Distribution of combined monosaccharides in sediments from the Lake Rawa Danau, West Java, Indonesia: Sources and diagenetic fate of carbohydrates in a tropical wetland

Abstract

Monosaccharide compositions were determined for a sediment core (RD-1) collected from a tropical wetland, Rawa Danau, West Java, Indonesia (location 6°11′ S and 105°59′ E) to assess the sources and diagenetic fate of carbohydrates in a tropical wetland based on the acid-hydrolysis monosaccharide compositions. Total monosaccharides (TCHO; normalized to organic carbon) and individual monosaccharide abundances were variable and mostly dominated by glucose through out all depths. The high TCHO, uneqimolar monosaccharide compositions and relatively low deoxysugars/pentoses ratio indicated that carbohydrates were preserved under reducing conditions. The monosaccharide compositional data and diagnostic parameters show that sources of sedimentary carbohydrates changes due to changes in terrigenous plant material which predominantly comprised of angiosperm plants. There are also few transitions between terrestrial and aquatic sources as the most dominant source of sedimentary carbohydrates. Principal component analysis (PCA) of the monosaccharide composition of potential source organisms and RD-1 samples revealed that sources of carbohydrates can be distinguished from the factor loading values. A cross plot of principal component one (PC1) and two (PC2) clearly separated terrestrial and aquatic sources since PC2 has positive values for terrestrial sources and negative values for aquatic sources. Vertical profile of PC2 indicated few major changes in sources of carbohydrates in Rawa Danau wetland associated to changes in local environment. Therefore, combination of monosaccharides composition to PCA is applicable for investigating the sources and fate of carbohydrates in natural environments.