Japanese Brome (Bromus japonicus)

Present distribution

Scientific name:	Bromus japonicus
Common name(s):	Japanese Brome

Map showing the present distribution of this weed.

Habitat:

Native to Europe and Asia (Stewart & Hebda 2000). In USA occurs in rangelands, picnic areas, paths, gravel pits, undisturbed mixed-grass prairie (Howard & Winkler 1994), wheat and alfalfa fields, pastures, meadows (Baskin & Baskin 1981), roadsides, alkaline flats (Stewart & Hebda 2000), hayfields and dry soils in waste or disturbed areas (Whitson et al 1992). Documented occurring at an altitude of 1500 m (Bates, Miller & Svejcar 2000), in an annual rainfall zone of 300 mm (Anderson et al 1992) and a temperature range between 37^oC and –40^oC (Karl, Heitschmidt & Haferkamp 1999). Able to grow in semi-shade and occurs in the understorey of Western juniper woodlands (PFAF 2006; Bates, Miller & Svejcar 2000). In WA it is a widespread weed of offshore islands, sandy soils and saline lakes from Shark Bay to Kalgoorlie (Hussey et al 1997).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:
Broadacre cropping; pasture dryland; pasture irrigation.

Broad vegetation types
Coastal scrubs and grassland; coastal grassy woodland; inland slopes woodland; montane dry woodland; grassland; plains grassy woodland; herb-rich woodland; montane grassy woodland; riverine grassy woodland; rainshadow woodland; boinka-raak; mallee woodland; wimmera / mallee woodland.

Colours indicate possibility of Bromus japonicus infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

