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. 2017 Mar 31;68(9):2345–2360. doi: 10.1093/jxb/erx085

Table 7.

The coefficients with their probability of significance of linear regression of 31 year average simulated PLUE (overall photosynthetic light-use efficiency as defined in Table 6) against three biochemical parameters (χgbs25, ATPreq, and χJmax25, representing the strength of the CCM, quantum requirement, and photosynthetic capacity, respectively) used in the C4 photosynthesis model, for four cases where potential or water-limited environments were combined with present or 2050 climate conditions

Potential level Water-limited level
Present climate 2050 climate Present climate 2050 climate
Coefficient Probability Coefficient Probability Coefficient Probability Coefficient Probability
Intercept 11.674 1.45 × 10–11 12.108 2.67 × 10–12 9.019 2.31 × 10–12 9.385 1.49 × 10–14
Nanjinga 0.097 0.56 0.102 0.50 –0.078 0.48 –0.112 0.15
Shizukuishia 0.167 0.32 0.415 0.01 –0.200 0.09 –0.051 0.49
χgbs25 –12.751 1.64 × 10–7 –10.574 3.91 × 10–7 –10.262 1.84 × 10–8 –8.406 2.23 × 10–9
ATPreqb –1.237 1.22 × 10–7 –1.244 3.46 × 10–8 –0.659 1.24 × 10–6 –0.676 1.40 × 10–8
χJmax25 0.0162 7.37 × 10–8 0.0150 5.12 × 10–8 0.0083 1.22 × 10–6 0.0072 7.76 × 10–8
R 2 0.963 0.965 0.961 0.976
Data points 18 18 18 18

a Site was included as the covariate in regression, with Los Baños as the reference having a coefficient of zero.

b Total ATP requirement per CO2 assimilated (= 3 + φ), i.e. 5 for C4 photosynthesis and 3.75 for cyanobacterial photosynthesis (see the text).