Foreword to the Original Edition
Indonesia, a country which is developing rapidly, is actively engaged on a wide variety of development projects. The eventual aim of Indonesian National Development is to achieve harmony between man and his God, between mankind and his environment, between races and between human ideals in this world and joy in the world hereafter.
The increase in the pace of development brings the risk of pollution and environmental degradation such that the structure and function of ecosystems which support life can be irretrievably damaged. Wise development must be based on a knowledge of the environment as an entity so that we can achieve a guarantee for the well-being of this generation and for those generations to come.
Many ecology books have been written but until now there had been no book available specially written for a part of Southeast Asia. The Ecology of Sumatra is therefore extremely important for, armed with this, readers will be better able to understand the physical and biological characteristics of this island. If the environment is better understood then the exploitation of natural resources in the context of development can be managed in a more rational way.
The team which produced this book was comprised of the following authors: Dr. Jazanul Anwar, Ir. Sengly Janus Damanik, M.Sc and Ir. OK. Nazaruddin Hisyam, MS together with Dr. Anthony J. Whitten. The first three are Staff at the Centre for Environmental and Resource Studies, University of North Sumatra, and the last was consultant to the above centre under a United Nations Development Program/World Bank project (No. INS/78/056) for environmental education. The project was administered for the Government of the Republic of Indonesia by the State Ministry of Population and Environment.
We express great thanks to the authors for their many hours of work in the production of this book. We specially thank Dr. A.J. Whitten and his wife, Jane Whitten, M. Phil who have worked extremely hard in encouraging, guiding and helping the staff of the Centre for Environmental and Resource Studies and in producing the English edition of The Ecology of Sumatra. They receive our sincere congratulations.
Finally, we hope that this book will encourage the execution of detailed ecological investigations on Sumatra by a wide range of investigations.
|
April, 1984 |
Prof. Dr. A.P. Parlindungan, S.H. |
Preface to the Original Edition
It is with great pleasure that I write the preface to The Ecology of Sumatra because it has been one of the major activities of the Centre for Resource and Environmental Studies at the University of North Sumatra over the last two years.
At this time in Indonesia's history when environmental awareness has penetrated so far both into the minds of the common man and into government policy at the highest levels, we must remind ourselves that although ecology (unlike environmental science) does not always directly influence policy making, legislation, politics or planning, it is the foundation of environmental science. An understanding of the components of ecosystems and the manner in which they interact is central to studying the environment and to conducting resource management. The study of those interactions and their effects is the study of ecology.
The book has been written primarily for those concerned with conducting environmental impact analyses and related studies in Sumatra. Before now it has been more or less impossible for such people to find relevant information on Sumatran ecosystems to help them with their work and as such we hope that this book represents a significant step in the history of Indonesian environmental science. It is hoped that the book will also be enjoyed by those with a general interest in Sumatra and Southeast Asian natural history, such as lecturers, school teachers, students and travellers.
|
April, 1984 |
Prof. Dr. Abu Dardak |
Notes
All the references used in the preparation of this book are, or soon will be, in the Documentation and Information Unit collection at the Centre for Resource and Environmental Studies, University of North Sumatra. It is hoped that this material will be consulted by readers to deepen their knowledge of particular aspects of Sumatran ecology, and to improve the standard of environmental impact analyses and similar studies. Readers are encouraged to consult or order this material: to assist them, the three-number classification of each book, paper or report is shown after the reference. Details of costs, etc., can be obtained by writing to the Centre's Director.
Reflections on Sumatra: 1983-1998
CONTEXT
It had been hoped by many, not least myself, that the re-publication of this book would allow a thorough revision and updating of the material and of the lessons. Unfortunately, I was unable to raise the funds to do this and the publishers eventually decided that, in order to meet the commitments to its partners to complete the Ecology of Indonesia series, the current book should be published. In reviewing the text it has been evident that there were not many mistakes, but it is obviously out-of-date. I hope the mistakes have been removed. The referencing system was cumbersome (though done for a good reason) and has been changed to a more conventional format.
It is very unfortunate that funds are not yet available for the republication of the Indonesian version which has also been out of print for many years. The Indonesian versions of the Ecology of Indonesia series have always been the primary reason for engaging in so much work, and it is hoped that a source of funds will emerge after the publication of this book. It is always most gratifying to see grubby, well-thumbed copies of the Indonesian versions in libraries. However, Indonesia's various problems at this time may make a translation an invariable proposition.
GOOD NEWS
First, the good news. The awareness of, interest in and commitment to the wise use of biological resources on Sumatra have all grown tremendously. Non-governmental groups have become effective and increasingly-trusted partners of the government and international development agencies. The human capacity and environmental awareness in government has also increased substantially, though clearly not to the extent necessary. More Indonesian scientists are getting into the field in the major national parks and elsewhere, as well as publishing their results in good Indonesian journals such as Tropical Biodiversity. This is important since this scientific presence and publicity increases security for, and awareness of, these sensitive areas.
Some companies have shown foresight and responsibility by replanting and caring for mangrove and other forest trees after exploitation of the original resource, sometimes in cooperation with local communities, but these efforts are very much outweighed by other less thoughtful land practices. Other good news, such as fruitful cooperation between Indonesian and foreign scientists, the production of the RePPProT maps, a new national park, and the discovery of new species, are all described in the following annex on new publications.
BAD NEWS - LAND AND HABITATS
The bad, and desperately sad, news is that despite these improvements the exploitation of timber and every other biological and physical resource appears to have progressed without restraint, though not without complaint. Greed and haste have ruled supreme. If one could argue that the people of Sumatra had benefited, especially those who once used and lived near those resources, maybe the loss would be felt less acutely. But instead there are numerous reports of derisory or no compensation, intimidation, corruption, evasion and bending of regulations, and of opaque planning processes.
Gone are all but a very, very few of the grand and awe-inspiring dryland lowland forests. As Laumonier (1997) says in his new and authoritative book, "The current situation of the forests of Sumatra is quite clear. There is no intact [dryland] lowland forest left.... In a few decades, [even disturbed] lowland forests will have disappeared completely in Sumatra if logged-over forests are not maintained under sustainable management." Hill forests have also been affected and are currently being decimated by the frenetic forest exploitation which precedes the impending disappearance of such a resource and by local agricultural transformation. The original, natural forests now remain simply as memories in the minds of those lucky enough to have seen them. Those who didn't experience them don't know what they have lost. Will it be the case in a few years, if a complete revision of The Ecology of Sumatra is produced, that it will have to be written of the lowland forests, as in the recent The Ecology of Java and Bali, that "it is in some ways pointless to describe what is essentially an historical situation. There are remnant disturbed areas, however, and for the sake of encouraging some interest in and understanding of these the descriptions in this chapter are provided" (Whitten et al. 1996)? One forest type which has now probably been erased totally from the landscape in its original and even modified form is the exceptional pure stands of ironwood forest. This very valuable resource has been squandered, its potential for regeneration bypassed, and the cultural links with Jambi lost.
I am writing this piece at a time when international attention is focused on Sumatra as never before because of the terrible forest fires and the thick, acrid smoke they produce. As this 'haze' sits over the land so transportation is disrupted, people's health suffers, and the grey cloak encourages those who might wish to add to the inferno to facilitate the clearance or deforestation of land before the rains come and the opportunity is lost. Never mind the wildlife. Debates rage, hosted by the world's media, as to whether the environmental disaster, during a severe El Nino-provoked drought period, is the fault of corporations and companies engaged in the large-scale conversion of land to tree-crops, timber plantations or transmigration settlements, or of farmers who are clearing land for crops. Supporters of the first reason are being branded as communists, and those supporting the latter are accused of being anti-people. Whatever the reason, it has been recommended for years that if farmers were given security of tenure on the land they farm they would be more likely to be concerned about its treatment. Since undisturbed tropical rain forest does not burn except under the most severe conditions, very few native Sumatra species of animals and plants are adapted to fire. As a result there is untold ecological damage and the extent of the burning means that forest re-growth will be very slow, even on those areas which are designated to be forest, such as protection forests and conservation areas, and even where social conditions permit it.
When The Ecology of Sumatra was originally written (1981-1983) industrial timber plantations were not in our vocabulary. The area of Sumatran forests cleared and replaced (or being replaced) with industrial timber estates now runs into the many hundred thousands of hectares. Some of these estates were established on degraded alang-alang lands where the conversion into productive lands is to be applauded. However, the majority of the estates have taken advantage of poorly-managed logging concessions, and managers and sponsors have even been accused of starting forest fires in order to lower the standing crop of the land below the level used as the criterion for conversion. These vast new areas are tied to pulpmills. Sumatra has the distinction of having the country's largest mill, which is currently being built by PT Tanjung Enim Lestari in South Sumatra at a cost of $1 billion. The factory alone required the clearance of over 1,000 ha of forested land. It will one day be supplied with 2 million m3 of timber annually from a plantation, but until these trees are mature it will use trees from natural forests. Local communities, who have traditionally derived a good income from jungle rubber, have written letters of complaint to prominent decision makers in the civil and military administration not least because the project harms them economically. The people's 'lack of cooperation' has not been appreciated, and adverse reporting of the issue has closed the local newspaper. In addition to the infamous Indo-rayon mill on the shores of Lake Toba, another pulp mill where safeguards have not proved effective is Indah Kiat's mill in Perawang, Riau, currently the largest operating pulp mill in the world, producing over 1 million m3 of pulp annually. Some sources believe that it is impossible to grow enough plantation timber on the land allocated to the mill. If this is so, it will have to take timber from the neighbouring peat forests which simply do not grow back in to the original forest, and many of which are on peat soils too deep for agriculture. Since second-hand mills have been installed, a cynic might suggest that when the natural forests have been cleared and pulped then the investors will have got the return on their investment and move elsewhere.
Even without fires and industrial timber estates, the lowland forests, selectively-logged and those under jungle-rubber use, would still be disappearing while areas under oil palm increase. Some of the growth in oil palm plantations is also due to the conversion of old rubber plantations. The sustainability of these enterprises may be questioned now that the gene for producing lauric acid (the product for which oil palm is primarily grown) has been successfully inserted in canola and has begun to be harvested. Given that this is a temperate crop which can be grown over large areas very efficiently it is not inconceivable that this will in due time displace the need for oil palm.
Large areas of mangroves all round Sumatra have been felled, partly for their fibre, partly as fuelwood, and partly to make way for shrimp ponds, in the hope of quick profit. It is ironic that only now that so much mangrove has been lost, have the long-term impacts been admitted by the Forestry Department's Director of Reforestation and Land Rehabilitation. Rehabilitation has been more difficult than was thought and protecting the areas from further attrition has also been problematic. After years of complacency it is now felt that mangroves should have protected status and licenses for aquaculture in mangrove areas should no longer be issued. Sadly the clock cannot be turned back. Apart from the problems of acid-sulphate soils, the devastating 'red virus' has knocked out 90% of the shrimp harvest in some areas and has discouraged consumers and traders. The investors will move on to some other project, leaving behind degraded land that will not quickly regenerate into the original, productive, diverse ecosystem.
National parks, the jewels in the crown of what should be one of the world's most significant protected area systems, are not secure. For example, the best parts (lowland, relatively undisturbed forest) of the original area of Leuser and Kerinci National Parks were given out as official and unofficial logging concessions. After many years of preparation and study, the government and the World Bank with the Global Environment Facility have agreed on a project to work with local governments and communities in and around Kerinci to safeguard its future and to help social and economic development. Barely had the project formally begun, however, than there were newspaper reports, later confirmed, that a local government road was cutting through the gazetted, mapped Park despite clear agreements that this would not be permitted. It had also been agreed that the logging companies around the present park would cooperate in the adoption of practices which would result in better forestry management, but even this component has been stalled. In addition, encroachment by cinnamon farmers appears to continue unhindered. It is important to remember in this regard that the people involved are not poverty-stricken farmers, but tenants acting for urban entrepreneurs.
Another internationally significant area is Siberut Island which is one of only four UNESCO-Man and Biosphere Program Biosphere Reserves in all of Indonesia. For over 15 years there have been persistent rumours and publicised plans for transmigration with plantations of oil palm or industrial timber. Vociferous international and national protests prior to an Asian Development Bank-funded conservation and development project on the island preceded the cancellation of logging permits, but by the time the companies actually left, most of the accessible and commercial timber had already been felled. The current developments are accompanied by tales of coercion and trickery in persuading local people to sign away their rights to land.
The exceptional Gunung Leuser National Park in northern Sumatra (van Schaik and Supriatna 1996) has also experienced decades of poor or no management despite considerable international NGO support, and as a result has suffered all manner of encroachments with no great protection from the conservation agency (PHPA), or others charged with enforcing policies and regulations (e.g., Whitten and Ranger 1986). It is to be hoped that things will change under its new, young, innovative management body, the International Leuser Foundation. This was established in place of, and with wider powers than, the government conservation agency. The Foundation has received a seven-year concession agreement to manage the 'Leuser ecosystem' which covers 1.8 million ha from which a new national park and surrounding buffer zone will be gazetted. The costs of management are shared between the Government's Reforestation Fund and the European Union. The involvement of the politicians, high-level provincial personalities, police, military, as well as Ministry of Forestry staff has resulted in perhaps the potential for the best management ever for the beleaguered park, and most other Indonesian parks. Their involvement has already prevented plans for roads and a transmigration scheme from proceeding, though this has led to pressure on the Foundation to develop alternatives. Some of this will be related to income-generating activities such as increased ecotourism and licensed exploitation of natural resources within the buffer zone. The Foundation and its program for integrated conservation and development are as yet young, and there are risks ahead, but their is great hope that it will be successful in its endeavours. Unfortunately it is impossible to envisage every conservation area receiving this type of attention.
BAD NEWS - WILDLIFE
With the loss of habitat, inevitably the populations of plants and wildlife have been reduced, separated and isolated. This, together with poaching, has taken some species to appallingly low numbers. For example, over the period 1990-1996 the numbers of Sumatran rhino in Kerinci National Park and adjacent forests fell from about 300 to just 30. The Sumatran rhino is the focus of a UNDP/Global Environment Facility project which is developing capacity to deal with rhino conservation in PHPA (the conservation agency) with the objective of arresting and reversing the decline due to poacher activity and habitat disturbance toward the national and global goal of recovery of viable populations of rhino species in Indonesia.
Disappearing only slightly less rapidly are tigers which have experienced a 95% decline throughout their range during this century. These 'protected species' are sought within Indonesia and beyond for their skins and body parts, and possibly just 500 remain of the Sumatran subspecies, many in areas now unable to sustain populations. While the trade in skins is largely domestic (highly skilled taxidermists can be found in major Sumatran towns), the illicit trade in parts focuses on China where, for example, tiger forelimbs sell for $1,000 per kg, and $320 buys a bowl of tiger penis soup for those with flagging libidos who are envious of the tiger's ability to copulate several times an hour (Plowden and Bowles 1997). If consumers realised that each copulation lasted a scant 15 seconds the bottom might fall out of the penis soup market.
