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Five countries in the Lancang–Mekong region, including Myanmar, Laos, Thailand, Cambodia, and Vietnam, are facing the threat of deforestation, despite having a high level of forest coverage. Quantitatively assessing the forest ecosystem status and its variations based on remote sensing products for vegetation parameters is a crucial prerequisite for the ongoing phase of our future project. In this study, we analyzed forest health in the year 2020 using four vegetation indicators: forest coverage index (FCI), leaf area index (LAI), fraction of green vegetation cover (FVC), and gross primary productivity (GPP). Additionally, we introduced an ecosystem quality index (EQI) to assess the quality of forest health. To understand the long-term trends in the vegetation indicators and EQI, we also performed a linear regression analysis from 2010 to 2020. The results revealed that Laos ranked as the top-performing country for forest ecosystem status in the Lancang–Mekong region in 2020. However, the long-term trend analysis results showed that Cambodia experienced the most significant decline across all indicators, while Vietnam and Thailand demonstrated varying degrees of improvement. This study provides a quality assessment of forest health and its variations in the Lancang–Mekong region, which is crucial for implementing effective conservation strategies. [ABSTRACT FROM AUTHOR]

Rice is by far the most important crop in Cambodia. The improvement of its productivity is strongly recommended, but information about cultivation environment, management and their effects on rice production in farmers’ paddy fields is quite limited. This study periodically measured the leaf area index (LAI) by using a plant canopy analyzer and conducted yield, water, soil and management investigations in 77 farmers’ paddy fields in the Bakan district, Pursat province, Cambodia in 2014. Because the LAI showed linear growth in almost all farmers’ fields, the LAI growth rate was determined by linear regression. The grain yield ranged from 70.8 g m −2 to 499.0 g m −2 and was positively correlated with the maximum LAI. The variability in the maximum LAI was mainly explained by the LAI growth rate, while the growth period had a significant correlation with the maximum LAI only in the broadcast fields, where earlier planting led to larger LAI. The result of the ANCOVA shows that the LAI growth rate was affected by seeding date, water status and soil condition (C content and C/N ratio) while the effect of planting method (transplanting/broadcasting) and N fertilizer was non-significant. The non-significance of effect of N fertilizer may imply the timing or method of application is improper. The results suggest that the key means to improve rice productivity are effective application of fertilizer and selection of planting methods dependent on the soil fertility, together with water-saving irrigation method. [ABSTRACT FROM AUTHOR]