Estimating the contribution of Spartina anglica biomass to salt-marsh sediments using compound specific stable carbon isotope measurements

Compound specific delta(13)C analyses were used to determine the relative i nput of a C-4 temperate grass (Spartina anglica) to primary biomass in a sa lt-marsh sediment. Lipid distributions revealed a C-32 n-alkanol homologue as a characteristically dominant component of Spartina anglica whilst the c ohabiting C-3 species, Puccinellia maritima, exhibited a C-26 maximum. The C-32 n-alkanol component was used to create an isotopic mixing model, betwe en organic matter derived from Spartina anglica and Puccinellia maritima, t o estimate their relative contribution to the primary biomass input of salt -marsh sediments. The application of sedimentary lipid isotope data to the model gave values of Spartina anglica contributions ranging from 37 to 100% . This investigation represents the first attempt to quantify inputs to sed imentary biomass based on compound specific stable carbon isotope technique s. (C) 1999 Elsevier Science Ltd. All rights reserved.