The future of our planet depends on the persistence of large tropical trees. The largest 1% of trees (>50cm in diameter) store half of the carbon in tropical forests, and their death releases this carbon back into the atmosphere. However, the causes and predictors of the death of these trees remain largely unknown because they are rare at the scale on which most studies are conducted (1-ha plots). In this study we assesses the mortality risk of large trees as a function of both their hydraulic traits and hydrological environment. Thereby, we aim to improve the conservation and management of tropical forests, as well as informing the estimation of carbon stocks and sinks, and the prediction models for the global climate.