Mark takes a “holistic” approach, balancing environmental performance across multiple metrics, and will continue to evolve based on industry feedback.
Beyond biodiversity and climate adaptation benefits, Sekaran said using local species makes “perfect business sense”.
“I don’t have to prune hedges, cut grass, or use fertiliser – and I don’t have insect problems. Ornamental plants attract pests and diseases in the built environment – and they struggle in the heat,” he said.
Sekaran led the development of a microforest composed of 80 per cent native species at City Square Mall in Little India last year. While the 260 square metre forest cost about S$69,000 (US$54,000) to establish, he said the expense was largely due to the two-month timeline, which required sourcing mature trees as well as saplings to meet developer City Development Limited’s deadline.
Veera Sekaran led the development of a 260 square metre microforest outside City Square Mall in Little India: Robin Hicks / Eco-Business
A Rambai tree (Baccaurea motleyana) in CDL’s microforest. Rambai is a species of fruit tree native to Thailand, Peninsular Malaysia, Sumatra and Borneo. It is critically endangered in Singapore. Image: Robin Hicks / Eco-Business
De-ornamentalise the ‘city in nature’
Sekaran is leading the development of a masterplan for the 150-hectare NUS campus and is pushing to “de-ornamentalise” the site by introducing more native species and allowing some areas to regenerate naturally.
Some of the native species grown at CDL’s microforest include the rambai tree (Baccaurea motleyana), which is critically endangered in Singapore, and the tongkat ali tree (Eurycome longifolio), a shrubby tree that produces flowers that are attractive to bees and birds, and is a source of traditional herbal medicine.
Sekaran said introducing more native-based green spaces would require a “mindset shift” among residents – one that began during the Covid-19 pandemic, when large areas of the city’s green spaces were left to grow wild.
“During Covid, more people began to sit in nature and appreciate that spontaneous greenery was not so bad. We started to move away from the manicured landscapes we had been used to under the ‘garden city’ model,” he said.
“Garden City” was the slogan adopted by Singapore in the 1960s under former prime minister Lee Kuan Yew’s vision of a clean, green, and liveable city. Over time, this has evolved into today’s “City in Nature” approach.
Striking the right balance between ornamental and native species remains a challenge, Sekaran said. Building owners are often reluctant to adopt more naturalistic planting, fearing it will attract wildlife in a city that is not always comfortable with close proximity to nature.
Supply chain constraints are another hurdle. Native species can be difficult to source from local nurseries, a concern echoed by Dr Stephan Gale, head of flora conservation at Kadoorie Farm and Botanic Garden in Hong Kong, on a podcast last year.
Sekaran described green spaces as “invaluable” to Singapore’s development, given the ecosystem services they provide, including clean air, water, and soil.
Although more than 40 per cent of Singapore is classified as green space, much of it is parks while a small proportion is truly wild – largely confined to nature reserves and secondary forests that have regenerated over abandoned villages and plantations in the past five decades.
Since 2021, Singapore has added 130 hectares of new parks. By 2030, more than 25 new parks and over 50 kilometres of additional park connectors are planned, according to the Urban Redevelopment Authority (URA).
However, the city-state is clearing significant areas of secondary forest for public housing. Up to 7,331 hectares – about 10 per cent of Singapore’s total land area – could be affected under URA’s urban development masterplan over the coming decade.
Maintaining local wild areas did not appear to be a major focus of Singapore’s climate adaptation plan, announced earlier this month to address heat resilience, coastal defence, and water security.
