"Funding - the bulk of the initial groundwork for this book was carried out as part of botanical surveys of Doi Chiang Dao Wildlife Sanctuary (1 995-1 996, funded by Office of Environmental Policy and Planning) and Doi Luang National Park (1 997-1 999, funded by the TRF/BIOTEC Special Program for Biodiversity Research and Training grant BRT 1 39029) The preparation and review of the manuscript in both English and Thai was supported by the East Asia Local Languages Field Guide project (funded by the World Conservation Union (IUCN) and The World Bank). Toyota Thailand Foundation, Kopfai Publishing Project and Toyota Motor Thailand Co., Ltd. provided the funding for publ ication and distribution. The generous support of these organisations is gratefully acknowledged. We would particularly like to thank Asst.Prof. Paitoon Leksawad, Dr.Tony Whitten, Dr. Scott Perkin, Preecha Photi and Sunee Wongwaisayawan for their support. Facilities- CMU Herbarium, Biology Department, Faculty of Science, Chiang Mai University provided institutional support at all stages of the project. Secretarial & computer work - Rungtiwa Panyayot, Greuk Pakkad Specimen collection & fieldwork - Natii Morci, Bucha Orkha, all the Forestry Department and Watershed Office staff who helped us throughout the project especially in Poi Chiang Dao Wildlife Sanctuary, Doi Luang and Doi Suthep-Pui National Parks. Specimen identification - J.F. Maxwell, Dr. Jamlong Pengklai, Dr. Piya Chalermglin Additional Photographs - Akom Manekul, Dr. Chavalit Vidthayanon, Cherdsak Kuarak, E.J. Haas, Dr.Oy Kanjanavanit, Richard Davies, M.R.Smansnid Svasti Illustrations - M.R.Smansnid Svasti (cover and forest profiles) Pranee Palee- (Ficus, Fagaceae) Taxonomic review - Dr. Chavalit Niyomtham (Leguminosae); Dr. Jam long Pengklai (Bombacaceae, Coniferae, Dipterocarpaceae, Elaeocarpaceae, Lauraceae, Lythraceae, Moraceae, Rubiaceae, Sterculiaceae, Tiliaceae); Dr. Kongkanda Chayamarit (Anacardiaceae, Capparaceae); Dr. Piya Chalermglin (Annonaceae, Magnoliaceae); Dr. Pranom Chantaranothai (Myrtaceae, Lecythidaceae) Preparation of use data - Tim Rayden, Kym Leggett, Kate Hardwick Editing & proof reading - Bandit Grivijitr, Kym Leggett, Dr Kobkiat Saengnil, Pranee P?lee, M.A. Smansnid Svasti, Tony Ball Translation of uses and Thai index Natenapit Jitlam Printing -Surasak lntanon & Amarin Printing & Publishing staffs. Herbariums, Libraries and Databases - CMU Herbarium, Biology Department, Chiang Mai University; Faculty of Pharmacy, Chiang Mai University; Royal Forest Department Herbarium, Bangkok; Queen Sirikit Botanic Garden, Chiang Mai; Faculty of Pharmacy , Mahidol University; Kasetsart University. Finally, we would like to thank our friends and families who encouraged and supported us throughout the process of preparing this book.....Genesis of Water and Life: Amidst changes and development in many fields, Thailand faces an alarming environmental crisis. In the last decades, the forest areas have been exploited at a fast rate which is one of the important causes of flooding, droughts and unpredictable climate. Conflicts over the management of natural resources have been an unavoidable part of life for our generation. The "Genesis of Water and Life" project was formed as �knowledge-based response to these issues. In 1994, a project was initiated by the Ministry of Agriculture to protect the watershed area by using more than 10 years of experience working at Kao Sammoen with the support of the UN. Our aim has been to promote harmony between humankind and nature by encouraging people to conserve natural resources through sustainable resource management and integrated agriculture. We are developing a variety of media in vernacular languages for com- munication amongst local peoples in the watershed areas. Additional equipment including motorcycles, televisions and portable video players have been provided for the convenience of Forestry Department officials. From 1997, we have cooperated with Chiang Mai University and "Gong Tun Chum Chon Rak Pa" (Forest Lovers' Community Fund) to support forest restoration by building firebreaks in the protected forests of the upper Ping and Wang watersheds which cover an area of more than 120,000 rai (19,200 hectares). By this means, we hope to save the watershed areas without changing the local people's lifestyle or faith. We also promote academic activities, arts and culture in the urban community to improve relationships in a joint effort to protect and conserve the natural environment . The book "A Field Guide to Forest Trees of Northern Thailand" is one of our recent project activities. We sincerely wish that this book will be a bridge that passes on knowledge, compassion and a sense of ecological awareness and conservation of trees in the forest area of Northern Thailand. His venerable Phra Dhamma Pitaka (P. Payutto) has admonished us that: "People in this generation have exploited a great amount of natural resources of the world.They have no awareness of our environment and have depleted the land, so it is necessary that they revolutionize themselves now together with creating an awareness of restoring the natural environment amongst new generations". His advice should be heeded by us all. Watersheds are the source of forests, water and life. We must all work together to conserve what is left of our natural heritage for future generations - Toyota Thailand Foundation..."