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(δD_(n-alkane))can be used as a proxy for paleoelevation reconstruction.However,the lack of systematic global analysis of δD_(n-alkane) values with respect to altitude limits the reliability of δD_(n-alkane )values for paleoaltimetry at the global scale.In this study,we analyzed the variation of δD_(n-alkane) values with altitude in terrestrial higher plants based upon our compiled globalδDn-alkane database.The general decrease in δD_(n-alkane) values with altitude corresponds to the variation in precipitationδD(δD_(prec))with altitude,suggesting that the δD_(n-alkanevalues) effectively reflect δD_(prec) values.When eliminating the effect of latitude at the global scale,the global δD_(n-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)^(-1) for dicots and monocots,respectively.Our study reveals that it is reliable to use δD_(n-alkanevalues) to gain information about paleoelevation at the global scale,and the global δD_(n-alkane-altitude) lapse rates provide an alternative to reconstruct paleoelevation at some δD_(n-alkane)-uninvestigated areas.