map showing the potential distribution of japanese brome

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	As a grass growing to a height up to 75cm (Whitson et al 1992), it is likely to cause only minimal impact on human access.	L	M
2. Reduce tourism?	Unlikely to reduce tourism as the weed would not be obvious to the ‘average’ visitor.	L	M
3. Injurious to people?	There is no information to suggest that this species possesses any properties injurious to humans.	L	MH
4. Damage to cultural sites?	Likely to have little or negligible effect on the aesthetics or structure of a cultural site.	L	M
Abiotic
5. Impact flow?	A terrestrial species, no impact on water flow.	L	H
6. Impact water quality?	A terrestrial species, no impact on water quality.	L	H
7. Increase soil erosion?	In one study roots reached depths of 150cm and root density surpassed that of five other annual bromes also occurring at a site (Howard & Winkler 1994). Not likely to cause soil erosion.	L	MH
8. Reduce biomass?	As a grass growing to 75cm in height (Whitson et al 1992), it is similar in stature to many indigenous grass species. It is therefore unlikely to cause a significant increase or decrease in vegetation biomass. Direct replacement of biomass by invader is probable.	L	M
9. Change fire regime?	Burning reduces Japanese Brome for 1-2 years and exclusion of fire in Northern mixed-grass Prairie communities in the USA improves conditions for Japanese Brome (Silzer 2006). However no information was found documented regarding its capacity to alter the fire regime.	M	L
Community Habitat
10. Impact on composition (a) high value EVC	EVC= Plains Grassland (BCS= E); CMA= Wimmera; Bioreg= Wimmera; CLIMATE potential=VH. Severe infestations can restrict perennial species establishment, slow the rate of and, possibly, alter the path of secondary succession (Andersen et al 1992). Has the capacity to displace some dominant species in the lower strata, however, the extent of the impact is not clear from the information available.	M	MH
(b) medium value EVC	EVC= Semi-arid woodland (BCS= D); CMA= Mallee; Bioreg= Lowan Mallee; CLIMATE potential=VH. Severe infestations can restrict perennial species establishment, slow the rate of and, possibly, alter the path of secondary succession (Andersen et al 1992). Has the capacity to displace some dominant species in the lower strata, however, the extent of the impact is not clear from the information available.	M	MH
(c) low value EVC	EVC= Shrubby Riverine Woodland (BCS= LC); CMA= Mallee; Bioreg= Murray Mallee; CLIMATE potential=VH. Severe infestations can restrict perennial species establishment, slow the rate of and, possibly, alter the path of secondary succession (Andersen et al 1992). Has the capacity to displace some dominant species in the lower strata, however, the extent of the impact is not clear from the information available.	M	MH
11. Impact on structure?	Bromus japonicus has become a dominant invading species, competing with desirable perennial species for establishment and growth. Severe infestations can restrict perennial species establishment, slow the rate of and, possibly, alter the path of secondary succession (Andersen et al 1992). It can establish and maintain high tiller densities in stands of native perennial grasses (Whisenant 1990). Likely to have an affect on the lower vegetative strata, however, the extent of the impact is not clear from the information available.	M	MH
12. Effect on threatened flora?	Bromus japonicus has become a dominant invading species, competing with desirable perennial species for establishment and growth (Andersen et al 1992). It can establish and maintain high tiller densities in stands of native perennial grasses (Whisenant 1990). Its impact specifically on threatened flora was not found documented.	MH	L
Fauna
13. Effect on threatened fauna?	Bromus japonicus has become a dominant invading species, competing with desirable perennial species for establishment and growth (Andersen et al 1992). Its potential to restrict indigenous vegetation may reduce suitable habitat for fauna, however, no specific information was found documented on the impact this species has on fauna.	MH	L
14. Effect on non-threatened fauna?	Bromus japonicus has become a dominant invading species, competing with desirable perennial species for establishment and growth (Andersen et al 1992). Its potential to restrict indigenous vegetation may reduce suitable habitat for fauna, however, no information was found documented on the impact this species has on fauna.	M	L
15. Benefits fauna?	In USA, the seeds are consumed by wild turkey and the foliage is a food source for various grazing mammals and provides cover for small birds and mammals (Howard & Winkler 1994). It is also known as a food source for cotton rats & prairie voles (Fleharty & Olson 1969) and would likely be utilised by local native rodents and birds. Likely to provide some assistance in food and/or shelter to native mammals and birds.	MH	H
16. Injurious to fauna?	Not documented as being injurious to fauna.	L	MH
Pest Animal
17. Food source to pests?	It is an important and highly palatable fall diet item of white tailed deer (Howard & Winkler 1994). Utilised as a food source by cotton rats (Fleharty &Olson 1969). Likely to provide a food source for similar minor pest species locally.	ML	H
18. Provides harbor?	Provides cover for small mammals (Howard & Winkler 1994) and in USA it is known as a food source for cotton rats & prairie voles (Fleharty & Olson 1969). Likely to provide harbour locally for minor pest species such as rodents.	ML	M
Agriculture
19. Impact yield?	The decrease of annual brome (B. japonicus) in pasture led to an increase in livestock performance demonstrated by an increase in steer weight from 69 to 81kg/hectare (Haferkamp et al 2001). B. Japonicus in pasture has the potential to decrease yield by >5%.	MH	H
20. Impact quality?	Recognised as a weed of wheat crops (Finnerty & Klingman 1962) and generally as a crop seed contaminant (McNeil & Peeper 1978; Wells et al 1986). Seed from crops of smooth brome grass (Bromus inermis) containing even small quantities of seed from weedy brome grass species (including B. japonicus), cannot be certified for sale (Finnerty & Klingman 1962). However, the level of impact B. japonicus specifically would have on agricultural quality is not clear form the information available.	M	MH
21. Affect land value?	No information was found documented to indicate this species would impact on land value.	L	M
22. Change land use?	No information was found documented to indicate this species would impact on land use change.	L	M
23. Increase harvest costs?	Recognised as a weed of wheat crops (Finnerty & Klingman 1962) and generally as a crop seed contaminant (McNeil & Peeper 1978; Wells et al 1986) with the potential to increase harvest time and costs. Seed from crops of smooth brome grass (Bromus inermis) containing even small quantities of seed from weedy brome grass species (including B. japonicus), cannot be certified for sale (Finnerty & Klingman 1962). However, the level of impact B. japonicus specifically would have on increasing harvest costs is not clear from the information available.	M	MH
24. Disease host/vector?	Identified as host plant of wheat dwarf virus, a disease of wheat, barley, oats, triticale and maize (Mehner et al 2003). Susceptible to wheat streak mosaic virus (McKinney & Fellows 1951). Host to diseases of important agricultural produce.	H	H

