Singapore’s City Square Mall Microforest Cools Urban Heat, Boosts Biodiversity

Singapore – A research-driven microforest at City Square Mall in Little India is demonstrably cooling surrounding temperatures by up to 5°C, while simultaneously enhancing biodiversity, according to a year-long study. The project, developed by City Developments Limited (CDL) in partnership with the National University of Singapore (NUS), has expanded to twice its original size following the positive findings.

Microforest Origins and Expansion

Launched in March 2025, the CDL MicroForest initially covered 2,800 square feet (260 sq m), roughly half the size of a basketball court. In January 2026, the microforest doubled in size to 5,600 sq ft, demonstrating CDL’s commitment to nature-based climate solutions. The project received support from the National Parks Board (NParks) and functions as a living laboratory for studying urban heat mitigation and biodiversity enhancement. CDL celebrated the first anniversary of the microforest on March 20, 2026, presenting the study’s findings at a public forum held at the Singapore Sustainability Academy.

Cooling Effects and Biodiversity Gains

Researchers from NUS found that temperatures within the microforest can be up to 5°C cooler than surrounding urban areas and roadsides. Channel NewsAsia reported on these findings, highlighting the potential of microforests as a nature-based solution to combat urban heat. Areas within 2 meters of the microforest’s edge also experienced lower temperatures compared to surfaces further away.

Beyond temperature reduction, the microforest is fostering increased biodiversity. Acoustic monitoring revealed higher levels of bird call activity within the microforest compared to surrounding areas. Researchers also observed an increase in the number of bird species utilizing the green space, including the black-crowned night heron and Swinhoe’s white-eye. The Edge Singapore detailed these biodiversity gains.

Environmental DNA sampling of soil revealed 70% more species within the microforest compared to a nearby grass patch. The presence of ecologically important organisms like millipedes and springtails – indicators of soil quality – further demonstrates the microforest’s positive ecological impact.

Mimicking Tropical Rainforests and Future Plans

Microforests are designed to replicate the layered structure and biodiversity of a tropical rainforest within a small footprint. For the CDL MicroForest, experts carefully selected a variety of native shrubs, saplings of different heights, and fruiting trees to attract native fauna. CDL Sustainability explains the design principles behind the project.

NUS researchers aim to develop a guidebook to provide guidance for the proper implementation of microforests, ensuring future projects effectively enhance biodiversity and reduce heat. CDL’s chief sustainability officer, Esther An, indicated that the company has at least two additional microforest initiatives in development, though specific locations have not yet been disclosed. Ms. An expressed hope that the study’s findings will encourage wider adoption of nature-based solutions, particularly in developments like data centers that often lack green spaces.

Community Response

Residents appreciate the microforest as a refuge from the heat. Kanegas Wari Kumar, a frequent visitor to City Square Mall with her daughter, noted the benefit of having an outdoor space that provides relief from the heat, especially for individuals with respiratory conditions.