Introduction:
Common barberry (Berberis thunbergii).
Berberis thunbergii is a shrub native to Japan. When introduced it can invade a variety of habitats from damp lowlands to dry roadsides and waste places. This species forms dense stands in a variety of these habitats, including closed canopy forests and open woodlands, wetlands, pastures and meadows. Berberis thunbergii is highly shade-tolerant and displaces a variety of native herb and shrub species in areas where it becomes well established. Manual hand-pulling is a favoured method of control as the species is easily unearthed. Chemical and mechanical methods are also often employed, depending on site conditions.
Description:
Berberis thunbergii is described as a compact, spiny shrub that commonly grows 0.6 - 0.9m tall (although it can grow up to 1.8m in height). Roots are shallow but tough. The smooth-edged leaves range from oval to spatulate in shape and are clustered in tight bunches close to the branches. The single spines bear small leaves in their axils. Yellow flowers bloom in May, are about one third of an inch wide, and are solitary or in small clusters of 2-4 blossoms. The bright-red fruits mature in mid-summer and hang from the bush during autumn and into winter. The berries are small, oblong, and found singly or in clusters.
Occurs in:
Natural forests, planted forests, ruderal/disturbed, scrub/shrublands.
Habitat description:
Berberis thunbergii can be found along roadsides, fences, old fields and open woods. It is known to tolerate a variety of habitats from damp lowlands to dry roadsides and waste places. Populations do not expand rapidly into oak-dominant forests or on extreme north-facing slopes.
Common barberry (Berberis thunbergii) Distribution in North America shown in green.
General impacts;
Berberis thunbergii is a popular ornamental plant and is present in gardens, parks, forests, and nature preserves. Its seeds are dispersed by birds and it is known to tolerate dense shade. When it escapes into natural areas its highly shade tolerant nature helps it to form dense stands in a variety of habitats, including closed canopy forests and open woodlands, wetlands, pastures, meadows and wastelands and dispace native herb and shrub species
Geographical range:
Native range: Japan.
Known introduced range: North America, Poland, Finland, Italy, Austria, Denmark, Germany, Netherlands and Australia.
Management information:
Mechanical:Mechanical removal of Berberis thunbergii is recommended because it is effective and minimally intrusive. In early spring, this is one of the first plants to leaf out and can be distinguished easily from other shrubby vegetation. The use of a hoe, weed wrench, or mattock is
Close up of Common barberry (Berberis thunbergii).
suggested to uproot the entire bush and associated roots; gloves will help protect hands from the spines. Hand pulling is effective for small populations of B. thunbergii, since plants pull up easily in most forested habitats. Hand pulling is an extremely effective method of reducing population and seed productivity; and it can be done during most of the year. If plants have fruit present, they should be bagged and disposed of to prevent seed dispersal. Mowing and cutting is appropriate for initial small populations or environmentally sensitive areas where herbicides cannot be used. Repeated mowing or cutting will control the spread of B. thunbergii but will not eradicate it. Stems should be cut at least once per growing season as close to ground level as possible.
Chemical: Foliar Spray method should be considered for large thickets of B. thunbergii where risk to non-target species is minimal. Glyphosate and Triclopyr are suitable for this method. The Cut Stump method should be considered when treating individual bushes or where the presence of desirable species precludes foliar application. Stump treatments can be used as long as the ground is not frozen. Glyphosate (Roundup) applied in early spring at first leaf out, when little else is in leaf, provides an effective means of eradicating B. thunbergii populations. B. thunbergii is a deciduous shrub, and occurs under closed canopy forest, it is not feasible to use conventional methods of remote sensing to detect its presence over large regions. The author further states that, the extensive nature of the invasion and its lack of documentation in scientific literature suggest that much more attention needs to be directed to the problem of the spread of B. thunbergii.
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