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Home > Plants, Pests & Pest Control > Pest Management > Noxious & Invasive Weed Program > NWAC > Risk Assessments > Glossy Buckthorn

Glossy Buckthorn Risk Assessment

Common Name: Glossy Buckthorn (and Cultivars)
Latin Name: Frangula alnus Mill. Also known as Rhamnus frangula

Reviewer: Anthony B. Cortilet
Affiliation/Organization: Minnesota Department of Agriculture

Date: 06/03/2013
FILE #: MDARA00024GLSBU_2_24_2014

Final Results of Risk Assessment

Review Entity | Outcome

  • NWAC Listing Subcommittee: Keep as a Restricted Noxious Weed.
    Comments: First review 06/20/2013, Final Review 08/12/2013
  • NWAC Full-group: Voted 13 – 0 to remain as a Restricted Noxious Weed.
    Comments: Reviewed 12/18/13   
  • MDA Commissioner: Approved NWAC Recommendation.
    Comments: Reviewed 2/24/2014


Box Question Answer Outcome
1 Is the plant species or genotype non-native? Yes. Glossy buckthorn is native to Europe, Asia, and North Africa. Go to Box 3.
2 Does the plant species pose significant human or livestock concerns or has the potential to significantly harm agricultural production?    
3 Is the plant species, or a related species, documented as being a problem elsewhere? Glossy buckthorn is currently regulated in five US states (including MN) and is also on many other state invasive species lists. It is listed as a species of concern throughout the northern US and Canada. Go to Box 6.
4 Is the plant species’ life history & growth requirements understood?    
6 Does the plant species have the capacity to establish and survive in Minnesota? Yes, glossy buckthorn is well established in Minnesota.  
6A Is the plant, or a close relative, currently established in Minnesota? Yes, it is documented in 50 Minnesota counties. In contrast to European buckthorn, glossy buckthorn primarily invades smaller woodland habitats but is more commonly found in wetland habitats including wet prairies, marshes, fens, sedge meadows, sphagnum bogs, and tamarack swamps. Go to Box 7.
7 Does the plant species have the potential to reproduce and spread in Minnesota? Yes. It has been documented as reproducing successfully and spreading in MN for several decades.  
7A Does the plant reproduce by asexual/vegetative means? No. Go to Box 7C.
7C Does the plant produce large amounts of viable, cold-hardy seeds? Yes, glossy buckthorn produces many fruit-encased seeds which are highly attractive to birds. Seeds can also remain dormant in the seedbank for many years. Got to Box 7F.
7F Are sexual propagules – viable seeds – effectively dispersed to new areas? Yes, birds are known to be a huge distribution vector for glossy buckthorn spread. Water, snow, small mammals and human activity are also highly responsible for spread. Go to Box 7I.
7I Do natural controls exist, species native to Minnesota, that are documented to effectively prevent the spread of the plant in question? No natural controls are known to exist. Go to Box 8.
8 Does the plant species pose significant human or livestock concerns or has the potential to significantly harm agricultural production, native ecosystems, or managed landscapes? Yes, glossy buckthorn is a threat to native ecosystems and managed landscapes. It has also been linked to agriculture as an overwintering host to the soybean aphid and as an alternate host for alfalfa mosaic virus and crown rust (Puccinia coronata Corda var. avenae), which causes oat rust disease.  
8A Does the plant have toxic qualities, or other detrimental qualities, that pose a significant risk to livestock, wildlife, or people? No, other than habitat degradation. (NOTE: as of time of completing this risk assessment, a publication is forthcoming producing evidence of laboratory studies that have shown impacts of the chemical emodin (a chemical in the leaves and berries of both European and glossy buckthorn that may have indirect impacts on certain amphibians). Go to Box 8B.
8B Does, or could, the plant cause significant financial losses associated with decreased yields, reduced crop quality, or increased production costs? Not determined at this time in agronomic systems (soybean aphid connection not well defined at this time and no clear impacts on MN Agriculture related to alfalfa mosaic virus and crown fungus).  Could be detrimental to forestry operations, but financial losses are not well documented at this time. Go to Box 8C.
8C Can the plant aggressively displace native species through competition (including allelopathic effects)? Yes, glossy buckthorn infestations have been shown to displace native plants and significantly reduce wetland and forest biodiversity. Glossy buckthorn infestations have been shown to cause significant changes to natural succession processes in wetland and forested habits, and create a more suitable environment for increased buckthorn production and spread. Buckthorn leaves are full of a toxin called emodin that discourages herbivory. Research is being conducted on impacts emodin has on the environment after falling from the tree. Studies have shown emodin can inhibit certain amphibians such as frogs from successfully producing offspring. Studies vary on allelopathy for glossy buckthorn. Some suggest allelopathy is occurring in the soil but cannot determine any single target yet. Other studies suggest that multiple soil changing characteristics in buckthorn populations are simply to blame and not a result of any allelopathy. Go to Box 9.
9 Does the plant species have clearly defined benefits that outweigh associated negative impacts? None that would outweigh the negatives. Buckthorns are thought to be beneficial as wildlife cover and food in transition areas between wetlands, forests and grasslands and the berries are sought after by small mammals and birds.  
9A Is the plant currently being used or produced and/or sold in Minnesota or native to Minnesota? No, it was sold in Minnesota until becoming a Restricted Noxious Species in 1999. Go to Box 10.
10 Should the plant species be enforced as a noxious weed to prevent introduction &/or dispersal; designate as prohibited or restricted? Yes.  
10A Is the plant currently established in Minnesota? Yes, see Box 6. Go to Box 10B.
10B Does the plant pose a serious human health threat? No, glossy buckthorn does not pose a serious threat to humans. Go to Box 10C.
10C Can the plant be reliably eradicated (entire plant) or controlled (top growth only to prevent pollen dispersal and seed production as appropriate) on a statewide basis using existing practices and available resources? No, glossy buckthorn is hard to control for multiple reasons. It is a forest species which makes traditional large-scale herbicide application unfeasible on large stands. Seed banks continue to produce buckthorn seedlings following treatments requiring long-term management and a large commitment of time and financial resources by landowners. Recruitment of seeds from neighboring sources through birds and mammals is problematic in areas being reclaimed or restored of buckthorns. List as a Restricted Noxious Weed.



