Tree regeneration trends in forests of the northeastern USA and their implications for resilience and restoration

Abstract

Tree regeneration is vital to shaping characteristics of future forests, including vulnerability to climate change; resilience to pests, pathogens and disturbance; and departure from historical species composition. We used data from nationwide forest inventory plots to investigate trends in sapling abundance and recruitment as well as tree density for common tree species from 2003 to 2023 across forests of the northeastern United States . Tree seedling composition was then examined using (1) predicted sapling recruitment based on seedling abundance and (2) abundance of small‐sized seedlings (5–15 cm and 15–30 cm tall). We assessed forest vulnerability to climate change using projected future habitat suitability, resilience using species‐level trait scores, and departure from historical composition based on early colonial land surveys, in all cases weighted by relative abundance of trees, saplings, and seedlings within forest inventory subplots. Sapling abundance and recruitment suggested improved climate change suitability relative to existing tree composition, yet also lowered resilience based on species trait scores. These seemingly contradictory results arise from declining sapling recruitment in northern tree species such as Abies balsamea and Betula papyrifera that are projected to fare poorly in future climates, yet persistently low sapling abundance of species that are more resilient to disturbances, pests, and pathogens, including Acer rubrum , Acer saccharum and Quercus species. Regeneration patterns suggested shifts away from historical species composition overall, although with considerable variability among genera. In contrast to saplings, composition of seedlings <30 cm tall indicated both decreased climate change vulnerability and greater resilience to various stressors and disturbance, suggesting that management targeted at survival and growth of already‐established seedlings could help to shape more resilient forests in the future.

Citation

Harris, Lucas B.; Pastore, Melissa A.; D'Amato, Anthony W. 2026. Tree regeneration trends in forests of the northeastern USA and their implications for resilience and restoration. Ecological Applications. 36(5): e70288. 18 p. https://doi.org/10.1002/eap.70288.