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Exploration, collection, and conservation of
PROS SEM NAS MASY BIODIV INDON
Volume 1, Nomor 3, Juni 2015
Halaman: 428-433
ISSN: 2407-8050
DOI: 10.13057/psnmbi/m010308
Exploration, collection, and conservation of dipterocarps in Riau
Islands
Eksplorasi, koleksi dan konservasi jenis-jenis dipterokarpa di wilayah Riau Kepulauan
ATOK SUBIAKTO1,, HENTI HENDALASTUTI RACHMAT2,
1
Pusat Penelitian dan Pengembangan Konservasi dan Rehabilitasi, Badan Litbang Kehutanan, Kementerian Kehutanan dan Lingkungan Hidup. Jl.
Gunung Batu No. 5. PO Box 165, Bogor 16001, Jawa Barat. Tel. +62-251-8633234; 7520067. Fax. +62-251 8638111. ♥email: [email protected]
2
Balai Penelitian Teknologi Serat Tanaman Hutan, Kotak Pos 04/BKN Bangkinang 28401, Riau, Tel. +627627000121,Fax. 0762-21370; email:
[email protected]
Manuskrip diterima: 11 Februari2015. Revisi disetujui: 30 April2015.
Subiakto A, Rachmat HH. 2015. Eksplorasi, koleksi dan konservasi jenis-jenis dipterokarpa di wilayah Kepulauan Riau.Pros Sem Nas
Masy Biodiv Indon 1: 428-433.Kekayaan dan keragaman jenis-jenis dipterokarpa di daratan Sumatera sudah terdokumentasi dengan
baik dan dikenal di seluruh dunia.Namun demikian, keberadaan dan kekayaan jenis dipterokarpa pada rentetan pulau-pulau kecil sisi
timur daratan Sumatera yang berbatasan dengan Negara tetangga Malaysia dan Singapura belum tergali secara optimal, padahal dari
segi phyllogeography keberadaan jenis-jenis dimaksud pada pulau-pulau tersebut akan sangat menarik terutama dalam menggali sejarah
evolusi dan penyebaran. Penelitian ini bertujuan untukmencatat jenis-jenis dipterokarpa yang tumbuh di masing-masing lokasi dan
mengumpulkan materi genetik tumbuhan dari lokasi tersebut untuk dikembangkan di persemaian sebagai upaya koleksi dan pelestarian
jenis-jenis dipterokarpa secara exsitu. Kegiatan eksplorasi dilakukan di wilayah Kepulauan Riau mencakup P. Lingga, P. Singkep, P.
Bintan, P. Batam dan P. Bunguran (Kep. Natuna). Dari hasil eksplorasi tersebut tercatat jumlah jenis dipterokarpa yang ditemukan untuk
masing-masing pulau adalah 13 jenisdi P. Lingga, 2 jenis di P. Singkep, 7 jenis di P. Batam, 10 jenis di P. Bintan, dan 21 jenis di P.
Bunguran-Kepulauan Natuna. Jumlah material genetik berupa anakan alam yang terkoleksi bervariasi untuk setiap pulau, masingmasing berturut turut untuk Pulau Lingga, Bintan, Batam dan Bunguran-Kepulauan Natuna adalah 5900, 329, 25, 160. Anakan alam
diperlakukan di dalam sungkup berkelembapan tinggi dan memakai naungan yang selanjutnya pemberian naungan dikurangi secara
bertahap setelah hari ke-90.
Kata kunci: Eksplorasi, konservasi, dipterokarpa, Riau kepulauan
Subiakto A, Rachmat HH. 2015. Exploration, collection and conservation of dipterocarps in Riau Islands. Pros Sem Nas Masy Biodiv
Indon 1: 428-433. The diversity and richness of dipterocarps in Sumatra mainland have been well documented and known throughout
the world. On the other hand, the existence and the diversity of dipterocarps in small islands along the eastern part of Sumatera
mainland, which is directly bordered with neighboring countries of Malaysia and Singapore; have not been thoroughly studied.
