Singapore's Garden City concept may be extended further to encompass ecosystems that encourage biodiversity

Attracting the birds and the bees
Business Times 8 Apr 08;

Another major area for conservation lies off Singapore's shores, in its rivers and canals. The country has lost much of its coastal mangroves, important breeding grounds for fish, and 60 per cent of its coral reefs, according to marine biologist Peter Ng of NUS.

A primary task is to bring silt levels down. Stirred up by erosion and ship movement, silt cuts the amount of light entering the water, stifling corals and seagrass.

Singapore's Garden City concept may be extended further to encompass ecosystems that encourage biodiversity, reports MATTHEW PHAN

BIODIVERSITY seldom comes to mind when one thinks of the living environment. Yet biodiversity - which refers to the number and variety of organisms in an area - merely extends Singapore's Garden City concept.

Originally conceived in 1968, the Garden City vision aimed to soften the harsh concrete landscape of the city, and create a lush, aesthetic environment to make residents and foreign investors alike feel comfortable.

Over time, it has evolved into a broad model for managing urban plant and animal life: 9 per cent of Singapore's area is dedicated to park and natural land, with four gazetted nature reserves, thanks in part to the public's calls.

But environmentalists say there is a need to push the concept further.

'The Garden City had a different set of objectives, it wasn't about biodiversity per se,' said Shawn Lum, a biologist at the National Institute of Education and volunteer with the Nature Society.

But the two are not mutually exclusive. The Garden City can be a perfect platform for creating urban ecosystems - whether animals are attracted to live in a green space depends on the landscaping and the plants used, said Dr Lum.

Parts of Singapore, such as the Botanic Gardens or the patches of mature trees around Tanglin, draw many birds, for example. But other areas, such as Bishan Park, while pretty, are 'relatively sterile in animal life', he said.

But put in fruit trees and flowering plants, and you could attract birds and butterflies. At Alexandra Hospital, for example, the gardens now host over 500 plant species, with 101 butterfly and over 60 bird species sighted.

Even though 95 per cent of Singapore's natural forest is gone, there is huge potential for biodiversity in Singapore, said Dr Lum.

This is thanks in part to its extensive park connector systems, which act as stepping stones from one patch of green to another, and help animals cross urban areas.

Singapore has some 70 km of park connectors, including a 42 km network that connects the East Coast to Changi Beach, Pasir Ris Park, and others such as Bedok Reservoir Park.

The Urban Redevelopment Authority aims to expand this to 200 km of connectors by 2012, and over 400 km in the longer term, as 'green corridors' that link the parks to homes and even the town centres, it told BT.

Gardens in the sky

Another huge potential area is in skyrise greenery, such as 'green roofs' and 'vertical greening', or planting gardens on the rooftop or down the walls, respectively.

Despite assumptions that rooftop gardens are elaborate and require special roofs to bear the weight, many modern green roof designs are lightweight and require minimal maintenance.

They do not compromise the roof's waterproofing and instead, help with drainage and temperature control, architects say.

Instead, green roofs, for which select cities such as Chicago have become well known, improve the quality of living and allow optimal land use, said the URA, which is helping to integrate balconies and sky terraces into building designs. For example, NParks promotes skyrise greenery and advises building owners on how to manage them.

It is also collaborating with the Building Construction Authority (BCA) and the National University of Singapore (NUS) to test different wall-greening systems. The project, Living Walls in HortPark, features eight walls that fit an industry-standard reinforced concrete wall measuring 6m by 4m - the equivalent of two storeys of a building.

A variety of local and overseas systems are tested to measure their environmental impacts, such as thermal and sound insulation, or impact on rainwater quality.

As for biodiversity, imagine you are a bird, looking down on a city, says Dr Lum. Any area with substantial open patches of green space - whether in a park or on top of HDB blocks, schools, factories or even along the street - could be a habitat.

Another major area for conservation lies off Singapore's shores, in its rivers and canals. The country has lost much of its coastal mangroves, important breeding grounds for fish, and 60 per cent of its coral reefs, according to marine biologist Peter Ng of NUS.

What with one of the world's busiest ports, and other coastal developments like marinas and land reclamation, 'let's not fool ourselves and say they don't impact the system, because they do', said Dr Ng.

What has changed, though, is that Singapore is far more concerned now, compared to 40 years ago, with mitigating impact.

A primary task is to bring silt levels down. Stirred up by erosion and ship movement, silt cuts the amount of light entering the water, stifling corals and seagrass.

Rather than using granite breakwaters, like in the past, Singapore aims to achieve this by redesigning the coastal landscape and reintroducing plants and corals, said Dr Ng. 'We used to think of mangroves as mosquito swamplands', he said. 'But they are useful as breakwaters, and for water containment and filtration'.

And if corals, seagrass and spunges come back, the marine facade, 'now very sterile and boring', will liven up, he said.

Fortunately, Singapore sits at the edge of the Coral Triangle, one of the richest areas in terms of marine life on the planet. 'The current brings things from A to Z here from all over the place,' said Dr Ng. 'If we have the right structures and clean water, animals will come back'.

One ongoing initiative is Singapore's first coral nursery, located off Pulau Semakau, which seeks to grow coral fragments and transplant them to strengthen existing reefs.

Similar efforts are taking place with Singapore's reservoirs and canals under the ABC Waters programme, which seeks to turn them into lush locations for water sports.

Here, too, biodiversity plays a dual purpose. Underwater plants, for example, can not only beautify a canal but also regulate water flow, improving the drainage system, according to Dr Ng.