Abstract

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. (C) 2020 Elsevier Ltd. All rights reserved.