According to an article by Arun Bose and coworkers**, changes in forest composition associated with climate change have been observed in the forests of the North-Eastern United Sates. The occurrence of American Beech trees (Fagus grandifolia) has increased while at the same time the number of sugar maples (Acer saccharum), red maples (Acer rubrum) and birch trees (Fagus grandifolia) has declined resulting in a clear shift in species composition. The increased dominance of beech trees raises concerns about a lack of biodiversity. Also, the American beech is disease prone and commercially less desirable than other tree species.
**Bose, A. K., Weiskittel, A. and Wagner, R. G. (2017), A three decade assessment of climate-associated changes in forest composition across the north-eastern USA. J. Appl Ecol, 54: pp. 1592–1604.