PEATLAND EVOLUTION IN SOUTHEAST ASIA DURING THE LAST 35,000 CAL YEARS: IMPLICATIONS FOR EVALUATING THEIR CARBON STORAGE POTENTIAL Raphael Wust 1 , Jack Rieley 2 , Susan Page 3 , Sander van der Kaars 4 , Wang Wei-Ming 5 , Geraldine Jacobsen 6 , Andrew Smith 6 1 School of Earth and Environmental Sciences, James Cook University, Australia, 2 School of Geography, University of Nottingham, United Kingdom 3 Department of Geography, University of Leicester, United Kingdom 4 School of Geography, Monash University, Australia: current address: Department of Palynology and Climate Dynamics, University of Göttingen, Germany 5 Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, China 6 Australian Nuclear Sciences and Technology Organisation, Australia Corresponding author Email: raphael.wust@jcu.edu.au SUMMARY Over the last few years, the tropical peatlands of SE Asia have received both environmental and political international attention particularly since the failure of the Mega Rice Project on the vast peatlands in Central Kalimantan, Indonesia and the subsequent large peatland fires during the El Niño years of 1997/98 and 2002 that blanketed the region with a persistent haze that caused health and environmental concerns. The 1997/98 peatland fires of Indonesia and Malaysia were estimated to have contributed between 0.81 and 2.57 Gt of carbon to the atmosphere as a result of burning peat and vegetation in Indonesia. Research data for peat deposits from across SE-Asia demonstrate that most have present accumulation rates of >1mm yr -1 which makes them carbon sinks. This status has been significantly altered, however, as a result of land use change to intensive timber production and agriculture, including oil palm plantations. These all require artificial lowering of the water table that ultimately leads to increased oxidation of the organic matter. Understanding the development and structure of tropical peatlands is critical owing to their global importance as carbon sequestering systems. This study has shown that peatland evolution in SE-Asia occurred throughout the late Pleistocene but was absent during the LGM when conditions may have been drier and more seasonal. Although peatlands developed and accumulated organic material rapidly during the last 14,000 years, most large lowland peatlands of SE-Asia started forming only after the mid-Holocene sea level highstand around 6,000-5,000 years ago. However, even thereafter, several metres (up to 11 m) of peat accumulated within those systems since accumulation rates often exceeded 1 mm yr -1 (Neuzil, 1997) . Because tropical peatlands represent such large carbon sinks and deforestation and land use changes has such an adverse affect on them (e.g. increasing risks of peatland fires and hence atmospheric CO 2 contributions) urgent action is needed to identify environmentally sound and sustainable ways of managing these ecosystems. INTRODUCTION Over the last few years, the tropical peatlands of SE Asia have received both environmental and political international attention because they are the world’s largest near-surface reserves of terrestrial organic carbon and hence represent a significant potential for transferring additional carbon to the atmosphere. For example, the failure of the Mega Rice Project on the vast peatlands in Central Kalimantan, Indonesia, and the subsequent large peatland fires during the El Niño years of 1997/98 and 2002 that