When Landscaping Goes Bad: The Incipient Invasion of Mahonia bealei in the Southeastern United States

Abstract

Woodlots are forest islands embedded within an urban matrix, and often represent the only natural areas remaining in suburban areas. Woodlots represent critical conservation areas for native plants, and are important habitat for wildlife in urban areas. Invasion by non-indigenous (NIS) plants can alter ecological structure and function, and may be especially severe in remnant forests where NIS propagule pressure is high. Woody shrubs in the Family Berberidaceae have been well documented as invaders of the forest-urban matrix in North America. Mahonia bealei (Berberidaceae) is a clonal shrub native to China, and is a popular ornamental in the Southeastern United States. Mahoni bealei is listed as ''present'' on some local and state floras, but almost nothing is known regarding its invasion potential in the United States. We sampled 15 woodlots in Clemson, South Carolina, to assess the invasion of M. bealei and other woody non-indigenous species (NIS). M. bealei invaded 87% of the woodlots surveyed and species richness of NIS on these woodlots varied from 5 to 14. Stepwise-multiple regression indicated that less canopy cover and older M. bealei predicted greater abundance of M. bealei, and that not all subdivisions were equally invaded (P < 0.0001; r 2 ¼ 0.88). The impact of M. bealei on native flora and fauna may be considerable, and it is likely to continue to spread in the Southeastern United States. M. bealei should be recognized as an aggressive invader in the Southeastern United States, with the potential for negative impacts on native flora and fauna.

Biological invasions: a field synopsis, systematic review, and database of the literature

“…Many narrative reviews are limited to a particular invasive taxon, either more broadly to plants (Richardson et al 2000; Mitchell et al 2006) or animals (Snyder and Evans 2006), or to a single functional group or species (e.g., zebra mussels, Karatayev et al1997; ants, Wetterer et al 2006) or they focus on specific geographic regions (e.g., Foxcroft et al 2010), habitats (e.g., Van Auken 2000; Weis 2011), or on particular aspects of invasions such as ecological or economic impacts (e.g., Mack and D'Antonio 1998; Kenis et al 2009). Other reviews have emphasized more specific questions, for example, focusing on efforts to quantify the prediction of the success of invasive plants and birds (e.g., Kolar and Lodge 2001), impacts of invasive plants (Vilà et al 2011; Pyšek et al 2012), or comparisons of native and invasive species in more limited subsets of species and restricted regions (e.g., Blackburn and Duncan 2001; Cadotte and Lovett-Doust 2001; Allen et al 2006). So, in addition to relying upon formal systematic review methodology, our research synthesis is more comprehensive than previous reviews.…”

Common juniper, an overlooked conifer with high invasion potential in protected areas of Patagonia

“…Unlike other woody plants that became invaders of natural environments associated with urban areas 81 , 82 , J. communis was infrequently found as an ornamental or a living fence plant. Therefore, the current use of this species does not represent a major threat in terms of invasion spread.…”

Evaluation of antimicrobial activity of certain Chinese plants used in folkloric medicine

“…It was interesting to note that the extracts of Mahonia fortunei (stems and leaves) and Mahonia bealei (stems) showed strong antimicrobial activity against the multiresistant Staphylococcus aureus, and the inhibition zones of them were more than 20 mm in diameters, followed by Berberis thunbergii stems extracts (19.78 mm in diameters). Mahonia bealei in southeastern United States (Allen et al 2006) and Berberis thunbergii (Silander et al 1999) in the New England were aggressive invaders. They may pose the greatest threat to biodiversity in local areas.…”