Molecular n-alkyl leaf waxes of three dominant plants from the temperate forest in South America.

• In general, no linear relationship between leaf waxes and elevation is observed. • Chusquea sp. n -alkanoic acid abundance is correlated with precipitation and aridity. • A. araucana n -alkane ACL and abundance are correlated with temperature. • High relative abundance of n -alkanoic acids (>60%) in the three plant species. • Different abundance and ACL among species in both n -alkanes and n -alkanols. The n -alkyl leaf waxes of the temperate forest of South America are poorly studied, despite being a biogeographically isolated forest spanning wide environmental conditions. To evaluate whether local species adaptation and environmental changes influence the n -alkyl leaf wax composition, we measured the molecular abundance and distribution of n -alkyl leaf waxes (n -alkanoic acids, n -alkanes and n- alkanols) of three dominant native species from southern temperate forest in South America. We surveyed Araucaria araucana (n = 9), Nothofagus dombeyi (n = 17) and Chusquea sp. (n = 21) at different elevations. The relationship of n -alkyl leaf wax abundance and distribution with elevation is not significant in any species, except for n -alkane ACL (average chain length) in Chusquea sp. Significant correlations are found for n -alkanoic acid abundance with precipitation and aridity in Chusquea sp. and n -alkane abundance and ACL with temperature in A. araucana. These data suggest a species-specific response to environmental variables. The main similarity in the three species is a higher abundance of n -alkanoic acids (>60%) relative to other n -alkyl leaf waxes. Only n -alkanols are not correlated to any environmental variable, and neither ACL nor C max overlap among species. These results suggest n -alkanols as a potential chemotaxonomic indicator at a lower taxonomic level in the region. [ABSTRACT FROM AUTHOR]