Vegetation Response to Oak Savanna and Woodland Restoration in the Mid-South USA

The decline and degradation of oak savanna and woodland communities throughout the Mid-South underscores the need to develop management techniques capable of their efficient and successful restoration. Therefore, my objectives for this work were to document plant community response to variations in canopy disturbance level, fire seasonality, and herbicide control of hardwood midstories. In Chapter One, I provide a thorough review of the current body of knowledge concerning open-oak communities and their restoration, with specific focus on herbaceous and woody plant response to canopy disturbance, fire, and herbicide midstory management. Chapter Two details the response of herbaceous and woody vegetation to variations in canopy disturbance level and fire-season during a replicated experiment in Tennessee. I conclude that higher canopy disturbance levels and fire application positively impacted restoration goals with increases in herbaceous groundcover, richness, and diversity. Limited differences among the fire-season treatments were observed, with similar, prolific resprouting of mesophytic oak competitor species following both fire-season treatments. I suggest exploration into burn timings that will limit this resprouting such as earlier fall or spring fires, to accelerate the restoration timeframe. Chapter Three addresses herbaceous and woody vegetation response to woody midstory herbicide treatments. Herbicide treatments reduced the cover and density of woody plants more than fire alone, and included reductions of larger size classes that were unaffected by fire. Herbicide applications were most effective following late growing-season fire. These reductions occurred without harming desirable understory herbaceous vegetation, and increased graminoid cover within heavy canopy disturbance and growing-season fire treatments. Herbicide treatments cost $193.61ha^-1. Incorporating the valuable lessons learned through this research will improve the efficiency of future restoration attempts and result in the return of healthy and sustainable oak savannas and woodlands in the Mid-South.