LAUSR

Abstract Leaf wax n -alkanes are terrestrial plant biomarkers that have characteristics that are widely employed as proxies for climatic conditions. Understanding the relationship between different environmental factors to the amounts and types of leaf wax n -alkanes in modern plants is crucial for the application of these proxies to paleoenvironmental reconstructions. However, the effects of climate conditions on plant wax characteristics remain complicated due to the interactions among temperature, precipitation and phylogeny. To evaluate the effect of temperature with minimized interfering factors, we collected 106 Artemisia plants across a 15 °C mean annual temperature gradient along the 400 mm isohyet in China. Both total n -alkane concentration (∑alk) and carbon preference index (CPI) varied greatly but did not correlate with temperature. Average chain length (ACL) increased with temperature, especially summer temperature (T JJA , June–August), indicating that ACL could be used as proxy for temperature. The stable carbon isotope compositions of n -C 27 , n -C 29 and n -C 31 were very similar in each plant (−38.2‰ to −30.0‰, −39.0‰ to −30.2‰, −38.7‰ to −30.5‰, respectively), which reflects a similar biosynthetic process for all three n -alkane homologues of Artemisia . There was a positive relationship between δ 13 C of bulk leaf tissues (δ 13 C bulk ) and of n -alkanes (δ 13 C alk ), and the average offset of δ 13 C 29 relative to δ 13 C bulk (e C29/bulk ) was −7.1‰. Increasing trends in both δ 13 C bulk and δ 13 C 29 were found with temperature. However, correlation of δ 13 C bulk with temperature (R 2  = 18%) was much weaker than that of δ 13 C 29 with temperature (R 2  = 60%). Therefore, δ 13 C 29 appears to be a better proxy of paleotemperature than δ 13 C bulk .