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Dziuk, P.M. 1998. Buckthorn and its control. Minnesota Department of Agriculture Pest Alert; 4 pages.

EDDMapS. 2013. Early Detection & Distribution Mapping System: Glossy Buckthorn Distribution in Minnesota. The University of Georgia- Center for Invasive Species and Ecosystem Health. Accessed June 2013.

Elizabeth J. Czarapata. 2005. Invasive Plants of the Upper Midwest: an illustrated guide to their identification and control. University of Wisconsin Press. 215 pages.

Howell, J.A., and W.H. Blackwell, Jr. 1977. The history of Rhamnus frangula (glossy buckthorn) in the Ohio Flora. Castanea 42(2): 111-115.

Invasive Plant Species Assessment Working Group. 2013. Glossy Buckthorn (Rhamnus frangula). Fact Sheet. 2 pgs. Accessed June 2013.

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Krock, S.L. and C.E. Williams. 2002. Allelopathic potential of the alien shrub Glossy Buckthorn, Rhamnus Frangula L: A laboratory Bioassay. Journal of the Pennsylvania Academy of Science 76(1): 17-21.

The University of Maine Cooperative Extension Publications, Maine Invasive Plants Bulletin #2505. Common (Rhamnus cathartica) and Glossy (Frangula alnus) Buckthorn (Buckthorn Family). Accessed June 2013.

Michigan Department of Natural Resources & Michigan Natural Features Inventory. 2012. Glossy Buckthorn (Frangula alnus). Invasive Species – Best Control Practices. 8 Pages. Accessed June 2013.

MN Department of Natural Resources. 2013. Glossy or alder buckthorn (Rhamnus frangula). Accessed June 2013.

MN Department of Transportation. 2013. Minnesota Noxious Weeds. Accessed June 2013.

The Richard B. King Laboratory. 2007. Northern Illinois University. Invasive Species, Habitat Restoration, and Reintroduction Biology of the Spotted Salamander. Accessed June 2013.

University of Minnesota Extension. 2000. Buckthorn Control. Accessed June 2013.

USDA Plants Database. 2013. Plants Profile: Frangula alnus Mill. Accessed June 2013.