Status and Distribution of Aquilaria Spp. in Indonesia, and the Sustainability of the Gaharu Trade
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Status and distribution of Aquilaria spp. in Indonesia, and the sustainability of the gaharu trade Tonny Rakhmat Soehartono Thesis submitted to the University of Edinburgh for the degree of Doctor of Philosophy "a Institute of Ecology and Resource Management The University of Edinburgh May, 1999 (/ I hereby declare that all the work in this thesis was composed by myself except where identified. Status and distribution ofAquilaria spp. in Indonesia, and the sustainability of the gaharu trade Abstracts Aquilaria is a genus of tropical trees which has recently been the focus of international conservation concern. The species of this genus are a source of gaharu, a fragrant resinous wood, which ranks among the most highly valuable non-timber forest products world-wide. Most, if not all, gaharu being traded is harvested from natural forest. As a result of this trade, it has been suggested that the population density of Aquilaria spp. in natural forest in countries such as Indonesia, India and Malaysia, has been depleted. For the last 20 years, Indonesia has been one of the major exporting countries for gaharu. The objectives of this study were to estimate the population density and distribution of Aquilaria spp., and to evaluate the impact of trade in gaharu on populations of the species in natural forests. Investigations were made of factors influencing regeneration, reproductive ecology and stand structure of Aquilaria, and the status of the species was evaluated in relation to IUCN categories of threat and CITES criteria. The impact of trade in gaharu was assessed by field surveys and analysis of trade data. Six species of Aquilaria are recorded in Indonesia; A. beccariana, A. cumingiana, A. hirta, A.filaria, A. malaccensis and A. microcarpa. Based on the national forest inventory (NFl), the density of Aquilaria spp. in Sumatra appears to be lower than in Kalimantan (0.4 h&' and 0.36 ha' and 0.83 ha-'and 1.17 ha in lowland and upland Sumatra and Kalimantan respectively). A. malaccensis has the highest germination probability and A. filaria the lowest. A positive relationship between light availability and seedling growth was recorded in the field for A. malaccensis and A. microcarpa. Mortality of these species in natural populations was found to vary with size class; highest mortalities were recorded for seedlings. These data were used to parameterize a matrix model to predict population dynamics under different harvesting regimes. The value of trade was found to fluctuate from year to year, rising to a maximum of $US 6 million in 1996. Based on trade data and field analysis of harvesting, it was estimated that 59,000 trees of Aquilaria species were felled in East Sumatra in 1992 and 80,000 trees were felled in East Kalimantan in 1996. Matrix models predicted that harvesting of the species will be sustainable provided that the annual cutting level is set at a maximum of 30% of harvestable individuals with a minimum dbh >10 cm. According to IUCN criteria, the species should be considered as vulnerable to extinction. The species also qualifies for listing under Appendix II of CITES. The implications of the designations for conservation and sustainable use of the species are discussed. 11 Acknowledgements I am very grateful to the International Tropical Timber Organization and the Ministry of Forestry of Indonesia for sponsoring my study at the University of Edinburgh. Special thanks and appreciation to my supervisor Dr. A. Newton who introduced and brought me into the world of sciences. My thanks and appreciation also to my field supervisor Dr. A. Mardiastuti who advised me during the time I spent collecting data in the fields. Thanks to Warsito, head of Kutai National Park, for helping my research in Kutai National Park, Dr Eva. Wollenberg of CIFOR for sponsoring my field study in Kayan Mentarang, East Kalimantan, Edi Zulkarnaen and Suparto of SBKSDA, West Kalimantan, Lida Maulida of Fahutan IPB, CETFOHR-1NDECO and Gregory Hambali, the owner of a gaharu plantation at Bogor. I am grateful to my colleagues, gaharu collectors in Riau, Sumatra, East and West Kalimantan as well as gaharu traders and exporters in the regions of Jakarta and Surabaya. I would also like to thank Kebun Raya, Bogor and Herbarium Bogoriensis, Bogor as well as the National Forest Inventory Project, Ministry of Forestry of Indonesia. Other individuals who should be singled out for special mention from among the numerous persons who helped me in various ways are Noer Azam Achsani, Lany, Ajang Apui, Bastar, Is Mugiono, Dr. H. Wiriadinata and Dr. Dedi Damedi, F. Sulaeman, S. Aliman, Sutopo, Yana Juhana, Yuyu Rahayu, C. Candrakirana, U. Batarfie, S. Oldfiled, C. Lusty, Dr. A. Gilles, S. Bekessy, A, Robertson, A. Rowden, S. Heredia, C, Fox, S. Wilson, K. Misbahuzaman, S. Anwar, G. Tjakrawarsa, Dr. S. Wiradinata, Krist, Ati, Dra. Subandiyah, J. Morman and Dr. R. Ennos. Finally, I would like to express my great appreciation and thanks to my son, Anugrah Firdaus Soehartono and my daughter, Gadis Khasanah Soehartono for giving me consistent spirit and light during my three years of study in Indonesia and Edinburgh. 