To determine the effects of these invasive shrubs on the state’s forests, doctoral student Dennis Tarasi sampled forested plant communities in North Carolina with varying levels of autumn olive or Chinese privet dominance. His findings showed that the dominance of these shrubs correlated with significant changes in the forests, including the overall loss of native species and a significant decline in young trees. Chinese privet “invasions” corresponded to greater native species loss and structural changes than those by autumn olive. Many invasive species also have been documented as negatively affecting soil and available light.
Tarasi assessed changes in soil moisture levels, air temperature and light availability, emphasizing locations that were heavily invaded compared to those with little invasion. He found that the heavily invaded sites were more shaded and cooler across the entire summer. Soil moisture did not appear affected. Tarasi then removed invasive shrubs from several sites in his study; this action increased light availability and air temperature with little effect on soil moisture. Land managers, scientists, policymakers and many others can apply Tarasi’s research and methods to manage ongoing invasions.