Taxonomy

Berberis thunbergii | Thunberg's Barberry

Distribution

Status

Conservation status

Not Assessed

First reported in the wild

1997

Invasiveness

Invasive species - risk of Medium Impact

Introduction pathways - 1

Escape from Confinement

Introduction pathways subclass - 1

Ornamental purpose

Invasive score

14

NAPRA Ireland risk assessed

No

Species Biology

Identification

Deciduous shrub up to 2m in height, leaves 1-3cm obovate (ovate with the narrower end at the base) and green to purple, flowers yellow and red up to 20mm, fruit bright red (Stace, 1997).

Ecology

To date there are no impacts recorded for this species in Ireland due to its limited distribution. However in the United States it has become a major pest species in deciduous woodlands, forming dense thickets and smothering native vegetation (Ehrenfeld, 1997). The plant is not browsed by deer in the United States, so control once established is costly as Berberis control needs to be accompanied by deer culls in order to be allow the regrowth of native vegetation (Dávalos et al., 2015).

Habitat

Woodland, forest and other wooded land; Grasslands and landscapes dominated by forbs, mosses or lichens; Constructed, industrial or other artificial habitats

Reproduction

Seeds germinate in May in the United States with the seedlings rapidly becoming established and has relatively low rates of mortality during the first year (Ehrenfeld, 1999). The plant displays a positive density-dependence of recruitment along with an apparent lack of density-dependence of mortality (recruitment is higher and morality is not affected by the number of plants present) allowing dense thickets to form (Ehrenfeld, 1999). Local dispersal of seeds may also occur through small mammals and birds (Ehrenfeld, 1999).

Pathway and vector description

Widely sold as an ornamental plant and as an alternative to Berberis vulgaris.

Mechanism of impact

Competition, Bio-fouling, Other

Broad environment

Terrestrial

Habitat description

Found mainly in woodlands (Reynolds, 2002).

Species group

Plant

Native region

Temperate Asia

Similar species


Berberis vulgaris (Common barberry)

Distribution

World distribution(GBIF)

Irish distribution

Established - Rare/Localised. Only records to date are from Co Waterford though this may be an artefact of recording effort. Sold widely as an ornamental so likely under recorded

Native distribution

Native to Japan (Preston et al., 2004), considered invasive in North America (Ehrenfeld, 1997).

Temporal change

Date of first record category

1991-2000

Fifty year date category

1951-2000

Records submitted to Data Centre in 2020

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How can you help

Report any sightings to the National Biodiversity Data Centre.

References

Publications

Reynolds, S.C.P. (2002) A catalogue of alien plants in Ireland. National Botanic Gardens. Glasnevin, Dublin. Stace, C. (1997). New Flora of the British Isles 2nd Edition. Cambridge University Press, Cambridge. Ehrenfeld, J. G. (1999). Structure and dynamics of populations of Japanese barberry (Berberis thunbergii DC.) in deciduous forests of New Jersey. Biological Invasions, 1(2-3), 203-213. Ehrenfeld, J. G. (1997). Invasion of deciduous forest preserves in the New York metropolitan region by Japanese barberry (Berberis thunbergii DC.). Journal of the Torrey Botanical Society, 210-215. Dávalos, A., Nuzzo, V., & Blossey, B. (2015). Single and interactive effects of deer and earthworms on non-native plants. Forest Ecology and Management. Preston, C.D., Pearman, D. A. & Dines, T. D. 2002. New atlas of the British and Irish flora. An atlas of the vascular plants of Britain, Ireland, the Isle of Man and the Channel Islands. Oxford University Press.

CABI Datasheet

Global Invasive Species Database