We parameterized the forest canopy model MAESTRA using extensive ecophysiological data obtained in 2006. The following tree species: Acer rubrum (red maple), Betula nigra (river birch), Paulownia elongata (princess tree) and Quercus nutallii (nuttall oak) were intensively measured in response to soil water stress.  The model was used to simulate net ecosystem production for each species and the results were verified against sap flux and biomass production.  Furthermore, we ran a series of simulations to quantify the water stress impact on species-specific carbon exchange. Measurements showed that the level of tolerance to soil moisture stress is a species-specific attribute. Moreover, our procedure allowed us to separate and quantify individual effects of physiology on carbon exchange rates, where measurement and modeling data gave evidence that respiring biomass, leaf area, and leaf physiology were substantial factors causing differences in carbon exchange rates among species. Using the MAESTRA model to predict carbon gain under drought stress conditions, we observed measured versus modeled estimates within 2% for red maple, 12% for river birch, 5% for princess tree, and 7% for nuttall oak.  The work provides evidence that MAESTRA can become a good predictive process-based growth model for quantifying spatially explicit carbon dioxide exchange rates at the species level.