Tuesday, November 11, 1997

Environment

Vital to save peat swamps

By Tan Cheng Li

SOME 800,000ha of forest and plantations burned in Indonesia last month. But it wasn't just any forest. It was peat swamp forest, in particular. At the same time, some 160ha of peat forest was also ablaze in Kampung Penadah, Pekan, in Pahang. It took two weeks for the firemen to douse the flames.

There is a pattern in these fires, say wetlands experts. Peat swamp infernos have become more common in this region in recent years, according to Faizal Parish, executive director of conservation group Wetlands International Asia Pacific.

Faizal Parish: 'Peat swamp fires are becoming more common.'

"This was not the case up until 10 years ago," he says. The advent of peat swamp fires, he adds, parallels logging and draining of water from peat swamps.

In Indonesia, some of the more persistent fires over the years have been in peat swamps. In 1982, the over 3.5 million hectares of forest burnt in east Kalimantan included 550,000ha of peat swamp. A 1987 fire destroyed another 12,000ha at two sites in south Sumatra.

In both cases, says Parish, the worst affected were sites which had been changed by drainage, logging and adjacent land development — activities which influence the water tables in the peat swamps.

"Lowering water tables and opening up the forest canopy promotes the risk of fire in peat soils."

And if peat swamps in Malaysia continue to be drained of their life-sustaining water, Indonesia's experience will be replicated here, he warns. "The fires will be burning here and not in Indonesia."

To a certain extent, they already have. In October 1995, 16ha of the Bukit Tunggal Forest Reserve, adjacent to the North Selangor Peat Swamp Forest in Batang Berjuntai, went up in smoke. In early 1989, a fire at Batang Berjuntai raged for three months.

Wetlands International noted four blazes in Malaysia this year. There were two cases in Pekan, Pahang. Three months ago, tracts of land at the Raja Musa and Sungai Karang Forest Reserves which make up the North Selangor Peat Swamp Forest in Sabak Bernam, Selangor, also caught fire. Parts of the Kuala Langat North Peat Swamp, also in Selangor, were also ablaze between June and October.

Parish says in all the incidents, the fire had spread from nearby land which had been torched. Although there is insufficient documentation, he says up to 2,000ha could have been affected by fires in the last few months.

Peat swamps occur inland just beyond coastal mangroves, often spread over some 3km to 5km on the floodplain of rivers. They are characterised by an 8m to 20m thick layer of peat, which is mainly semi-decayed plant material accumulated over some 8,000 years. As long as the peaty soil is saturated with water, the swamp eco-system is in balance.

Draining of peat swamps for development will dry up the peat soil, making the forest vulnerable to fires, such as this blaze last month in Kampung Penadah, Pekan in Pahang.

But draining the peat swamp — for planting oil palm and rubber, logging, aquaculture, industrial and residential development, or to mine tin and peat — spells trouble. Canals dug into the peat, in effect, bleeds the swamp of the very medium that is its basis of existence.

When the water level recedes, the upper layer of plant material dries up, thus becoming combustible fuel.

Once a fire breaks out in peat swamps, it is an arduous task controlling it — flames often continue to smoulder underground, fed by the dried peat. In the recent Sumatran fires, Malaysian fire-fighters resorted to digging out the smouldering coal.

In Manitoba, Canada, during the 70s, fire-fighters were still checking for flames five years after the fires were doused to identify hot spots not visible to the eye.

Even after a peat fire is put out, another threat emerges. The succession of vegetation such as lallang, often makes the site susceptible to fire once again.

Consequences of draining peat swamps

Peat fires in the region have aroused the concern of the standing committee of the Ramsar Convention on Wetlands, an international treaty on conservation and wise use of wetlands.

Says committee chairman Louise Lakos: "The members of this international conservation body drew attention to the fact that a large proportion of the area burning (in Indonesia) is peat swamp forest, which constitutes an important global wetland type which we cannot afford to lose. Time is short and action is needed urgently."

South-East Asian countries, particularly Indonesia and Malaysia, have over 20 million hectares or 60% of the world's tropical peatlands. In the recent Sumatran infernos, some of the largest fires had raged along the borders of the Berbak National Park, one of only two Indonesian Ramsar sites, and one which harbours about half of the virgin peat forest remaining on Sumatra.

(Ramsar sites are wetlands of international importance listed under the Ramsar Convention.)

"Fires on peatland are unique in that they create many times more smoke per hectare than other forest types, and they are almost impossible to extinguish without restoring the naturally high water levels in the swamps," says Jamil Hamzah, acting manager of Wetlands International.

