• D'Appollonio, Jennifer
  University of Maine Graduate School
  

Japanese barberry (Berberis thunbergii DC.) has become invasive in forests of the northeast since its U.S. introduction as an ornamental shrub in 1875. This non-native invasive species can occupy a wide range of environmental conditions, has a longer growing season than most native species, multiple methods of reproduction, and forms thickets under which few other plants can persist. Effective control strategies and management of invaded forest stands would be improved by knowledge of how Japanese barberry regenerates in the forest, whether it forms a seed bank, and to what extent it impacts other plant species. This study focused on the following questions: (1) Which species successfully regenerate under a Japanese barberry overstory? (2) How does forest canopy cover affect the regeneration of Japanese barberry and other species? (3) Does a portion of Japanese barberry seeds from previous years remain viable in the soil for more than one growing season?