Phyllogeography of dipterocarps species from small islands particularly in the eastern part of Sumatra region is important information to
reveal evolution history and their distribution. The aim of this research was to record the dipterocarps species growing naturally at each
islands surrounding eastern part of Sumatra mainland and to collect genetic materials for preservation and exsitu conservation effort.
Exploration was carried out in the island of Lingga, Singkep, Bintan, Batam, and Bunguran (Naturan Islands). Total number of the
species found for each of the island was as follow: Lingga 13 species, Singkep 2 species, Batam 7 species, Bintan 10 species, and
Bunguran 21 species. Number of genetic materials taken for each of the island was 5900, 329, 25, 160 consecutively for the island of
Lingga, Bintan, Batam and Bunguran. Wildings were kept and treated in shaded-high humidity nursery chamber and after 90 days of
care the shading was gradually decreased.
Keywords: Exploration, conservation, dipterocarps, Riau Islands
INTRODUCTION
The tropical rainforests in Southeast Asia are
characterized by a high species diversity of trees
(Whitmore 1984). Dipterocarpaceae is a tree family with
more than 450 species in 13 genera in Asia (Ashton 1982;
Londoño et al. 1995; Morton 1995). They confine to
tropical climates with a mean annual rainfall exceeding
1000 mm and/or dry season of less than six months. They
usually grow in mixed stands (Ashton 1988). The highest
species diversity of dipterocarps is observed in evergreen
rainforests in Peninsular Malaysia, Sumatra and Borneo
(Ashton 1982; Symington 1943; Whitten et al. 1987). In
particular, Borneo is the main center of dipterocarps with
the highest number of endemic species (155 species).Many
different species of dipterocarps can be found on entirely
different soil types and in nearly all of the different forest
types of Southeast Asia (Lamprecht 1989). Based on
theobservation of herbarium collection in Herbarium
Bogoriense (Purwaningsih 2004), in Indonesia most
SUBIAKTO & RACHMAT –Dipterocarps of Riau Island
dipterocarps were distributed in thealtitude of 0-500 m and
500-1000 m.
The Sundaland biogeographic region of South-East
Asia covers Malay Peninsula, the large islands of
Sumatera, Java, Borneo and smaller islands surrounding
them. Due to repeated sea level rises and falls, plant species
in Sundaland are likely to have experienced major cycles of
range expansion, vicariance and, probably, speciation.
Gathorne-Hardy et al. (2002) divided the rainforests in this
region into two geographic units: the Indian Ocean side of
Sumatera and the eastern part of Borneo. The importance
of the Sunda Shelf as a migration pathway for plants by
serving a savannah corridors have been proposed by a
number of previous authors (e.g. Morley 2000; Bird et al.
2005; Wurster et al. 2010).Several phylogeographic
analyses have been carried out as a powerful tool to infer
past demographic.Even though many studies have been
carried out to dipterocarps population in Borneo and
Sumatera for various research objectives, which include
population expansionas well as population structure and
migration, there is lack information to those dipterocarps
growing in the small islands surrounding Sumatera and
Borneo or known as Riau Islands. The objectives of the
429
study were: (i) to identify dipterocarps species growing in
the Riau Islands; (ii) to collect genetic materials of the
species and transplant them at the Bogor nursery for
conservation purposes.
MATERIALS AND METHODS
Research area
Riau islands have thousands of islands with scenic
beaches and various forest formations. Several important
islands in this area are The Islands of Bintan, Batam,
Lingga, Singkep, and Natuna. The island of Batamand
Bintan lies within the central core group of islands, while
Lingga and Singkep are to the south of the main
archipelago. Up to the northeast between Borneo and
mainland Malaysia lies the Natuna Islands. The islands are
supposed to be important for the distribution and migration
of many plants and animals including dipterocarps.
Exploration and collection activities were carried out in
those 5 main islands of the archipelago.
