Stable sulfur isotope hydrogeochemical studies using desert shrubs and tree rings, Death Valley, California, USA

The delta(34)S values of two dominant xerophytes, Atriplex hymenehytra and Larrea tridentata, in Death Valley, California, vary similarly from +7 to +18 parts per thousand, corresponding isotopically to sulfate in the water supplies at a given location. Going radially outwards, tree ring data from a phreatophyte tree, Tamarix aphylla, show a distinct time dependence, with delta(34)S values increasing from +13.5 to +18 parts per thousand for soluble sulfate and from +12 to +17 parts per thousand for total sulfur. These data are interpreted in terms of sulfur sources, water sources and flow paths, and tree root growth.