ABSTRACT. The current paper acts as an introduction to nine following papers concerning the hydrology and biodiversity of Nee Soon freshwater swamp forest. Freshwater swamp forest is a threatened and overlooked ecosystem in the Southeast Asian region and in Singapore. Characterised by predominantly mineral soils supporting forest that contains a subset of the flora and fauna of lowland forest, but with the addition of important habitat specialists, freshwater swamp forest is fed by an array of hydrological processes. As conservation management depends on good hydrological and biological understanding, a research programme was designed to tease out the roles of the various hydrological components. The background, management concerns, and aims of the project are detailed.

ABSTRACT. Nee Soon freshwater swamp forest is the last remaining primary freshwater swamp forest left in Singapore and it contains a rich diversity of native and locally threatened fauna. As native terrestrial snails and slugs are poorly studied and understood in Nee Soon freshwater swamp forest, an extensive survey was conducted to establish their current status. A total of 19 species was recorded, of which one was recorded for Singapore for the first time. Amphidromus atricallosus temasek, a recently described subspecies endemic to Singapore, was found to be more commonly distributed than previously known from the swamp forest. Results also indicate that despite low overall abundance, Nee Soon freshwater swamp forest harbours a rich diversity of land snails and slugs. Any future long term changes in climate or topography, or short term changes in hydrology, might affect their distribution and diversity.