(MY) bioindicator of the jungle's health

[Guest guest]

Heart of NATURE - The Straits Times

JESSICA LIM

 

SEPT 11:

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Every living thing in a forest, from the humble moss to giant mammals, is a

bioindicator of its state of health. JESSICA LIM tags along with some

researchers to see how organisms perform this function.

 

When botanist Dr Kamaruddin Mat Salleh entered Bukit Belata Forest Reserve,

he immediately noticed thick undergrowth of resam ferns choking the trail’s

opening.

 

Further in, he pointed out the overwhelming dominance of thorny jungle

palms, known locally as bertam. Large hardwood trees were few, and other

plantlife were mostly young trees or shrubs.

 

To Dr Kamaruddin’s trained eye, the presence of these plants showed it was a

secondary forest which had been heavily logged two to four decades back.

 

" When trees are logged, rain washes away humus-rich top soil. Ruthless

resam’ ferns colonise the infertile area in turn paving the way for

sun-loving shrubs to grow, " he said, adding it takes decades to fully

restore a forest.

 

From August 22 to 26, 140 researchers combed the 12,200- hectare Bukit

Belata Forest Reserve for data vital to the area’s management and

conservation. About 1,000ha are designated to be Malaysia’s first herb

forest.

 

For these researchers, collecting data is no walk in the park. They are

trained to pick out indicators that tell them the " health " of their area of

study, whether it be insects, animals, parasites, moss, ferns, higher

plants, rocks or fish.

 

 

Furry little mammals

 

 

Armed with mousetraps, pisang emas and bright red oil palm fruits,

Universiti Sains Malaysia animal ecologist Dr Shahrul Anuar Mohd Sah led his

team into the forest.

 

They kept their eyes peeled for potential trap locations — usually a little

way off the trail, close to vegetation, under logs or between bushy nipah

fronds.

 

" We put traps where they forage. The rats and squirrels we hope to catch eat

mostly insects, fruits and worms, " he said.

 

The team also put up mist nets, which like their name suggests, are fine,

barely visible nylon nets stretched across probable bird or bat flying

paths.

 

The traps were checked twice daily and animals caught were identified,

measured and weighed.

 

Universiti Kebangsaan Malaysia ecologist Dr Shukor Md Nor said the catch

from the expedition was low, showing that the area was still " recovering " .

 

The traps yielded several common tree shrews, long-tailed giant rats and

Malaysian field rats, while the mist nets caught a few common bats — all of

which are hardy species adapted to surviving harsh conditions.

 

" It is more difficult for animal populations to naturally ‘replenish’

themselves compared to plants in disturbed forests like this, especially

since it is surrounded by palm oil estates. "

 

" While smaller mammals can probably find their way back, chances are, large

mammals may never be found here again, " said Dr Shukor.

 

Creatures that swim

 

A few small streams which break off from Sungai Bernam flow across the

reserve. During the dry season, like last month, the streams dry up to

barely a trickle.

 

Laden with a 15kg backpack electrofisher, UKM ichthyologist Abdullah Samat

and his team clambered down steep ravines to reach the rivers.

 

The electrofisher, which is worn like a backpack, uses a weak electric pulse

(about 400 volts) to stun freshwater fish in streams less than two metres

deep.

 

When stunned, the fish float motionlessly for a few seconds, during which it

is netted. They are identified, counted and weighed.

 

Abdullah Samat, who has studied fish since 1985, said that most fish caught

at Bukit Belata were small and common, like fighting fish, snakeheads, barb

fish, seluang and catfish.

 

" There is no previous baseline data on fish here, so we don’t know if the

population is increasing or decreasing. My guess is, the fish population

dwindles like this every dry season, so there may not be anything to be

alarmed about. "

 

" It usually balances out. When the river dries up, it’s easy for birds to

catch the fish. But then there is also more resources for the fish that are

left, so they multiply fast, " he said, adding that they were also an

indicator of water quality.

 

Moss, ferns and all things green

 

Peering under rocks and roots, UKM postgraduate student Ong Lai Peng gazed

intently at tiny plants most of us walk by without a second glance — mosses.

 

" In a dry forest like this, you have to really search to find mosses. You

have to know where to look, " she said, saying mosses were important for

water catchment.

 

Elsewhere, the higher plants team led by Dr Kamaruddin measured every tree

with diameters over 5cm within a randomly selected 100m by 100m area. From

there, its biomass was calculated.

 

Kamaruddin said that a forest area’s biomass was an indicator of

productivity and economic value, and a " healthy " forest would have one of

about 400 tonnes per hectare.

 

The team also did an area survey to find out whether plants were common,

rare, endemic or introduced. A checklist of over 300 species was compiled.

 

With a wistful smile, Kamaruddin said Bukit Belata was less interesting than

other forests he had seen.

 

" It has been very heavily logged, perhaps without proper supervision. We

found only two species of ginger here. A pristine forest would have a lot

more. "

 

Buzzing, flying, crawling insects

 

" Too bad it’s a full moon tonight. We’ll get some insects, but not many, "

said UKM insect researcher Dr Norela Sulaiman looking up at the clear night

sky.

 

Dr Norela explained that moonless nights were best for data collection

because insects would mistake the artificial light from light-traps for the

moon, and come a-buzzing.

 

A light trap is made out of a large piece of thin white cloth stretched to

form a three-walled " house " and a 160-watt mercury menthol.

 

Because insects are at the bottom of the food chain, Dr Norela said a

thriving population indicated a healthy ecosystem. As pollinators they are

indispensable to restoring the balance of disturbed forests.

 

Although the light trap was swarming with insects like cicadas, stick

insects, moths and grasshoppers, Dr Norela said it was nothing compared to

the amount of insects caught at primary forests.

 

Invading every part of the forest were legions of termites, and hot on their

trail were Universiti Putra Malaysia termite authority Dr Ahmad Said Sajap.

 

He explained that termite population sizes according to species showed how

far the forest was regenerating.

 

" In a disturbed forest, dead trees are abundant. So there will be a lot of

wood termites compared to a primary forest, which will have more soil

termites, " he said.

 

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