Copyright © 2010 Peter Martin Rhind
Plant Formations in the Sumatran BioProvince
Peter Martin Rhind
Sumatran Lowland Dipterocarp Forest
These luxuriant forests are some of the most diverse on Earth with comparable levels of
species diversity to the richest forests in Borneo and New Guinea and comprise over 100
species of dipterocarps, six of which are endemic. Some of the mature parts can have up
to four distinct tree stories as well as shrub and herbaceous layers. The emergent trees,
which can reach heights of 60 m, are mainly dominated by dipterocarps such as
Anisoptera costata, Dipterocarpus crinitus, Hopea dryobalanoides, Parashorea lucida and
Shorea macrocarpa. Other important upper canopy trees are Dyera costulata, Fragraea
gigantea, Koompassia malaccensis, Mangifera rigida, Myristica gigantea, Polyathia
hypoleuca and the endemic Heritiera sumatrana (Sterculiaceae), Horsfieldia triandra
(Myristicaceae) and Polyalthia sumatrana (Annonaceae). Among the many trees of the
sub-canopy are Aporusa elmeri, Dacryodes rugosa, Diospyros buxifolia, Diplospora
singularis, Drypetes longifolia, Gironniera hirta, Nephelium cuspidatum, Timonius
hydrangefolius and Xanthophyllum elmeri, while smaller trees of up to 15 m include an
abundance of Aglaia tomentosa, Aporosa frutiscens, Baccaurea javonica, Croton
oblongus, Fordia johorensis and Koilodepas glanduligerum. The endemic small tree
Baccaurea sumatrana (Euphorbiaceae) like many other trees of these forests produces
flowers and fruit at the base of its trunk - a phenomenon known as cauliflory. Other
endemic small trees are Casearia cuspidata (Flacourtiaceae), Daphniphyllum
sumatraense (Daphniphyllaceae), Diplycosia apiculifera (Ericaceae) and Gomphandra
fusiformis (Icacinaceae).
In the undergrowth shrubs such as Agrostistachys longifolia, Gonocaryum gracile,
Psychotria robusta and Rinorea anguifera are common as is the small tree fern Cyathea
moluccana and palms like Licuala ferruginea and Pinanga malaiana. Endemic shrubs
include Arthrophyllum papyraceum (Araliaceae), Clethra sumatrana (Clethraceae), Saraca
tubiflora (Fabaceae) and Thottea reniloba (Aristolochiaceae). Lianas and climbers are
common especially climbing palms mostly represented by rattans like Calamus flabellatus,
Daemonorops depressiuscula and Korthalsia rigida, while other climbing species include
Agelaea macrophylla, Fissistigma kentii, Hugonia costata, Salacia macrophylla,
Sarcostigma paniculata, Smilax leucophylla, Uncaria calophylla, Willughbeia firma and
endemic Aristolochia singalangensis (Aristolochiaceae) and Erycibe ramiflora
(Convolvulaceae). On the ground some of the most common species are Hanguana
malayana, Labisia pumila, several orchids such as Cystorchis saceosepala and ferns like
Lindsaea doryphora. These forests are also famously know as habitat for the plant with the
world’s largest flower (Rafflesia arnoldii), which is a parasite of the vine Tetrastigma, and
the plant with the world’s tallest flowers, the endemic Amorphophallus titanium (Araceae).
This magnificent arum has flowers up to 2 m tall and produces a fetid odor that attracts
small bees that act as pollinators.
Sumatran Riparian Forest
These forests, confined to riverbanks, undergo temporary flooding during heavy rain. They
show considerable floristic diversity and vary according to location and flooding regime. On
the west coast the enormous Canarium pseudodecumanum is often the dominant
emergent species reaching heights of up to 50 m, while the main canopy trees, at heights
of 25 m, include Antiaris toxicaria, Blumeodendron kursii, Dracontomelon dae, Pometia
pinnata, Pterospermum javanicum, Santiria apiculata and the endemic Neoscortechinia
sumatrensis (Euphorbiaceae). In southern areas other species may dominate including
Copyright © 2010 Peter Martin Rhind
Alstonia spathulata, Canthium dicoccum, Dillenia excelsa, Ficus retusa, Gluta renghas,
Kayea ferruginea, Koompassia excelsa, Myristica elliptica, Neesia malayana and several
endemic species like Mangifera gedeba (Anacardiaceae), Shorea sumatrana and Vatica
venulosa (Dipterocardiaceae).
