1. LeafWeb (leafweb.ornl.gov) Objectives - Provide plant physiologists and photosynthesis researchers a reliable tool for analyzing leaf gas exchange measurements - Develop a global database of critical leaf biochemical and physiological parameters for ecosystem and land surface models Approach - Web-based automated SErvice in Exchange for Data Sharing (SEEDs)

2. The most influential data and model in the carbon cycle research Keeling CurveFarquhar-von Caemmerer- Berry (FvCB) Model LeafWeb estimates FvCB parameters from leaf gas exchange measurements

3. Instruments Li-Cor 6400Walz GFS - 3000 Globally, thousands of units are used by plant scientists

4. Yet data starvation contributes to unsatisfactory terrestrial carbon cycle model performance Terrestrial Biogeochemistry Models cannot get seasonal cycles of CO2 right (Hoffman et al 2009) No consistency in terrestrial carbon cycle models (Friedlingstein et al 2006)

5. LeafWeb strives to connect the two communities

6. Although the FvCB model was developed 30 years ago, its parameters has not been correctly estimated from measurements because: FvCB is a change-point model FvCB is over-parameterized with respect to typical A/Ci curves The FvCB model dictates the order of photosynthetic limitation states These facts are considered in LeafWeb

7. LeafWeb support structure Theoretical analysis Numerical solutions Validation of numerical solutions Web implementation Data harvest and managementData synthesis Forcing SFA Modeling / data assimilation Forcing SFA MOFLUX CDIAC

8. Data flow through LeafWeb Data collected from the user - Core variables - Variables to put the leaf in its environment User option of Share or not to share data Graphic capabilities Results to the user If the Share option is selected, the data are available to the general public; graphic function is enabled to the user If not to share, data and results are not archived, no graphic function

9. Future efforts Get users to know LeafWeb Get users to use LeafWeb Relax data format requirement Implement C4 photosynthesis program

10. Comment from Graham Farquhar: “I am very interested……as are the reviwers” Comments from anonymous reviewers: “The methods presented in this manuscript may constitute a very significant advance in the estimation of the parameters of the FvCB model of carbon assimilation, and could be the definitive solution to a longstanding problem. They might be of even broader importance, in the study of change-point models in general. ” “Given the potential value of this work, and the very real possibility that the authors have achieved a remarkable breakthrough…… A self promotion (for the right cause) So Use LeafWeb!

12. Model representation