Major evolutionary trends in hydrogen isotope fractionation of vascular plant leaf waxes.
Hydrogen isotopic ratios of terrestrial plant leaf waxes (δD) have been widely used for paleoclimate reconstructions. However, underlying controls for the observed large variations in leaf wax δD values in different terrestrial vascular plants are still poorly understood, hampering quantitative paleoclimate interpretation. Here we report plant leaf wax and source water δD values from 102 plant species grown in a common environment (New York Botanic Garden), chosen to represent all the major lineages of terrestrial vascular plants and multiple origins of common plant growth forms. We found that leaf wax hydrogen isotope fractionation relative to plant source water is best explained by membership in particular lineages, rather than by growth forms as previously suggested. Monocots, and in particular one clade of grasses, display consistently greater hydrogen isotopic fractionation than all other vascular plants, whereas lycopods, representing the earlier-diverging vascular plant lineage, display the smallest fractionation. Data from greenhouse experiments and field samples suggest that the changing leaf wax hydrogen isotopic fractionation in different terrestrial vascular plants may be related to different strategies in allocating photosynthetic substrates for metabolic and biosynthetic functions, and potential leaf water isotopic differences.
Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island, United States of America.
Li
L
Gao
Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America.
Erika J
EJ
Edwards
Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, United States of America.
Yongbo
Y
Zeng
Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island, United States of America.
Yongsong
Y
Huang
D005075:Biological Evolution; D006859:Hydrogen / Q000737:chemistry*; D007554:Isotopes / Q000737:chemistry*; D009518:New York; D018515:Plant Leaves / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D014885:Waxes / Q000737:chemistry*
D007554:Isotopes; D014885:Waxes; D006859:Hydrogen