Part of wildlife corridor in Bukit Batok cleared for roadworks

The plot of land opposite the Bukit Batok Nature Park carpark, which is currently being cleared for road works. ST PHOTO: MARK CHEONG
NParks will plant tall native trees on the road verges and forest edge to replicate the natural structure of forests. ST PHOTO: MARK CHEONG

SINGAPORE - The clearance of a patch of secondary forest in Bukit Batok during road-widening works could disrupt a nature corridor identified by a national study as a link that wildlife can use to cross forest plots in Singapore.

Naturalists said the felling of trees connecting Bukit Batok Nature Park and Toh Tuck forest could hamper the movement of native tree-dwelling creatures such as flying squirrels and colugos, which have been found there.

Given that the forest patches are separated by Bukit Batok East Avenue 6, any reduction in vegetation will widen the gap, particularly for species that move by gliding from tree to tree, said mammal researcher Norman Lim from the National Institute of Education.

Said Dr Lim: “Unfortunately, without a targeted study to investigate the amount of connectivity before and after the clearance, it is difficult to gauge the impact and changes in connectivity.”

But a Land Transport Authority (LTA) spokesman told The Straits Times that it will adopt other measures to help wildlife get around.

This was done in consultation with the National Parks Board (NParks), which had identified the forested site as part of the Clementi Nature Corridor, she said.

The forested site in Toh Tuck is part of an ecological connection that facilitates animal movement between Bukit Timah Nature Reserve and the Southern Ridges, the spokesman added. Such corridors act as highways for wildlife, allowing them to find mates and food in other forest patches.

Acknowledging that road-widening works could affect a section of the crossing used by tree-dwelling animals, LTA said NParks will plant tall native trees on the road verges and forest edge in a multi-tiered manner to replicate the natural structure of forests.

LTA is also working with NParks to install artificial crossing aids such as poles and rope bridges to facilitate the movement of arboreal animals as new planting will take time to establish.

The clearance of the forested sites came as a surprise to some naturalists, who noted that NParks’ ecological profiling exercise (EPE) launched in February 2021 was meant to help developers become sensitive to links between the island’s green spaces.

Creatures like flying squirrels can travel between Bukit Batok Nature Park and Toh Tuck forest by traversing trees along the fringes. PHOTO: BRICE LI

Preserving continuous swathes of greenery is crucial, given the dearth of forest fragments outside nature parks and reserves, said National University of Singapore biology lecturer N. Sivasothi, who was consulted on the EPE.

He noted that the affected forest patches are located near the intersection of the Bukit Batok and the Clementi nature corridors, which might impact the wildlife moving between western catchment forests to the central nature reserves.

Said Mr Sivasothi: “These nature corridors are important pathways for animals to travel between areas of high biodiversity, which help rejuvenate green fragments.”

He added: “If the link is broken, green fragments become cut off from ecosystem functions available in a mature forest.”

The LTA spokesman said detailed environmental studies were not needed when the project was first proposed in 2016 as the works mainly impacted the fringes of secondary forest dominated by rubber trees. The project will cater to the expected increase in traffic in the vicinity.

The removal of trees at the road junction was deemed necessary to accommodate the widened road and for slope-regrading works to ensure slope stability, she added.

Still, LTA said it has worked closely with NParks on measures to reduce disturbance to wildlife.

“Where tree removal was required, pre-felling checks for wildlife nests were also carried out before commencing works,” the spokesman said.

The recent clearance follows other controversial tree-felling in Bukit Batok, including the levelling of a string of forest habitats in 2019 for an HDB Build-To-Order project.

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