Bones are believed to have healing powers, and whiskers and eyes also have uses, and are clearly easier to hide and trade than larger parts. Middlemen use skilled villagers, but have also turned to the most skilled of the forest peoples, the Kubu, to hunt for valuable species. The hunters are probably paid a derisory fee for their services despite the value of the product, but it compares well with the income derived from other activities. True to economic theory, the prices are rising as the beasts become rarer, and if it is true that even those in authority are guilty of complicity in the trade then the outlook is very bleak indeed. Certainly, the forces of the black market are so strong that all attempts from within and outside Sumatra have failed to stem the tide.
Sumatra is not the only Indonesian island where such stories can be related, and this is demonstrated in the recent volumes in the Ecology of Indonesia series (MacKinnon et al. 1996; Whitten et al. 1996; Monk et al. 1997; Tomascik et al. 1997). The nationwide progressive degradation and loss must be seen in its context: the government has supported the detailed work of RePPProT (see Annex following), the Indonesian Forestry Action Program, numerous bilateral and multi-lateral-supported projects related to rational land use, conservation and forests (Wells et al. 1998), the Biodiversity Action Plan (BAPPENAS 1993), the Atlas of Biodiversity (Anon. 1995), numerous wetland plans and strategies, out of all of which have come innumerable considered recommendations, proposals, arguments and pleas for sustainable development with restraint. A new conservation law has been passed and budgets to a larger number of national parks have increased.
And yet willful destruction continues. Those with little authority are easily scared off or won over when conflicts arise, the judiciary tends not to give high priority to such infringements, conservation budgets appear to be used up on prestigious activities rather than on the grunt work of patrolling and building relationships with those communities whose interest and cooperation are essential. It is easy to blame the private sector for many of the problems, but far more important is high-level political will. If this were truly engaged in commitment to a sustainable path for development, then the reduction of options through the loss of biodiversity, the direct and indirect degeneracy of land productivity and water quality, and the bypassing or unfriendly treatment of vulnerable people would not occur. What will it take to see meaningful change?
ACKNOWLEDGEMENTS
I wish to thank a small band of friends who agreed to read through this section and to give comments which have greatly improved it: Suraya Afiff, Sofia Bettencourt, Boeadi, Sengli Damanik, Wim Giesen, Andy Gillison, Kuswata Kartawinata, Ani Kartikasari, Margaret Kinnaird, Kathy MacKinnon, Kathyrn Monk, Øyvind Sandbukt, Carel van Schaik, Jito Sugarjito, David Wall, Tim Whitmore, and Jane Whitten (who did much else besides). Any mistakes and misinterpretations remain solely my responsibility.
|
March, 1998 |
Tony Whitten |
ANNEX 1
Publications
A great deal has been written about Sumatra in the last 15 years and it is beyond the scope of this book to provide an exhaustive list of publications. However, a selection of books and papers appearing in peer-reviewed journals is given below to provide direction for those interested in the biology and fate of Sumatra.
Of singular importance and significance are the reports and sets of 1:250,000 maps produced by the RePPProT project (RePPProT 1988). This systematic baseline study mapped for the first time the biophysical environment, not only of Sumatra but later the entire country, and where and how it was being used. Areas appropriate and still available for different types of development or conservation were identified by comparing land qualities with development and conservation criteria and with existing land use and land status. One of its major contributions was in exposing gross discrepancies between existing forest function boundaries (as agreed by inter-Ministerial consensus in 1983) and what the boundaries should be rationally and ecologically. It also produced for the first time a comprehensive database and analysis of climatic data. In addition, the Sumatra study, together with seven other regional volumes were summarised in a National Overview with an atlas of thematic maps at 1:2,500,000 scale. Sadly and frustratingly, a major recommendation given by RePPProT, to remap the land use and land status of Indonesia every five years, has not been heeded and developments on Sumatra (as elsewhere in Indonesia), are taking place in ignorance of accurate and up-to-date land status and land use information.
Hundreds of papers are published each year on tropical ecology and many of them are relevant to the understanding of Sumatra. Two books on tropical forests by Whitmore (1984, 1990) are regarded as classics and should be consulted for solid information and interpretations. The long-awaited volume by Laumonier (1997) on the vegetation of Sumatra has recently appeared. It gives a critical appraisal of the methods used in vegetation surveys in the tropics. The small-scale eco-floristic physiographical classification of vegetation could form the basis of detailed monitoring of deforestation.
The coastal and marine environments around Sumatra are dealt with thoroughly by Tomascik et al. (1997), and the ecology, status and management of the peatlands and mangrove forests of eastern Sumatra have been a focus of interest by Asian Wetlands Bureau/Wetlands International in Bogor from which a list of the unpublished reports can be obtained. One widely-available publication is by Claridge (1994) concerning Berbak National Park.
In addition there are a number of coffee-table and travel books with exceptional photos and informative text (Griffiths 1989; Oey 1991; Stone 1994; Whitten and Whitten 1992, 1996a,b), the last two of which include some exceptional coverage of the Kubu people by Sandbukt (see also Sandbukt 1988). Ancient history and general human geography are dealt with in two new and very attractive encyclopaedias (Miksic 1996; Rigg 1996).
It is easier now to identify certain animal and plant species than it was in 1984. Larger trees can now be compared with the illustrations in Whitmore and Tantra (1986), and tree genera can in most cases be identified from the interactive key on the World Wide Web designed for use on Borneo (http://django.harvard.edu/users/ijarvie/borneo.htm) (Jarvie and Ermayanti 1996). Freshwater fish can be identified using the keys, descriptions and photographs in Kottelat et al. (1996 - this second printing also has an addendum of new species and name changes since the 1993 printing). The birds are now well served with a guide to the commoner species (Holmes and Nash 1990), and a guide to all species of the Sunda Region (MacKinnon and Phillipps 1993). There is also a bird watcher's guide to sites and species (Jepson and Ounstead 1997) and an annotated checklist (van Marie and Voous 1988). The mammals are well, if not perfectly, served by a guide to the species of Borneo (Payne et al. 1985). The snakes are now covered by an illustrated checklist (David and Vogel 1997). In addition, the first three guides from the Fauna Malesiana Project will soon be available and will be useful on Sumatra. These cover snails (Vermeulen and Whitten 1998), pest grasshoppers and allies (Willemse, in press), and flies (Osterbroek, in press).
Our knowledge of ecosystems, especially their dynamics, is generally rather weak. We are lucky that there are some areas in Sumatra where teams have worked and have had some significant impacts on the way the land is designated and managed.
Some globally significant studies are underway in central Sumatra by the Centre for International Forestry Research, based in Bogor, which is seeking indicators for the impact on land use on biodiversity by conducting baseline studies along disturbance and altitudinal gradients (Gillison 1996a,b: Gillison and Carpenter 1997). These are producing generic methods for rapid biodiversity assessment which potentially could provide a much needed information base for regional planners and managers.
A major team of natural and social scientists under NORINDRA (Norwegian-Indonesian Rain Forest and Resource Management Project) was stationed in Riau in 1991-92 and produced the most comprehensive analysis of people-forest interactions in Southeast Asia, major contributions to forest policy, understanding traditional and commercial use of forest resources, knowledge of biodiversity, and conservation. Indeed, the establishment of the Bukit Tigapuluh National Park was a direct result of the work and now conserves perhaps the only remaining major expanse (about 1,000 km2) of lowland forest left on Sumatra. Three important books on forest and resource management have appeared (Sandbukt and Øster-gaard 1993; Angelsen 1994; Sandbukt and Wiriadinata 1994) the third of which contains 27 papers on a wide range of subjects. In addition, a number of interesting papers have been published (e.g., Danielsen and Schumacher 1997), and Norwegian and Indonesian interest in the area continues.
There has been a very fruitful cooperation between Andalas University and Japanese scientists, and many papers, mainly on plant and insect ecology, have resulted (e.g., Hotta 1986; Kohyama and Hotta 1986; Hotta 1987; Okada and Hotta 1987; Sakagami et al. 1989; Yoneda et al. 1990; Oi 1990, 1996; Itino et al. 1991; Kato et al. 1991, 1993; Kohyama 1991; Aimi and Bakar 1992; Mukhtar et al. 1992; Koike and Syahbuddin 1993; Sianturi et al. 1995).
Work in the Gunung Leuser National Park has continued to produce seminal papers on wildlife and ecology and its management (e.g., the many papers by van Schaik and his colleagues, van Noordwijk 1985; Soegarjito 1986; Rachmatika and Wirjoatmodjo 1988; Griffiths 1989; te Boekhorst et al. 1990; Cant et al. 1990; Mukhtar 1994; Rijksen and Griffiths 1995).
The centennial anniversary of the massive eruption of Krakatau fell in 1983, and resulted in a rush of publications on a wide range of ecological topics related to the recolonisation of animal and plant species. The publications are too many to list but they are synthesised in a masterly book by Thornton (1996).
In southern Sumatra there has been some excellent work on traditional agro-forestry and its ecological and social benefits (Torquebiau 1984, 1986; Michon and Bompard 1987a,b; Gouyon et al. 1993; Thiollay 1994, 1995; Levang et al. 1997).
Bukit Barisan Selatan National Park is now also a major long-term research site thanks to the work started by the national and international staff of Wildlife Conservation International (O'Brien and Kinnaird 1996).
Research in the field and in laboratories has resulted in the formal naming of many new species: insects, notably in the ongoing Heterocera Sumatrana series covering the moths (e.g., Holloway 1990; Holloway and Bender 1990), as well as in other groups such as land snails (Djajasasmita 1988; Dharma 1993), freshwater crabs (Ng 1993; Ng and Tan 1995), fish (see 1996 insert in the printing of Kottelat et al. 1993), and plants amongst which are numbered several new and apparently endemic genera (Hotta 1987; Stone 1988; Hyde 1989; Burtt 1990; Nagamasu 1990; Kostermans 1992).
Possibly the most dramatic new species will turn out to be the 'orang pendek' or 'short man' of the Kerinci area which has been generally dismissed in the past. Since 1995 small teams, supported by Fauna and Flora International, have been trying to collect solid support for this creature's existence. A very impressive cast of a large foot print has been obtained which baffles mammal specialists and field workers alike, and even those who started as sceptics have reported positive sightings in the montane. Photo traps have been set in the forest, but despite a fascinating range of exceptional photographs of rarely seen large forest animals, the orang pendek itself has remained elusive.
REFERENCES
Abdulhadi, R., Mirmanto, E. and Kartaw-inata, K. (1987). Lowland dipterocarp forest in Sekunder, North Sumatra, Indonesia, five years after logging. In Dipterocarps (ed. A.J.G.H. Kostermans), pp. 255-273. MAB-UNESCO, Jakarta.
Aimi, M. and Bakar, A. (1992). Taxonomy and distribution of Presbytis melalophos group in Sumatra, Indonesia. Primates 33: 191-206.
Amato, G. et al. (1995). Assessment of conservation units for the Sumatran rhinoceros. Zoo Biol. 14: 395-402.
Andrew, P. (1992). The Birds of Indonesia: A Checklist (Peter's Sequence). Indonesian Ornithological Society, Jakarta.
Angelsen, A. (1994). Shifting Cultivation and 'Deforestation': A Study from Sumatra. Chr. Michelson Institute, Bergen.
Aumeeruddy, Y. (1995). Perceiving and managing natural resources in Kerinci, Sumatra. Nature and Resources 31: 28-37.
Bihari, M. and Lai, C.B. (1989). Species composition, density and basal cover of tropical rainforests on Central Sumatra, Indonesia. Trap. Ecol. 30: 118-137.
Bismark, M. (1991). Population analysis of longtail macaques Macaca fascicularis in various forest types. Bui. Pen. Hutan 532: 1-10.
Brady, M.A. (1989). A note on the Sumatra, Indonesia, peat swamp forest Fires of 1987./ Trop. For. Sci. 3: 295-296.
Brady, M.A. and Kosasih, A. (1991). Controlling off-site forest destruction during oil field development in Sumatra, Indonesia. Proceedings of the 20th Annual Convention, Indonesian Petroleum Association, Jakarta.
Burtt, B.L. (1990). Gesneriaceae of the Old World II. A new Didymocarpus from Sumatra. Edinb.J. Bot. 47: 235-238.
Cant, J.G.H. et al. (1990). Stress tests of lianas to determine safety factors in the habitat of orangutans Pongo pygmaeus in northern Sumatra, Indonesia. Am. J. Phys. Anthropol. 81: 203.
Claridge, G. (1994). Management of coastal ecosystems in eastern Sumatra: The case of Berbak Wildlife Reserve, Jambi Province. Hydrobiologia 285: 287-302.
Colfer, C.J.P., Gill, D.W. and Agus, F. (1988). An indigenous agricultural model from West Sumatra, Indonesia: A source of scientific insight. Agric. Syst. 26: 191-210.
Corbett, G.B. and Hill.J.E. (1992). The Mammals of the Indomalayan Region: A Systematic Review. Oxford University Press, Oxford.
Danielsen, F. and Schumacher, T. (1997). The importance of Tigapuluh Hills, southern Riau, Indonesia, to biodiversity conservation. Trop Biodiv. 4: 129-160.
Danielsen, F. et al. (1997). The Storm's stork Ciconia stormi in Indonesia: Breeding biology, population and conservation. Ibis 139: 67-76.
David, P. and Vogel, G. (1997). The Snakes of Sumatra: An Annotated Checklist and Key with Natural History Notes.
Dharma, B. (1993). Description of two new species of Amphidromus from Sumatra, Indonesia (Gastropoda: Pulmonata: Camaenidae). Apex 8: 139-143.
Djajasasmita, M. (1988). A new cyclophorid land snail from North Sumatra, Indonesia (Mollusca: Gastropoda, Cyclophoridae). Treubia 29: 271-274.
Dring, J., McCarthy, C. and Whitten, A.J. (1990). The herpetofauna of the Mentawai Islands, Indonesia. Indo-Australian Zool 1: 210-215.
Faust, T., Tilson, R. and Seal, U.S. (1995). Using GIS to evaluate habitat risk to wild populations of Sumatran orangutans. In The Neglected Ape; International Orangutan Conference and the Orangutan Population and Habitat Viability Analysis Workshop. Fullerton, California, and Medan, Indonesia. Jan 18-20, 1993. Plenum Press, New York, London.
Fuentes, A. (1994). Social organization in the Mentawai langur. Amer. J. Phys. Anthropol. Suppl. 18: 90.
Fujisaka, S. et al. (1991). Wild pigs, poor soils, and upland rice: a diagnostic survey of Sitiung, Sumatra, Indonesia. IRRI Research Paper Series, 155: 1-9.
Giesen, W. and Sukotjo. (1991). Lake Kerinci and the Wetlands of Kerinci Seblat National Park, Sumatra. Asian Wetlands Bureau, Bogor.
