Nitrogen deposition effects on current and future forests

Midwestern forests are a “hot spot” for nitrogen deposition - a pervasive, and perhaps irreparable, anthropogenic global change phenomena. Could this be driving declines in oak regeneration across Chicagoland?

Meghan Midgley collecting nitrogen deposition collectors from Thatcher Woods Forest Preserve in October 2016.


Nitrogen (N) deposition is among the most pervasive, and perhaps irreparable, anthropogenic global change phenomena. Midwestern forests exist within a matrix of fossil fuel-burning and intensive agriculture; as such, these forests are exposed to some of the highest levels of N deposition in the US. Concurrently, the relative abundance of oak seedlings and oak recruitment into the forest overstory have declined over the past several decades. In this project, we are (1) characterizing N deposition patterns across Chicagoland forests and (2) evaluating growth and physiological responses of red oak and sugar maple seedlings and their associated mycorrhizal fungi to N addition in a controlled greenhouse study. Given the limited resources available for managing natural areas, understanding the extent to which N addition alters seedling dynamics and where N deposition is most pervasive will aid land managers in maximizing oak regeneration success.

Funding Sources

The Morton Arboretum

Project Status