Some studies have demonstrated that leaf wax δDn-alkane values for a single species varied significantly with seasons. However, it is still not clear that the seasonality patterns of leaf wax δDn-alkane values in higher plants. Meanwhile, few efforts have been pursued to assess the effect of the light slopes (sunny vs. cloudy) on leaf wax δDn-alkane values. In this study, we systematically investigated plant wax δDn-alkane values and soil n-alkane δD values along different light slopes in different seasons (spring vs. autumn), as well as the relationship of n-alkane δD values between plant leaves and soil. We found that plant wax δDn-alkane values were D-enriched by ca. 20‰ in spring relative to autumn, and ca. 10‰ in the sunny slope than in the cloudy slope. Moreover, surface soil n-alkane δD values varied consistently with plant wax δDn-alkane values for different seasons and light slopes. More importantly, plant wax δDn-alkane values showed clear seasonal variations, but varied slightly with light slopes. The variations of plant wax δDn-alkane values can be recorded in soil n-alkane δDn-alkane values. In addition, we found that leaf wax δDn-alkane values in a majority of species differed significantly among woods, non-woods and grasses at a site. Therefore, we suggested a good choice to sample at the site dominated by woods when leaf wax δDn-alkane values are utilized as a proxy for the reconstruction of the paleoenvironment.
Keywords: Hydrogen isotope; Leaf wax; Light slope; Season; n-Alkane.
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