Gillison, A.N., Liswanti, N. and Ismail Rach-man (1996a). Rapid Assessment, Kerinci Seblat National Park Buffer Zone: Preliminary report on plant ecology and overview on biodiversity assessment. CIFOR Working paper No. 14.
Gillison, A.N., Liswanti, N. and Arief-Rachman, I. (1996b). Contributors. In: Final Report, Rapid Ecological Assessment in HPH Pt Serestra II and HPH PT Bina Samaktha. Pre-implementation, Integrated Conservation and Development Project, Kerinci Seblat National Park, World Wildlife Fund for Nature, Indonesia Program. Bappenas, The World Bank. (Published 1997.)
Gillison, A.N., and Carpenter, G. (1997). A plant functional attribute set and grammar for dynamic vegetation description and analysis. Functional Ecology 11: 775-783.
Gouyon, A.., de Foresta, H. and Levang, P. (1993). Does 'jungle rubber' deserve its name? An analysis of rubber agroforestry systems in southeast Sumatra. Agrofor. Syst. 22: 181-206.
Griffiths, M. (1989). Indonesian Eden: Aceh's Rainforest. Jakarta.
Hoggarth, D.D. and Utomo, A. (1994). Fisheries ecology of the Lubuk Lampam River floodplain in south Sumatra, Indonesia. Fisheries Research 20: 191-213.
Holloway, J.D. (1990). The Limacodidae of Sumatra. Heterocera Sumatrana 6: 9-77.
Holloway, J.D. and Bender, R. (1990). The Lasiocampidae of Sumatra. Heterocera Sumatrana 6: 137-204.
Holmes, D. (1996). Sumatra bird report. Kukila 8: 9-56.
Holmes, D. and Nash, S. (1990). Birds of Sumatra and Kalimantan. Oxford, Kuala Lumpur.
Hotta, M. (1986). Diversity and Dynamics of Plant Life in Sumatra: Forest Ecosystem and Speciation in Wet Tropical Environments. Sumatra Nature Study (Botany), Kyoto University.
Hotta, M. (1987). A new rheophytic aroid Schismatoglottis okadae new species from West Sumatra, Indonesia. Contrib. Biol. Lab. Kyoto Univ. 27: 151-152.
Hyde, KD. (1989). Intertidal mangrove fungi from North Sumatra, Indonesia. Can. J. Bot. 67: 3078-3082.
Inoue, T. et al. (1993). Population dynamics of animals in unpredictably-changing tropical environments. J. Bioscience 18: 425-455.
Itino, T., Kato, M., and Hotta, M. (1991). Pollination ecology of the two wild bananas, Musa acuminata subsp. halaba-nensis and M. salaccensis: chiropterophily and ornithophily. Biotropica 23: 151-158.
Jepson, P. and Ounstead, R. (1997). A Bird Watcher's Guide to the World's Largest Archipelago. Periplus, Singapore.
Kato, M. et al. (1991). Pollination of four Sumatran Impatiens species by hawkmoths and bees. Tropics 1: 59-73.
Kato, M. et al. (1993). Inter- and intra-specific variation in prey assemblages and inhabitant communities in Nepenthes pitchers in Sumatra. Trop. Zool. 6: 11-25.
Kobayashi, M. et al. (1996). Indonesian medicinal plants. XVIII Kompasinol A, a new stilbeno-phenylpropanoid from the bark of Koompassia malaccensis. Chemical and Pharmaceutical Bulletin (Tokyo). 44(12):2249-2253.
Kohyama, T. (1991). Simulating stationary size distribution of trees in rain forests. Ann. Bot. 68:173-180.
Kohyama, T. and Hotta, M. (1986). Growth analysis of Sumatran Monophyllaea, possessing only one leaf throughout perennial life. PI. Sp. Biol. 1: 117-125.
Koike, F. and Syahbuddin (1993). Canopy structure of a tropical rain forest and the nature of an unstratified upper layer. Funct. Ecol. 7: 230-235.
Kostermans, A.J.G.H. (1992). An important economical new Durio sp. from northern Sumatra. Econ. Bot. 46: 338-340.
Kottelat, M. (1994). Freshwater fish biodiversity in western Indonesia: State of the art, threats and need for pragmatic biodiversity approach of systematics. Rev. Suisse Zool. 101: 853.
Kottelat, M., Whitten, A.J., Wiryoatmodjo, S. and Kartikasari, A. (1993). Freshwater Fishes of Western Indonesia and Sulawesi. Periplus, Singapore. Reprinted in 1996 with a separate summary of new species, name changes, etc.
Kunkun, J.G. (1986). Ecology and behaviour of Presbytis thomasi in northern Sumatra, Indonesia. Primates 27: 151-172.
Laumonier, Y. (1990). Search of phytogeographic provinces in Sumatra, Indonesia. In The Plant Diversity of Malesia (ed. P. Baas, K. Kalkman and R. Geesink), pp. 193-212. Kluwer, Dordrecht.
Laumonier, Y. (1997). The Vegetation and Physiography of Sumatra. Kluwer, Dordrecht.
Levang, P., Michon, G. and Foresta, H.D. (1997). Forest agriculture or agro-forestry? Indonesian examples of farmers' strategies adapted to environments with mediocre fertility. Bois For. Tropiques 251: 29-42.
Lim KS. (1997). Further notes on the avifauna of the Riau archipelago. Kukila 9: 74-77.
MacKinnon, J. (1997). Protected Areas Systems Review of the Indo-Malayan Realm. World Conservation Monitoring Centre, Cambridge.
MacKinnon, J. and Phillipps, K. (1993). A Field Guide to the Birds of Borneo, Sumatra, Java and Bali. Oxford University Press, Oxford.
Meijer, W. (1997). Rafflesiaceae. Flora Malesiana I 13: 1-42.
Michon, G.M. and Bompard, J.-M. (1987a). Indonesian agroforestry practices: A traditional contribution to the conservation of rain forest resources. Rev. Ecol. Terre Vie 42: 3-38.
Michon, G.M. and Bompard, J.-M. (1987b). The damar gardens (Shorea javanica) in Sumatra. In Dipertocarps (ed. A.[.G.H. Kostermans), pp.3-7. MAB-UNESCO, Jakarta.
Miksic, J. (ed.) (1996). Ancient History. Indonesian Heritage Encyclopaedia Vol. I. Archipelago Press, Singapore.
Mukhtar, A., Nazif, M. and Setiawati, T. (1990). Habitat and behaviour of red lutung (Presbytis melalophos) in Bukit Sebelah Protection Forest, West Sumatra. Bui. Pen. Hutan 528: 1-12.
Mukhtar, A.S. (1994). Some aspects of elephant ecology in Sekunder Forest Complex, Leuser Mountains National Park. Bui. Pen. Hutan 564: 1-23.
Mukhtar, E. et al. (1992). Regeneration process of a climax species Calophyllum cf. soulattri in tropical rain forest of West Sumatra. Tropics 2: 1-12.
Nagamasu, H. (1990). A new Symplocos (Symplocaceae) from Sumatra. Blumea 35: 229-232.
Ng, P.K.L. (1993). Parathelphusa maindroni, a peatswamp crab from Peninsular Malaysia and Sumatra (Crustacea: Decapoda, Bracyura: Parathelphusidae). Malay. Nat. J. 46: 189-200.
Ng, P.K.L. and Tan, C.G.S. (1995). Geosarma notophorum sp. nov. (Decapoda, Brachyura, Grapsidae, Sesarminae), a terrestrial crab from Sumatra with novel brooding behaviour. Crustaceana 68: 390-395.
O'Brien, T.G. and Kinnaird, M.F. (1996). Birds and mammals of the Bukit Barisan Selatan National Park, Sumatra, Indonesia. Oryx: 207-217.
Oey, E. (1991). Sumatra. Periplus, Singapore.
Ohsawa, M. et al. (1985). Altitudinal zonation of forest vegetation on Mt. Kerinci, Sumatra: with comparisons to zonation in the temperate region of East Asia. J. Trop. Ecol. 1: 193-216!
Oi, T. (1990). Population organization of wild pig-tailed macaques Macaca nemestrina nemestrina in West Sumatra, Indonesia. Primates 31: 15-32.
Oi, T. (1996). Sexual behaviour and mating system of the wild pig-tailed macaque in West Sumatra. In Evolution and Ecology of Macaque Societies (ed.J.E. Fa), pp.342-368. Cambridge University Press, Cambridge.
Okada, H. and Hotta, M. (1987). Species diversity of wet tropical environments. II. Speciation of Schismatoglottis okadae, an adaptation to the rheophytic habitat of mountain streams in Sumatra, Indonesia. Contrib. Biol Lab. Kyoto Univ. 27: 153-170.
Osterbroek, P. (in press). The Families of Diptera of NW Borneo, Indonesia, and East New Guinea. Fauna Malesiana Foundation, Leiden.
Payne, J., Francis, C.M. and Phillipps, K. (1985). A Field Guide to the Mammals of Borneo. Sabah Society, Kota Kinabalu.
Plowden, C. and Bowles, D. (1997). The illegal market in tiger parts in north Sumatra. (Oryx 59-66.
Rachmatika, I. And Wirjoatmodjo, S. (1988). Feeding ecology of Glyptothorax major (Bagaridae, Siluriformes) in the Alas River, Southeast Aceh, Sumatra, Indonesia. Berita Biol. 3: 396-399.
Rampino, M.R. and Self, S. (1992). Volcanic winter and accelerated glaciation following the Toba super-eruption. Nature (Lond.) 359: 50-52.
Rao, M. and van Schaik, C.P.(1997). The behavioural ecology of Sumateran orangutans in logged and unlogged forest. Trop. Biodiv. 4: 173-186.
RePPProT (1988). Sumatra. Regional Physical Planning Programme for Transmigration, Natural Resources Institute and Direktorat Bina Program. Direktorat Jenderal Penyiapan Pemukiman, Departemen Transmigrasi, Jakarta.
Riggs, J. (ed.) (1996). Human Environment. Indonesian Heritage Encyclopaedia Vol. 2. Archipelago Press, Singapore.
Rijksen, H. and Griffiths, M. (1995). Leuser Development Masterplan. Institute for Forestry and Nature Research, Wageningen.
Ruedi, M. and Fumagalli, L. (1996). Genetic structure of gymnures (genus Hylomys; Erinaceidae) on continental islands of Southeast Asia: Historical effects of fragmentation. J. Zool. Syst. Evol. Res. 34: 153-
Sakagami, S.F. et al. (1989). Nests of myrmecophilous stingless bee Trigona moorei. How do bees initiate their nest within an arboreal ant nest? Biotropica 21: 265-274.
Sandbukt, Ø. (1988). Resource constraints and relations of appropriation among tropical forest foragers: the case of the Sumatran Kubu. Res. Econ. Anthrop. 10: 117-156.
Sandbukt, Ø. and Østergaard, L. (1993). Bukit Tigapuluh: Rain Forest and Resource Management. WWF and Ministry of Forestry, Jakarta.
Sandbukt, Ø. and Wirtiadinata, H. (1994). Rain Forest and Resource Management: Proceedings of the NORINDRA Seminar. Indonesian Institute of Sciences, Jakarta.
Santiapillai, C. and Ashby, K.R. (1988). The clouded leopard in Sumatra. Oryx 22: 44-45.
Scheffrahn, W., de Ruiter, J.R. and van Hooff, J.A.R.A.M. (1996). In Evolution and Ecology of Macaque Societies (ed. J.E. Fa), pp.20-42. Cambridge University Press, Cambridge.
Shine, R. et al. (1995). Biology and commercial utilization of acrochordid snakes, special reference to karung (Acrochordus javanicus). J. Herpetol. 29: 352-360.
Shine, R., Harlow, P.S., Keogh, J.S. and Boeadi (1996). Commercial harvesting of giant lizards: the biology of water monitors Varanus salvator in southern Sumatra. Biol. Cons. 77: 125-134.
Sianturi, E.M.T. et al. (1995). Nest structure, colony composition and foraging activity of a tropical-montane bumblebee Bombus senex (Hymenoptera: Apidae), in West Sumatra. Jap. J. Entomol. 63: 657-667.
Siebert, S.F. (1989). The dilemma of a dwindling resource: rattan in Kerinci, Sumatra. Principes 33: 79-87.
Sourrouille, P. et al. (1995). Molecular systematics of Mus crociduroides, an endemic mouse of Sumatra. Mammalia 59: 91-102.
Stone, B.C. (1988). New and noteworthy Malesian Myrsinaceae II. Emblemantha new genus from Sumatra, Indonesia. Proc. Acad. Nat Sci. Phila. 140: 275-280.
Stone, B.C. (1990). Studies in Malesian Myrsinaceae V. Additional new species of Ardisia. Proc. Acad. Nat. Sci. Phila. 142: 21-58.
Stone, D. (1994). Tanah Air: Indonesia's Biodiversity. Archipelago, Singapore.
Sugarjito, J. (1986). Ecological constraints on the behaviour of Sumatran orangutans (Pongo pygmaeus abelli) in the Gunung Leuser National Park, Indonesia. Pressa Trajectina, Utrecht.
Suharti, S. (1991). The profile of shifting cultivators in the nature reserve of Isau-Isau, Pasemah, South Sumatera. Bui. Pen. Hutan 544: 39-49.
Sukardjo, S. (1987). Natural regeneration status of commercial mangrove species Rhizophora apiculata and Bruguiera gymnorhiza in the mangrove forest of Tanjung Bungin, Banyumasin, South Sumatra, Indonesia. For. Ecol. Manage. 20:233-252.
Supriatna, J. et al. (1996). A preliminary survey of long-tailed and pig-tailed macaques in Lampung, Bengkulu, and Jambi provinces, Southern Sumatra, Indonesia. Trop. Biodiv. 3: 131-140.
Tan, S.-H. and Tan, H.-H. (1995). The freshwater fishes of Pulau Bintan, Riau Archipelago, Sumatera, Indonesia. Trop. Biodiv. 2: 351-368.
te Boekhorst, I.J.A., Schurmann, C.L. and Sugaijito, J. (1990). Residential status and seasonal movements of wild orangutans in the Gunung Leuser Reserve, Sumatra, Indonesia. Anim. Behav. 39: 1098-1109.
Thiollay, J.-M. (1994). Rain forest raptor community in Sumatra: The conservation value of traditional agroforests. J. Raptor Res. 28: 51.
Thiollay, J.-M. (1995). The role of traditional agroforests in the conservation of rain and forest bird diversity in Sumatra. Conserv. Biol. 9: 335-353.
Thornton, I. (1996). Krakatau: The Destruction and Reassembly of an Island Ecosystem. Harvard University Press, Cambridge, Mass.
Torquebiau, E.F. (1984). Man-made dipterocarp forest in Sumatra. Agroforestry Syst. 2: 103-127.
Torquebiau, E.F. (1986). Mosaic patterns in dipterocarp rain forest in Indonesia and their implications for practical forestry. J. Trop. Ecol. 2: 301-325.
