Where's the diversity?

NParks has begun planting more native trees and plants lately, but experts say public attitudes need to change to accept more organic landscapes
Straits Times 29 Jan 11;

IN THE Garden City, trees used to take the limelight while wildlife took a backseat. But the latter is shaping up to be an increasingly important part of the deal.

More native trees, as well as a greater variety of them, are now being planted along roads and in parks to attract birds, butterflies and other wildlife that will sustain the ecosystem. The National Parks Board now draws from a palette of more than 400 species of trees for roadside planting, double what was used in the early days of the Garden City.

Singapore is also spearheading conservation efforts in urban settings, having helped develop a global index on cities' biodiversity which has already been tested by cities like Curitiba in Brazil and Nagoya in Japan.

The reasons for this are simple but often overlooked: Plants cannot exist without wildlife, and greater biodiversity can make it easier to maintain urban greenery.

As it is, declining bee populations in Europe and the United States have worried food producers because bees are crucial for pollinating plants like almonds, citrus fruits, pears and cucumbers.

Closer to home, the proliferation of pest birds like Javan mynas and house crows in some areas is due in part to the streetside planting scheme adopted in the early years. As the city needed to green rapidly in the 1970s, it focused on a limited choice of fast-growing trees like the rain tree, angsana and African mahogany. This dense, monotonous green canopy provided Singapore's city folk with shade, cut out noise and reduced dust. But the neat and orderly 'lollipop' style of street plantings made it hard for many native birds to survive.

Dr Ho Hua Chew, the vice-chairman of the Nature Society's conservation committee, blames it on the 'destruction of the untidy patches of woodlands and hedges all over urban Singapore and the countryside'.

Within years, these organic landscapes were replaced with a neat and orderly mixture of concrete, evenly spaced trees and lawns, he says. These trimmed lawns and fields provided the Indonesian Javan mynas with ideal ground to hunt for their natural food like grasshoppers and worms. But their increase is believed to have ended up muscling out the melodious - and native - Oriental magpie robin here.

In the 1980s, the Garden City's subsequent choices of trees were based more on aesthetic and sensual, rather than ecological, reasons: The pink poui and boungainvilleas made their debuts to add colour to the landscape, while fruit trees and fragrant plants were introduced in housing estates, parks and schools for variety.

The National Parks Board's director of streetscape, Mr Simon Longman, says: 'We didn't specifically choose trees that would be a refuge for birds or a food source for birds along the streetscape. But there are some which incidentally provided food for birds, like the buah salam tree.'

This medium-sized tree bears small red berries.

Over in condominiums, the plantings are driven more by fashion than environmental concerns. Arborist Jacqueline Allan from landscaping company Nature Landscapes says: 'Everybody tends to go for a certain set of trees. And then when somebody tries something new, everybody tries that too.'

More than 20 years ago, she notes, coconut trees were all the rage. About 10 years later, developers started taking a liking to palms. Today, she says, the Central American bucida genus of trees seem to the 'in thing'. It's no wonder then that the landscape of modern Singapore, just like its people, has become very cosmopolitan, or even exotic.

'Most of the species here are brought in from somewhere. Some, like the Jacaranda, have already taken up citizenship,' she quips, referring to the South American import with lilac-coloured flowers planted in many older condominiums.

But how the infusion of foreign talent has affected local biodiversity remains unclear. For sure, the rapid development of the city has had an impact on native flora. A 2009 guide to native vascular plants - the dominant type of plants - published by the Raffles Museum of Biodiversity Research revealed that 29.8 per cent are globally or nationally extinct.

As if that is not bad enough, the local ecology also has to contend with humans who demand greenery at their doorsteps but recoil at the untidiness that can come along with it.

According to Mr Tay Ah Bah, the senior horticulture manager of town management firm EM Services, public housing residents often ask for trees to be trimmed when they block the view from their flats. They also complain regularly about insects flying into their homes when trees get too close. In response, town councils select trees that do not support as much insect life, he says.

But insects sustain birdlife. Dr Shawn Lum, president of the Nature Society, says the little critters are an important part of the diet for birds like orioles, flycatchers and magpie robins.

In recent times, NParks has introduced different and more plants native to this region to support wildlife, in the process also making Singapore's streetscape more resilient to disease outbreaks and insect attacks. But it maintains that it will continue to choose trees primarily for their stability and ability to thrive in an urban environment.

Dr Lena Chan, deputy director of NParks' National Biodiversity Centre, hopes the Republic's growing crop of high-rise gardens and network of green trails linking its parks could potentially serve as stepping stones for wildlife to feed, rest and move around this densely built-up island.

But for that to happen, there needs to be greater variety in Singapore's urban greenery. Dr Lum says: 'The more complexity you have, the more animals you can support.'

But the experts concede it will be an uphill task getting urbanites to accept this more organic or even spontaneous environment.

'It kind of goes against our ingrained aesthetic... people in their 30s or younger are accustomed to seeing fairly uniformed or structured, orderly landscapes,' says Dr Lum.

Beyond that, Singaporeans will also need to get used to the idea of sharing the island with a variety of creatures, big and small. The recent sightings of deer and wild boar around the nature reserves, for example, were cause for excitement but also some unease about having wildlife at close range. On this front, Dr Chan thinks a good old-fashioned dose of give-and-take is in order.

'We need to remind people that if you want to live in a house right next to a nature reserve, remember to take into consideration that you are also infringing on an area where the monkeys were before. (Don't) complain about them. They were there first.'


If you want a butterfly, don't kill the caterpillar
Straits Times 29 Jan 11;

Three things you can do to support local biodiversity:

go easy

# Don't freak out when you see a caterpillar: It is a butterfly in waiting.

If a caterpillar nibbles the leaves of your festive plants, don't reach for the bug spray. Simply hide the hole-ridden plant behind other flowering plants.

Experts say the caterpillars usually don't cross over. They hang onto certain types of plants and chomp on only particular types of leaves.

go wild

# Loosen up: Not all gardens need to be manicured. Letting wild grasses and plants grow would support more varied types of wildlife beyond those already adapted to city life.

go native

# Go native and make your neighbourhood nursery go native: The plant nursery business is demand-driven, so if more customers request native plants, the nurseries will bring in more of such plants.

A comprehensive list of native vascular plants - the dominant type of plants - can be found at http://rmbr.nus.edu.sg/raffles_museum_pub/flora_of_singapore_tc.pdf

Alternatively, you can browse the National Parks Board website http://floraweb.nparks.gov.sg

Information from Dr Lena Chan, deputy director of the National Parks Board's National Biodiversity Centre, and Associate Professor Hugh Tan from the National University of Singapore's Department of Biological Sciences