Figure 1. Research site in Riau Islands: 1. Singkep, 2. Lingga, 3. Batam, 4. Bintan, and 5. Bunguran (Natuna Besar)
430
PROS SEM NAS MASY BIODIV INDON 1 (3): 428-433, Juni 2015
Methods
Species exploration
Field visits were conducted during January to
December 2013 to five main islands in Riau, namely;
Bintan, Batam, Lingga, Singkep, and Bunguran/ Natuna
Besar (Natuna Islands). Each exploration routes in every
island was determined purposively based on the discussion
and interview result with key local forester. The discussion
result would determine the most probable area for
dipterocarps exploration and collection in each of the
island. We ask a local forestry officer to guide our route of
exploration. In average, we spent 3-7 days of field visit in
each island and generally 2 days trip was needed for every
delineated route. Routes taken at each islands are as follow:
Since our objectives was to explore the presences of
dipterocarps species growing naturally in each island, we
did not conduct detailed and comprehensiveanalysis of
vegetation to identify the composition and abundance of
the species. We briefly recorded the data for the species
those were found along our designated transect line. We
explore at about 20 m to the right and 20 m to the left at
every 20 m interval of the transect axes in each line route
for each of the island. The length of each route was varied
to 3-7 km. We noted our finding on species and estimate of
number available and took some genetic materials to be
raised in nursery whatever available (seed, wildings,
cutting materials).
Collection and conservation effort
Collection and conservation of the species for each of
the island were conducted by propagating the species out of
their habitats, both vegetatively and generatively. For
generative materials, we took the available wildings present
at the exploration sites. Only those less than 20 cm were
taken to be transplanted at our nursery in Bogor, except for
D.aromatica in Lingga those size in average were 25-30
cm. Seedlings were pulled carefully to avoid the breakage
of their roots. We applied cutting propagation for
vegetative materials. Cutting materials were taken from the
50 cm-height or more dipterocarps wildings. We cut 10-15
cm of orthotropic branches and stored them immediately
into zipped plastic bag and sprayed periodically once in an
hour during transport from forest to hotel.
Cutting experiments and nurturing of the wildings
were conducted in the nursery of CRRDC, Bogor Indonesia. Cutting experiment was carried out based on the
previous KOFFCO technique that was proven to be
successful for many species of dipterocarps (Sakai et al.
2002; Subiakto et al. 2005).Wildings were kept in shaded
nursery chamber of 1-meter high shade. The shade consists
of 1 layer black netting roofing that would be able to
reduce the light intensity to about 25 %. Every week the
seedlings conditions were checked to determine the proper
time for further treatment. After keeping them under the
closed-shaded chamber for a period of 12weeks, the
plastics cover were opened and a month later the wildings
were moved out to a more open area in nursery. Watering
was done twice daily during their acclimatization stage in
the chamber, done once in the morning before 10.00 a.m.
and once in the late afternoon after 4.00 p.m to ensure
wildings receive enough water during their initial growing
stage.
Data analysis
The occurrence of dipterocarps in each island was
described by species by islands. Total numbers of survived
cutting and wilding for the conservation purposes was
described by definite numbers by genus.
RESULT AND DISCUSSION
Results
Species occurrence by island
Sumatera mainland has been known for its rich
biodiversity on dipterocarps. Historically, the area was
forested and owned enormous numbers of dipterocarps
species. Compare to those the mainland, small islands
surrounding Sumatera and Borneo (hereinafter refer to
Riau islands), is still lacking information for its potency
and biodiversity for their dipterocarps. Our exploration has
opened up the fact that those islands still maintain various
dipterocarps species grown naturally in their limited forest
cover. Species occurrence is shown in Table 2.
Collection and conservation effort
The study was not only carried out to explore the
dipterocarps grown naturally in each of island but also to
collect genetic materials to be transplanted outside their
natural habitat. This is necessary because deforestation and
or forest conversion were serious threats occurred in
islands. Table 3 showed numbers of genetic materials
collected in each of the islands by genus. The numbers
indicated current genetic materials survived and or grow
well in the nursery after 1-1.5 years of acclimatization. All
genetic materials have already been ready-to-plant stock
piles.
Discussion
Singkep is an island in the Lingga Archipelago. It is
separated from the east coast of Sumatra by the Berhala
Strait. Singkep has undergone vegetation destruction due to
extensive tin mining. Previous study by Sambas et al.
