Global-scale altitude effect on leaf wax n-alkane δD values in terrestrial higher plants

Numerous field studies have shown that leaf wax n-alkane δD values(δDn-alkane) can be used as a proxy for paleoelevation reconstruction. However, the lack of systematic global analysis of δDn-alkanevalues with respect to altitude limits the reliability of δDn-alkanevalues for paleoaltimetry at the global scale. In this study, we analyzed the variation of δDn-alkanevalues with altitude in terrestrial higher plants based upon our compiled global δDn-alkanedatabase. The general decrease in δDn-alkanevalues with altitude corresponds to the variation in precipitation δD(δDprec) with altitude, suggesting that the δDn-alkanevalues effectively reflect δDprecvalues. When eliminating the effect of latitude at the global scale, the global δDn-alkane-altitude lapse rate for all species was-1.01±0.10‰(100 m)-1, while these lapse rates were-1.03±0.13‰ and-0.47±0.13‰(100 m)-1for dicots and monocots, respectively. Our study reveals that it is reliable to use δDn-alkanevalues to gain information about paleoelevation at the global scale, and the global δDn-alkane-altitude lapse rates provide an alternative to reconstruct paleoelevation at some δDn-alkane-uninvestigated areas.