Isotope values of leaf tissues, leaf waxes, and xylem waters across elevational gradients@en

Leaves and woody stems as well as soils and surface waters were collected from two elevational gradient transects across the Coastal and Sierra Nevada Mountains of Northern California. Specimens of Acer macrophyllum, Quercus lobata, Quercus kelloggii, Quercus douglasii, Alnus rubra, Pinus sabineana, Pinus ponderosa, and Pinus jeffreyi were collected during the 2006-growing season. In addition to plant specimens, soil and water samples were collected from plant collection locations along the transect. Here, carbon and hydrogen isotope values of normal-alkanes (n-alkanes), carbon and nitrogen isotope values of bulk leaf material, as well as hydrogen and oxygen isotope values of xylem water are presented from eight co-occurring tree species from ninety-three localities. Carbon and hydrogen isotope values of n-alkanes extracted from soils and hydrogen and oxygen isotope values of surface waters are also presented. Leaf wax n-alkanes were extracted, isolated, identified, and quantified following Tipple and Pagani, 2013 (Geochimica et Cosmochimica Acta, 111, 64-77). The carbon and hydrogen isotope values of leaf wax n-alkanes were conducted following Tipple et al., 2018 (Oecologia, 187, 1053-1075) and Tipple and Pagani, 2013, respectively. The carbon and nitrogen isotope values of leaf materials were measured according to Tipple et al., 2018. Xylem waters were extracted from woody stems and both the hydrogen and oxygen isotope values of xylem and surface waters were measured following Tipple and Pagani, 2013. The purpose of this study was to assess isotope values across steep elevational gradients to better understand the environmental factors and species specific effects responsible for shaping the carbon and hydrogen isotopic compositions of plant materials.