## 4 Results
### CO\({}_{2}\) Sequestration Estimates and Errors
#### 4.4.2 Actual CO\({}_{2}\) Estimates Considering the Errors  
The CO\({}_{2}\) sequestration amount by the forests in Japan was calculated after each error was taken into consideration as discussed in Section 4.4.1. Table 7 shows the summary of the final output of the total CO\({}_{2}\) amounts when these errors are considered. In Table 7, the summary of the total CO\({}_{2}\) calculated from this study is listed when each of the error cases is considered. Four different cases of potential errors were examined: land cover misclassification, reliability of the backscattering model, dependency of the tree age curve, and the sequestration value. The tree age curve is listed as N/A because it is simply the errors caused by the growth trend of the trees, and giving an estimation by using other Prefectural Governments' tree age curve information will give results similar to those obtained using the Oita data. However, for the errors from land cover mapping misclassification, backscattering model and sequestration values, and after considering the backscattering model and sequestration value errors together, the estimation was calculated. In the table, Avgval Minval and Maxval represent the average, minimum and maximum sequestration value used for the estimation, respectively. Mintot and Maxtot represent the minimum total and maximum total CO\({}_{2}\) sequestration by each category, respectively. Thus, for backscattering model error cases in the coniferous category, the total CO\({}_{2}\) amount was estimated using the average sequestration value (the value listed in Table 3). Values in brackets written after N/A are the total sequestration outputs listed in the tables of deciduous and evergreen broadleaf forests (Tables 4 and 5). \begin{table}
\begin{tabular}{c} **Age** \\ **(years)** \\ \end{tabular} & **Min** & **Max** & **Min** & **Max** \\ \hline
0–5 & 3.26 & 3.49 & 1.95 & 2.75 & 1.23 & 1.84 & 0–5 & 1.72 & 4.16 & 1.56 & 3.44 \\
5–10 & 11.75 & 18.43 & 8.70 & 11.78 & 5.38 & 8.64 & 10–15 & 3.80 & 9.92 & 3.43 & 10.29 \\
15–20 & 14.23 & 18.08 & 9.90 & 13.15 & 5.99 & 8.88 & 15–20 & 5.17 & 8.33 & 5.14 & 8.57 \\
20–25 & 11.13 & 13.23 & 7.70 & 9.49 & 5.29 & 7.31 & 20–25 & 5.08 & 7.20 & 5.32 & 7.60 \\
25–30 & 9.55 & 10.93 & 7.50 & 8.20 & 4.68 & 5.98 & 25–30 & 3.97 & 5.56 & 4.18 & 5.70 \\
30–35 & 7.99 & 8.71 & 6.39 & 6.98 & 5.03 & 5.95 & 30–35 & 3.60 & 5.45 & 3.80 & 5.70 \\
35–40 & 6.30 & 6.71 & 5.63 & 6.61 & 4.55 & 5.27 & 35–40 & 2.12 & 4.81 & 2.28 & 4.94 \\
40–45 & 5.19 & 5.91 & 4.61 & 5.40 & 3.85 & 4.78 & 40–45 & 1.86 & 4.34 & 1.90 & 4.56 \\
45–50 & 4.37 & 5.89 & 3.79 & 5.01 & 3.46 & 4.51 & 45–50 & 1.86 & 3.70 & 1.90 & 3.80 \\
50–55 & 3.44 & 5.75 & 3.23 & 4.94 & 3.02 & 3.78 & 50 over & 0.60 & 3.41 & 1.50 & 3.61 \\
55–60 & 2.79 & 5.82 & 2.72 & 4.55 & 2.58 & 3.78 & & & & & \\
60–65 & 2.08 & 5.28 & 2.01 & 3.65 & 1.71 & 2.93 & & & & & \\
65–70 & 1.32 & 4.35 & 1.04 & 2.77 & 0.97 & 1.98 & & & & & \\
70–75 & 1.32 & 3.89 & 0.97 & 2.39 & 0.97 & 1.22 & & & & & \\
75 over & 0.59 & 2.06 & 0.22 & 0.79 & 0.24 & 0.53 & & & & & \\ \hline \end{tabular}
\end{table} 
Table 6: CO\({}_{2}\) sequestration minimum and maximum values for each forest type and tree age class. Errors of misclassification were considered by using the percentage of the total area of each distributed forest class modified based on the actual misclassification percentage shown in Figure 15. For example, 4% and 6% of coniferous classes were misclassified to evergreen broadleaf and deciduous broadleaf forests, respectively. Thus, 4% and 6% of the total area from those forest classes, respectively, were subtracted and added to the coniferous class (this is determined as the maximum status). At that point, the deciduous and evergreen broadleaf status was determined as the minimum status. On the other hand, 25% and 15% were misclassified to the coniferous class when they were likely to be evergreen and deciduous broadleaf forests, respectively.