SIEMENS

The old man dressed in simple overalls doesn’t quite fit into the overall picture. After all, this is the sophisticated lobby of Tiger Towers, one of Singapore’s most modern skyscrapers. And he certainly won’t need the hedge clippers he’s carrying if he’s got a reservation at the gourmet restaurant in the building or if he’s heading for the up-market hairdresser on the 40th floor.

In fact, Lee comes here every evening because this is his workplace. Before he retired, Lee, who is now 70 years old, was a renowned architect and innovative urban planner who accompanied Singapore’s growth. But now he has turned his hobby into a profession. Lee is one of Singapore’s officially designated "vertical gardeners." He strolls leisurely over to the elevators at the other end of the lobby, enters one, presses the button for the top floor, and looks into a small retina scanner, as usual.

In a fraction of a second, the fingerprint chip in the elevator button and the retina sensor recognize his identity. "Access permitted," says a woman’s soft voice, and the elevator zooms upwards. The elevator doors open slowly, revealing a view of a different world. A wave of bird song and the chirping of countless insects rolls toward Lee. A canopy of leaves and flowers arches over him, and there is a smell of damp earth and exotic flowers.

A narrow footpath winds its way from the elevator through the green thicket of plants and loses itself between a pair of hibiscus bushes. Lee shoos back a chicken that is about to join him in the elevator and dives into the tropical garden.

As though he had passed an invisible barrier, the temperature suddenly changes - the perfectly air-conditioned world of Tiger Towers is transformed into the hot and humid climate of a rainforest. But when Lee pulls out his PDA, this wilderness is revealed to be the perfect illusion of an exotic jungle - an ultramodern greenhouse on the top floor of one of the city’s countless skyscrapers.

With just a few clicks, Lee can monitor, control, and make changes to this artificial world. Countless sensors are buried in the soil to monitor its temperature, moisture, and nutrient content. An intelligent management system automatically controls the amount of sunlight coming in as well as the ventilation and irrigation. The systems are powered by solar cells mounted all over the building. Lee is actually more of a manager than a gardener here, because the actual gardening work is done by robots that scurry through the underbrush on their metal legs.

Nonetheless, in this verdant setting Lee is more than just an extra. He played a major role when this "green floor" was designed, and the success of this concept justifies his efforts. In spite of its jungly appearance, the garden is more of a natural plantation than a park. Between the bushes and hanging vines, there are flourishing beds of vegetables, mangoes, bananas, and other tropical fruits that are sold at a profit.