Abstract

Plant waxes, widely used as biomarkers for paleoenvironmental reconstructions in boreal peatlands, remain relatively understudied in Andean "bofedales" peat meaning that their application in these ecosystems requires a better understanding of local vegetation. This study therefore compares four plant wax classes - n-alkanoic acids, n-alkanes, n-alkanols, and sterols - in leaves and sheaths of Distichia muscoides and Oxychloe andina, that form cushions (or mounds), in a bofedal in northern Chile. Analyses indicate that wax concentrations were higher in D. muscoides and n-alkanoic acids were dominant in both species and showed significant differences in the average chain length (ACL; O. andina = 27.3, sigma = 0.78; D. muscoides = 26.8, sigma = 0.18; p < 0.05), while those for the n-alkanes were similar. Mean n-alkanol abundances were significantly higher in D. muscoides (171.5; sigma = 76.7 mu g/g) than in O. andina (32.1; sigma = 53.5 mu g/g, p < 0.05) and among sterols, beta-sitosterol was the most abundant in both species. Plant wax distributions were similar between organs, except for the ACL of the n-alkanoic acids in D. muscoides (leaves = 26.8, sigma = 0.2; sheaths = 25.9, sigma = 0.1; p < 0.001). For both species, leaf-sheath differences in plant wax abundance and size suggest that leaves contribute most to peat (similar to 4x n-alkanoic acids, similar to 2x n-alkanes). The study reports four compound classes detected in "cushion" plants towards their application in the bofedales peat of the Andean Altiplano. In particular we find that n-alkanes show minimal differences between species, suggesting suitability for testing for compound-specific isotopic analysis-based paleoclimate proxies in bofedales. beta-Sitosterol is highly abundant and may serve as a biomarker for the presence of the studied species. Overall, the bofedales have potential as archives of plant wax from these cushion plants towards paleoenvironmental reconstructions.