Seasonal variations of leaf wax n-alkane molecular composition and δD values in two subtropical deciduous tree species: Results from a three-year monitoring program in central China
| Autor: | Kui Wang, Philip A. Meyers, Bingyan Zhao, Yu Hu, Xianyu Huang |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Wax
010504 meteorology & atmospheric sciences Liquidambar formosana biology Atmospheric circulation Subtropics 010502 geochemistry & geophysics biology.organism_classification Atmospheric sciences 01 natural sciences Monitoring program Deciduous Geochemistry and Petrology visual_art visual_art.visual_art_medium Period (geology) Precipitation 0105 earth and related environmental sciences |
| Zdroj: | Organic Geochemistry. 118:15-26 |
| ISSN: | 0146-6380 |
| DOI: | 10.1016/j.orggeochem.2018.01.009 |
| Popis: | We investigated the seasonal variations of the molecular and hydrogen isotopic compositions of leaf cuticular n-alkanes (δDalk) in two subtropical deciduous tree species (Quercus chenii, Liquidambar formosana) over a three-year period. Average chain length values of long chain n-alkanes in both species are lower in young leaves than in mature ones. The δDalk values in both tree species show seasonal fluctuations that can be as large as 78‰ in a single year. The seasonal changes in molecular and isotopic compositions suggest that leaf wax n-alkanes in these subtropical deciduous tree species integrate environmental information over a large portion of the annual growth cycle in response to fluctuations in environmental stresses (e.g. storms, droughts). In addition, the changes reveal that seasonal patterns of δDalk can differ between different deciduous species at the same location and among different years. Spring leaves collected in 2014 had more negative δDalk values than those collected in 2015 and 2016, possibly responding to differences in annual precipitation D/H ratios and associated atmospheric circulation. These preliminary results highlight that extended seasonal monitoring of leaf wax δDalk values can improve their application to reconstructing paleohydrological histories. |
| Databáze: | OpenAIRE |
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