Parashorea malaanonan Forest
The following is an
excerpt of JED Fox's PhD thesis. The article stays fairly true to the original
with minor changes. Most measurements are
changed to the Metric System.
Mata Mull Hill Silabukan
FR Banggi Is Last
Coastal areas of Darvel Bay contained a high
proportion of this species with few other trees growing as emergents. The Mostyn
area, cleared in the early 1950s for the establishment of oil palm
plantations, where porous loamy soils are developed on volcanic basalt lava, had
a timber stand exceeding 2000 cu. ft/acre (130 cu. m/ha) with 80% being P. malaanonan
1952). Further north on hilly ground in the Silam area with soils derived from
the Basement Complex, coastal areas yielded 90–98% of the type species (Walton
The Forest in Mt. Silam, Lahad Datu
Stocking data for plots totalling 3.4 acre (1.4 ha)
enumerated from 12 ins girth (10 cm diam) in the Silam area showed that P.
malaanonan the most abundant large tree with 38% of trees over 6 ft and 54%
of those over 9 ft. girth. Other emergent species are typically Shorea
guiso (SB) and Hopea sangal
(though this species is often small) with the Rubroshorea species such as S. leprosula, S. parvifolia and S. johorensis.
absent in the Silam area and the most common species of the main canopy are
Hopea sangal, Cynometra elmeri, small trees of the emergent species, large Diospyros
spp., Eugenia [Syzygium]
Meiogyne viragata, Sympetalandra borneensis,
and Dialium platysepalum. In the lower
canopies, the genus Diospyros is well
represented, and Aglaia, Dillenia,
Hydnocarpus, Meiogyne, Paranephelium,
and Teijsmanniodendron are also
Individual large trees occur of 9–12 ft girth (90–120 cm diameter) and 160
ft (50 m) or more in height. Dryobalanops
lanceolata, Dipterocarpus spp. and Koompassia
excelsa are scarce.
The unfelled forest just above the sea at Silam is
almost pure S. guiso as
are some of the other Darvel Bay areas [see
The Forest at Lormalong Settlement Scheme, Mostyn,
The Lormalong Settlement Scheme near Mostyn where the
chert spilite is adjacent to basalt carried a similar forest on low lying land
with P. malaanonan, S. guiso, and H.
sangal. Other large tree species in this area were the dipterocarpsS. parvifolia, S. leprosula, S. seminis (SB),
H. nervosa, also Barringtonia anacardifolia, Eniscosanthum grandifolium, Alangium
griffithii and Plachonia
valida. The lower Tingkayu River area, passing through the Chert Spilite
Formation and felled over in late 1960s had - in addition to P. malaanonan - S. argentifolia, S. seminis, D. caudiferus and
Koordersiodendron pinnatum, Dracontomelon puberulum and Planchonia.
Higher up the Tingkayu on the alluvium, Eusideroxylon
zwageri was a constituent of an essentially similar forest with the
following other non-dipterocarps as trees of the main canopy: Ganua
kingii, Irvingia malayana, Castanopsis sp.,
Beilschmiedia tawahense and Mallotus
Plots laid down in the Mostyn area on different soils
(A.R.R.B. 1960) showed that there were few specific differences but Dipterocarpus
was absent on the volcanic soil. More details work on the only remaining forest
on basalt (Madai FR) in the are showed the preponderance of Parashorea
malaanonan. A relascope survey of 158 acres (64 ha) gave a total basal area
as 139 sq. ft./acre with stem 5.8 stems over 8 ft girth of basal area 53 sq.ft. P. malaanonan comprised 31% of all stems and 62% of those
over 8 ft girth gave the following stocking values for stems over 12 ins. girth.
A complete stand table for 2 plots totalling 5 acres
(2 ha) of this forest showed that, as on the Chert Spilite, Eusideroxylon
is absent and Dr. lanceolata occurs
mainly as smaller trees. Shorea pauciflora,
at least locally, is the commonest emergent associate of P. malaanonan.
The Forest of Timbun
The forest of Timbun Mata Island on Chert Spilite
Formation also belong mainly to this type. P.
malaanonan is locally gregarious on steep slopes with S.
guiso, Cynometra elmeri, Pterocymbium tinctorum and
Pterospermum stapfianum (the two latter seral species suggesting frequent
windfalls), also with palms and liana abundant. On less steep slopes, though
still the predominant species, P.
malaanonan is found in association with Rubroshorea species
S. johorensis, S. leprosula, S. smithiana, and
S. ovalis and, infrequently Dr.
lanceolata and D. caudiferus.