Ungar, P.S. (1996). Feeding height and niche separation in sympatric Sumatran monkeys and apes. Folia primatalol. 67(3): 163-168.
Van Marie, J.G. and Voous, KH. (1988). The Birds of Sumatra: An Annotated Checklist. British Ornithologists' Union, Tring.
van Noordwijk, M.A. (1985). The socio-ecology of Sumatran long-tailed macaques (Macaca fascicularis). II. The behaviour of individuals. Elinwijk, Utrecht.
van Schaik, C.P. (1985). The socio-ecology of Sumatran long-tailed macaques (Macaca fascicularis). I. Costs and benefits of group living. Elinwijk, Utrecht,
van Schaik, C.P. (1986). Phenological changes in a Sumatran rain forest. J. Trop. Ecol. 2: 327-348.
van Schaik, C.P. and Griffiths, M. (1996). Activity periods of Indonesian rain forest mammals. Biotropica 28: 105-112. van Schaik, C.P. and Mirmanto, E. (1985). Spaual variation in the structure and litterfall of a Sumatran rain forest. Biotropica 17: 196-205.
van Schaik, C.P. and Noordwijk, M.A. (1985). Evolutionary effect of the absence of felids on the social organization of the macaque on the island of Simeulue. Folia primalol. 44: 138-147.
van Schaik, C.P. and Noordwijk, M.A. (1985). Interannual variability in fruit abundance and the reproductive seasonality in Sumatran long tailed macaques. J. Zool. 206: 533-549.
van Schaik, C.P. and Supriatna, J. (1996). Leuser: A Sumatran Sanctuary. Yayasan Bina Sains Hayati, Depok.
van Schaik, C.P. et al. (1995). Estimates of orangutan distribution and status in Sumatra. In The Neglected Ape (ed. R.D. Nadler), pp.109-116. Plenum, New York,
van Schaik, C.P., van Amerongen, A., and van Noordwijk, M.A. (1996). Riverine refuging by wild Sumatran long-tailed macaques (Macaca fascicularis). In Evolution and Ecology of Macaque Societies (ed. J.E. Fa), pp.160-181. Cambridge University Press, Cambridge.
Vermeulen, J. and Whitten, T. (1998). Guide to the Land Snails of Bali. Fauna Malesiana Foundation, Leiden.
Wallach, V. (1988). Status and redescription of the genus Padangia with comparative visceral data on Collorhabdium and other genera (Serpentes: Colubridae). Amphib-Reptilia 9: 61-76.
Wells, M., Khan, A. and Jepson, P. (1998). Investing in Biodiversity: Integrated Conservation Development Projects in Indonesia. The World Bank, Washington D.C.
Weaver, J.S. Ill (1989). Indonesian Lepidos-tomatidae (Trichoptera) collected by Dr. E.W. Diehl. Aquat. Insects 11: 47-63.
Whitmore, T.C. (1984). Tropical Rain Forests of the Far East. Clarendon, Oxford. Whitmore, T.C. (1990). Introduction to Tropical Rain Forests. Oxford University Press, Oxford. (Second edition due 1998).
Whitmore, T.C. and I G.M. Tantra (1986). Tree Flora of Indonesia. Forest Research and Development Centre, Bogor.
Whitten, A.J. and Damanik, S.J. (1986). Mass defoliation of mangrove in Sumatra, Indonesia. Biotropica 18:176.
Whitten, A.J. and Ranger, J. (1986). Logging at Bohorok. Oryx 20: 246-248.
Whitten, J. and Whitten, A.J. (1987). Analysis of bark eating in a tropical squirrel. Biotropica 19: 107-115.
Whitten, T. and Whitten, J. 1992. Wild Indonesia. New Holland, London.
Whitten, T. and Whitten, J. 1996a. Indonesian Heritage Encyclopaedia Vol. 4: Plants. Archipelago, Singapore.
Whitten, T. and Whitten, J. 1996b. Indonesian Heritage Encyclopaedia Vol. 5: Wildlife. Archipelago, Singapore.
Whitten, T., Whitten, J., Mittermeier, C., Supriatna, J. and Mittermeier, R. (1998). Indonesia. In Megadiversity: Earth's Biologically Wealthiest Nations (ed. R. Mittermeier, P.R.G1, and C. Mittermeier), pp. 74-97. Cemex, Prado Norte.
Whitten, T., Soeriaatmadja, R.E. and Afiff, S. (1996). The Ecology of Java and Bali. Periplus, Singapore.
Wibowo, A. (1990). The effect of fire on alang-alang grassland ecosystem in Benakat, South Sumatra, Indonesia. Bui. Pen. Hutan 521: 19-30.
Willemse, L.P.M. (in press). Guide to the Pest Orthoptera of the Indo-Malayan Region. Fauna Malesiana Foundation, Leiden.
Yoneda, T., Tamin, R. and Ogino, K. (1990). Dynamics of above ground big woody organs in a foothill dipterocarp forest, West Sumatra, Indonesia. Ecol. Res. 5: 111-130.
COUNTIES OF SUMATRA BY PROVINCE
Aceh
1. Greater Aceh
2. Pidie
3. North Aceh
4. West Aceh
5. Central Aceh
6. East Aceh
7. Southeast Aceh
8. South Aceh
9. Langkat
North Sumatra
10. Deli Serdang
11. Dairi
12. Tanah Karo
13. Simalungun
14. Asahan
15. Central Tapanuli
16. North Tapanuli
17. Labuhan Batu
18. South Tapanuli
19. Nias
West Sumatra
20. Pasaman
21. Limapuluh Kota
22. Agam
23. Padang Pariaman
24. Tanah Datar
25. Solok
26. Sawahlunto Sijunjung
27. Pesisir Selatan
Riau
28. Kampar
29. Bengkalis
30. Upper Indragiri
31. Lower Indragiri
32. Riau Archipelago
Jambi
33. Kerinci
34. Bungo Tebo
35. Tanjung Jabung
36. Bangko Sarolangun
37. Batanghari
Bengkulu
38. North Bengkulu
39. Rejang Lebong
40. South Bengkulu
South Sumatra
41. Musi Rawas
42. Musi Banyuasin
43. Bangka
44. Belitung
45. Lahat
46. Muara Enim
47. Lower Ogan Komering
48. Upper Ogan Komering
Lampung
49. North Lampung
50. Central Lampung
51. South Lampung
Part A
The process of land formation, land movements, climatic change and evolution have been operating for thousands of millions of years and we see the result of them as natural ecosystems and as ecosystems disturbed or created by man. The chapter in this first section summarizes what is known about these processes in relation to Sumatra in order to provide a background against which later chapters can be viewed. As we learn about the past and its influence on the present we can better predict and understand the possibilities for the future.
Chapter One
GEOMORPHOLOGICAL AND GEOLOGICAL HISTORY
About 250 million years ago, at the beginning of the Mesozoic era (table 1.1), the earth's continents formed a single land called Pangea. During the Triassic, roughly 230 million years ago, Pangea broke into two, with Laurasia (North America, Europe and Asia) splitting off from Gondwana-land (India, Australia, Africa, South America and Antarctica). Gondwana-land began to split into its separate parts 200 million years ago during the Jurassic, and India floated towards Asia at about 10-18 cm per year (figs. 1.1 and 1.2). By the early Tertiary, about 70 million years ago, India and the plate on which it lay began to collide with and move under Asia. Its major thrust caused the uplift of the Himalayas, and one of the associated thrusts caused the uplift of the Barisan Mountains that run the length of Sumatra. The movement of the Indian Plate under Asia caused great earthquakes, and although the rate of movement is now less, almost all the earthquakes experienced in Sumatra (and Java, Burma, etc.) today are caused by those continuing movements. The main parts of Southeast Asia remained in more or less their present relative positions throughout this period although their absolute positions moved north and south of the equator.
As the Barisan Range buckled upwards, so a corresponding downward thrust formed the deep channel to the west of Sumatra, and the secondary upward thrusts that occurred at different times along its length formed the chain islands from Simeulue to Enggano. A very deep trough falling to the Indian Plate itself was formed to the west of these islands. A smaller trough was formed to the northeast of the Barisan Range and is represented today by low hills and plains (fig. 1.3). The alluvial eastern plains are narrower in the north of Sumatra either because sedimentation was slower or because subsequent subsidence of the land was faster (Verstappen 1973).
The southeast of Sumatra, including the islands of Bangka and Belitung, forms part of the stable Sunda Shelf (see fig. 1.9) and occasional ancient granite outcrops, particularly on Bangka, are indications that the geological foundation of the Sunda Region1 is not far below the surface.
The rocks of the Barisan Range are largely sedimentary, laid down over about 100 million years between the late Palaeozoic and early Mesozoic eras up to 180 million years ago. The Barisan Range began to be lifted and formed in the early Palaeocene 60 million years ago, but between the Oligocene and Miocene epochs, 35 million years later, there was considerable subsidence. Sedimentary rocks laid down by the sea then covering much of Sumatra can be found today in west and east Sumatra and some places inland. At about that time andesitic vulcanism was important in south Sumatra. A major upthrust occurred 20 million years ago and this mountain building activity was accompanied by considerable faulting and violent volcanic activity. No significant faulting has occurred since then. A final period of mountain building activity occurred between the Pliocene and Pleistocene about 3 million years ago, and some faulting, block-faulting, creation of rift valleys and horizontal offsetting of land accompanied this. The Semangko Fault Zone, traceable from Semangko Bay in the south to Weh Island in the north, is the largest. At the same time there was sedimentation and folding in eastern Sumatra, generally parallel to the island's axis (Verstappen 1973).
Figure 1.1. Geographical distributions of continents in the Jurassic period (±160-140 million years ago).
After Smith and Briden 1977
Figure 1.2. Geographical distributions of continents in the Palaeocene period (±70 million years ago).
After Smith and Briden 1977
Figure 1.3. A generalised cross-section through Sumatra and the western islands to show the folding caused by the Indian Plate colliding with the Asian Plate.
The volcanoes of the Quaternary period (the last million years) are located in the mountainous areas and are usually associated with faults. Ash and other products from these volcanoes cover great areas of the higher Barisan area, particularly in the south. In general, the most recent volcanoes are in the northern half of Sumatra - Lembuh in Aceh; Sinabung, Sibayak and Sorikmerapi in North Sumatra; Merapi and Talong in West Sumatra -but volcanic activity continues at Kaba near Pasemah, hot springs occur in parts of Bengkulu, and the most famous of contemporary volcanic eruptions (1883) occurred at Krakatau (p. 343). In the same way that the andesitic products of the Krakatau eruption fertilised many of the previously infertile areas of Lampung, so the products of the (geologically) recent volcanic activity northwest of Lake Toba flowed both south and far to the east to give fertility to the Karo highlands and the plantation areas, respectively.
Figure 1.4. A church damaged by an earthquake near Lake Toba in 1983.
A.J. Whitten
One of the greatest ever volcanic eruptions occurred 75,000 years ago when the formation of Lake Toba began. This is very recent in geological terms and stone-age axes have been found below the 'ash' that reached Peninsular Malaysia. The deep Semangko Fault allowed molten material to flow up towards the earth's surface. This created enormous pressures and the land rose up as a result between where the Wampu and Baruman Rivers now flow and formed the Batak Tumour. Eventually the tumour exploded and the 'ash', or Toba tuff, ejected during the eruptions spread over 20,000-30,000 km2, reaching Sri Lanka, the Bay of Bengal and the Andaman Islands. In some areas near Lake Toba the tuff is 600 m thick. About 1,500-2,000 km3 of material was ejected, the greatest volume known from any explosion, and it has been estimated that over 1,000 km3 of this ash was deposited in just nine days (Francis 1983). With so much material removed, the top of the volcano collapsed, forming a huge crater. A second minor series of eruptions built up a second volcano inside the crater, and when this too collapsed the volcano split into two halves - the western slope forming Samosir Island and the eastern slope forming the peninsula between the towns of Parapat and Porsea (fig. 1.5). The second explosion probably occurred as recently as 30,000 years ago (Francis 1983). The Toba crater and island are correctly called a 'resurgent caldera', and at 100 km long, Toba is easily the largest such in the world. For comparison, the extensively reported explosion of Mount St. Helen's in Washington State, U.S.A., ejected only 0.6 km3 of material and left a crater only 2 km in diameter (Francis 1983). Many of the lakes in Sumatra such as Maninjau and Ranau occupy the tops of old volcanoes (Hehuwat 1982).
Figure 1.5. The formation of Lake Toba. (a) After pressure caused the earth's crust to bend upwards, a major vent opened and the major eruption occurred, (b) The loss of so much magma caused the volcanic cone to be forced up again, and a minor explosion occurred, (c) The second cone broke in two, forming Samosir Island and the Parapat Peninsula.
After Hehuwat 1982
SOILS
The first ever soil map produced for a tropical region was of part of Sumatra (Groondsoortenkart van een gedeelte van Deli), published in 1901 (Young 1976). Soil maps of various scales now exist for most of the island, and convenient maps with text have been published by BPPP/Soeprapto-hardjo et al. (1979) and Scholz (1983). A detailed description of the soil types will not be attempted here. Descriptions, uses and limitations of the various soils can be found in the above references.
The eastern fringe of Sumatra and the land on either side of the major rivers are dominated by hydromorphic soil, frequently with alluvial soils or grey hydromorphic soils (so important for the plantation industry) behind them. The swampy eastern portions of Riau, Jambi and South Sumatra are dominated by organosols, but these soils also occur in parts of southeast and south North Sumatra, West Aceh, northwest and south West Sumatra. The majority of lowland Sumatra is covered by yellow podzolic soils formed from a variety of parent materials. The soils of the mountainous areas have very complex distributions but, again, various forms of red-yellow podzolic soils associated with altosols or litosols predominate. Over the limestone areas brown podzolic and renzina soils occur, and andosols and brown-grey podzolic soil appears over the volcanic rocks. The western coast is fringed with sandy regosols for most of its length. Both the western and eastern islands are largely overlain by red-yellow podzolic soils, but the soils on the eastern islands are associated with podzols overlying Tertiary sandstone and with litosols over the intrusive granite.
Adapted from BPPP/Soepraptohardjo et al. 1979
CLIMATES
Palaeoclimate
During the last two million years there has been a worldwide alternation of colder and warmer climates. The colder periods, or glacials, were associated with lower sea levels (fig. 1.6) because cooling of areas that are now temperate locked up a great deal of water as ice, thus preventing its return to the sea (fig. 1.7). Minor changes in sea level have probably continued up to the present (fig. 1.8). The maximum sea level during the last interglacial was only 3 to 6 m higher than the present level (Jancey 1973; Haile 1975; Geyh et al. 1979) but Tjia (1980) reports sea levels up to 50 m higher than present at various times during the last two million years. The minimum sea level was about 180 m lower than at present, more or less outlining the Sunda Shelf and exposing three times more land in the Sunda Region than is visible now. The Sunda Shelf is an extension of the Asian continent (fig. 1.9) and lies between 40-200 m below present sea level. When exposed, the shelf was bisected by the Great Sunda River, which arose between Belitung Island and Borneo and flowed northeast between the North and South Natuna Islands (Tjia 1980). The extremes of sea level did not last very long and for most of the Quaternary the sea lay only some 30-80 m below present sea level.
