A hybrid model that couples the physiology model STAND-BGC to the forest vegetation simulator (FVS) was parameterized from comprehensive ecophysiological data collected on Acer rubrum (red maple), Betula nigra (river birch), Paulownia elongata and P. fortunei (princess tree), Quercus nutallii (nuttall oak), and Quercus phellos (willow oak) in 2006. We ran a series of simulations to quantify the water stress effects on species-specific annual carbon gain, growth, and yield. Simulations on a species-specific basis allowed assessment of the predicted effects of drought on stand production. Using the hybrid model FVS-BGC in comparison to measured values, we observed under predictions for willow oak (10%), river birch (12%), nuttall oak (20%), and princess tree (24%), and over predictions for red maple (5%) with respect to the measured height under both well-watered and drought stress conditions. Thus, we demonstrate that tree-to-tree variation is important to consider, especially when soil water content varies due to hydrological changes across a landscape. Model calibration and opportunities for improving deciduous tree prediction accuracy is also discussed.
