The dynamic coupled biogeochemical/ecological model chain ForSAFE-Veg was used to evaluate ecological effects of atmospheric nitrogen (N) and sulfur (S) deposition in the context of a changing climate at two hardwood forest sites in the eastern United States. Model sites were located in a mixed oak forest of Shenandoah National Park and a mixed oak-sugar maple forest of Great Smoky Mountains National Park. The composition of understory plant communities was modeled to determine the alignment between plant species niche preferences and ambient conditions and to estimate changes in relative species abundances under various scenarios of future atmospheric N and S deposition and climate change. Results of this research suggested that future climate change might compromise the potential for the forests to maintain habitat suitability for characteristic species. With expected future climate change, preliminary results indicated that sustained future N deposition above 7.4 and 5.0 kg N/ha/yr is expected to decrease habitat suitability for characteristic plant species of the Shenandoah NP and Great Smoky Mountains NP sites, respectively. A peer-reviewed journal article was published in 2018.