The Effect of Prescribed Fire and Deer Exclusion on an Oak-hickory Woodland of West-central Illinois

Midwestern oak woodlands and savannas are one of the most critically endangered ecosystems in the U.S. The use of fire by Native American’s maintained diverse oak woodlands and savannas prior to European settlement, however logging and fire suppression has led to dense oak woodlands with lower diversity and poor conditions for oak regeneration. White-tailed deer browsing has also been implicated as a hindrance to oak regeneration. We used 100 m2 plots to sample ground flora vegetation from 2013-2017 in an oak-hickory woodland of West-central Illinois with four treatments: burned/exclosed, burned/not exclosed, unburned/exclosed, and unburned/not exclosed (n = 10 per treatment). Our goals were to determine how periodic prescribed fire and deer herbivory effect herbaceous and woody ground flora. We used mixed effect models to test effect of treatment and treatment-by-year interactions on ground flora and seedlings. We found that burning promoted herbaceous richness (P = 0.02), annual forbs (P P P = 0.02), density of large (0.5–1.49m tall) seedlings (P P = 0.08). Large offsite hardwood seedlings (i.e., Northern Red Oak) had highest densities on exclosure plots after four years (P = 0.02), large mesic tree seedling densities and old field herb cover was highest on unburned exclosure plots (P P = 0.017). Deer browsing of the ground layer showed temporal variation throughout the sample period (P = 0.013). Our results demonstrate that periodic prescribed fire can be used for common woodland management goals such as promoting species richness and decreasing woodland structure. These results may better inform land managers in West-central Illinois as decreasing woodland structure, increasing richness, and hardwood regeneration are common objectives in natural areas.