There is no information about climates for any low-water (glacial) period other than the most recent, about 15,000 years ago. It has been estimated that the regional sea surface temperature was only about 2° to 3°C below today's temperature (Climap 1976) so that the lowlands, at least, remained quite warm. On the highest mountains, however, where ice very occasionally forms today, large glaciers formed (Walker 1982). Until recently, glaciers had been confirmed only on Mt. Kinabalu (Sabah) and on various peaks in New Guinea. Now, however, it has been shown that glaciers once existed on Mt. Leuser, Mt. Kemiri and Mt. Bandahara in the Mt. Leuser National Park (van Beek 1982). The largest of these, on Mt. Leuser, measured about 100 km2 and it is calculated that the temperature at the snowline (then about 3,100 m) was 6°C colder than now. When the glaciers melted, peat began to form and the oldest peat at the bottom of a small lake near the summit of Mt. Kemiri has been given a radiocarbon date of 7,590 ± 40 years before present.
During low-water periods the greater land area and consequent deflection of ocean currents changed weather patterns and air circulation, with the result that rain fell more seasonally and total annual rainfall almost certainly decreased (Walker 1982).
Figure 1.6. The location of past (thicker lines) and present (thinner lines) coastlines. Number represents years before present.
Figure 1.7. Hydrological cycles (a) in warm conditions, and (b) in cold conditions. Note the fall in sea level because water cannot flow to the sea.
Figure 1.8. Changes in sea level during the last 6,000 years.
After Tjia 1980
Present Climate
The climate of Sumatra is characterised by abundant rainfall moderately well distributed through the year, with the wet and dry seasons much less clearly defined than in Java and eastern Indonesia.
Rairfall. Rainfall in Sumatra is very variable, dependent somewhat on the topography, and ranges from over 6,000 mm per year in areas to the west of the Barisan Range, to less than 1,500 mm per year in some areas of the east, which are blocked from humid winds by the Barisan Range and the Malay Peninsula. Out of 594 rainfall stations in Sumatra, 70% have annual rainfall of over 2,500 mm. Over much of the island the driest months are normally associated with the northeasterly monsoon between December and March, and the main rainy season usually falls during the transition period before the northeasterly monsoon and after the southwesterly monsoon which last from May to September. A secondary rainy period occurs in about April which is after the northeasterly and before the southwesterly monsoon. Southern Sumatra, however, has a single pronounced dry season around July, and the northern tip of Aceh has a pronounced dry season in February (Scholz 1983). Figure 1.10 shows the distribution of climatic zones, the definitions of which are as follows:
Zone A—more than the nine consecutive wet months, and two or less consecutive dry months.
Zone B—seven to nine consecutive wet months and three or less consecutive dry months.
Zone C—five to six consecutive wet months and three or less consecutive dry months.
Zone D—three to four consecutive wet months and two to six consecutive dry months.
Zone E—up to three consecutive wet months and up to six consecutive dry months.
Figure 1.9. The Sunda Shelf showing greatest area of land exposed during the driest periods of the last two million years (shaded area), major rivers and present-day coastlines.
After Tjia 7980
"Wet" and "dry" are defined as more than 200 mm rainfall/month and less than 100 mm/month, respectively (Oldeman et al. 1979).
An important point to note is the considerable difference between the climates of Sumatra and Java (table 1.3). On Sumatra 71% of the land area has seven or more consecutive wet months and up to three consecutive dry months, whereas only 27% of Java experiences similar conditions (Oldeman et al. 1979).
Figure 1.10. Climatic zones.
After Oldman et al. 1979
After Oldman et al. 1979
Temperature. The annual fluctuations in temperature are very small for almost all locations in Sumatra. Daily variations are greatest in the drier months when the Sun is not obscured by clouds and when the heat escapes quickly at night because there are no clouds to insulate the earth. The differences in temperature between locations are caused mainly by altitude, and this is discussed further on page 277.
Wind. There is great variability in the winds but in general they blow from the north from December to March, and from the south from May to September. Where there are breaks in the Barisan Mountains, monsoon winds are channelled and wind speed may be greatly increased. Some westerly winds of Sumatra are particularly famous. For example:
Angin Depek—at Air Tawar near Takengon between April and October. This stormy wind is named after a fish that comes to the surface at this time and is easily caught.
Angin Bohorok—in areas of North Sumatra. It is not feared because of its strength but because it is very dry and can damage crops, particularly tobacco. Angin Bohorok is a föhn wind, that is, a depression (low atmospheric pressure) moving to the east of the Barisan Range, draws air into itself from the west of the range. The air ascends the western slopes, clouds form and there is heavy rain. When it reaches the eastern slopes, the air is still warm, but it has lost most of its moisture, so it blows down as a very warm, dry wind. It starts in the Karo highlands and is funnelled into upper Langkat and upper Deli Serdang through the Bohorok depression.
Angin Padang Lawas—east of Padang Sidempuan is a particularly serious föhn wind, drying the soil and making most forms of agriculture virtually impossible (Oldeman et al. 1979).
VEGETATION
Palaeovegetation
The oldest Sumatran forests for which we have evidence are those that formed the coal seams during the Carboniferous period, about 300 million years ago. Coal is the highly compressed remains of undecayed swamp vegetation, sandwiched between layers of marine sedimentary deposits. These primeval swamp forests covered much of the earth many millions of years before the first gymnosperm (e.g., conifer) or angiosperm (flowering) trees evolved. The earliest 'trees' were in fact primitive ferns, and some, such as the giant club-moss Lepidodendron, reached 30 m in height. By the Tertiary many of the plants now found in forests had developed; for example, a leaf imprint of a Dipterocarpus leaf and a fossil dipterocarp fruit have been found in southern Sumatra dating from this era (Ashton 1982).
The tropical rain forests of today have been commonly regarded as relics from the Tertiary period, a kind of living museum, and phrases such as 'unchanged for thousands of years' are often written. Evidence from many tropical regions now show that this is wrong (Flenley 1980a,b). The climate has changed during at least the last 30,000 years (p. 12), both in temperature and rainfall, and this in turn affected the vegetation.
In the drier, more seasonal periods of the Pleistocene the areas with a wet, non-seasonal climate would have contracted as the area of seasonal climate extended, but the exact amount of change is unknown. Populations of plants restricted to the wet, non-seasonal forest would therefore have had their ranges constricted, but contact between populations could have been maintained to indeterminate degrees by occasional transfer between patches of suitable forest in the seasonal areas, as indeed occurs today in parts of Java (Whitmore 1982). It is possible that monsoon forest and perhaps even dry savannah forest (Whitmore 1984) would have occupied some of Sumatra and other parts of the Sunda Region. There is, however, no evidence from the few studies of preserved pollen from lowland sites in the region, of any replacement of non-seasonal forest by seasonal forest during or since the Tertiary (Maloney 1980a,b; Morley 1980, 1982; Whitmore 1982b), but this may yet be revealed by future research.
The palaeovegetation of Sumatra has been studied by investigating fossil pollen preserved in sediments of small lakes in the Kerinci and Toba regions. The sediment core taken from Lake Padang at 950 m south of Lake Kerinci revealed evidence of vegetation changes over the last 10,000 years. About 8,300 years ago an upper montane forest characterized by Myrica trees and the conifer Podocarpus gave way to a lower montane forest with abundant oaks (Fagaceae), suggesting that as the climate warmed up, so the upper montane species2 retreated up the mountains (Morley 1980, 1982).
The sediment core taken from Pea Sim-Sim at 1,450 m on the Siborong-borong Plateau south of Lake Toba was found to cover the last 18,500 years. Up to 16,500 years ago a mosaic of subalpine and upper montane forest probably existed on the plateau (Maloney 1980a,b). Oak forest became established about 16,500 years ago and persisted until ± 12,000 years ago. 7,500 years ago montane vegetation becomes less important in the samples and Eugenia species, possibly from swamp forest, predominate. From these studies it appears that before the climate began to warm about 8,000-9,000 years ago, the vegetation zones (next section) had been lowered by 350-500m. A review of the late Pleistocene vegetation in Sumatra has been published by Maloney (1983c).
Present Vegetation
Sumatra supports a wide range of vegetation types and, due to its recent connection to Asia (p. 12), these are very rich in species. For species diversity the Sumatran forests are comparable to the richest forests of Borneo and New Guinea and are richer than those found on Java, Sulawesi and other small islands (Meijer 1981). Sumatra has 17 endemic genera of plants (compared with 41 in Peninsular Malaysia/southern Thailand; 59 in Borneo; and 10 in West Java), and has some unique and spectacular species such as Rafflesia arnoldii, the largest flower in the world, and Amorphophallus titanum, the tallest flower in the world.
Sumatra supports a broad altitudinal range of vegetation types (chapter 9), and some other distinctive vegetation types characteristic of the soil or topography on which they occur (chapter 8). Dipterocarp trees such as Shorea, Dipterocarpus and Dryobalanops dominate much of the tall lowland forest, forming a continuous canopy, and are capable of producing over 100 cubic metres of high-quality logs per hectare (chapter 7). The peat swamps of the east coast show characteristic forest formations of great commercial importance and botanical interest (chapter 5). The sandy west coast supports various types of coastal forest (chapter 3), but the east coast is dominated by very extensive areas of mangrove forest (chapter 2). In the south, large peaty freshwater swamps are found (chapter 6). These vegetation types are summarised in table 1.4, and the distribution of the natural vegetation (i.e., not disturbed by man) of Sumatra is shown in figure 1.11.
The bibliographies by Tobing (1968) and Jacobs and de Boo (1983) are very useful as preliminary means of exploring the older literature on Sumatran vegetation and plants.
The distribution of vegetation types between provinces is uneven (table 1.5) - for instance, Riau has no montane forest but has the largest areas of peat swamp and mangroves, and West Sumatra has almost no mangroves and little swamp but considerable areas of montane forest.
The natural, remaining and protected areas of different vegetation types are shown in table 1.6 both for 1982 and for 1996. These figures have been calculated from a range of sources such as air photos, satellite images, vegetation maps, and consultative meetings (Laumonier 1997; MacKinnon 1997). The largest percentage drops are for heath forest and freshwater swamp, the first of which is unlikely to lead to any productive land use (see p. 253). The loss of mangroves is due to widespread conversion to coastal aquaculture. Also of major significance is the large loss of freshwater swamp probably to irrigated agriculture. A sense of these losses can be gained from the forest cover maps from 1932 and 1982 (fig. 1.12) and from 1996 (fig. 1.13). The extreme patchiness of lowland forests is shown in figure 1.14. Considering the fires of 1997-98 the current figures, if available, would show an even greater loss, particularly for peat swamp forest, freshwater swamp forest, and the other inland lowland forests.
After van Steenis 1957, and Whitmore 1984. For a more detailed division see the chart by Kartawinata 1980
*The figure for heath forest may be a considerable overestimate (see p. 253).
After FAO/MacKinnon 1982a
Figure 1.11. Natural vegetation.
After MacKinnon 1997
Figure 1.12.
A) Remaining forest in 1932;
A) van Steenis 1935;
Figure 1.12.
B) remaining forest in 1982.
B) After FAO/MacKinnon 1982a
Figure 1.13. Remaining forest in 1996.
After Conservation Science Program—World Wildlife Fund-U.S.A.
The approximate 1996 remaining forest areas, existing reserves and proposed reserves in each of the provinces are shown in figures 1.15 to 1.22. It should be noted that it is very difficult to differentiate selectively logged/disturbed forest from primary forest by analysis of air photos or satellite images. The forest areas given are, therefore, where tree cover exists rather than where unspoilt natural ecosystems may be found. Most types of forest which have suffered limited disturbance are able to regenerate successfully if left alone (p. 339) and so the forest areas shown do have ecological meaning. Table 1.6 shows clearly that certain vegetation types have been reduced in area far more than others and that some vegetation types still have no protection. Montane forests have lost an average of one-third of their natural area, whereas between two-thirds and four-fifths of lowland forest have disappeared. This reflects the severity of land-use conflicts. Note that the lowland forests which have been reduced the most are those on the fertile alluvial and volcanic soils. Generally less than 10% of the natural vegetation types currently receive any protection, and those vegetation types with the least area in reserves are those that have been most reduced in area.
Figure 1.14. The remaining lowland forests of Sumatra, 1996.
After WWF-US
*The estimate for heath forest may be too high - see p. 253.
After FAO/MacKinnon 1982; MacKinnon 1997
Figure 1.15. Remaining forest, reserves and proposed reserves in Aceh. 1, 2 and 3. Gunung Leuser; 4 and 5. Serbojadi; 6. Lingga Isaq; 7. Kuala Langsa; 8. Jantho; 9. Gunung Seulawah Agam; 10. Aneuk Laut; 11. Langsa Kemuning; 12. Kuala Jambu Air; 13. Rantau Pala Gadjah; 14. Singkit Barat; 15. Pulau Bangkaru; 16. Perairan P. Weh and P. Beras; 17. Perluasan Gunung Leuser Bengkong; 18. Pulau Simeulue; 19. Curah Serbolangit.
After FAO/MacKinnon 1982a
Figure 1.16. Remaining forest, reserves and proposed reserves in North Sumatra. 1. Sekundur; 2. Langkat Selatan; 3. Langkat Barat; 4. Lau Debuk-debuk; 5 and 14. Sibolangit; 8 Karang Gading/Langkat Timur Laut; 6. Dolok Tinggi Raja; 7. Dolok Surungan; 9, 10, 11 and 12. Nias; 13. Padang Lawas; 15. Bandar Baru; 16. Sibolga; 17. Dolok Sembilin; 18. Dolok Sepirok; 19. Sei Prapat; 20. Lau Tapus.
After FAO/MacKinnon 1997
Figure 1.17. Remaining forest, reserves and proposed reserves in West Sumatra. 1. Rimbo Panti; 2. Batang Palupuh; 3. Beringin Sati; 4. Lembah Anai; 5. Megamendung; 6. Lembah Harau; 7 and 10. Indrapura (Gunung Kerinci); 8 and 9. Teitei Batti; 11. Lunang; 12. Malampah - Alahan Panjang; 13. Lembah Anai extension; 15. Danau Maninjau; 16. Gunung Singgalang; 17. Gunung Merapi; 18. Gunung Sulasihtalang; 19. Bukit Sebelah and Batang Pangeran; 20. Bajang AirTarusan Utara; 21. Kambang/Lubuk Niur; 22. Gunung Sago/Malintang/Karas; 23. Muara Siberut.
