Climate change impacts on the suitability of lowland and upland crop systems in Lao PDR

Climate change is a major driver of changes in agricultural systems, with effects playing out differently across crop types and biophysical conditions. Studies have so far not investigated differences between lowland and upland crop systems when projecting consequences of climate change on agricultural production in Southeast Asia. To model the change in crop suitability under different climate scenarios for major crops in Lao PDR and analyse differentiated impacts across lowland and upland crop systems. We use a modified version of the EcoCrop suitability model, adding additional considerations for precipitation seasonality, to project the change in crop suitability in Lao PDR under different climate scenarios for the medium term future (2041–2070). The analysis compares impacts across lowland and upland village areas for six major crops: Paddy rice, upland rice, maize, cassava, banana, and rubber. Further, we contextualize the results with data from a survey of eight lowland and four upland villages in Savannakhet Province. For all the included crops, we find that changes in climatic suitability will be significantly more negative (higher decrease or smaller increase) in lowland village areas than in upland village areas. In particular, rice suitability is projected to decrease considerably in lowland areas due to increases in heat and variability in wet season precipitation, while higher temperatures improve the suitability of non-rice crops in upland areas due to lower cold stress, with the largest increases being for maize, cassava, and banana. Local crop data from Savannakhet Province further reveals how climate change impacts can increase the risks to production and food security in rice focused systems in lowland areas. These results indicate that upland crop systems in Lao PDR may fare better than lowland systems under future climate change and highlight the importance of differentiating between agricultural production systems when projecting impacts of climate change in Southeast Asia. • First study comparing lowland and upland climate change impacts on crop suitability. • Upland areas will face less negative climate change impacts than lowland areas. • Heat stress in lowland areas will drive decrease in suitability for several crops. • Lower cold stress and changes in precipitation drive changes in upland areas. • Negative impacts for food security, but improved opportunities for cash cropping.