Some preliminary observations on peat-forming mangroves in Botum Sakor, Cambodia

Until recently, peatlands in Cambodia were relatively unknown despite numerous efforts to locate and identify them. In 2012-2014, mangrove vegetation on the south-western coast of Cambodia was found to be growing on top of a peat layer underlain by marine clay. Believing that more mangrove peat might remain to be discovered, additional surveys were conducted in 2015, focusing on part of the east coast of Botum Sakor National Park and the riverine mangroves outside the National Park boundary. A total area of 4,768 ha of mangrove peat was confirmed to be present. Overall, the peat layer within this mangrove area is not very thick, with about half of all measurements in the range 50-100 cm and the deepest record 135 cm. In total, 26 mangrove species were recorded during the survey, including 20 tree species. Most were typical (either true or associate) species and very similar to those found in other mangrove forests in Cambodia and elsewhere in Southeast Asia. Although the mangrove peat area confirmed is small, it nevertheless contributes to the total peatland extent and carbon stock of the ASEAN region. Mangrove peat ecosystems, such as the one studied here, are not common in Southeast Asia and deserve more detailed and in-depth studies.