After FAO/MacKinnon 1982a
Figure 1.18. Remaining forest, reserves and proposed reserves in Riau. 1. Kerumutan Baru; 2. Pulau Berkeh; 3. Pulau Burung; 4. Pulau Laut; 5. Danau Bawah and Pulau Besar; 6. Bukit Muncung and Sel Gemuruh; 7. Muara Sungai Guntung; 8. Seberida; 9. Bukit Baling Baling; 10. Kerumutan Lama; 11. Peranap; 12. Siak Kecil; 13. Pantai Cermin; 14. Pulau Bulan; 15. Pulau Penyengat; 16. Istana Sulatan Siak; 17. Candi Muara Takus; 18. Pulau Pasar Panjang; 19. Gian Duri; 20. Buaya Bukit Batu; 21. Danau Tanjung Padang; 22. Danau Belat/Besar Sekok/Sarang Burung; 23. Air Sawan; 24. Bakau Muara; 25. Bakau Selat Dumai; 26. Tanjung Sinebu/Pulau Alang Besar; 27. Natuna Besar.
After MacKinnon 1997
Figure 1.19. Remaining forest, reserves and proposed reserves in Jambi. 1. Berbak; 2. Gunung Indrapura; 3. Bukit Topan; 4. Gunung Tujuh; 5. Batang Marangin Barat/Menjuta Ulu; 6. Sangir Ulu/Batang Tahir; 7. Kelompok Hutan Bakau Pantai Timur; 8. Bukit Besar; 9. Gunung Sumbing/Masural; 10. Hutan Sinlah; 11. Batang Bungo; 12. Singkati Kehidupan.
After MacKinnon 1997
Figure 1.20. Remaining forest, reserves and proposed reserves in South Sumatra. 1. Gumai Pasemah; 2. Isau - Isau Pasemah; 3. Gunung Raya; 4. Rawas Hulu Lakitan; 5. Subanjeriji; 6. Dangkau; 7. Terusan Dalam; 8. Bentayan; 9. Paraduan Gistang; 10. Sungai Terusan Dalam; 11. Bukit Halal; 12. Gunung Patah; Bepagut, Muara Duakisan; 13. Bukit Natiagan Hulu/Nantikomering Hulu; 14. Bukit Dingin/Gunung flomnn' 15. Palembang Plabiu.
After MacKinnon 1997
Figure 1.21. Remaining forest, reserves and proposed reserves in Bengkulu. 1. Sumatra Selatan I (part); 2. Semidang Bukit Kabu; 3. Nanuua; 4. Bukit Gedang Seblat; 5. Bukit Gedang Seblat (northern extension); 6. Bukit Gedang Seblat (southern extension); 7. Toba Penanjung; 8. Pungguk Bingin; 9. Dusun Besar; 10. Bukit Raja Mandara/Kaur Utara; 11. Bukit Hitam/Sanggul/Dingin; 12. Bukit Balairejang; 13. Hulu Bintuanan/Palik Lebang/Lair/Wais Hulu/Lekat/Bukit Daun; 14. Bukit Regas/Hulu Sulup; 15. Bukit Kaba.
After MacKinnon 1982a
Figure 1.22. Remaining forest, reserves and proposed reserves in Lampung. 1. Way Kambas; 2. Sumatra Selatan I; 3. Gunung Betung; 4. Krui Utara/Bukit Punggul; 5. Tanqkitebak/Kota Agung Utara/Wai Waja; 6. Tanggamus; 7. Rebang.
After FAO/MacKinnon 1982b
In terms of the loss of genetic diversity, the figures in table 1.7 show that in general the vegetation types under most pressure, such as lowland forest and heath forest, are also the richest or most diverse in terms of plant species. Similarly, the vegetation types under most threat support the greatest diversity of plant species. For example, 245 Sumatran bird species live in lowland forest, 158 species in lower montane forest, 62 species in upper montane forest, and only two commonly live in the sub-alpine zones (p. 303) (FAO/MacKinnon and Wind 1979).
After FAO/MacKinnon 1982b
FAUNA
Palaeofauna
Nothing is know for certain about the Sumatran Pleistocene fauna or the fauna of any earlier period. Dubois investigated some caves in the Padang highlands in 1890 and found subfossils of 15 mammal species from several thousand years ago (table 1.8) (Dubois 1891). The prehistoric remains of orangutan, gibbons, leaf monkeys, long- and pig-tailed macaques, tapir, banteng cattle and Javan rhinoceros show that all of these species are somewhat smaller in size today than at that time, and similar size differences have been found for animal remains in Niah caves, Sarawak (Hooijer 1962). This reduction in size is probably a response to the warmer temperatures now prevailing (Edwards 1967). Larger animals have a lower area: volume ratio, thus reducing the rate of heat loss. As a result, larger animals are better able to survive at lower temperatures.
Orangutan are found only north of Lake Toba, leopard and banteng are now extinct in Sumatra and the Javan rhinoceros is almost certainly extinct in Sumatra. Inhabitants of Deli, near what is now Medan, are said to have known a 'buffalo rhinoceros' (peaceful) and a 'pangolin rhinoceros' (savage). The latter was probably the Javan rhinoceros and would doubtless have been hunted to ensure people's safety. Two Javan rhinoceros were shot at Tanjung Morawa (just outside the present limits of Medan) in 1883, and the last eight known from Sumatra were shot in South Sumatra between 1925 and 1982 (Hazewinkel 1933). An unconfirmed shooting of a Javan rhinoceros on the southern boundary of the Way Kambas National Park in 1961 has also been reported (FAO/Wind et al. 1979).
Some mammals of the Sunda Region used to be more widespread than they are today (Hooijer 1975) (table 1.9), perhaps because the flooding of land bridges prevented recolonisation by a species after it had become extinct on one island. It is important to remember that the low sea levels were accompanied by lower temperatures, thus allowing plants and animals of cooler regions, such as the mountain goat Capricornis sumatraensis, which is nowadays restricted to mountains, to expand their range and cross over to Sumatra from the Asian mainland (p. 291).
The Niah caves of Sarawak have revealed similar finds to the Padang caves, but in the lowest (= oldest = 30-40,000 years old) levels of cave sediment at Niah, remains of a giant pangolin Manis palaeojavanica have been found (Harrisson et al. 1961; Medway 1972c). This had previously been found in Java at the famous fossil sites of Trinil, Rali Gajah, Jebis, Ngan-dong and Sampling. These sites give the best impression in Southeast Asia of what the Pleistocene fauna was like.
After Hooijer 1975, and the Earl of Cranbrook, (pers. comm.)
Fossils only sample part of the fauna; for example, the larger animals are emphasised because they have more robust bones. In addition, fossils only form under certain conditions; most bones rot in tropical rain forest and so forest fauna are under-represented, but preservation can occur in open plains, along lake shores, along rivers and in dry caves. Considering the land bridges which have existed between Java and Sumatra, some if not most of the Javan fossil fauna probably once lived on Sumatra, and it is therefore worthwhile to consider the palaeofauna of Java.
Among the most interesting finds in the Javan fossil beds dating from about 700,000 years ago were various forms of man's immediate forbear, Homo erectus, who had probably arrived from southern China. Homo erectus was, as the name suggests, erect in stature, and ate mainly seeds and fruit, hunted opportunistically or scavenged, used simple stone tools and lived in groups. His demise was probably caused by an inability to compete with the more advanced Homo sapiens.
Remains of eight species of elephants, as many as three coexisting at one time, were found in the same fossil beds as the human remains, together with remains of tapir and three species of rhinoceros. There were usually three species of pig living in the same area at any one time, two species of antelope, a hippopotamus and three or four species of deer. These forms were preyed upon by hyenas, wild dogs, early forms of the tiger and leopard as well as sabre-toothed cats (Hooijer 1975; McNeely 1978; Medway 1972c).
In the absence of relevant information from Sumatra itself, one is left with many question about the changes - man-made, climatic, etc. - that have influenced the fauna which exists today. One such question is: why should the leopard have become extinct when it occurred on Sumatra until only a few thousand years ago, still exists on Java and in Peninsular Malaysia, is excellently adapted to hunting in mountains, forests or plains, and when there is an abundance of monkeys and other suitable prey?
Present Fauna
Sumatra is one of the richest islands in Indonesia for animals. It has the most mammals (201 species) and its bird list (580 species) is second only to New Guinea. Indeed, new mammal species are still being discovered or recognised (Bergmans and Hill 1980; Musser 1979). This great wealth is due to the large size of Sumatra, its diversity of habitats and also its past links with the Asian mainland (pp. 12 and 42). Nine species of mammal are endemic to mainland Sumatra and a further 14 species are endemic on the isolated group of Mentawai islands (table 1.10).
Sumatra has 15 other species confined only to the Indonesian region, including orangutan. The island also harbours 22 species of Asian mammals found nowhere else within Indonesia (table 1.11). In addition, Sumatra has populations of several mammals which are virtually extinct in other parts of Indonesia (e.g., Sumatran rhinoceros, elephant, tiger and the dhole or forest dog Cuon alpinus) (FAO/van der Zon 1979).
* Endemic to the Mentawai Islands.
Adapted from Corbett and Hill 1992; Ruedi and Fumagalli 1996
Figure 1.23. Young Mentawai gibbon, one of the four primate species endemic to the Mentawai Islands off West Sumatra.
A.J. Whitten
Sumatra has an extremely rich bird fauna. Of its 580 species, 465 are resident and 21 are endemic (table 1.12). The Sumatran list includes 138 bird species confined to the Sunda Region, including 16 species found only on Java and Sumatra and 11 species occurring only on Borneo and Sumatra. Thirty-one Asian species found in Sumatra are not found on any other Indonesian islands (e.g., the great hornbill Buceros bicornis) (FAO/MacKinnon and Wind 1979).
A phenomenon exhibited by birds is that of migration or making regional seasonal movements between two areas.3 Sumatra has about 120 species of migrant birds (FAO/van der Zon 1979; King et al. 1975) but very little has been confirmed about their movements. Studies have been conducted in Peninsular Malaysia for several decades, however, and we can be sure that the general principles found for migrant birds there apply also to Sumatra. The majority of the information below comes from Medway (1974b) and Nisbet (1974).
After Andrews 1992; van Balen (pers. comm.)
About 60% of the migratory species that visit the area breed only in the Palaearctic (see fig. 1.24), 25% breed in the Palaearctic and tropical south and/or Southeast Asia, and 15% breed elsewhere in the Oriental Realm. It is estimated that perhaps 12-15 million birds leave the eastern Palaearctic for the south every year, although many species do not come further south than 10°N (e.g., India, the Philippines and Indochina). They fly south in order to avoid the winter of the northern regions when food is in short supply, and therefore they would be expected to be seen in Sumatra from September to February with a few present in March and August. It seems likely that many species merely pass through Peninsular Malaysia on migration and that Sumatra is their ultimate destination. It has been suggested by Nisbet (1974) that 11 species make Peninsular Malaysia and/or Sumatra their principal wintering areas (table 1.13).
Most birds migrate by night since they need the day to feed but some, such as birds of prey, which have to use hot air currents to gain height in the air, and barn swallows Hirundo rustica, which feed on small insects while flying, migrate by day. Huge congregations of swallows can be seen roosting along telephone or electricity wires in many towns (p. 414) - for example, along Jl. Prof. M. Yamin in Jambi and the J1. Sutomo area in Medan. Barn swallows have been studied in urban and rural Peninsular Malaysia by Medway (1973b) and comparative studies from Sumatra would be valuable.
After Nisbet 1974
The actual mechanism of migration has been studied a great deal and it seems that birds orientate themselves with reference to both star patterns and the earth's magnetic field (Wallraf 1978; Wallraf and Gelderloos 1978; Wiltschko and Wiltschko 1978). Part of the knowledge of migration is inherited but young birds frequently make errors of direction and distance. For these young birds in particular, migration is hazardous because they have no experience of the destination yet have to find a suitable location, find food in sufficient quantities to build up fat stores for the trip back north, and to leave on time. In the few species that have been studied in Peninsular Malaysia, the date of departure of a species varies by only three or four days from year to year. It seems that some environmental cues such as high or low insect abundance, leaf-fall of trees (see p. 219) or some climatic feature must be responsible. There is no shortage of possible environmental cues: what is needed is an investigation into their reliability, and observations of whether birds actually respond to them.
Reptiles, amphibians and fishes have been studied taxonomically in depth by authors such as de Beaufort, Bleeker, Fowler, van Kampen, Kottelat, Koumans, de Rooij, Tate Regan and Weber, but the amount of ecological knowledge on these animals is extremely small. There are enormous gaps in our knowledge of invertebrates, not just in knowing something about their ecology, but also in knowing simply what exists. The bibliographies by Tobing (1968) and Jacobs and de Boo (1983) are extremely useful as preliminary means of exploring the earlier literature on the Sumatran fauna.
BIOGEOGRAPHY
Differences between Realms/Zones
For the purposes of zoogeography the world is divided into six realms (fig. 1.24) and Sumatra falls within the Oriental Realm. The majority of animal species in the Oriental Realm are not found elsewhere and in some cases whole subfamilies, families, and even orders are confined within its boundaries, such as leaf monkeys (subfamily Cercopithinae), gibbons (family Hylobatidae), and flying lemurs (order Dermoptera). Only one family of birds (which are obviously more mobile than mammals) is endemic to the Oriental Realm and that is the Irenidae (fairy blue-birds Irena, leafbirds Chloropsis and ioras Aegilhina) (King et al. 1975). This family seems to have its centre of evolution in Sumatra (Dunn 1974).
Figure 1.24. Zoogeographical realms of the world.
Within the Oriental Realm there are distinct differences between regions; the Isthmus of Kra in southern Thailand, which is usually taken as the boundary between the Sunda Region (which includes Sumatra) and mainland Asia, is one of the more obvious regional boundaries. It coincides with a change in vegetation (dry to the north and wet to the south) which is reflected in the fauna (fig. 1.25).
A peculiar zoogeographic distribution has been described by Hoffman (1979). The millipede Siphoniulus albus used to be the only species of a monotypic genus, family and order, and until recently was known from only one specimen found near Lake Maninjau in 1890. A second member of the genus has now been found in Guatemala and Hoffman argues that human intervention in this distribution is extremely unlikely. How one explains this widely separated distribution has not yet been established.
Figure 1.25. Range limits of lowland forest birds in the Malay Peninsula. The length of the horizontal bars is proportional to the number of species/subspecies reaching their limit at the different latitudes.
After Wells 1974
For the purposes of phytogeography, Sumatra falls within the floral region of Malesia (which includes all the Indonesian islands, northern Borneo, Papua New Guinea, southern Thailand and the Philippines) and its flora is distinct from that of Asia and Australia. The disjunction at the Isthmus of Kra is very marked, with 375 genera of plants reaching their northern limit there and 200 genera their southern limit. Within the Malesian region, Sumatra is classified as being part of West Malesia together with the Philippines, Borneo, part of southern Thailand, and Peninsular Malaysia (van Steenis 1950) (fig. 1.26). There are some similarities with the western part of Java but that is classified as a sub-region of South Malesia.
