Modifications in the alkane composition of cuticular waxes from spruce needles (Picea abies) and ivy leaves (Hedera helix) exposed to ozone fumigation and acid fog: comparison with needles from declining spruce trees

Abstract

Our study on the chemical composition of cuticular waxes showed that the configuration of alkane homologues, in needles from declining spruce trees as well as in artificially polluted ivy leaves and spruce needles, presented a significant shift towards lower molecular weight chains. On the contrary, in both materials ageing was characterized by increasing chain lengths. This work emphasizes the importance of the short and long carbon chains as representative parameters of chemical alteration of cuticular waxes. As far as alkanes are concerned, pollutants may change cuticular wax composition by acting on sites of their metabolic biosynthesis rather than through a direct passive chemical contact effect. Key words: Picea abies, Hedera helix, forest decline, ozone, acid fog, waxes, cuticles, alkanes.