Sumatran Swamp Forest
These forests occur in areas that are periodically flooded for relatively long periods of up to
four months or more, and their floristic composition varies according to factors such as
frequency and duration of flooding. As a result they are much more varied than forests of
well-drained ground. In east Sumatra the main canopy trees are Artocarpus kemando,
Baccaurea bracteata, Blumeodendron tokbrai, Campnospermum auriculatum, Mangifera
paludosa and Parartocarpus venenosus. These can reach heights of up the 25 m or so,
but often towering above these are various emergents like Alstonia pneumatophora and
several dipterocarps such as Dipterocarpus apterus and Shorea balangeran that can
reach 50 m or more. Among the associated endemic trees are Casearia gigantifolia
(Flacourtiaceae) and Vatica teysmanniana (Dipterocarpaceae). In the undergrowth palms
like Eleiodoxa conferta, Licuala spinosa, Oncosperma tigillarum are common as are
various rattans such as Calamus caesius, Daemonorops geniculata and Korthalsia
flagellaris. Shrubs may be present including the endemic Erycibe sumatrensis
(Convolvulaceae). Ferns are also characteristic and besides Stenochlaena palustris, a
climbing species with edible shoots, there are species such as Mesophlebion
chlamydophorum, Microsorum musifolium, Paragramma longifolia, Pyrrosia lanceolata,
Vittaria elongata, and in more open areas tree ferns like Cyathea contaminan. At ground
level, not surprisingly, members of the Cyperaceae are common and may include
Thoracostachyum bancanum and the endemic Scleria sumatrensis.
Sumatran Peat Swamp Forest
Mainly confined to the east coast at the central and southern parts of the island, these
forests are particularly abundant from the Musi delta to the Siak River. The peat deposits
are usually about 50 cm deep but can be up to 20 m in places, and as a result of the low
nutrient status and high acidity of these soils their floras are not as species-rich or as rich
in endemics as other forests. Their floristic composition varies from place to place, but in
southern Sumatra the most representative canopy trees are Campnospermum coriaceum,
Durio carinatus, Mezzettia leptopoda, Santiria laevigata, Tetramerista glabra and Xylopia
fusca. These reach heights of 35 m, but exceeding these by a further 15 m or so are
various emergents like Dyera lowii and Shorea teijsmanniana. Among the many smaller,
sub-canopy trees are Blumeodendron tokbrai, Combretocarpus rotundatus, Parastemon
urophyllus, Tetractomia obovata, the endemic Neoscortechinia sumatrensis
(Euphorbiaceae) and numerous species of Diospyros. The few palms include the
emergent Livistonia hasseltii and the bright-red sealing wax palm Cyrtostachys lakka.
Shrubs in the undergrowth are mostly Antidesmus montanum, Dacryodes rostrata,
Eugenia setosa, Goniothalamus malayanus, Ixora malayana and Memecylon oligoneura.
However, the flora that is specific to peat swamps is very limited, but includes, for
example, the endemic dipterocarp Vatica teijmanniana (Dipterocarpaceae). Some of these
peat swamp forests are described as pole forests because of the dominance of long
straight trees.
Sumatran Hill Forest
In certain places, such as the Barisan Hills, the forest between altitudes of about 150-500
m has a different species composition from lowland forests. They are still classed as
dipterocarp forests and have canopies reaching 40 m or so. The emergent species reach
heights of 55 m and typically include Shorea bracteolate, S. gibbosa and S. hopefolia,
Copyright © 2010 Peter Martin Rhind
while the canopy may include Albizia spendens, Alstonia scholaris, Artocarpus
anisophyllus, Magnolia elegans, Whitfordiodendron atropurpurea and the endemic
Parashorea aptera (Dipterocarpaceae). The middle and lower tiers show the appearance
or greater abundance of Aidia cochinchinensis, Chisocheton patens, Crypteronia griffithii,
Ctenolophon parvifolius, Diospyros lanceifolia, Gymnacranthera farquhariana, Horsfieldia
polyspherula, Kitabalia maingayi, Pellacalyx lobbii and the endemic Knema lampongensis
(Myristicaceae). Other endemic trees include Knema sumatrana (Myristicaceae), Shorea
conica and Vatica obovata (Dipterocarpaceae). At ground level, the steep slopes are one
of the favourite habitats of Rafflesiaceae. Species include Rafflesia arnoldi, the endemic R.
gadutensis and the more modest but just as fascinating Rhizanthes zippelii.