Figure 1.26. Floral region of Southeast Asia.
After van Steenis 1950
Differences within the Sunda Region
It has already been shown that the flora and fauna of the Sunda Region are similar largely because of the land bridges that once connected the various parts (pp. 12, 17, 34). When the sea level last rose, Sumatra was cut off first from Java, then Borneo, and lastly Peninsular Malaysia, and this is reflected in the degree of similarities between the biota (figs. 1.27, 1.28, 1.29). For both animals and plants, Java is more different from Sumatra than either Borneo or Peninsular Malaysia.
Not all species arrived in, or moved through, the Sunda Region by the same routes or at the same time, and this is reflected in their distributions (table 1.14). With our present knowledge it is not possible to state precisely why the tiger never managed to get to Borneo or the lesser mouse deer to Java but the information available about climate, sea levels and vegetation allows hypotheses to be formulated.
Figure 1.27. Percentage of combined totals of plant species shared between the major parts of the Sunda Region.
After FAO/MacKinnon 1982b
Figure 1.28. Percentage of combined totals of bird species shared between the major parts of the Sunda Region.
After FAO/MacKinnon 1982b
Figure 1.29. Percentage of combined totals of mammal species shared between the major parts of the Sunda Region.
After FAO/MacKinnon 1982b
Care must be taken when discussing the apparent absence of a species. For instance, it was only recently that one particular biogeographical anomaly was resolved. Isoetes is a type of aquatic fern with a worldwide distribution but it had never been collected on Sumatra until it was found at the small lakes of Danau Sati and Danau Landah Panjang near Kerinci in 1972 (Flenley and Morley 1978). Similarly, the bent-winged bat Miniopterus pusillus was known from most of the Oriental Realm except Sumatra (Lekagul and McNeely 1977) until a team from CRES caught one in a cave in North Sumatra in 1982 (Hill 1983).
Many animals are dependent on walking or being carried on rafts for their dispersal from one area to another, but birds, bats, and many insects can fly and can be blown to new areas by strong and perhaps freak winds. Some spiders can also be dispersed by wind. For example, three small nets were held 18 m above the sea surface from a boat sailing in part of the East China Sea, 400 km from the nearest land, and after about two weeks 105 young spiders had been caught. Many of the species caught which are known from Sumatra are also known from Sri Lanka, China, the Philippines and even Australia and Africa, a distribution which illustrates the effectiveness of their means of dispersal (Okuma and Kisimoto 1981).
Differences within Sumatra
It is well known that remote, small islands support fewer species than large islands close to the mainland. After a certain length of time the total number of species on an island will remain more or less constant, and this total number of species is an equilibrium between the colonisation of the island by immigrant species and the extinction of its existing species. The rate of colonisation is clearly higher when an island is near the mainland because more species stand a chance of crossing the gap. Also, the rate of extinction is clearly greater when an island is smaller because the population of any species will be smaller and the chance of disease and other events reducing the population to zero or a non-viable number will be greater. These effects are illustrated in figure 1.30 and represent the foundation of the Theory of Island Biogeography.
Figure 1.30. The relative number of species on small, distant islands (a) and large, close islands (c). The number of species on large, distant islands or small, close islands, (b) is intermediate.
The relationship between island size and number of species is relatively constant for a given group of animals and plants. An example for birds is shown in figure 1.31 and an analysis for mammals has recently been published (Heaney 1984). In general, however, reducing the island area by 10, halves the number of species. The depauperisation of species is not random and the large animals (which have relatively large range requirements and low population densities) are usually the first to be lost. Thus there are no tigers, clouded leopard, elephant or Sumatran rhinoceros on any of the islands west of Sumatra. It often happens on islands, however, that a few species are more abundant and fill a wider niche than they do on the nearby mainland where they have more competitors for the same resources (Whitten 1982a; Whitten 1980).
Island size also affects the body size of a particular species. In Prevost's squirrel Callosciurus prevosti, for example, which is found in Sumatra, Peninsular Malaysia and Borneo, the smallest individuals are found on the smallest islands. Body size increases with island size and the largest individuals are found on Penyelir Island (280 km2) and Rupat Island (1,360 km2) in Riau. On progressively larger islands body size decreases, but the Prevost's squirrels found on mainland Sumatra and Borneo are not as small as those found on very small islands. The reasons for this bell-shaped curve are the differences found between islands in predation pressure, food limitations, competition between species, and selection for physiological efficiency (Heaney 1978).
Figure 1.31. The number of land and freshwater birds on various islands and archipelagos in Indonesia, together with the Philippines and the whole of Irian. 1. Christmas; 2. Bawean; 3. Enggano; 4. Sawa; 5. Simeulue; 6. Alor; 7. Wetar; 8. Nias; 9. Lombok; 10. Belitung; 11. Mentawai; 12. Bali; 13. Sumba; 14. Bangka; 15. Flores; 16. Sumbawa; 17. Timor; 18. Java; 19. Sulawesi; 20. Philippines; 21. Sumatra; 22. Borneo; 23. New Guinea.
It was clear from table 1.10 on page 37 that the Mentawai Islands have a large number of unique mammals found nowhere else in the world. In fact, 85% of the non-flying mammals are endemic at some level (Anon. 1980a). The reason for this can be seen in figure 1.6: it is more than half a million years since the Mentawai Islands had a land connection via the Batu Islands to the mainland. Long geographical isolation of the islands has allowed the evolution of endemic species and the survival of relicts of an early Indo-Malayan fauna and these 'primitive' forms are extremely significant in studies of the evolution of present Sumatra and Asian biota (Anon. 1980a).
The islands to the east of Sumatra have recent connections with the larger landmasses (Dammerman 1926). They may even have acted as stepping stones to other islands for animals drifting across the sea on rafts of rotting vegetation carried down rivers during floods. From island biogeographic theory we would expect these islands to have relatively few species and not a great number of endemic forms. This appears to be the case: the Riau/Lingga archipelago and Anambas/Natuna archipelago have no endemic mammal species (although they have some endemic subspecies), and their mammals are far more similar to those on Sumatra and Borneo than are those of Mentawai (table 1.15). It also appears that the mammals of Bangka and Belitung Islands and the Anambas/Natuna archipelago have a greater affinity with Borneo than with Sumatra.
Two Sumatran islands, Simeulue and Enggano, have probably never had land connections with the mainland and have extremely impoverished faunas-for instance, there are no squirrels on either island. Simeulue has three endemic species of snake, one endemic bird (and 20 endemic subspecies-one of a species not found on the Sumatran mainland), and a type of macaque and a type of forest pig that may be distinct species (Mitchell 1981). Enggano has 17 species of mammal (a similar number to Simeulue) of which three are endemic (De Jong 1938; Sody 1940). Two of the 29 bird species are endemic as is one of the snakes (Lieftinck 1984).
The contrast between the biota of Sumatra's islands and that of Sumatra itself is by no means the only variation that exists. Within the mainland of Sumatra there are barriers caused by rivers that are too wide, or mountains that are too high, for animals to cross. One of the best illustrations of this is the distribution of the many species and subspecies of leaf monkeys (fig. 1.32). The major boundaries limit the distributions of whole species or separate ecologically equivalent species. The minor boundaries limit gene exchange and separate subspecies.
Perhaps the most surprising zoogeographic boundary, because it is not obviously caused by a river or strait, is that which runs SW/NE through Lake Toba. Seventeen bird species are found only to the north of Lake Toba and 10 only to the south (J. MacKinnon, pers. comm.). Table 1.16 shows some examples of split distributions among the mammals. In the cases of the tapir and tarsier there is nothing that entirely replaces them in their ecological niche in the north, but Thomas' leaf monkey is more or less the ecological equivalent of the banded leaf monkey, as the white-handed gibbon is to the dark-handed gibbon (Gittins 1978). Clearly there must have been a cessation of gene flow along the islands that led to such isolated and differentiated faunas. The division between the northern and southern faunas approximately coincides with the position of Lake Toba, and is possibly caused by the wide barrier of bare, volcanic material resulting from the huge eruption. Alternatively, the area affected by drying föhn winds (p. 17) near Padang Lawas may once have been covered with species-poor heath forest (p. 253) and may have represented a significant barrier to animal movement, particularly during the drier periods of the Pleistocene. The Sumatran range of the tapir (found also in Peninsular Malaysia) and of the tarsier (found also in Borneo), is restricted to the lowland forests south of Lake Toba, and presumably these never reached further north.
Data from FAO/van der Zon 1979
Figure 1.32. Zoogeographic boundaries and units. Thicker lines indicate major boundaries, thinner lines indicate minor boundaries.
After MacKinnon, unpubl.
Figure 1.33. The distinctive rhomboidal leaves of the rare palm Johannesteijsmannia altifrons in logged-over forest in Sekunder, North Sumatra.
A.J. Whitten
Figure 1.34. The dried leaves of the rare lowland forest palm Johannesteijsmannia altifrons used as roofing material near Sekunder, North Sumatra.
A.J. Whitten
Many species of plants and animals are restricted to specific habitats within a zoogeographic region, such as dry lowland, mountaintops or mangrove, either because they are unable to compete successfully against other species in other habitats, or because they are tolerant of only a certain range of conditions. One plant with such subtle restrictions to its distribution is the handsome palm Johannesteijsmannia altifrons. This palm has been collected from various localities in the northern half of Sumatra but it is most accessible in the Sekundur portion of the Mount Leuser National Park, around which local people use the leaves for roofing their houses (fig. 1.34). It is found only on hillsides, not ridges or valley bottoms, and may be present in one valley but absent in the valleys on either side, despite seemingly identical geology, vegetation and topography (Dransfield 1972).
PREHISTORY AND HISTORY
Prehistory of Man
The prehistory of Sumatra is poorly known, even by comparison with that of neighbouring landmasses. Unlike Java, Sumatra has as yet produced no fossil remains of early hominids (human ancestors). Unlike Java, Borneo, the Malay Peninsula, Sulawesi, Flores and Luzon, it contains few if any non-marine fossil deposits of pre-Holocene/post-Mesozoic date.
It is not known when stone-age man arrived in Sumatra, but what may be rough stone tools found in Peninsular Malaysia beneath ash from the Toba eruption some 30,000 years ago might indicate the presence of stone-age man in the Sunda Region from at least that time. What effect the fall of dust had on those people is hard to imagine.
Early man throughout the world inhabited caves. Caves provided shelter, warmth during the periods of lower temperatures, a certain degree of security, and were the focal points of activity (Harrisson 1958). In the Sunda Region the most extensive archaeological excavations of caves have been at Niah, Sarawak, but a similar body of knowledge could result from work at Tiangko Panjang cave in western Jambi. This just one of about 10 sites in southern Sumatra discovered at the start of this century that has revealed stone and wood tools (fig. 1.35), but surveys showed it was the site most likely to contain information spanning a long period (Bronson and Asmar 1976).
Tiangko Panjang cave is about 13 m above the valley of the Tiangko River, a tributary of the Mesumai River. The rock face above the cave entrance is steep, and although the descent to the valley floor is less steep, it is sufficiently difficult to make the location secure from unwanted intrusions. The cave is a tunnel 24 m long and 5-8 m high and wide. With almost 200 m2 of floor space, clear headroom, good ventilation, and a well-lighted and sheltered courtyard as well as a secure location, the cave would seem to be a desirable dwelling place for early men.
Figure 1.35. Sites in southern Sumatra where prehistoric stone tools have been found. Caves in the Payakumbuh Region were probably inhabited by prehistoric man; a CRES team visiting caves at Lho'Nga, North Aceh, found sea shells in cave deposits which were probably taken there by prehistoric man.
After Bronson and Asmar 1976
A few small pits have been dug in the cave floor, and radiocarbon dating of charcoal samples from different depths showed that man was inhabiting the cave at least 10,000 years ago when the cave floor was 135-160 cm below its present level.
The floor deposits contained hundreds of small stone flakes, many of which had been used as tools. This indicates a culture rather more advanced than that which produced large rough flakes (Palaeolithic), but not as advanced as that which produced, for example, smooth axe heads (Neolithic). Remains of vertebrate animals included a single human tooth, a few deer teeth, a few bone fragments (usually burned) from deer-sized animals, numerous bat bones, many turtle shell fragments, moderate numbers of vertebrae and long bones from small-chicken sized birds, a moderate number of fish vertebrae, and teeth of rat-sized rodents. The most common invertebrate remains were snails, the majority of them from two edible freshwater species, Brotia costula and Pila sp. (fig. 1.36). Pila is now uncommon near the Tiangko River but Brotia is often eaten by the present inhabitants of the area. Remains of freshwater snails have also been found in Niah cave (Harrisson 1958) and in caves in Peninsular Malaysia (Evans 1918; Medway 1966a).
Figure 1.36. Shells of Brotia and Pila, both of which were eaten by prehistoric man. Each is about 1 cm long.
There is no sign of agriculture or domestication of animals in any of the remains. We do not know if these early men had begun to experiment with agriculture or animal husbandry as there are no archaeological remains to offer proof. Indications of rice in cave deposits are generally clear enough and have been found in caves in Sulawesi dating from 6,000 years ago (Glover 1979a). It seem that the inhabitants of Tiangko Panjang were successful enough at exploiting wild forest produce not to need true agriculture until long after other peoples of the region had fully entered the Neolithic culture.
Exploration and analysis of data from Tiangko Panjang cave is not complete but it has many similarities to Niah cave, where considerable data have been collected. Because of this it is felt justifiable to consider findings from Niah. The stages of man's development there have been described as Early Stone Age (30,000-60,000 years ago) with chopping tools; Neolithic (± 4,000 years ago) with axes, pottery, mats, and nets; Intermediate II (±2,000 years ago) with elaborate pots and the first metal; and Iron Age (±1,300 years ago) with iron, glass beads, and imported ceramics (Harrisson 1958).
At Niah, remains of 58 species of mammals have been found among the archaeological remains (Medway 1979). It is assumed that no large animals other than flying or scansorial (climbing) types, or natural cave-dwellers, could freely enter the Niah cave (which is more difficult to enter than Tiangko Panjang cave) and hence that all remains of such large animals owe their presence in the cave to the intervention of man. In addition, the skeletal remains are dispersed and fragmented and many of them are charred - all suggesting that man was the cause of their presence. Most of the orangutans were juveniles and this can also be interpreted as proof that they were killed by man since, while it is possible that old, dying animals might climb into the cave, it is difficult to imagine why young ones would enter and die there (Medway 1979).
It has been suggested by palaeontologists working in different parts of the world that man has played a significant role in the late Pleistocene or early Holocene extinction of certain animal species - particularly of the gigantic types (either absolutely large, or large by comparison with modern relatives), collectively called the Pleistocene 'mega-fauna'. Opinion is not unanimous but man is now often accepted as a central contributive factor in the progressive decline of many species that occurred in late- and postglacial Europe and northern Asia, and in the abrupt elimination of the North American mega-fauna about 11,000 years ago and of giant birds in New Zealand much more recently.
