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Thunberg's Barberry

Berberis thunbergii

Summary 5

Berberis thunbergii (Japanese barberry,Thunberg's barberry, or Red barberry) is a species of Berberis, native to Japan and eastern Asia.

Ecological threat in the united states 6

Japanese barberry forms dense stands in natural habitats including canopy forests, open woodlands, wetlands, pastures, and meadows and alters soil pH, nitrogen levels, and biological activity in the soil. Once established, barberry displaces native plants and reduces wildlife habitat and forage. White-tailed deer apparently avoid browsing barberry, preferring to feed on native plants, giving barberry a competitive advantage. In New Jersey, Japanese barberry has been found to raise soil pH (i.e., make it more basic) and reduce the depth of the litter layer in forests.

Impacts and control 7

More info for the terms: fire management, invasive species, natural, presence, restoration, shrub, shrubs

Impacts: Information regarding Japanese barberry impacts in invaded communities includes evidence that Japanese barberry invasion displaces native shrubs [52] and causes changes in soil properties (see Soil characteristics and feedback loops). On a study site in northern New Jersey dominated by Japanese barberry, the native understory shrubs deerberry and hillside blueberry were significantly (P<0.05) less abundant than on uninvaded sites [52]. Japanese barberry persistence in invaded stands may also alter successional patterns (see Successional Status).

Japanese barberry invasion can alter soil microbial composition and increase nitrate concentrations [51,53,55]. High nitrate concentrations may result in higher nitrogen losses due to leaching or might make these sites more susceptible to invasion by other weedy plants. The researchers suggest that even if Japanese barberry is removed, "it is very likely that differences in the soils will persist for a prolonged period after that, which might significantly impede the restoration of native flora in the cleared sites" [54].

One study also provides evidence that invaded sites support more biomass in the shrub layer than uninvaded sites [29]. There is concern that additional biomass in invaded stands may increase the likelihood of fire in those stands 21, although this did not seem to be the case during the growing season on sites studied in Massachusetts 86,88.

Control: Information presented in the following sections comes primarily from literature reviews and may not be comprehensive. It is intended to contribute to understanding disturbance adaptations of Japanese barberry and to present considerations for the context of fire management. For more detailed information on control of Japanese barberry, go to individual references cited here or to local extension services.

Japanese barberry may be best controlled by preventing its establishment and by eliminating small, newly expanding populations [92]. Individual Japanese barberry plants may be controlled by handpulling or digging, as it has a shallow root system [45,100]. However, this method is difficult and time consuming [92] and it is important to remove as much of the underground material as possible because Japanese barberry is likely to sprout from rhizomes left in the soil. Sprouts may be controlled by pulling or herbicide applications [45]. Pulling common barberry in the early 1900s effectively eradicated it from many sites [92].

Japanese barberry is especially easy to see in the winter and early spring before deciduous plants leaf out. If plants have fruit present, they should be bagged and disposed of to prevent seed dispersal [95].

Prevention: Prohibiting the commercial sale and planting of Japanese barberry may help limit the establishment and spread of new populations [92]. Native alternatives include coastal sweet pepperbush (Clethra alnifolia) and northern spicebush (Lindera benzoin) [100].

Observations by Ehrenfeld [26] suggest that Japanese barberry spreads into relatively undisturbed forests from forest edges. Forest reserves less than 2,400 to 4,900 acres (1,000-2,000 ha) in size would be especially vulnerable to invasion because of their large perimeter to area ratios [26]. Maintaining large forest and natural areas uninterrupted by roads and development may help prevent the establishment and spread of Japanese barberry and other invasive species.

Integrated management: Information on integrating mechanical control (cutting) with prescribed burning is presented in the Fire Management Considerations section. Some combinations of mechanical and chemical control are described in the following sections.

Physical/mechanical: Handpulling is an effective method of reducing Japanese barberry populations and seed production, and it can be done during most of the year. It is most effective for small Japanese barberry plants and small populations [95]. Older shrubs can be dug when soil is moist [100]. When pulling Japanese barberry by hand or removing by other mechanical methods, it is important to remove as much of the root system as possible and to minimize soil disturbance [45,95]. Shrubs can be cut at the base in winter or spring instead of digging, and herbicide can then be used on resprouts. Once removed from old field habitats, regular mowing may prevent reestablishment [45,100]. Repeated mowing or cutting controls the spread of Japanese barberry but does not eradicate it. Stems need to be cut at least once per growing season, as close to ground level as possible. Hand-cutting of established clumps is difficult and time consuming due to the long, arching stems and prolific thorns [95].

Fire: See Fire Management Considerations.

Biological: A review by Silander and Klepis [92] suggests that there may be some potential for biological control of Japanese barberry using nonnative tephritid flies, though the potential for biocontrol has not been studied for this species in North America.

Chemical: Treatment with systemic herbicides like glyphosate and triclopyr has been effective for controlling Japanese barberry (review by [100]). The Southeast Exotic Pest Plant Council [95] suggests that large thickets of Japanese barberry may be foliar sprayed with herbicides such as glyphosate or triclopyr in areas where risk to nontarget species is minimal. They recommend using the cut-stump method (cutting stems at or near ground level and applying herbicide to the stump) when the ground is not frozen. The cut-stump method is especially useful where the presence of desirable species precludes foliar application. Glyphosate is most effective for controlling Japanese barberry when applied in early spring at leaf out, when little else is in leaf [92].

Cultural: No information is available on this topic.

Sources and Credits

  1. (c) James Gaither, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/13892958@N07/4152920042
  2. (c) Milo Pyne, some rights reserved (CC BY-NC), uploaded by Milo Pyne
  3. (c) Dalgial, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/thumb/b/bc/Berberis_thunbergii_fruit_1.JPG/460px-Berberis_thunbergii_fruit_1.JPG
  4. (c) Gmihail, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Berberis_thunbergii_habitus.jpg
  5. Adapted by Kate Wagner from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Berberis_thunbergii
  6. (c) Unknown, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/22948519
  7. Public Domain, http://eol.org/data_objects/24634887

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