## 2 Materials and Methods
### Simulation of SIF\({}_{760}\), GPP, and ET
#### 2.3.2 Calibration for Leaf Chlorophyll Fluorescence and Photosynthesis Parameterization  
As its fluorescence parameterization was proposed based on the data of crops such as cotton, tobacco, and maize [49], calibration is required before estimation. We used the measured leaf photosynthetic and fluorescence parameters of _Phragmites australis_ in the rapid vegetative growth and peak growth periods (Section 2.2.4) to calibrate the leaf parameter \(K_{N}^{0}\), \(\alpha\), and \(\beta\) (Kn0, Knalpha, and Knbeta in the inputs of the SCOPE model, respectively) of the chlorophyll fluorescence parameterization scheme [50] in the biochemistry module:  
\[K_{N}\;=\;\left(\frac{F_{m}}{F_{m}^{\prime}}-1\right)(K_{F}+K_{D}), \tag{1}\]  
\[K_{P}\;=\;\left(\frac{F^{\prime}{}_{m}}{F_{t}}-1\right)(K_{F}+K_{D}+K_{N}), \tag{2}\] \begin{table}
\begin{tabular}{l l l l l l} \hline \hline \multicolumn{2}{c}{**Input**} & \multicolumn{2}{c}{**Interpretation**} & \multicolumn{2}{c}{**Unit**} & \multicolumn{2}{c}{**Value**} \\ \hline
**Leaf optical** & & & & & \\ C\({}_{\text{ab}}\) & Chlorophyll content in PROSPECT & \(\mu\text{g cm}^{-2}\) & Table 1(a) & - \\ C\({}_{\text{dm}}\) & Dry matter content in PROSPECT & g cm\({}^{-2}\) & 0.012 & \\ C\({}_{\text{w}}\) & Water content in PROSPECT & g cm\({}^{-2}\) & 0.009 & [26] \\ \hline
**Leaf physiology** & & & & & \\ V\({}_{\text{cmo}}\) & Maximum carboxylation capacity & \(\mu\text{mol m}^{-2}\,\text{s}^{-1}\) & Table 1(a) & [46] \\ \(K_{n}^{0}\) & Parameter for empirical Kn (NPQ) model : & & & 1.997 & \\ \(K_{n}^{alpha}\) & \(K_{n}\;=\;\frac{K_{n}^{0}\times(1+K_{n}^{0}\times x^{6/\mu n}}{K_{n}^{\mu n} \times x^{6/\mu n}}\) & & 3.818 & [49] \\ \(k_{n}^{beta}\) & Fluorescence quantum yield efficiency & - & 0.04989 & \\ \hline
**Canopy** & & & & & \\ LAI & Leaf area index & m\({}^{2}\) m\({}^{-2}\) & Table 1(a) & \\ LIDFa & Leaf inclination & - & \(-0.35\) & - \\ LIDFb & Variation in leaf inclination & - & \(-0.15\) & \\ hc & Vegetation height & m & 2.5 & \\ \hline
**Meteorology** & & & & & \\ R\({}_{\text{in}}\) & Broadband incoming shortwave radiation & & & \\  & (0.4–2.5 \(\mu\)m) & & & \\ R\({}_{\text{ii}}\) & Broadband incoming longwave radiation & \({}^{\circ}\)C & Observation & - \\ T\({}_{\text{a}}\) & Air temperature & & & & \\ u & Wind speed & & & \\ P & Air pressure & & & \\ \hline \multicolumn{2}{c}{**(a)**} \\ \hline \hline \multicolumn{2}{c}{**Input**} & \multicolumn{2}{c}{**Value**} \\ \hline  & **October–March** & **April–May** & **June** & **July** & **August** & **September** \\ \hline
**Leaf optical** & & & & & \\ C\({}_{\text{ab}}\) & 11.74 & 71.92 & 95.84 & 83.14 & 75.61 & 62.53 \\
**Leaf physiology** & & & & & \\ V\({}_{\text{cmo}}\) & 70 & 80 & 100 & 120 & 120 & 90 \\
**Canopy** & & & & & \\ LAI & 0.67 & 1.85 & 1.89 & 2.84 & 1.67 & 1.02 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The inputs of the SCOPE model. (a) Specific usage values of the parameters C\({}_{\text{ab}}\) (chlorophyll AB content, \(\mu\text{g cm}^{-2}\)), V\({}_{\text{cmo}}\) (maximum carboxylation capacity, \(\mu\text{mol m}^{-2}\) s\({}^{-1}\)), and LAI (leaf area index, m\({}^{2}\) m\({}^{-2}\)) in the model. \[x\ =\ 1-\frac{\left(F^{\prime}{}_{m}-F_{\rm t}\right)/F^{\prime}{}_{m}}{(F_{m}-F_{ \rm o})/F_{m}}, \tag{3}\]  
\[K_{N}\ =\ \
u K_{N}^{0}\ {\rm with}\ v\ =\ \frac{(1+\beta)x^{\alpha}}{\beta+x^{ \alpha}}, \tag{4}\]  
where K is the probability coefficient that an excited atom follows a particular path, the symbol F stands for fluorescence, P refers to photochemistry, D represents intrinsic thermal dissipation present in dark-adapted plants, and the electrons control N for variable, energy-dependent thermal dissipation transport through the photosystem. The values of K\({}_{\rm D}\), K\({}_{\rm F}\), and K\({}_{\rm N}\) in this research are 0.95, 0.05, and NPQ, respectively. The values of F\({}_{m}\), F\({}^{\prime}\)\({}_{m}\), F\({}_{\rm t}\) F\({}_{\rm o}\), and NPQ were obtained through the methodologies detailed in Section 2.2.4.