Sumatran Submontane Forest
These forests range in altitude from about 800 to 1400 m and can be just as majestic as
the lowland forests with emergent trees reaching heights of 50 m or so, and many of the
trees have large buttresses. This is despite the fact that dipterocarps are far less common
and is largely superseded in terms of dominance by the Clusiaceae, Euphorbiaceae,
Fagaceae and Myrtaceae. Lauraceae, on the other hand, which you would expect to be
one of the dominant families of these forests, is not as prominent on Sumatra. The
characteristic upper canopy and emergent species include Altingia excelsa, Drypetes
minahassae, Lithocarpus hystrix, Neesia altissima, Parkia singularis, Podocarpus
imbricatus, Quercus oidocarpa, Santiria laevigata, Sarcosperma paniculatum, Shorea
platyclados and Toona sinensis. There are also numerous strangling figs such as Ficus
distica and F. elastica. In the sub-canopy between heights of 25 to 30 m the Fagaceae
and Myrtaceae become even more pronounced with species such as Castanopsis
tungurrut, Lithocarpus elegans, Quercus longiflora and at least 20 species of Eugenia -
species from other families include Casearia tuberculata, Chionanthus exycarpus,
Cryptocarya ferrea, Dacrydium elatum, Engelhardtia serrata, Radermachera pinnata,
Talauma candolei, Terminalia myriocarpa and endemics like Michelia salicifolia
(Magnoliaceae) and Trevesia arborea (Araliaceae). Smaller trees and shrubs include
Ardisia blumii, Bennettiodendron leprosipes, Canthium horridum, Diospyros
subrhomboides, Ellipanthus tomentosus, Garcinia urophylla, Symplocos fasciculate and a
number of endemics such as Dehaasia sumatrana, Gomphandra fusiformis (Lauraceae)
and Vaccinium gracilipes (Ericaceae). Tree ferns are locally abundant but mainly
represented by Cyathea hymenoides and the endemic Cyathea alderwereltii
(Cyatheaceae). Most of the lanoid species are similar to those of lowland forests, but
Chilocarpus costatus, Tetrastigma lanceolata, Uncaria elliptica and Ziziphus horsfieldii
appear to be characteristic of the sub-montane zones. Characteristic ground layer species
are Crytandra pilosa, Gomphostemma microcalyx, Pleomele angustifolia, Phrynium
capitatum and Sarcandra glabra. Grasses are rare but may include Oplismenus
compositus. Among the endemic herbaceous flora is Gomphostemma dolichobotrys
(Lamiaceae).
Sumatran Montane Forest
These forests occur between altitudes of about 1400 and 1900 m and can be seen, for
example, on Mount Kerinei (Sumatra’s highest mountain), and an active volcano. They
usually consist of two tree layers - the canopy that reaches heights of 30 m and a sub-
canopy between 10 and 20 m. Below this is a shrub layer ranging in height from 5 to 10 m.
Fagaceae (including Lithocarpus pallidus and Quercus gemelliflora), Lauraceae (including
Litsea tuberculata), Myrtaceae (including several species of Eugenia), some Theaceae
(including Haemocharis buxifolia and Schima wallichii) and a number of Sapotaceae
constitute the main upper canopy species. In places the endemic Trevesia sumatrana
(Araliaceae) grows gregariously by virtue of its root and stem-suckers. Other endemic
Copyright © 2010 Peter Martin Rhind
trees include Horsfieldia atjehensis (Myristicaceae) and Mastrix octandra (Cornaceae).
