## 1 Introduction
### 3-PG Model Description
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Meaning/Comments** & **Name** & **Unit** & **Value** & **Source** \\ \hline \multicolumn{5}{c}{Allometric relationships \& partitioning} \\ \hline \hline Foliage: Stem partitioning ratio \(\textcircled{@}D=2\) cm & pFS2 & 0.72 & This study \\ Foliage: Stem partitioning ratio \(\textcircled{@}D=20\) cm & pFS20 & 0.38 & This study \\ Constant in the stem mass v. diameter. relationship & aS & 0.0118 & [32] \\ Power in the stem mass v. diameter. relationship & nS & 3.223 & [32] \\ Maximum fraction of net primary production & pRx & 0.6 & [32] \\ (NPP) to roots & pRn & 0.2 & [32] \\ Minimum fraction of NPP to roots & pRn & 0.2 & [32] \\ \hline \hline \multicolumn{5}{c}{Litterfall \& root turnover} \\ \hline Maximum litterfall rate & gammaFx & 1/month & 0.0485 & [32] \\ Litterfall rate at \(t=0\) & gammaF0 & 1/month & 0.001 & [32] \\ Age at which litterfall rate has median value & tgammaF & months & 23 & This study \\ Average monthly root turnover rate & gammaR & 1/month & 0.02 & [32] \\ \hline \hline \multicolumn{5}{c}{Temperature modifier (fT)} \\ \hline Minimum temperature for growth & Tmin & degree \({}^{\circ}\)C & 0 & [32] \\ Optimum temperature for growth & Topt & degree \({}^{\circ}\)C & 17.5 & [32] \\ Maximum temperature for growth & Tmax & degree \({}^{\circ}\)C & 40 & [32] \\ \hline \hline \multicolumn{5}{c}{Frost modifier (fFRost)} \\ \hline Days production lost per frost day & kF & days & 1.0 & [32] \\ \hline \hline \multicolumn{5}{c}{Soil water modifier (fSW)} \\ \hline Moisture ratio deficit for f\({}_{\text{q}}=0.5\) & SWconst & 0.6 & This study \\ Power of moisture ratio deficit & SWpower & 7 & This study \\ \hline \multicolumn{5}{c}{Fertility effects} \\ \hline Value of “m” when FR = 0 & m0 & 0 & Default \\ Value of “fNutr” when FR = 0 & fN0 & 0.4 & This study \\ Power of (1-FR) in “fNutr” & fNn & 1 & This study \\ \hline \multicolumn{5}{c}{Age modifier (fAge)} \\ \hline Maximum stand age used in age modifier & MaxAge & years & 150 & This study \\ Power of relative age in function for fAge & nAge & 4 & Default \\ Relative age to give fAge = 0.5 & rAge & 0.95 & Default \\ \hline \multicolumn{5}{c}{Stem mortality \& self-thinning} \\ \hline Max. stem mass per tree \(\textcircled{@}1000\) trees/hectare & wSx1000 & kg/tree & 175 & This study \\ Power in self-thinning rule & thinPower & & 1.3 & This study \\ \hline \multicolumn{5}{c}{Specific leaf area} \\ \hline Specific leaf area at age 0 & SLA0 & m\({}^{2}\)/kg & 8 & This study \\ Specific leaf area for mature leaves & SLA1 & m\({}^{2}\)/kg & 4 & This study \\ Age at which specific leaf area = (SLA0+SLA1)/2 & tSLA & years & 3 & [32] \\ \hline \multicolumn{5}{c}{Light interception} \\ \hline Extinction coefficient for absorption of & K & 0.5 & Default \\ PAR by canopy & fullCanAge & years & 3 & [32] \\ Age at canopy cover & fullCanAge & years & 0.033 & This study \\ Maximum proportion of rainfall & MaxIntcptn & 0.033 & This study \\ evaporated from canopy & & & \\ LAI for maximum rainfall interception & LAImaxIntcptn & 5 & This study \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Physiological Principles in Predicting Growth (3-PG) Parameters of Chinese fir.