Global synthesis of stable hydrogen and oxygen isotope compositions of plant water and source water and re-quantified deuterium offsets

This dataset compiles and reanalyzes published stable isotope measurements of hydrogen (δ²H) and oxygen (δ¹⁸O) in plant water and source water across global terrestrial ecosystems. The dataset supports a global synthesis investigating deuterium (δ²H) offsets between plant water and source waters under different conceptual scenarios of soil and plant water pools. The compiled data were derived from 110 peer-reviewed studies across 212 globally distributed field sites, covering a wide range of climate zones, ecosystem types, soil conditions, and plant functional types. Source waters include multiple soil water pools and groundwater, while plant waters include bulk xylem/plant water and sap flow water. In addition to raw isotope data, this dataset includes processed results from re-quantification of δ²H offsets using linear and non-linear possible source water line (PWL) approaches and model comparison metrics. All data were digitized or extracted directly from published sources and harmonized into a consistent format to enable cross-study comparison and synthesis.