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davidjpmoore / WUE_ci

A repository to explore the year by year effect of rising CO2 on potential photosynthesis given ci of tree rings
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Plot timeseries of A and L to verify coherence with WUE timeseries #5

Open davidjpmoore opened 6 years ago

davidjpmoore commented 6 years ago

Need to estimate a gs proxy (gs') from the A/ci analysis. Calculate A and gs' and verify that these are plausible given the WUE estimates

davidjpmoore commented 6 years ago

Using the definition of Ls from Lawlor, David W. "Limitation to Photosynthesis in Water‐stressed Leaves: Stomata vs. Metabolism and the Role of ATP." Annals of botany 89, no. 7 (2002): 871-885.

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The calculation is reasonably simple. We know ci from the tree rings, we know ca from the historical record (source?). Vc and Jmax are taken from Griffin (pers comm) Ls = ((A-Atk)/A)*100

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This assumes that Vcmax is the dominant control of photosynthesis. If instead we assume that most photosynthesis is carried out in sub-saturating light then RuBP is limiting. Using Vcmax from Griffin and Jmax' is downweighted

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Stomatal limitation does depend on whether we assume Vc or J limitation.

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