Global changes in temperature and rainfall are provoking increasingly prolonged periods of drought stress, which results in forest dieback. Potential mechanisms of plant mortality under drought include damages to the hydraulic system and the depletion of nonstructural carbohydrates (NSC). We designed an experiment on seedlings of 12 tree species to assess the mechanisms behind plan mortality under drought. The experiment consisted in a first phase of light manipulation where individual plants were alternatively placed under light or shade aiming to manipulate carbohydrate contents. Subsequently, we started a drought phase until full mortality was reached. Plant water potential (predawn and midday) was measured weekly during the experiment. NSC contents were measured in five different harvest campaigns along the experiment.

The database is made of four different tables. The first table (‘Mortality_Percentage’) contains data of plant mortality over time. Mortality was visually assessed by the percentage of dead leaves per plant, evaluated by observing changes in leaf coloration. The second table (‘Mortality_Kaplan_Meier’) contains the same plant mortality data but organized for a Kaplan Meier regression, including the number of elapsed days between the start of the experiment and the plant death. The third table (‘NSC_Data’) contains nonstructural carbohydrate contents, including soluble sugars (fructose, glucose, sucrose) and starch, measured on three different organs (leaves, stem, root) at five different campaigns during the experiment. The fourth table (‘Water_Potential_Database’) contains weekly measurements of predawn and midday water potentials across the drought experiment. All tables depict individuals from two treatments (light, shade) from the light acclimation phase.