Xu, Lingze ， Gao, Hongkai ， An, Wenling ， Duan, Zheng
2025-08-01 ENVIRONMENTAL RESEARCH COMMUNICATIONS 2025 7(卷), 8(期), (null页)
Tree-ring width chronologies have been widely used to reconstruct past hydroclimate variability, including precipitation, temperature, and streamflow. However, their relationship with evaporation-a key component of ecosystem water use-remains poorly quantified and understood. Here, we systematically evaluate the relationship between tree-ring width and observed hydrometeorological variables across 25 catchments within the contiguous United States. We find that in 9 of 19 catchments, tree-ring width exhibits the strongest correlation with evaporation from January to September ( E ), evaporation from May to August ( E5-8 ) or transpiration ( ET ), rather than precipitation or streamflow. These catchments are predominantly located in semi-arid regions and the southern western United States, where root zone moisture limitation strongly constrains tree growth. Our results demonstrate that tree-ring width can serve as a robust proxy for catchment-scale actual evaporation, particularly in water-limited ecosystems.