Bridge for biodiversity: Eco-Link to reconnect Bukit Timah and Central Nature Reserves

When the Bukit Timah Expressway (BKE) was completed in 1986, it divided our last primary rainforest.
To heal this gap, NParks and the Land Transport Authority are working on a bridge to allow trees and animals across the BKE! It will be a first of its kind in Southeast Asia.

How does the BKE hurt biodiversity in the forest?
With the Bukit Timah Expressway between the Bukit Timah Nature Reserve and the Central Catchment Nature Reserve, animals could no longer move safely between the two forests. Or became roadkill when they made the attempt.
Divided into smaller populations, animals risk inbreeding. As animals have a role in pollinating plants and dispersing seeds, plant variety will also be affected by reduced animal diversity. Thus over the long term, biodiversity in these forests will be affected, particularly in the smaller Bukit Timah Nature Reserve. Among the animals currently affected include the rare Banded leafmonkey.

The bridge will hopefully allow healthy exchange of wildlife to resume between the two forest areas. In the longer term, this may help restore the ecological balance in the fragmented habitats and reduce the loss of valuable biodiversity.

What will the bridge be like?
Called the Eco-Link, the bridge will be built over two high points on opposite slopes along the BKE. The hour-glass shaped bridge will be 50m wide at its narrowest point. It will be 'densely' planted up like a forest habitat. This will provide a safe green corridor to encourage small birds and shy animals to move between Bukit Timah Nature Reserve and the Central Nature Reserve.

A hiking track will be developed on one side of the bridge as a recreational green belt for human visitors to enjoy, and this will also serve as an alternative entry to the western part of Central Nature Reserve.

Where will it be located?
Currently, the spot being considered is about 600m north of Rifle Range Road between the Pan-Island Expressway and Dairy Farm exits. But the precise location has not been decided yet. The general location was picked as being the least damaging on the nature reserves at either end. During the building of the bridge, the sensitive nature areas around the bridge will be protected.

Construction is expected to start in the middle of next year with completion in 2013.

Were other options considered?
NParks had also explored the options of building overhead or underground ecological links between the two reserves, as well as the possibilities of re-routing the BKE as a flyover or underpass.

Will it work?
The Eco-Link is the first of its kind in Southeast Asia. But 'eco-passages' have been used successfully in other countries. In 2006, an 800m-long 'eco-duct' for deer, foxes and other animals was opened in Holland. The US$19 million (S$26.3 million) bridge spans a highway and a railway.


Related articles

• Eco-Link on the NParks website.
  
• Bridge across BKE to link nature reserves Besides humans, it will allow animals, plants to cross the expressway, Grace Chua StraitS Times 19 May 10;
• Bridge to link two nature reserves by 2013 Grace Chua, Straits Times 6 Sep 09;
  
• Eco-corridor for Bukit Timah and Central Catchment Nature Reserve from Spotlight on Nature 9 Nov 09;
  
• Rare Singapore monkey species in better shape than thought Study finds number of banded leaf monkeys 3 times greater than previously believed, Victoria Vaughan, Straits Times 10 Apr 10;