Introduction
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Unsustainable extraction of Shorea
albida from Peat Swamp Forests.
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The
Andulau region straddles Brunei's administrative districts of Belait and
Tutong. The area is known for its inland Peat Swamp Forests, dominated by
Shorea albida, a species of dipterocarp know locally as "Alan". Towards
the north coast of Brunei, adjacent to the highway which runs between Bandar
Seri Begawan and Kuala Belait, the Alan forests are suffering severe
degradation due to a variety of causes, and inland the forests in the hilly
regions are being subjected to continuous, unsustainable logging.
Forestry
Shorea albida is a member of the Red Meranti
group. It can grow up to 70 metres in height, and has a large, open,
dome-shaped crown. The trunk is straight, the bark is deeply fissured, and
the heart wood is a rich, orange-brown colour.
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Ecological devastation of the S. albida
forest due to fire, logging, water extraction and sand mining.
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Accumulations of peat derived from this species can
reach up to 20 metres thick. The trees' height is greatest at the edge of
these peat domes, where they are known as "Alan Batu" (batu = stone);
however these forms tend to have a hollow heart. Nearer the centre of the
peat domes tree height may only reach 40 metres, and these forms are called
"Alan Bunga" (bunga = flower); the heart is not hollow and it is these trees
which are targeted for timber.
S. albida has been an important timber tree in
Brunei for decades. After extraction, natural reforestation can occur in the
Alan Bunga zones, but the Alan Batu tend not to regrow. There appears to be
no effort at sustainable forestry of this species and there is no
replanting. So these forests will continue to shrink in size.
Sand Mining
The main highway which crosses the flat, coastal
plains cuts across areas where the sediments underlying the peat are mainly
loose sand. Large areas of the Alan forests in this area have suffered
severe environmental degradation caused by forest fires, timber extraction
and sand mining.
The process of sand mining requires water to be pumped
out in order to access the sand deposits. Water extraction also occurred
during construction of the highway. Consequently the water table is being
slowly lowered and this has long term implications for the survival of the
peat swamp ecosystem and thus of S. albida itself. The amount of
degradation to which the forests near Sungei Liang have been subjected
amounts to total destruction of a fragile ecosystem.
Associated Flora
A stroll into the Alan forests is well worthwhile to
see the Fanged Pitcher-Plant (Nepenthes bicalcarata). The scientific
name of this exotic species comes from the two, distinctive structures
located on the underside of the lid, rather like the fangs of a viper.
The pitchers vary in form and colour depending on
their height from the forest floor. The ground pitchers are more orange in
colour and possess a pair of 'wings' facing the stem, while the aerial
pitchers are smoother in form, and generally green in colour. The pitcher
can grow up to 20 cm in length and 15 cm in diameter.
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Fungi of the forest floor
include the Bull's Eye Fungus Calostoma sp. (right). |
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As with some other pitcher plants, N. bicalcarata
shares a close relationship with some ant species which live towards the
base of the pitcher; the nature of this relationship is not well
understood.
The Alan forests are also a rich hunting ground for
enthusiasts of tropical fungi. In particular, keep an eye open for the
"Jelly Mushroom" which inhabits the forest floor - this has the appearance
of rather glutinous raw eggs !
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