(1999) identified the forest in island as mixed dipterocarps
forest dominated by Dipterocarpus rigidus at higher crown
level. At that time it was also predicted that Dryobalanops
sumatrensis (known also as Dryobalanops aromatica) that
was relatively abundant at sapling level would become the
dominant species in the future. However, current
exploration found that forest cover had extremely changed
and only small patchy of forested land remained. We did
not observe the previous estimation of the domination of D.
sumatrensis. Other than D. sumatrensis, Shorea falcifera
and Shorea singkawang are the dipterocarps that still can
be found at the island but have no natural regeneration at
the time of exploration.
Lingga is the closest neighbor island of Singkep.
Compare to Singkep, Lingga maintain wider forested area
SUBIAKTO & RACHMAT –Dipterocarps of Riau Island
with better condition of flora and fauna. The biggest
reserved forest in Lingga known as Gunung Daik (Mt.
Daik) with reach 1206 m asl. and become the highest point
in the island.Among four localities explored, we found 13
species with high abundance both for mature and their
juveniles. Similar to those other neighboring islands,
Lingga is also facing serious threats for illegal logging,
mining, and encroachment. Our observation during field
trip recorded that illegal logging may be the cause for
species scarcity. With current exploitation rate, we might
not see any mature dipterocarps in the next 5-10 years.
Batam is located in the crossroad of international trade
which consequently makes they are as one of the centers of
economic developments in Indonesia. The development is
so fast that can give negative impacts on ecosystems
because its fast economic growth and development have
becoming a particular pressure for floral and faunal
diversity. As the result, we found very heavily patched and
fragmented forest area in the island of Batam. Shorea
curtisii and Shorea parvifolia are among the most common
species to meet in the area. However, as the intact forested
land is quite difficult to find, both species are more
common to see along road side in sub-urban area.
Whenever there is wider development of the city, the
dipterocarps of the island might disappear.
There are several reserved forests in Bintan Island,
however most of the area have been facing serious threats
of destruction caused by illegal logging, encroachment,
forest conversion, mining, oil palm plantation, rubber
plantation, and establishment of housing and villages.
Forested area of Bintan Island determined to be only 22%.
In Bintan, the good forest cover was in a limited area on
the hills namely Gunung Bintan (Mt. Bintan). Extensive
deforestation was occurred since long time ago where
Table 1. Exploration routes conducted in each of island
Name of
Islands
Localities
Singkep
Muncung reserved forest
Lingga
Sungai Resun
Sunngai Besar
Mt. Daik track
Tanda waterfalls
Batam
Muka Kuning
Sungai Ladi
Bukit Bagi
Bintan
Bukit Enau (Mt. Bintan North entry)
Bekapur (Mt. Bintan South entry)
Lagoi
Bunguran
(NatunaBesar)
Mt. Ranai reserved forest
Sekunyam
Semedang
Secondary forest in Bunguran Barat and
BunguranTimur
431
Table 2. The occurrence of dipterocarpsspecies in each of island
Island
Naturally growing species
Abundance
Singkep
Shorea falcifera
Shorea singkawang
++
+
Lingga
Shorea singkawang
Shorea curtisii
Shorea falcifera
Shore sp.1
Dipterocarpus graclis
Dipterocarpus eurincus
Dipterocarpus coreacius
Dipterocarpus rigidus
Dipterocarpus elongatus
Vaticaumbonata
Dryobalanops aromatica
Hopea mirtifolia
Cotylelobium melanoxynon
++
++++
++++
+++
+
+++
+++
+
++++
++++
++++
++++
++++
Batam
Shorea curtisii
Shorea acuminata
Shorea bracteolata
Shorea parvifolia
Dipterocarpus sp.
Vaticasp.1
Hopea beccariana
+++
+
+
+
+++
+
+
Bintan
Shorea curtisii
Shorea falcifera
Shorea leprosula
Shorea macroptera
Dipterocarpus sp.1
Dipterocarpus sp.2
Vatica sp.2
Vatica sp.3
Hopea mengerawan
Hopea sp.
