Abundance and distribution of invasive woody shrub, Mahonia bealei, in the urban forest fragments of the southern Piedmont, USA

Abstract

Woody invasive plants are a pernicious threat to the structure and function of ecosystems worldwide. Due to the growing number of invasive species and the variable timeline of invasion, many invasive plants are unrecognized or underreported, leading to long-term ecological damage that is beyond the capability of cost-efficient management programs. Mahonia bealei is a woody shrub native to China that is invading urban forests of the southeastern U.S. and is likely underreported. This study (a product of a thesis research paper, https://scholarworks.gsu.edu/geosciences_theses/137/ ) identified and mapped all occurrences of M. bealei across 40 woodlots throughout DeKalb County, Georgia, and analyzed vital indicators in the habitats that may promote colonization and establishment. M. bealei was found in 90% of sample sites, frequently in large numbers within the forest interior. The high abundance of M. bealei combined with success in low-light environments indicates an aggressive and successful long-term invasion of the Southeastern Piedmont.