Unutilised land being scarce, there is an impulse here to optimise its use. That's only natural. Fortunately, the decision made for a large tract of swampy, forested land next to the 158-year-old Botanic Gardens was to leave it in its natural state. Being close to prime shopping areas and expensive residences, one would expect location, price per square metre and opportunity cost to figure strongly in the property equation.

Instead, $30 million was spent so the National Parks Board could create a Learning Forest, with donations of $2.08 million and $1.2 million from Keppel Corporation and Singapore Press Holdings, respectively.

Land cost and utility value matter, but land is also an essential platform for greenery and bio-diversity which offer environmental, social and indirect economic benefits. The aesthetic and amenity value too of what nature remains should rightfully be passed down to future generations. But that is a fraught task, as the Botanic Gardens' project shows. For example, of the 228 species of Singapore's native orchids, 170 are already considered extinct - silent victims, like other species, of the frenetic exploitation of land. What the present generation can now bequeath are the careful conservation of what is surviving, and the planting of saplings that will over time become giants, reaching 20 storeys or more into the sky.

In representing a broad recognition of the need to preserve the nation's natural heritage, the Learning Forest project shows how people can come together to safeguard the ecological commons. That process has to be extended thoughtfully to other suitable areas of the island, where flora and fauna cling to a fragile existence.