## 3 Results
### Measured vs. Simulated Daily and Monthly CO\({}_{2}\) Exchange Fluxes
#### 3.3.3 Net Ecosystem Exchange (NEE)
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & & & & \multicolumn{6}{c}{**Annual Mean CO\({}_{2}\) Fluxes**} \\
**Tree** & **Site** & **Period** & & \multicolumn{2}{c}{**Calibration**} & \multicolumn{2}{c}{**(kg C m\({}^{-2}\) month\({}^{-1}\))**} & \multicolumn{2}{c}{**Model**} \\ \cline{4-11}
**Species** & **Site** & **Period** & & \multicolumn{2}{c}{**Type**} & \multicolumn{2}{c}{**Measured**} & \multicolumn{2}{c}{**Simulated**} \\ \cline{4-11}  & & & & & **Mean** & **STD.** & **Mean** & **STD.** & \(r^{2}\)** & **ME** & **RMSPEn** \\ \hline \multirow{5}{*}{**FI-Hyy**} & \multirow{5}{*}{**2004–2009**} & **GPP** & multi-site & 0.09 & 0.09 & 0.07 & 0.08 & 0.90 & 0.81 & 0.43 \\  & & **GPP** & site-specific & 0.09 & 0.09 & 0.07 & 0.08 & 0.94 & 0.87 & 0.36 \\  & & **NEE** & multi-site & 0.02 & 0.05 & 0.01 & 0.03 & 0.65 & 0.53 & 0.68 \\  & & & site-specific & 0.02 & 0.05 & 0.01 & 0.03 & 0.87 & 0.71 & 0.53 \\ \hline \multirow{5}{*}{**_Pinus sylvestris_**} & \multirow{5}{*}{**2006–2010**} & **GPP** & multi-site & 0.11 & 0.09 & 0.10 & 0.08 & 0.93 & 0.91 & 0.30 \\  & & **GPP** & site-specific & 0.11 & 0.09 & 0.09 & 0.07 & 0.95 & 0.86 & 0.37 \\  & & **NEE** & multi-site & 0.01 & 0.06 & 0.03 & 0.04 & 0.89 & 0.66 & 0.58 \\  & & **NEE** & site-specific & 0.01 & 0.06 & 0.02 & 0.04 & 0.88 & 0.78 & 0.47 \\ \cline{2-11}  & & **GPP** & multi-site & 0.13 & 0.09 & 0.10 & 0.09 & 0.84 & 0.72 & 0.52 \\  & & **NEE** & site-specific & 0.13 & 0.09 & 0.13 & 0.10 & 0.80 & 0.76 & 0.49 \\  & & **NEE** & multi-site & 0.04 & 0.04 & 0.03 & 0.04 & 0.69 & 0.62 & 0.61 \\  & & & site-specific & 0.04 & 0.04 & 0.04 & 0.04 & 0.65 & 0.58 & 0.65 \\ \hline \multirow{5}{*}{**FI-Sod**} & \multirow{5}{*}{**2005–2008**} & **GPP** & multi-site & 0.05 & 0.06 & 0.02 & 0.03 & 0.96 & 0.54 & 0.67 \\  & & **NEE** & site-specific & 0.05 & 0.06 & 0.02 & 0.03 & 0.73 & 0.35 & 0.80 \\  & & **NEE** & multi-site & 0.00 & 0.02 & 0.00 & 0.01 & 0.44 & 0.38 & 0.78 \\  & & & site-specific & 0.00 & 0.02 & 0.00 & 0.00 & 0.46 & 0.24 & 0.86 \\ \hline \multirow{5}{*}{**_Picea abies_**} & \multirow{5}{*}{**DE-Tha**} & \multirow{5}{*}{**2006–2010**} & **GPP** & multi-site & 0.17 & 0.13 & 0.13 & 0.10 & 0.96 & 0.82 & 0.42 \\  & & & site-specific & 0.17 & 0.13 & 0.16 & 0.11 & 0.93 & 0.90 & 0.31 \\  & & & site-specific & 0.05 & 0.06 & 0.05 & 0.05 & 0.87 & 0.87 & 0.36 \\  & & & site-specific & 0.05 & 0.06 & 0.06 & 0.05 & 0.82 & 0.80 & 0.45 \\ \cline{2-11}  & & **GPP** & multi-site & 0.14 & 0.11 & 0.12 & 0.10 & 0.92 & 0.89 & 0.33 \\  & & **GPP** & site-specific & 0.14 & 0.11 & 0.13 & 0.10 & 0.94 & 0.91 & 0.30 \\  & & **NEE** & multi-site & 0.01 & 0.06 & 0.04 & 0.05 & 0.58 & 0.35 & 0.80 \\  & & & site-specific & 0.01 & 0.06 & 0.02 & 0.03 & 0.83 & 0.70 & 0.55 \\ \hline \multirow{5}{*}{**_Pagus sylvatica_**} & \multirow{5}{*}{**2004–2007**} & **GPP** & multi-site & 0.12 & 0.13 & 0.11 & 0.13 & 0.82 & 0.81 & 0.43 \\  & & **GPP** & site-specific & 0.12 & 0.13 & 0.10 & 0.12 & 0.83 & 0.80 & 0.44 \\  & & & **NEE** & multi-site & 0.05 & 0.10 & 0.03 & 0.07 & 0.71 & 0.67 & 0.57 \\  & & & site-specific & 0.05 & 0.10 & 0.03 & 0.08 & 0.75 & 0.72 & 0.52 \\ \cline{2-11}  & & & **GPP** & multi-site & 0.15 & 0.15 & 0.11 & 0.12 & 0.94 & 0.80 & 0.44 \\  & & & site-specific & 0.15 & 0.15 & 0.13 & 0.15 & 0.93 & 0.91 & 0.29 \\  & & & **NEE** & multi-site & 0.02 & 0.09 & 0.03 & 0.06 & 0.85 & 0.79 & 0.45 \\  & & & site-specific & 0.02 & 0.09 & 0.03 & 0.06 & 0.86 & 0.80 & 0.45 \\ \hline \multirow{5}{*}{**_Pagus sylvatica_**} & \multirow{5}{*}{**2005–2009**} & **GPP** & multi-site & 0.15 & 0.16 & 0.12 & 0.12 & 0.92 & 0.84 & 0.40 \\  & & & site-specific & 0.15 & 0.16 & 0.16 & 0.17 & 0.95 & 0.94 & 0.23 \\  & & & **NEE** & multi-site & 0.04 & 0.10 & 0.04 & 0.07 & 0.85 & 0.79 & 0.45 \\  & & & site-specific & 0.04 & 0.10 & 0.05 & 0.09 & 0.86 & 0.84 & 0.39 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Averaged annual means of monthly aggregated measured and simulated GPP and NEE fluxes obtained with either site-specific or multi-site parameters.