1. Measurement and Interpretation of Water Vapor Isotopic Fluxes Xuhui Lee Yale University School of Forestry and Environmental Studies

2. Collaborators University of Minnesota John Baker, Tim Griffis Yale University Kyounghee Kim, Ron Smith, Lisa Welp Campbell Scientific Steve Sargent, Bert Tanner Chinese Academy of Sciences Xiaomin Sun, Xuefa Wen, Guiru Yu

3. Transpiration, photosynthesis, leaf water enrichment, and the Pelect effect H 2 O + CO 2 CH 2 O + O 2 sunlight xylem water

4. TDL system for measuring water vapor and flux isotope ratios dripper dry air enriched water manifold N 2 gas pump bypass flow reference cell sample cell 2 3 4 5 gradient interface air 1 air 2 1 Flux isotope ratio

5. Soybean field, Minnesota

6. Instrument Tower Great Mountain Forest, Connecticut

7. Eddy Covariance Instrument, Great Mountain

8. Tunable Diode Laser Analyzer, Great Mountain

9. Dripper Calibration Device

10. Water Vapor Gradient Aug 30 – Sep 7, 2005 Rain Dew

11. Seasonal variation of  ET,  P and  X Great Mountain, 2005 precipitation ET xylem water of overstory trees

12. Isotopic composition of water pools Soybean field, Minnesota, 2006

13. 18 O in H 2 O and CO 2 Soybean, Minnesota, 2006

14. CO 2 and 18 O-CO 2 Profiles Soybean, Minnesota, 2006