+++
++++
+
+
+
+
+
+
+
+
Bunguran
(Natuna
Besar)
Shorea ovalis
Shorea falcifera
Shorea parvifolia
Shorea atrinervosa
Shorea scaberrida
Shorea curtisii
Shorea singkawang
Shorea materialis
Shorea sp.2
Shorea sp.3
Dipterocarpus vagineus
Dipterocarpus palembanica
Dipterocarpus eurincus
Dipterocarpus crinitus
Dipterocarpus costulatus
Dipterocarpus sp.
Vatica umbonata
Vatica teysmaniana
Hopea beccariana
Hopea mirtifolia
Cotylelobium lanceolatum
+
++++
+
+
+
+
++
++
++
++
++
+
++
++
+
+
+
+
++
+++
+
Notes: + = < 5 individuals; ++ = 6-10 individuals; +++ = 11 -15
individuals; ++++ = > 15 individuals
PROS SEM NAS MASY BIODIV INDON 1 (3): 428-433, Juni 2015
432
Table 3. Number of genetic materials collected by genus
Island
Genus
Singkep
-
Lingga
Shorea
Vatica
Dryobalanops
Hopea
Cotylelobium
Dipterocarpus
Batam
Shorea
Vatica
Hopea
Bintan
Bunguran
(NatunaBesar)
Collection of genetic materials
(wilding, cutting, seeds)
200
60
100
100
100
30
Notes
None juveniles available at the time of
exploration
Juveniles for particular species were abundant at
the time of exploration
10
5
10
The forested lands were patchy and fragmented,
mothers trees were often found along the side of
the road
Shorea
Vatica
Dipterocarpus
Hopea
300
10
9
10
Mt. Bintan was still in good condition however
the juveniles were abundant only for Shorea
species at the time of exploration
Shorea
Dipterocarpus
Hopea
Cotylelobium
120
10
20
10
Juveniles of most species were abundant,
however they were already too big (height>50
cm) to be transplanted to nursery in Bogor
forest were cleared for Uncaria gambir plantation followed
by rubber plantation. Secondary forests are now developed
into denser canopy with the vegetation type of mixed
dipterocarps forest (Gossling 2003). Among 5 reserved
forests in the island, Gunung Bintan (Kecil and Besar)
reserved forests are remained the best in term of biological
condition. Even though there are fewer disturbances to
Gunung Bintan, the remaining small fragmented forest
cover have been put the species into serious threats for the
extinction.Our study recorded at least there are 10 species
of dipterocarps grown naturally in Bintan. Considering its
small forested land, the numbers is somehow quite
interesting with Shorea falcifera seemed to be the most
abundance species occurred in the island.
Natuna Island in the South China Sea, retain
considerable pristine forest habitats, which support an
enormous diversity of flora and fauna. Comprehensive
surveys of its faunal diversity have been carried out and
determined the area as one of the biodiversity hotspot. Our
study focused to explore the diversity of dipterocarps
species in the biggest island namely Natuna Besar or
Bunguran. Bunguran Island is famous for its unspoiled
forested hill slopes of Gunung Ranai, the island's highest
topographical feature. The occurrence of forested area
together with its biodiversity is better compare to other four
explored islands. The condition might happen due to its
geographic position which is remote and difficult to be
accessed. Its remote and less access have been an effective
constrain for commercial timber activities by companies. In
the island, we found at least 21 species of dipterocarps with
the availability of natural regeneration. However we could
not bring many of the genetic because in average the
available wildings were more than 30 cm in height and it
would be too big to be transplanted in Bogor nursery.
Bigger wilding will have lower survival rate during
acclimatization.
Beyond our expectation, the forests in Riau Islands are
still keeping an enormous numbers of naturally growing
dipterocarps, however the future of dipterocarps remain
uncertain due to forest conversion. For all five explored
islands, we can collect and tend more than 1000 stock piles
in our nursery even though it doesn’t cover all existed
species from all the islands visited. Since the rate of habitat
change and modification are in the alarming level,
collecting and transplanting species out of its natural
habitat might be one of the conservation efforts to be done.
ACKNOWLEDGMENTS
Authors are grateful to KOMATSU Indonesia and
Conservation
and
Rehabilitation
Research
and
Development Center collaboration project for funding all
the expenses during field trip. We are also grateful to
Forestry District Officer Natuna for their help in field trip
guidance.
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