This project focuses on the spatio-temporal variability of water uptake of Amazonian tree species through the monitoring of stable oxygen and carbon isotopes in water and wood samples, in order to predict their responses to hydrological climate change. Together with dendrochronological studies (year-ring and wood-growth models), and the atmospheric measurements at the ATTO-tower, the project evaluates tree responses to intensified hydrological regimes, as well as their relation to annual and decadal anomalies of the sea surface temperatures of the tropical Atlantic and Pacific. Simultaneously, the results will be used to determine growth responses of trees to increasing atmospheric CO2 concentrations.