A functional-structural model will then be used to take inputs from the C-dynamic model and the molecular and cellular models to predict individual organ growth in response to enhanced NO_3- uptake. The outputs of this model will include predicted rates of transpiration and photosynthetic efficiency, and distribution of C and N resources between above- and below-ground organs using PlantGro. Additional predicted outputs include leaf growth contribution to the above ground structure (leaf canopy) for light interception. Model outputs will be used as inputs and feedbacks for other levels in the merged model.