Projections of oil palm area in Malaysia and Indonesia to assess the relationship between plant growth and water consumption

Abstract. Palm oil is a widely used agricultural crop in the world, and most of them are produced in Malaysia and Indonesia covering millions of hectares. However, climate change which induces water stress and extreme weather such as El Niño poses a risk to oil palm production. Therefore, it is crucial to identify areas vulnerable to climate change to prioritize adaptation actions for sustainable palm oil production. Several studies have implemented vulnerability assessments for climate change using a limited number of climate variables, despite the complex relationships among vegetation and various water components. Given these situations, this study aims to identify areas vulnerable to climate change for oil palms by analyzing the relationship between vegetation productivity and climate variables, and their changes from 2002 to 2012 and from 2013 to 2022. This analysis utilized satellite-based multiple water components and applied principal component analysis. The identified vulnerable areas were then compared with the biophysical suitability map from another study. Severe El Niño impacts from 2015 to 2016 were also assessed as an indicator of the actual decline in productivity. The results showed that more than half of the study area had experienced water stress recently, particularly in Java, southern Borneo, and the southern New Guinea islands. There was a discrepancy between the biophysical suitability map and the identified vulnerable areas in this study, especially in the southern part of Borneo. These findings highlighted the importance of considering multiple water components in tropical regions and future projections for appropriate palm oil cultivation areas.