The U.S. Army is committed to good stewardship of lands within military installations. The Army is also committed to achieving "training to standard" for its forces and therefore is interested in a method of determining optimum levels of training activities such that military preparedness is maximized and ecological impacts and their costs are minimized. A key requirement to the successful implementation of such an optimization is the development of a successional dynamics model that predicts ecological responses to military and non-military stressors. A prototype simulation model has been developed, in part, using Land Condition Trend Analysis (LCTA) data from five Army installations. The model is based on responses of individual species and ecological processes to stressors. The model currently has climatic, edaphic, plant, decomposition, and animal modules. Current stressors include drought, nitrogen, fire, herbivory, and tactical maneuvers. The core model is adapted to forest, grassland, shrubland, and desert ecosystems. Site-specific data can be added to calibrate the model to a specific ecosystem within an installation. The model has been calibrated with LCTA data and applied to multiple plant communities at five installations: Fort Bliss, TX; Fort Carson, CO; Fort Hood, TX; Fort Riley, KS; and Yakima Training Center, WA.