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, reveal ed that non-emergent (submerged and floating-leaved) species displayed enha nced abundances of mid-chain length, C-23 and C-25 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 ho mologues (> C-29). A proxy ratio, P-aq, has been formulated to reflect the non-emergent aquatic macrophyte input to lake sediments relative to that fr om the emergent aquatic and terrestrial plants. (C) 2000 Elsevier Science L td. All rights reserved.