Common sub-canopy trees are Actinodaphne glomerulata, Chionanthus oxycarpus,
Cinnamomum subavenium, Cryptocarya densiflora, Distylium stellare, Drypetes
subsymetrica, Elaeocarpus mastersii, Eugenia longiflora, Ficus lanatus, Garcinia
gaudichaudii, Lindera subumbelliflora, Memecylon oleifolium, Notaphoebe umbelliflora and
Urophyllum arborescens. There are also many endemic small trees such as Brassaiopsis
sumatrana (Araliaceae ), Gomphandra dolichocarpa (Icacinaceae), Illicium sumatranum
(Illiciaceae), Xanthophyllum ancolanum (Polygalaceae), and several endemic tree ferns
like Cyathea senax and C. verrucosa (Cyatheaceae). Climbers are still relatively common
and include, for example, the endemic Passiflora sumatrana (Passifloraceae). There are
also many epiphytic species such as the endemic fern Pyrrosia asterosora
(Polypodiaceae). The undergrowth is typically very rich in Myrsinaceae (such as Ardisia
korthalsiana) and Rubiaceae (such as Hypobathrium microcarpum) but here also can be
found several endemics like Lithocarpus orbicularis (Fagaceae), Polygala sumatrana
(Polygalaceae), Rhododendron frey-wysslingii (Ericaceae) and Rubus banghamii
(Rosaceae). The endemic titan arum, Amorphophallus titanium (Araceae) also occurs at
these altitudes, and these forests form the main habitat of the magnifcent, endemic
parasites Rafflesia micropylora and R. gadutensis (Rafflesiaceae) where they parasitize
vines of the genus Tetrastigma. The herb layer mainly includes members of the
Gesneriaceae (such as Cyrtandra anisophylla), Liliaceae (such as Dianella ensifolia) and
Rubiaceae (such as Ophiorrhyza sansuinea). Other herbaceous ground layer species
include several grasses like Lophatherum gracile and Joinvillea borneensis, ferns such as
Diplazium cordifolium, and the endemic Trigonotis hirsuta (Boraginaceae), which seems to
be mainly confined to elephant trails.
Sumatran Upper Montane ‘Mossy’ Forest
These forests range roughly between altitudes of 1900 to 2500 m in a zone where the
cloud layer is relatively constant allowing moss and liverworts to flourish. On mountains
such as Sinabung and the Talamau this generally coincides with a belt of the endemic
Pandanus sumatranus (Pandanaceae), but the principal tree families are Fagaceae,
Mystaceae and Theaceae. Other abundant canopy trees are Acronodia punctata,
Lithocarpus suffruticosus, Symingtonia populnea and Vernonia arborea, which can reach
heights of 25 m. Other noteworthy trees of the canopy are the three endemic species
Glochidion lutescens (Phyllanthaceae), Rhododendron atjehense (Ericaceae) and
Quercus steenisii (Fagaceae). Characteristic trees of the underlying layers are Michelia
salicifolia, Saurauia micrantha, Weinmannia blumei and the endemic Symplocos robinsonii
(Symplocaceae). Most trees are covered in a thick layer of epiphytic mosses and branches
are usually festooned with Usnea lichens. Another characteristic feature of these forests is
the abundance of aerial, epiphytic shrubs of the family Ericaceae such as the endemic
Diplycosia cinnabarina, Rhododendron pibigermen and Vaccinium bartlettii, while other
epiphytes include various endemic ferns of the genus Selliguea (Polypodiaceae) such as
S. bakeri, S. brooksii and S. pseudoacrostichum. The shrub layer is often dominated by
Ardisia javanica, while other less common species include Casearia tuberculata, Ilex
triflora, Macropanax dispermus, Meliosma lanceolata, Myrica javonica, Neolitsea javonica,
Saurauia micrantha, Schima wallichii, Viburnum lutescens, various endemic ericoids like
Diplycosia tetramera and Rhododendron ridleyi (Ericaceae), and the endemic tree ferns
Cyathea punctulata and C. trachypoda (Cyatheaceae), although neither of these is more
than about 50 cm tall. On the ground common species are Calanthe flava, sedges like
Carex cruciata and C. myosorus and ferns such as Asplenium caudatum, Athyrium
gedeanum, Belvisia mucronata and Dryopteris poleacea.
