Acid sulfate soils on the west coast of Sri Lanka: A review

Abstract

This article provides a general introduction to acid sulfate soil materials including those in Muthurajawela, a marsh of high ecological significance on the western coast of Sri Lanka. This peat bog is identified as one of the country's two acid sulfate soils landscapes. It covers ~3000 ha in area and contains a 3 to 7 m thick peat layer. Here we review the acid sulfate soils landscape of Muthurajawela marsh providing a broad description of the marsh, including its environmental setting, soil/peat characteristics along with the threats it faces. Furthermore, we briefly discuss the biogeochemistry of coastal acid sulfate soils (CASS) and the relationship to Muthurajawela. Finally, we discuss potential impacts of acid sulfate soil materials on the Muthurajawela marsh, and thereby, identify gaps in the understanding of the marsh's geochemistry. Our study identified that future investigations are required to assess the acidity status in the marsh, partitioning behaviour of trace elements in acid sulfate soil materials and to assess the impact of salt water intrusion and extreme weather events on acid sulfate soil materials.