Drought in a warmer, CO2-rich climate restricts grassland water use and soil water mixing

Soil water sustains terrestrial life, yet its fate is uncertain under a changing climate. We conducted a deuterium labeling experiment to determine if elevated atmospheric CO2, warming, and drought impact soil water storage and transport in a temperate grassland. Elevated CO2 created a wetter rootzone compared to ambient conditions, whereas warming decreased soil moisture. Soil water remained well-mixed in all global change treatments except for summer drought combined with warming and elevated CO2. These combined treatments caused the grassland to conserve water and restricted soil water flow to large, rapidly draining pores without mixing with small, slowly draining pores. Our results suggest that drought in a warmer, more CO2-rich climate can severely alter grassland ecohydrology by constraining post-drought soil water flow and grassland water use.

Methods
This dataset includes a combination of hydrological, meterological, soil hydrological modeling results, and stable isotope tracer records following a deuterium tracer experiment in a climate manipulation study (ClimGrass or ClimGrassHydro). See Supplemental Materials of Radolinski et al. ("Drought in a warmer, CO2-rich climate restricts grassland water use and soil water mixing") for detailed breakdown of methodology. 

The "Metadata_ClimGrassHydro_label_paper_v4.xlsx" file provided includes detailed information on data structure, methodology, and content.