An n-alkane proxy for the sedimentary input of submerged/floating freshwater aquatic macrophytes

Lipid analysis of aquatic plants from lakes on Mt. Kenya, E. Africa, revealed that non-emergent (submerged and floating-leaved) species displayed enhanced abundances of mid-chain length, C23 and C25 n-alkanes. In contrast, the emergent aquatic plants had n-alkane distributions similar to those of the terrestrial vegetation, typically dominated by the long-chain length homologues (>C29). A proxy ratio, Paq, has been formulated to reflect the non-emergent aquatic macrophyte input to lake sediments relative to that from the emergent aquatic and terrestrial plants.