## 3 Results
### Temporal Distribution  
The temporal distribution characteristics of grassland production along the China-Mongolia Railway in Mongolia are shown in Figure 3. In the past ten years, grassland production has shown a slightly increasing trend. Fluctuation in the first five years was minor and grassland production did not change greatly. However, fluctuation in the latter five years showed that grassland production increased. Grassland production in 2006 was the lowest in 10 years at \(8250.80\times 10^{4}\) t, and the highest in 2012, reaching \(11660.09\times 10^{4}\) t. Average grassland production of the study area for 10 years was \(9709.88\times 10^{4}\) t, and average grassland production in the four years was above the average level in 2011, 2012, 2013, and 2015. The average grassland production in other years was approximately \(8500\times 10^{4}\) t (Table 3). The statistical results of grassland production (total production) of grassland types are shown in Table 4. Due to the difference in grassland areas, the average grassland production of different grasslands differed greatly over ten years in high to low mountain forest steppe, steppe and dry steppe, desert steppe, mountain steppe, and mountain desert steppe. The mountain forest steppe had the highest average grassland production at \(5992.43\times 10^{4}\) t and was mainly distributed along the Choir-Sukhbaatar Railway, while the mountain desert steppe had the lowest average grassland production at \(138.76\times 10^{4}\) t and was scattered along the railway. The average grassland production of steppe and dry steppe was \(1536.07\times 10^{4}\) t and was mainly distributed along the Choir-Zonghara Railway; desert steppe was \(1533.85\times 10^{4}\) t and was mainly distributed along the Zamyu Uud-Choir Railway; and mountain steppe was \(506.77\times 10^{4}\) t and was mainly distributed along the Sainsh  
Figure 3: Annual grassland production along the China–Mongolia Railway in Mongolia from 2006 to 2015. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Grassland Types**} & \multicolumn{10}{c}{**Production (Total Yield) (\(\mathbf{10^{d}}\) \(\mathbf{0^{d}}\))**} \\ \cline{2-13}  & **2006** & **2007** & **2008** & **2009** & **2010** & **2011** & **2012** & **2013** & **2014** & **2015** & **Average** \\ \hline Steppe and dry steppe & 1248.65 & 1336.21 & 1504.31 & 1286.44 & 1312.83 & 1671.88 & 1999.06 & 1901.42 & 1265.87 & 1834.07 & 1536.07 \\ Mountain steppe & 385.45 & 424.22 & 473.79 & 409.83 & 434.35 & 615.38 & 702.50 & 652.40 & 394.04 & 575.78 & 506.77 \\ Mountain forest steppe & 5253.22 & 5819.43 & 5600.82 & 5173.74 & 5760.14 & 5689.95 & 6890.72 & 7041.84 & 5542.36 & 7710.06 & 5992.43 \\ Mountain desert steppe & 1226.62 & 126.67 & 1332.21 & 123.57 & 130.81 & 134.61 & 170.58 & 166.57 & 117.27 & 162.63 & 138.76 \\ Desert steppe & 1258.85 & 1454.11 & 1546.86 & 1287.12 & 1395.83 & 1616.06 & 1897.24 & 1780.52 & 1317.69 & 1782.39 & 1533.85 \\ Total & 8250.80 & 9160.64 & 9259.79 & 8280.70 & 9033.97 & 9727.89 & 11,660.1 & 11,542.8 & 8637.24 & 11,524.9 & 9707.88 \\ \hline \hline \end{tabular} Note: There are some potential errors in the grassland production estimation results in Tables 3 and 4. The \(\mathbf{R}^{d}\) of the optimal model is 0.72, and the regression relationship can explain 72% of the variation of the dependent variable.  
\end{table} 
Table 4: Annual grassland production of different grassland types along the China-Mongolia Railway in Mongolia from 2006 to 2015.