What impact did early man in the Sunda Region have on the fauna? Palaeolithic people would probably have set traps and snares to catch medium- and large-sized mammals, and bearded pig Sus barbatus was consistently the most commonly caught. Other prey were rhinoceros, tapir, mouse deer, and sambar deer. As with any trapping effort, as distinct from deliberate hunting, success depended on an animal coming into the trap and the impact on even local populations of a species was probably negligible.
With the advent of Mesolithic technology, with perhaps a greater use of bone as tips for arrows and spears, there was an increase in the numbers of arboreal mammals (such as monkeys and squirrels) caught. Even so, pigs remained the major source of meat. With the exception of the pigs (which are anyway very fecund), the pre-Neolithic man did not concentrate on any one species and his prey species were taken in an opportunistic rather than deterministic fashion. It seems likely that his impact on the wild populations was trivial (Medway 1979).
By the time the Neolithic culture had begun (about 4,000 years ago at Niah) (Harrisson 1958), man was beginning to make use of a few crop plants such as sago, and to have domestic animals such as pigs Sus scrofa (Medway 1973a) and dogs Canis familiaris (Clutton-Brock 1959; Medway 1977). He then needed to clear land for his agriculture but as the human population was still very low, this probably had little impact on the forest. It was, however, the beginning of the end.
Figure 1.37. On Siberut, the largest of the Mentawai Islands, monkeys are traditionally hunted with bow and poisoned arrows. The monkey skulls are cleaned, decorated, and hung in houses and it is hoped that the monkey souls will remain in them happily and help the hunters hunt more monkeys. The gibbon (below) is rarely hunted.
A.J. Whitten
As the population grew, so a greater area of land had to be cleared. Loss of forest is the single greatest threat to the majority of forest biota and should not be underestimated (Olson and James 1982). In Java, for example, less than half the mammal fauna survived the mid-Pleistocene and the arrival of modern man Homo sapiens (McNeely 1978). For some species, however, there would have been benefits from limited clearance. Herbivores such as deer, tapir, Javan rhinoceros and elephant are relatively common in 'edge habitats', but their presence in or near crops would have encouraged a certain amount of hunting.
There is evidence of forest clearance 11,000 years ago on Taiwan, and of agriculture between 14,000 and 8,000 years ago in Thailand. Archaeological evidence for agriculture dating from about 9,000 years ago has been found in New Guinea and rice was probably cultivated in Sulawesi 6,000 years ago (Glover 1979a). There is little data available on the early activities of man in Sumatra but the studies of pollen samples from Sumatran lakes described on page 18 provide some information. Morley (1980, 1982) found some evidence of forest disturbance near Kerinci from about 7,500 years ago but firmer evidence was found from about 4,000 years ago. Maloney (1980), studying in the Toba highlands, found strong evidence of forest clearance about 6,200 year ago but changes in the pollen record 8,000 and 9,200 years ago may have been a result of man's activities. Rather less convincing evidence from one of the small lakes in the Toba highlands suggests forest clearance began about 17,800 years ago, but this may have been due to fire rather than felling. However, the possibility that man was using fire to clear forest in order to make hunting game easier should not be discounted (p. 282).
More information about prehistoric man comes from a number of sites in East Aceh and eastern North Sumatra where enormous middens (rubbish piles) consisting largely of cockle shells have been found (Schur-mann 1931). These are the remains of the distinctive 'Hoabinhian' culture which is known from sites in southern China, through Indochina to Peninsular Malaysia and Sumatra (Glover 1977). Amongst the millions of cockle shells are found stone tools, bones of both animals and man, and other artifacts such as pottery in the upper (newer) layers. The range of dates for the Sumatran sites are not certain but 8,000-3,000 years before present seems likely. Very little is known about these people but their culture seems to have spanned the stages of hunting-gathering (hunting a wide range of animals and harvesting useful wild or semi-domesticated plants) in the early period, to being the prime movers for the development of agriculture in Southeast Asia. The information from the sites is not unequivocal but the people do seem to have brought many species of plants such as candlenut Aleurites, betel nut Areca, kenari Canarium, cucumber Cucumis, gourd Lage-naria, betel pepper Piper, and mentalun Terminalia into cultivation (Glover 1979a). Their exploitation of cockles probably resulted in changes in the cockle populations (Swadling 1976) and this may have caused the settlements to move in search of unexploited areas. Most of these middens have now been more or less destroyed for the manufacture of slaked lime for whitewash (McKinnon 1974).
In later prehistoric periods, the story of Sumatra is no more complete or clear; many finds do not have recorded locations and the total are relatively few. Bronze-Iron Age bronze kettledrums have been found near Lake Kerinci, Bengkulu and Lake Ranau, other bronze vessels from the Kerinci area, and statues from Bangkinang in West Riau (van Heekeren 1958).
Megaliths - large stones either set standing, hollowed out or carved into a bas relief showing scenes of animals and men - have been found in Lampung (e.g., at Kenali and Bojong), Riau and West Sumatra (on the banks of the River Kamparkanan), and in Jambi (near Kerinci), but the most famous megaliths are those on the Pasemah Plateau (Bengkulu/South Sumatra), and on Samosir and Nias Islands. It used to be thought that the stones at Pasemah dated from historic times, but it is now known that they were made much earlier (perhaps 100 A.D.) during the Bronze-Iron Age (Glover 1979b; van Heekeren 1958; Heine-Gelde 1972). The megalithic culture of Samosir continued until quite recently and on Nias certain vestiges remain today. Virtually nothing is known of how people in the Bronze-Iron Age culture lived in Sumatra nor how they interacted with their environment, other than that they were agriculturists.
The last remaining living elements of the megalithic culture on Nias, of hunter/gatherer culture of the Kubu people of Jambi/Riau/West Sumatra (Löeb 1972), and of Neolithic/Bronze Age culture on Siberut Island (Schefold 1980; Whitten 1982b) are still available for environmental study now. Although there is a new awareness of the information that can be learnt from people who live close to, and rely upon, the natural environment, it is already too late to learn anything much from the orang Sakai and Akit of Siak, the orang Lubu and Ulu of South Tapanuli, the orang Benua or Mapur of the Riau/Lingga archipelago and Bangka Island or from the orang Enggano (Löeb 1972; Jaspan 1973).
History - Its Effects on Natural Ecosystems
The transition between prehistory (with no written records) and history (written records) will clearly depend upon the people under consideration; for some, such as those on Sumatra's east coast, history began perhaps a thousand years earlier than for some of the inland tribes. In comparison with Java, there is as yet relatively little known about the early historical period of Sumatra, except about the economics and politics of the Srivijaya Empire (Wolters 1970). A review of Sumatra's early history is given in Miksic (1979).
Sumatra became known to Indian traders as the Island of Gold and settlements may have been established on the Sumatran coast by 200 A.D. The earliest Hindu-Buddhist artefact found in Sumatra (in Palembang) is a statue of Buddha, which dates from the late fifth century. The earliest known written inscriptions (in fact the oldest in Indonesia) date from 683-686 A.D. (i.e., the early period or Sailendra Dynasty of the Srivijaya Empire) and were found near Palembang and at Kota Kapur on Bangka Island (Heine-Gelde 1972).
Figure 1.38. An early Buddha from near Palembang.
A.J. Whitten
A few statues of Buddha and other remains from before 1000 a.d. have been found in Jambi, Simangambat (South Tapanuli) and by the Lematang River near Palembang, but most Hindu-Buddhist remains of temples or inscribed stones on Sumatra date from the eleventh to thirteenth centuries. Two sites with remains of temples or biara are worthy of particular mention: Muara Takus on the Kampar Hulu River near Bangkinang, Riau, and Padang Lawas in South Tapanuli (Schnitger 1938). Sumatra also had close trading ties with South India, and a Tamil inscription written in 1088 A.D. found near Barus, now a small port in Central Tapanuli, describes one such commercial relationship (Heine-Gelde 1972). In about 1281 the first Islamic kingdoms were established on Sumatra's coast (although Islam probably entered Sumatra through Barus) but it was a few centuries before their influence affected the rest of Sumatra (Löeb 1972).
The environmental impact of those and other inland kingdoms during the first half of the second millennium is not certain. The temple sites at Muara Takus and Padang Lawas were not centres of population and probably had only a ceremonial function although they may have been on trading routes (Miksic 1979). Hindus from India introduced wet rice culture, the plough, cotton and the spinning wheel to Sumatra. We may therefore envisage small, more or less permanent, rural communities surrounded by a limited area of sawah. A gold mine may have been nearby. Around these there would have been some areas in which people practised genuine shifting agriculture (i.e., leaving fields fallow for 25-30 years before using them again). This type of land use creates a floristically diverse forest edge and favours many species of animals as well as maintaining and conserving soil structure and nutrients. Towns probably only existed as trading centres, primarily on the east coast.
The earliest substantial settlement found in the whole of Indonesia is Kota Cina, halfway between Medan and Belawan in North Sumatra (Manning et al. 1980). This may date back to 1000 A.D. At that time, seagoing vessels would have been able to anchor in the immediate vicinity of Kota Cina itself, but coastal accretion, a common phenomenon at many places on Sumatra's east coast, has resulted in the site being progressively isolated from navigable waters. Chinese documents written in 1282 mention a locality that is possibly Kota Cina. It was a dependency of Srivijaya (although by then Srivijaya had lost most of its power), and was known as a source of fragrant resins (damar) (Milner et al. 1978). Kota Cina appears to have been a very cosmopolitan town, for remains of Chinese and Persian ceramics and other pottery, Chinese coins, Indian Buddha statues, and coins from Sri Langka have been found, Kota Cina was abandoned by the late fourteenth century at the same time that Islam was beginning to become established, Malacca was becoming the region's major trading centre, and relations between Sumatra and Java were disturbed because of the increasing power of the Majapahit Empire.
It is not known precisely what was exported from Kota Cina but damar resin, camphor and beeswax from the highlands were likely products, and gold, lead ore, ivory and fine timber probably contributed to the trade. There is no evidence of Sumatran agricultural produce being exported, and the impact of Kota Cina and similar settlements on natural ecosystems was probably minimal.
A settlement from the same period as Kota Cina may have existed at Muara Kumpeh, 72 km downstream along the Batanghari from the city of Jambi (p. 85). This settlement may have been similar in its function then as Sungsang, at the mouth of the Musi River in South Sumatra, is now (McKinnon 1982).
In northern Southeast Asia, archaeological remains have been found for many cities, their satellite towns and hinterlands. In southern Southeast Asia, however, with the exception of Java, no such early cities have been found. Yet Srivijaya, the hypothetical capital of the Sumatra-based empire of the same name, should rival Central Java and southern Thailand for producing the first capital city in the Sunda Region. It was the administrative and intellectual centre of an empire which is known from Chinese historical records to have ruled the seas of Southeast Asia and to have lasted for over live hundred years from before 700 A.D.
Palembang has always been identified as the location of Srivijaya. It used to be a port nearer the sea, it has a strategic position for local and international trade, Chinese sailing directions indicate Srivijaya was in the Palembang area, and some ancient inscriptions had been found there that mention Srivijaya. In 1974, thorough archaeological excavations were conducted and not a single piece of evidence could be found for a settlement or related hinterland dating from before the fourteenth century - when the empire had already begun to crumble (Bronson and Wisseman 1978).
This has some important environmental/historical implications. Palembang was supposed to be the only early (pre-1000 A.D.) urban site south of the Thailand/Malaysia border. Now that Palembang, and probably the whole area drained by the Musi River, has been ruled out, there remains no example, even supposed, of an early urban culture in Sumatra.
Srivijaya did exist, but it must have been a form of habitation that would have been described as a city by a visitor, yet not leave obvious remains. One of the four requirements suggested by Bronson and Wisseman for such a city is that it exist in comparative isolation from its hinterland (Bronson and Wisseman 1978). This seems unlikely at first but at the peak of the history of Malacca in the fifteenth and sixteenth centuries, this important port was surrounded by uninhabited forest, and its population of about 20,000 people depended on supplies from Java and Thailand for its subsistence. Thus, even though the Srivijaya Empire was being coordinated from Sumatra, its emphasis was on controlling and profiting from trade rather than on controlling the interior, and so the impact on the natural environment may have been very slight. Some trade in Sumatran goods may have been conducted from the town of Srivijaya (as at Kota Cina later) but it could have served as an entrepot, similar to Singapore at its founding.
The ineffectiveness of Srivijaya as a cultural missionary, except at a few places along the coast, is illustrated by the survival in nearby areas of forest people with primitive cultures: the orang Mapur in the interior of Bangka Island, the Kubu of the Jambi/Riau forest, the Akit of the Siak and Bengkalis Region, and the nomads of Batam Island (Sopher 1977).
The history of the islands to the east of Sumatra was also not greatly affected by the Srivijaya Empire: as stated before, Srivijaya was more concerned with trade than with territory. Instead, the Orang Laut, specifically the Celates, were far more important. These were groups of nomadic people, not necessarily pirates, whose culture and economy were based on the coasts and seas. They tended to build settlements away from established centres of population (Sopher 1977) and, because they were concerned only with marine products, they never strayed inland from the coast. For example, the hilly interior of Belitung Island was completely deserted until tin mining began in 1851, although there were numerous settlements of Orang Laut around the coast (Sopher 1977).
So, it was with the arrival of Portuguese, Dutch and British in the sixteenth, seventeenth, eighteenth and nineteenth centuries that most of the natural ecosystems of Sumatra received their first major shocks. Before then the majority of the landscape probably consisted of low-density, small-scale agriculture among a scarcely-disturbed forest and with virtually no urbanisation (Marsden 1811). To supply the spice trade, land had to be cleared and early plantations of tobacco and other crops were also established. However, not all large-scale land clearance was directed towards the plantation industry or even conducted in response to Christian missionary influence. Burton and Ward (1827) were the first Europeans to enter the Toba Region and the description of their journey from Sibolga in 1824 makes instructive reading because they depict a largely deforested land, much of it planted with rice. For example:
The woodland had already given place to grassy plains; and the mountain on which we stood had been cleared on every side for cultivation, merely retaining its original forest in a tuft at the top... The soil now became sandy and grey and the hills were entirely free from wood, and planted with the sweet potato in many instances to the very tops... The principal object of the picture was an uneven plain, ten or twelve miles long and three broad, forming a vast unbroken field of rice... The plain was surrounded by hills from five hundred to one thousand feet high, in a state of cultivation; and the whole surrounding country was perfectly free from wood, except the summits of two or three mountains said to be the abode of monstrous serpents and evil spirits.
Descriptions, land-use maps and photographs of the Toba, Alas and Karo areas at the turn of the century are surprisingly similar to today (von Hügel 1896; Volz 1909, 1912).