Readme for ‘isotope summary data’
This data is from a project that injected deuterium into different depths (10 cm, 20 cm, 45 cm, 75 cm and 150 cm) at different times of the growing season (1-3 = early, mid, late) at the United States Sheep Experiment Station, Dubois, ID, USA. Sampling was performed in 2013. 

Date: value range is 1 to 3.  Values of ‘1’ are from the early season (May). Values of ‘2’ are from the peak season (June). Values of ‘3’ are from the late season (July). 

Depth: value range is 0, 10, 20, 45, 75 and 150. Values represent the depth of injection in cm. Values of ‘0’ are from control plots that did not receive deuterium injections. 

Species: value range is AGCR, ARTR, BASA, Other, POSE, and PSSP. AGCR = Agropyron cristata, ARTR = Artemisia tripartita, BASA= Balsamorhizae sagittata, Other = other species, POSE = Poa secunda, and PSSP = Pseudoroegneria spicata.

18O: value range is -24 to 13. The concentration of the 18O isotope in sampled plant stem water (values are in delta notation (relative to the VSMOW standard)). 

D: value range is -189.3 to 1263.4. The concentration of the deuterium isotope in plant stem water samples (values are in delta notation (relative to the VSMOW standard)). 

Dexcess: value range is -272.8 t 724.5. Dexcess is a measure of the deuterium concentration in excess of the amount of deuterium that is expected based on the concentration of 18O atoms. This measure removes the effect of natural evaporative enrichment.  It was calculated as Dexcess = D – (8*18O + 10).