## 3 Results and Analysis
### Long-Term Trends for Forest Ecosystem Status from 2010 to 2020  
#### 3.2.1 Long-Term Trend in Vegetation Evaluation Indicators  
Figure 5 presents FCI differences for five countries in the Lancang-Mekong region for the period 2010-2020. Owing to the 5-year update period for fine classification products, the FCIs were extracted in 2010, 2015, and 2020, respectively. The differences in FCI were calculated between 2020 and 2015 (filled left slash in Figure 5) and between 2015 and 2010 (filled cross in Figure 5). The results indicated that the proportion of decreased FCI (Figure 5 azure bars) was higher than that of increased parts for all countries in the Lancang-Mekong region. Moreover, except for Myanmar, the decrease trend in FCI from 2020 to 2015 was stronger than that from 2015 to 2010 for the other countries in the region (Figure 5 red bars).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Country**} & \multirow{2}{*}{**FCI (\%)**} & **Annual Average** & **Annual Maximum** & **Annual** \\  & & **LAI** & **FVC (\%)** & **Cumulative** \\  & & & **GPP (gC/m\({}^{2}\))** \\ \hline Overall & 55.73 & 3.41 & 93.51 & 2879.54 \\ Cambodia & 59.88 & 2.98 & 90.41 & 2689.23 \\ Laos & 54.85 & 3.99 & 95.37 & 3093.06 \\ Myanmar & 65.93 & 3.58 & 94.80 & 2845.99 \\ Thailand & 46.43 & 3.00 & 91.16 & 2903.91 \\ Vietnam & 43.81 & 3.32 & 93.78 & 2824.06 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Statistics of the forest coverage index (FCI), annual average leaf area index (LAI), annual maximum fraction of green vegetation cover (FVC), and annual cumulative gross primary productivity (GPP) for forest ecosystem in each country in the year 2020.  
Figure 6 presents the spatial distribution of the differences in three vegetation evaluation indicators (annual average LAI, annual maximum FVC, and annual cumulative GPP) over the forest ecosystem in the Lancang-Mekong region from 2010 to 2020. The figure indicates that the areas with increasing trends in the three vegetation evaluation indicators were distributed in southeastern Vietnam, northeastern Thailand and western Myanmar. Conversely, the areas with decreasing trends in the three vegetation evaluation indicators were distributed in Laos, Cambodia, and northern Myanmar (Figure 6a-c). Figure 5d provides a summary of three vegetation evaluation indicators from 2010 to 2020 for five countries in the Lancang-Mekong region. The results showed that Cambodia and Laos experienced a higher proportion of decrease trends (75.36%, 66.29%, and 64.08% for Cambodia and 72.39%, 62.33%, and 55.78% for Laos) for the three vegetation evaluation indicators (i.e., annual average LAI, annual maximum FVC, and annual cumulative GPP) compared to increase trends (24.64%, 33.71%, and 35.92% for Cambodia and 27.61%, 37.67%, and 44.22% for Laos). In addition, Myanmar and Thailand had a higher proportion of increase trends for annual maximum FVC (59.12% for Myanmar and 60.57% for Thailand) and annual cumulative GPP indicators (55.98% for Myanmar and 60.54% for Thailand) compared to  
Figure 4: Spatial distribution of EQI for each country in the Lancang-Mekong region in 2020. (**a**) EQI; (**b**) summary of statistics EQI.  
Figure 5: Forest coverage index (FCI) differences from 2020 to 2015, and 2015 to 2010 for five countries in the Lancang–Mekong region. The azure and red colors demonstrate the proportion of increased and decreased areas of FCI, and the filled cross and left slash demonstrate the FCI change from 2015 to 2010 and from 2020 to 2015, respectively.  
the annual average LAI indicator (40.70% for Myanmar and 46.20% for Thailand). Among these five countries, Vietnam demonstrated the best recovery trend for the annual average LAI (54.01%) and annual cumulative GPP (66.04%) indicators, and an almost stable trend for the annual maximum FVC indicator (48.57%) (Figure 6d).