Copyright © 2010 Peter Martin Rhind
Sumatran Subalpine Forest
Above the upper montane forest on Mt Kerinii from about 2400 to 2700 m is a peculiar
zone dominated by ferns of the family Gleicheniaceae such as Dicranopteris pubigera and
Gleichenia volubilis. It has never been fully explained in ecological terms since above this
zone is another forest zone. These sub alpine forests, however, are very twisted and
stunted and rarely achieve more than about 15 m in height. The dominant canopy trees
are Ilex pleiobrachiata and Symplocos cochinchinensis var. sessilifolia, while a sub-canopy
at about 10 m largely consists of Ardisia laevigata, Meliosma lanceolata and the endemic
tree fern Cyathea trachypoda (Cyatheaceae). Below this are various shrubs including the
endemic Gaultheria abbreviata and Rhododendron aequabile (Ericaceae). The forest floor
is typically covered with the fern Plagogyria pycnophylla and the brambles Rubus
elongatus and R. alpestris. Among the endemic herbaceous species at this altitude is
Heracleaum sumatranum (Apiaceae).
Sumatran Rhododendron-Vaccinium Alpine Scrub
Above an altitude of about 3000 m most trees give way to a dense ericaceous scrub
characterized by Rhododendron retusum and the endemic Vaccinium miquelii (Ericaceae).
There are also many other endemic ericoids including Diplycosia atjehensis, D. glauciflora,
D. sumatrensis, Gaultheria acroleia, G. atjehensis, G. kemiriense, Rhododendron
adinophyllum, R. aequabile and R. sumatranum, while other endemic shrubs or small trees
include Lithocarpus atjehensis (Fagaceae) and Symplocos sumatrana (Symplocaceae).
One of the last trees to peter out is Myrica javanica but at these altidudes it grows no more
than about 8 m high. The ground layer consists of tussocky species like Carex hypsophyla
and Gahnia javanica and occasional herbs such as Anaphalis javanica and the two
endemic species Pyrola sumatranum (Pyrolaceae) and Senecio sumatrana (Asteraceae).
Ferns, such as Dicranopteris pubigera, Gleichenia volubilis and Hypolepis punctata, are
also present.
Further information required.
References
Bihari, M. & Lal, C. B. 1989. Species composition, density and basal cover of tropical
rainforest of central Sumatra. Tropical Ecology, 30: 118-137.
Campbell, D. G. & Hammond, H. D. 1989. Floristic Inventory of Tropical Countries. The
New York Botanical Garden.
Chapman, V. J. 1977. Wet coastal formations of Indio-Malesia and Papua New Guinea. In:
Ecosystems of the World 1 - Wet Coastal Ecosystems. Ed. V. J. Chapman. Elsevier
Scientific Publishing Company.
Kurz, S. 1876. A sketch of the vegetation of the Nicobar Islands. Journal of the Asiatic
Society of Bengal, 45: 105-164.
Laumonier, Y. 1997. The Vegetation and Physiography of Sumatra. Kluwer Academic
Press.
Leith, H. & Werger, M. J. A. 1989. Ecosystems of the World 14B - Tropical Rain Forests.
Elsevier Scientific Publishing Company.
Copyright © 2010 Peter Martin Rhind
Ohsawa, M., Nainggolan, P. H. J., Tanaka, N. & Anwar, C. 1985. Altitudinal zonation of
forest vegetation on Mount Kerinci, Sumatra: with comparisons to zonation in temperate
regions of East Asia. Journal of Tropical Ecology, 1: 193-216.
Steenis, C. G. G. J. van. 1957. Outline of the vegetation types in Indonesia and some
adjacent regions. Proceedings of the Pacific Scientific Congress, 8: 61-97.
Thothathri, K. 1962. Contribution to the flora of the Andaman and Nicobar islands. Bulletin
of the Botanical Survey of India, 4: 281-296.
Whitten, T., Damanik, S. J., Anwar, J. & Hisyam, N. 2000. The Ecology of Sumatra.
Periplus.
Dostları ilə paylaş: |