Local occurrence of Drypetes /Cynometra /Dialium
on dry, rounded hills with P. malaanonan
absent may represent late secondary forest following fire. Diospyros
macrophylla is the commonest species of the genus on Timbun Mata, and in the Darvel Bay area generally where perhaps
the genus reaches its greatest abundance in both species and density in Sabah.
This species was one of the most abundant species of non-dipterocarps recorded
in RP 233 at Silam, which covered 30 acres (12 ha) along with Koordensiodendron
pinnatum, Phoebe macrophylla, Nephelium mutabile, Neonauclea bernardoi,
Lophopetalum javanicum and Dillenia
The Forest of Mull Hill, Tawau
The olivine basalts of the Tawau area have different
types, e.g. Type C on the flatter areas, Type
E on steep slopes marginal with Type F. All are deficient in Dipterocarpus however, and in this respect similar to the Madai
forests. In contrast the forest on Mull Hill, a basic intrusion in the
Tawau area, is floristically similar to Madai basalt.
P. malaanonan and S. pauciflora are
the commonest larger species, S. guiso, and Drypetes kikir (cf
Drypetes on Timbun Mata), are present and nearby are Scaphium
longipetiolatum, Shorea symingtonii (An) and S. superba (SB).
Data from 4 plots of 1 acre (1.6 ha) for the forest at Tangah
Nipah, east of Lahad Datu on the Tabanak Conglomerate Formation, showed that the
genera Dipterocarpus, Dryobalanops
were all absent in this area where Shorea
guiso, Cynometra elmeri, Koordersiodendron pinnatum and Sympetalandra
borneensis were present as
associates of P. malaanonan, with
several Rubroshorea species present, including S.
argentifolia locally abundant. North
of Lahad Datu, across the Segama River, on Labang Formation, Type A merges with Type
B. In the area felled 1967–68 by Timber Producers of Sabah part contained
Type A species. P. malaanonan, Hopea
sangal, Cynometra elmeri,
tomentella, Eusideroxylon zwageri, Dryobalanops lanceolata with Dipterocarpus
spp. occurred in another part.
The Forest in Silabukan
FR, Lahad Datu
Further east of Lahad Datu in Silabukan
FR, the P.
malaanonan type is represented in the Bakapit Catchment area. A relascope
survey in Block 11 covering 173 acres (70 ha) of V.J.R. No. 14 (A.R.R.B. 1964)
gave total basal area over 12 ins as 119 sq. ft/acre with 3.5 stems over 8 ft.
girth of basal area 29 sq. ft. The geology of this area is rather mixed being
described as the Tungku Formation, with P.
malaanonan forests occurring on volcanic breccia. P.
malaanonan does not occurs on
the carbonaceous sandstones and clays with conglomerates, further east and north
in Silabukan FR, while in the hills of the Bagahak Range, Type
E is predominant. Type A reappears on Togopoi Formation at the end of the
East of Silabukan FR coastal forests on podsols at
Sabahat are similar to, but taller than, those on ultrabasic at Malawali
with presence of the Anthoshorea species
S. bracteolata and S. gratissima.
These are similar to forests in coastal Pahang described by Beveridge (1953).
They occur as emergents to 30 m above a low scrub tangle on white sands just
behind the Casuarina equisetifolia
fringe at Sabahat, whereas on Malawali they found on slopes (where
Gymnostoma nobile is absent) with Eugenia
alcine in a low forest to 20 m. Shorea
bracteolata is also present elsewhere on the northern islands under Gymnostoma
with Callophyllum obliquinervium, Santiria
The Forest in Banggi Island
The lowland forest on Banggi Island has affinities
with Darvel Bay P. malaanonan forest.
This species and S. guiso, Hopea sangal
and Koordersiodendron pinnatum
are all present, but the most characteristic tree is Dipterocarpus
warburgii (elsewhere a tree of riverine swamps,
see here), and D.
gracilis is also common. Coastal limestone forests also have affinities (see
here). One further forest requiring mention is the
coastal association at Kampong Sibumbong, Banggi Island, of S.
guiso, S. bracteolata, Cynometra elmeri, Koordersiodendron pinnatum,
Dipterocarpus gracilis and Semeocarpus sp. as large
trees. This merges inland with an ultrabasic forests with dipterocarps Cotylelobium
melanoxylon, Vatica papuana and V.
umbonata present as small trees under an emergent canopy of Gymnostoma
The P. malaanonan type of dipterocarp forest is probably the most commercially
valuable. The main areas of managed forest containing this type are parts of
Silabukan FR, Silam Extension and Ulu Segama FR and parts of
Tingkayu FR. The
main occurrence is coastal and is association with comparatively good soils and