Native tree planting resists non-native plant invasions in riparian forest restoration


Hammer, Chad F., and John S. Gunn. “Native tree planting resists non-native plant invasions in riparian forest restoration.” Invasive Plant Science and Management (Submitted).


Non-native invasive plant species are a major cause of ecosystem degradation and impairment of ecosystem service benefits in the United States. Forested riparian areas provide many ecosystem service benefits and are vital to maintaining water quality of streams and rivers. These systems are also vulnerable to natural disturbances and invasion by non-native plants. We assessed the effects of planting native trees on disturbed riparian sites and their ability to resist invasive plants in central Vermont in the northeastern United States. The density (stems/m2) of invasive stems was higher in non-planted sites (=4.1 stems/m2) compared to planted sites (=1.3 stems/m2) More than 90% of the invasive plants were Japanese knotweed (Fallopia japonica). There were no statistically significant differences in total stem density of native vegetation between planted and non-planted sites. Other measured response variables such as native tree regeneration, soil properties and soil function showed no statistically significant differences or trends in the paired riparian study sites. The results of this case study indicate that tree planting in disturbed riparian forest areas may assist conservation efforts by minimizing the risk of invasive plant colonization.