## 3 Results
### Long-Term Characteristics of Three Products
#### 3.2.2 Comprehensive Assessment of Long-Term Changes in LAI/FVC/GPP  
Figure 8 presents the trend comparison map of LAI, FVC, and GPP, at a per-pixel level. The dark green and dark red pixels (i.e., ID 0) represent the three products showing consistent positive and negative trend directions, respectively. The agreed positive tendency among three datasets is unambiguous across most of the northeastern (e.g., Jianzha, Guide, Tongren counties, etc.) and part of the northwestern TRSR (e.g., Zhiduo and Golmud counties). A few agreed positive pixels were also found in the western part of Dari County. In addition, the areas of agreed negative are usually concentrated in the northern TRSR (e.g., Qumalai county) and parts of the southeastern TRSR (e.g., Dari and Gande counties). Table 4 displays the statistical information of the metrics of interannual consistency derived from trend analysis. The trend direction of all datasets agrees in 76.08% of the whole TRSR, collectively displaying agreement with positive tendencies of 2.50% and very few negative tendencies of 0.06%. The light-colored pixels (i.e., ID 1, 2, and 3) indicate regions where two out of three products synchronously display a positive, negative, or insignificant trend, while the third product exhibits an inconsistent tendency. In this region, FVC most often shows an inconsonant tendency where the oth  
Figure 8: Spatial patterns of long-term trend comparison estimated from LAI, FVC, and GPP during the 2000–2018 growing season across the TRSR. The dark-colored pixels with ID 0 represent total agreement in the trend direction, i.e., total agreed in positive (P0), negative (N0), and insignificant changes (INS0), while light-colored pixels with ID 1, 2, or 3 represent total disagreement, i.e., total disagreed in positive (P1, P2, or P3), negative (N1, N2, or N3), and insignificant changes (INS1, INS2, or INS3), and the meanings of each ID are shown in Section 2.3.4.  
accordant trend direction. The pixels with ID 2 accounts for about 13.96% of the whole TRSR. Conversely, LAI (i.e., the pixels with ID 1) and, to a lesser extent, GPP (i.e., the pixels with ID 3), show relatively few inconsistencies for 6.15% and 3.81% pixels, respectively. Figure 9 depicts the correlation comparison map derived from the Spearman correlation analysis by LAI, FVC, and GPP from the 2000 to 2018 growing season. The pixels with ID 0 indicate a consistent positive or negative correlation for three products. Accordantly, positive correlations among all products are obviously across the majority area of the northeastern (e.g., Gonghe, Jianzha, Guide counties) and northwestern (e.g., Golmud county) TRSR. In addition, there are a few consistently positively correlated pixels found in the northern parts of the study area (e.g., Maduo county). Table 4 shows the statistical results of the interannual correlated comparison derived from the correlation analysis. The rank relation among all datasets agrees in 38.96% across the whole TRSR, respectively, revealing a positive correlation of 23.08% and a negative correlation of less than 0.01%. The percentages of light-colored pixels with ID 1, 2, and 3 \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Types**} & \multicolumn{3}{c}{**Trend**} & \multicolumn{3}{c}{**Correlation**} \\ \cline{2-7}  & **Positive** & **Negative** & **Insignificant Changes** & **Positive** & **Negative** & **Insignificant Correlation** \\ \hline
0 & 2.50\% & 0.06\% & 73.52\% & 23.08\% & \textless{}0.01\% & 15.88\% \\
1 & 1.22\% & \textless{}0.01\% & 4.93\% & 1.44\% & \textless{}0.01\% & 31.80\% \\
2 & 0.31\% & 0.07\% & 13.58\% & 7.43\% & \textless{}0.01\% & 5.31\% \\
3 & 1.33\% & 1.17\% & 1.31\% & 12.27\% & \textless{}0.01\% & 2.79\% \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparison statistics of the agreement metrics of interannual variation difference, derived from three products. Figure 9: Spatial patterns of long-term correlation comparison calculated by LAI, FVC, and GPP during the 2000–2018 growing season across the TRSR.