Peat swamps are like giant sponges that absorb and soak up excessive rain and river water, thus controlling floods during the rainy season and releasing essential water supplies during the dry season. Haphazard development, however, will rob peat forest of this sponge-like feature.

And just like a sponge, you just need to press on one corner, and water will seep out.

"Thus, a single canal can potentially drain the whole swamp. Even one small agriculture scheme can endanger the whole peat swamp," says Parish.

And this is a feature of the current scenario. Because most peat reserves in Malaysia sit within larger unprotected state-owned forests, they are threatened by development in the surrounding areas.

Nearly all state-owned (termed state land) forests are earmarked for farms, plantations, residential estates or industrial sites — all of which requires the peat forest to be pumped dry.

Canals dug into peat soils will drain the forest of its life-sustaining water, making the forest vulnerable to fires. -- Picture by Wetlands International

Parish cites an example: In one reserve that looks intact as only the surrounding stateland forest is logged, a major drainage canal 20km long outside the reserve has lowered the water table by 2m. That, asserts Parish, will have an impact on the forest reserve.

Even in Pahang, which houses the country's most significant peat swamp, only a quarter of its 325,000ha peat swamp is protected as forest reserves.

To plug this inadequacy, Parish recommends that any drainage scheme in peat swamps undergo a broader study. If one part of the peat forest is to be drained, then an impermeable bund reaching deep into the soil should be built to cordon off the site to be developed. This, he says, will prevent water seepage from the remaining peatland.

In the long run, however, Parish asserts that peat swamps must be maintained as one operating unit: "It should be managed in a broader perspective, such as for multiple uses and not just for timber."

And because the survival of peat swamps depends on a naturally high water level to prevent the soil from drying out, the obvious thing to do is to avoid activities which require the swamps to be reclaimed.

Parish says this stand is supported by the Malaysian Agriculture Research and Development Institute (Mardi).

"After 30 years of studying how best to develop peat swamps, Mardi concluded that it is wiser not to because it will be expensive and difficult."

Mardi found appropriate uses to be conservation, sustainable forestry and agroforestry. Agriculture is to be avoided, unless there are already existing farms.

Logging is now considered a major cause of peat swamp depletion but Parish says the activity can be sustainable if cutters adhere to logging cycles and transport logs on rail tracks which will not affect the hydrology.

He says floating logs on canals is not advisable because waterways will drain the peat. However, a Wetlands International recommendation seven years ago that the canal system be banned in the North Selangor peat forest was never taken up by the State Government.

While some may argue that rail skids and the construction of bunds will incur heavier investment and may not be economically viable for small areas, Parish argues that not protecting the peat environment may be even more expensive.

"Currently, the culprits do not bear the costs resulting from fires, such as the cost of floods, loss of water supply, health effects and reduced productivity. It is the general population that is shouldering the burden."

In the long term, peat swamp loss will surely have repercussions extending beyond just a hazy sky. Drained or burnt peat swamps will lose their crucial functions: soaking and storing water to mitigate floods and as a water catchment; buffering coastal lands from the intrusion of salty marine water; filtering pollutants which will otherwise degrade lakes, rivers and groundwater; providing timber and non-timber products; and providing critical wildlife habitat, particularly for the endangered Sumatran rhinoceros.

Once dried, the peat will oxidise and break down, causing the soil to collapse. An area in Pontian, Johor, has subsided by 1.2m since it was drained in the early 70s. Once an area is lowered, flood problems may occur more frequently.

Just as important is the peat swamp's role as a carbon store. The semi-decayed vegetation locks up large amounts of carbon, thereby preventing it from escaping into the atmosphere as carbon dioxide, the chief culprit in global warming. About 15% of the global carbon store in peatlands can be found in tropical peat swamps.

"Prolonged peat fires are releasing a massive amount of carbon dioxide, contributing to global warming and long-term climate disruption," says Parish.

Once lost ...

Regeneration of a damaged peat swamp forest will not be easy; after all, it took some 7,000 years for the peat to form. While rehabilitation of peat swamps has been inadequately studied, Parish says current information indicates it may take some 50 years for a damaged forest to re-establish itself; that is, assuming that its hydrology was not significantly spoiled.

In Kelantan and Terengganu, there are vast tracts of land covered with only gelam (melaleuca or paperbark) trees.

"These were once rich peat swamps," says Parish, "but drainage for agriculture over the past 50 years has resulted in the existing degraded forest. Fires have certainly occurred here in the past, so now only the fire-resistant gelam trees are standing."

And that's exactly what will happen to the country's remaining peat swamps if these forests continue to be drained and filled. And Malaysia will be a source of choking haze, not just Indonesia.

Copyright © 1997 Star Publications (M) Bhd (No: 10894-D). All rights reserved.