NParks on mission to rescue critically endangered orchids

We would have easily missed the critically endangered orchids lining the "trail" if not for the eagle-eyed researchers pointing them out.

To prevent us - and the growing number of hikers venturing into Clementi Forest - from literally stamping these two orchid species out of existence in Singapore, the National Parks Board (NParks) staff gently prised each individual from the leaf litter and placed them into a plastic box.

We had joined NParks on an orchid rescue mission into the forest last Wednesday. The aim was to collect individuals from two rare orchid species, Dienia ophrydis and Zeuxine clandestina, and nurture them at the Singapore Botanic Gardens to ensure their survival.

The numbers of both orchid species have dwindled sharply following an influx of hikers into Clementi Forest, after footage depicting it in its early morning splendour spread on social media last October.

Clementi Forest sits on land zoned for residential use. The Government said in January that the site will still be earmarked for this purpose although there was no immediate need to develop it.

Nature enthusiasts hope the plot can be rezoned as a nature park - but Singapore residents could be loving the forest to the detriment of its inhabitants.

"People enjoy Singapore's nature areas for their ambience," acknowledged Mr Lua Hock Keong, deputy director of NParks' National Biodiversity Centre, and one of the researchers on the trip.

"But many are often not aware that these green spaces have biodiversity too."

SENSITIVE PLANTS

The common snout orchid (Dienia ophrydis) was once presumed nationally extinct until it was rediscovered in Clementi Forest in 2011 by an NParks team that included Mr Lua during a biodiversity survey.

Today, that forest and the Nee Soon Swamp Forest are the only places where this orchid is known to persist.

But human impact is taking a toll.

Before hikers turned up in droves, Mr Lua had counted about 50 of the plants clustered at one site. Later, he went back and found fewer than 20. By March, just one remained.

NParks staff such as Mr Ang Wee Foong, centre director of the Seed Bank, often make trips to Singapore's forests and nature areas to source materials such as seeds or plant cuttings that will allow them to nurture future generations of native plants.

On these trips, parent plants are left behind. But last Wednesday's visit was different. It was a salvage mission to rescue as many orchids as they could find.

The plainness of both orchid species makes them the wallflowers of their natural habitats.

A tropical rainforest assaults the senses - birds call, humidity clings to the skin, plants outdo one another with large, showy leaves, and streams gleam with an oily sheen. This sheen, we learnt from NParks' group director of conservation Lim Liang Jim, is "forest kombucha".

Microbes in the water break down organic matter such as dead leaves, making these nutrients available once again to the rest of the forest. The oil on the surface is a by-product of these processes, he explained.

These orchids are ground-dwelling species, unlike their showier cousins that tend to be epiphytes that grow above ground on branches and get moisture from the air, or water flowing along the branches and tree trunks during rain.

These terrestrial orchids develop a rhizomatous stem bearing short roots that worm their way through the topmost layer of fallen plant debris before reaching the soil, Mr Ang explained.

But the constant pounding of feet on this layer of topsoil can compact it - with disastrous consequences for plants like these orchids that depend on this layer to gain a foothold in the forest.

Ground orchids also rely on mycorrhiza - a type of fungus invisible to the naked eye - to help them thrive in the forest environment, Mr Lua added.

ENSURING SURVIVAL

Last week's rescue mission was not the first for Mr Ang or Mr Lua. NParks staff have been making salvage trips since Mr Lua noticed a decline in orchid numbers.

Some of those collected earlier are now bearing seed pods.

Nature guide Ivan Kwan advises visitors to keep to existing trails.

"Even within Clementi Forest and other unofficial hiking areas, paths have already been created (due to) trampling. If people keep to these paths, the impact from high visitorship can be lessened," he said, adding that people should also not litter, or feed or harass wildlife.

"It's great that more people are taking the time to enjoy nature in Singapore, but we need to be careful and make sure we don't love our green spaces to death."

This article first appeared in The Straits Times.