111 Contents Abstracts Acknowledgements Table of contents iv CHAPTER I. INTRODUCTION 1 1.1. The world is tropical forest 2 1.2. Sustainable of forest resources 4 1.3. Indonesian forest resources 6 1.4. Aquilaria spp. 11 1.5. Focus of research 19 1.6. Research objectives 20 References 23 CHAPTER II. DISTRIBUTION AND POPULATION STATUS OF Aquilaria spp. IN INDONESIA 28 11.1. Introduction 29 11.2. Materials and methods • 32 11.3. Data analyses 36 11.4. Results 37 11.4.1. Quality of the NFl data 37 11.4.2. Species distribution and identification 38 11.4.3. Estimated species density and stand structure 39 11.4.4. Indices of dispersion 41 11.4.5. Fitted Probability distribution 41 11.4.6. Relationship between environmental variables and density ofAquilaria spp. 42 11.4.7. Rate of deforestation 43 11.4.8. Conservation status 43 11.5. Discussion 62 11.5.1. Data Quality 62 11.5.2. Data on species distribution 63 11.5.3. Population density 66 11.5.4. Conservation status 68 References 71 CHAPTER III. REPRODUCTIVE BIOLOGY OF Aquilaria spp. 76 III. 1. Introduction 77 111.2. Study areas 79 111.3. Methods 80 111.4. Results 84 111.4.1. Species identification 84 111.4.2. Flowering and Fruiting 85 111.4.3. Pollination 86 111.4.4. Seed production and fruit/seed size 87 111.4.5. Seed germination 88 111.4.6. Seedling demography and seed dispersal 88 iv 111.5. Discussion 99 111.5.1. Flowering and fruiting phenology 99 111.5.2. Pollination 101 111.5.3. Seed production and seed dispersal 102 111.5.4. Seed germination 106 111.5.5. Management implications 107 References 109 CHAPTER IV. REGENERATION OF Aquilaria spp. 114 IV. 1. Introduction 115 IV.2. Study area 116 IV.3. Material and Methods 117 Results 121 IV.4.1. Field observation 121 IV.4.2. Nursery experiment 121 Discussion 135 IV.5.l. Regeneration 135 IV.5.2. Survivorship 141 IV.5.3. Management implications 143 References 145 CHAPTER V. SUSTAINABILITY OF CURRENT HARVESTING GAHARU 151 V.I. Introduction 151 V.2. Study areas 153 V.3. Methods 155 V.4. Results 159 V.4.1. Harvest techniques 159 V.4.2. Aquilaria spp. encountered in the field visits 159 V.4.3. Harvesting 160 V.4.4. Ecological impacts of harvesting 160 V.4.5. Yield 161 V.4.6. Production 161 V.4.7. Felling estimate 162 V.4.8. Population structure 163 V.5. Discussion 181 V.5.1. The extent and pattern of harvesting 181 V.5.2. Felling impacts 182 V.5.3. Sustainability of gaharu harvesting 184 V.5.4. Management action 187 References 189 CHAPTER VI. TRADE IN GAHARU 195 VI. 1. Introduction 196 VI.2. Methods 198 v VI.3. Results 199 VI.3. 1. Trading place and producers of gaharu 199 VI.3.2. Collectors and traders 200 VI.3.3. Collecting visits and cost of collection 202 VI.3.4. Gaharu and its grade 203 VI.3.5. Price 203 VI.3.6. Trade mass 205 VI.3.7. Conservation status 206 VI.4. Discussion 223 VI.4. 1. Trade in gaharu 223 VI.4.2. Value 225 VI.4.3. Sustainability 227 VI.4.4. Gaharu and CITES 229 References 233 CHAPTER VII. CONCLUSION 236 VII. 1. What is the current population density and distribution of Aquilaria spp? 237 VII.2. Are the species regenerating naturally? 240 VII.3. What are the factors influencing regeneration? 241 VII.4. What is the impact of the trade in gaharu on the populations of the species in natural forests? 242 VII.5. What is the conservation status of the species in relations to IUCN Categories and CITES Convention? 244 VII.6. Are the species being sustainably harvested? And will the trade in gaharu in Indonesia be sustainable? 247 VII.7. Limitations 252 VII.8. Recommendations 254 References 256 vi CHAPTER I INTRODUCTION I.!. THE WORLD IS TROPICAL FOREST Tropical forest is a unique and valuable resource for supporting natural systems and improving human activities. Lying on each side of the equator between 27° North and 24° South latitude, tropical forest provides habitat for nearly half of all the world's animal and plant species, including many genera and families not found in the rest of the world. The major regions of tropical forest are South America, Central Africa and the large islands of Southeast Asia (Longman and Jenik, 1987; Whitmore, 1972). This type of forest has acted in the past as a reservoir of genetic diversity and has been a centre of evolutionary activity from which the rest of the world's flora and fauna have been recruited.