A potential World Heritage Area Dr James True Swire Institute of Marine Science, University of Hong Kong Center of Excellence for Biodiversity of Peninsular Thailand, Prince of Songkla University The Andaman Bioregion What is the Andaman bioregion? The Andaman Bioregion is composed of 6 distinct ecoregions, each explaining part of the story of Andaman Thailand 1. Northern Mangroves 2. Northern Offshore Islands 3. Central Beach and Gallery Forests 4. Greater Ao Phang-nga 5. Southern Mangroves & Birdnest Islands 6. Southern Offshore Islands The 6 ecoregions of the Andaman Bioregion of Thailand The ecoregions of the Andaman Bioregion are informed by biogeographical boundaries of the Thai Peninsula Wells (1976) Avifaunal transition zone Steenis (1950) Angiosperm transition zone (Monsoon forests) Northern limit of Malesian flora Whitmore (1984) Kangar-Pattani Line (Malesian flora) Since the Pleistocene, SEA is characterized by 2 major biogeographical provinces Major transit route/ bottleneck Terrestrially, this pattern of vicariance is seen in both animals and plants Dendrogram based on extant large animal faunas, showing two major groupings: one with Indo-Chinese affiliations, one with Sundiac affiliations (Tougard, 2001) Molecular genetic survey of freshwater prawns, (Macrobrachium rosenbergii) by de Bruyn et al. 2005 Where else does this happen? The Panamanian Isthmus has been in place ~3 million years; The Thai Isthmus has been in place for ~200 million years The Andaman side of the Thai Peninsula is even more interesting because of Holocene current patterns Indonesian Throughflow The 6 ecoregions capture these biogeographic transitions 1. Northern Mangroves & Inshore Islands Includes Lam Nam Kraburi Laem Son Mu Ko Phayam This ecoregion captures the northern Indo- Chinese/Sundiac boundary The undisturbed coastline of northern Ranong also supports complex near-shore habitats not found elsewhere in the Andaman 2. Northern Offshore Islands Includes Mu Ko Surin Mu Ko Similan These offshore islands capture the north Andaman oceanic biota 3. Central Beach & Gallery Forests Includes Mu Ko Ra- Ko Phra Khao Lak Lam Ru Khao Lampi Hat Thai Meuang Sirinart This ecoregion captures Austral flora from the first Pliocene invasion via Sundaland, uniquely combined with indigenous biota This area also includes the longest fringing reef in Thailand This reef defines the coast of Phang-nga and makes the dune ecosystems possible here 4. Greater Ao Phang-nga ecoregion Includes Ao Phang-nga Than Bok Khorani Had Noppharat- Ko Phi Phi Mu Ko Lanta This ecoregion encapsulates the drowned karst landscape and inshore islands surrounded by shallow seagrass meadows and mangrove forests Trang supports the largest breeding population of Dugongs in Thailand 5. Southern Coastal Forests and Birdnest Islands Includes Had Chao Mai Mu Ko Phetra Mu Ko Libong Thaleban Ko Tarutao This ecoregion captures the seagrass ecosystems of the inshore limestone islands and the composite flora of the monsoon transition zone Steenis (1950) Angiosperm transition zone (Monsoon forests) Whitmore (1984) Kangar-Pattani Line (Malesian flora) 6. Southern Offshore Islands Includes Mu Ko Adung-Rawi Hin Daeng/Hin Muang/Ko Roh Ko Racha This ecoregion captures the southern offshore biota, influenced by the Indonesian ThroughFlow The Andaman Coast Protected Area Network forms the core of the 6 ecoregions, each explaining part of the biogeographic story of Andaman Thailand Together these form the basis for a proposed World Heritage Area The Andaman Bioregion of Thailand satisfies all of the IUCN criteria The ecoregion complex is well-supported by available scientific evidence Each ecoregion supplies essential components of the overall narrative; the Andaman story is a synergy of transitions In combination, the ecoregion complex tells a quite remarkable story of a region that has provided a bridge between north and south, Laurasia and Gondwana, Asia and Australasia, for >200 million years There is nowhere else in the world where so many biogeographic transitions occur in such a small area