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	‘Low Winter temperatures prevent germination and induce dormancy in a large proportion of B. japonicus seed (Whisenant 1990)’. Extremely cold or warm temperatures suppressed germination in B. japonicus (Haferkamp et al 1995). Requires natural seasonable disturbances for germination.	MH	H
2. Establishment requirements?	A heavy thatch or litter layer improves germination rates (Howard & Winkler 1994). Able to grow in semi-shade and occurs in the understorey of Western juniper woodlands (PFAF 2006; Bates, Miller & Svejcar 2000). Can establish under moderate canopy and litter cover.	MH	M
3. How much disturbance is required?	Able to establish in undisturbed communities such as mixed-grass prairie (Howard & Winkler 1994). Establishes in relatively intact or only minor disturbed ecosystems, eg. grassland.	MH	MH
Growth/Competitive
4. Life form?	Annual, sometimes biennial, cool season grass (Finnerty & Kingman 1962; Harmoney 2006). Lifeform: grass	MH	MH
5. Allelopathic properties?	From the extensive literature on this species there was no information found documented to suggest it possesses allelopathic properties.	L	M
6. Tolerates herb pressure?	‘It is reported as increasing with moderate to heavy grazing (Howard & Winkler 1994)’. Continuous season-long grazing resulted in heavy Japanese brome composition (Harmoney 2006). ‘Some inflorescences were produced with even the most severe clipping treatments (Haferkamp & Karl 1999)’ Capable of seed production under normal grazing conditions.	MH	MH
7. Normal growth rate?	In one study, B. japonicus was negatively associated with the grass Poa pratensis and appeared most limited by a competitive interaction with P. pratensis (Ogle & Reiners 2002). In another, Mountain rye (Secale montanum) established rapidly and vigorously and significantly reduced the growth and reproduction of Bromus japonicus (Anderson et al 1992). Growth rate appears to be less than some species of the same life form.	ML	M
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Except in wet years fire tends to reduce B. japonicus populations, however, populations increase after 1-2 years (Howard & Winkler 1994). Spring germinating plants in northern latitudes are usually killed by frost before seeds are ripe (Howard & Winkler 1994). B. japonicus appears to show some susceptibility to fire & frost, however, insufficient information was found documented on its tolerances to other stresses so a medium ranking has been applied to this criterion.	M	L
Reproduction
9. Reproductive system	Reproduces entirely from seed (Howard & Winkler 1994). Capable of self-fertilization (Hedel, Christy & Gilmartin 1982 in Silzer 2006). Sexual reproduction (self and cross pollination).	ML	MH
10. Number of propagules produced?	In one study, up to 94, 212 seeds were produced in a year by B. japonicus in an area of 1m ²(Whisenant 1990). Around 10 plants could occur within a square metre of ground, therefore, one plant is easily capable of producing above 2000 seeds annually.	H	H
11. Propagule longevity?	Seeds typically remain viable in the seedbank for two to three years (Harmoney 2006). Seeds survive less than 5 years.	L	MH
12. Reproductive period?	An annual (or sometimes biennial) grass (Finnerty & Klingman 1962). Plant produces viable propagules for 1-2 years.	ML	H
13. Time to reproductive maturity?	An annual (or sometimes biennial) grass (Finnerty & Klingman 1962). Able to reach maturity and produces viable propagules in less than a year.	H	H
Dispersal
14. Number of mechanisms?	Seeds can be dispersed in animal hides and dung. In one study, the majority of seeds found in bison dung were Japanese brome (Heidel, Christy & Gilmartin 1982 in Howard & Winkler 1994). Seed spread via animal consumption and attachment.	MH	MH
15. How far do they disperse?	Seed dispersal is by animal consumption and attachment (Heidel, Christy & Gilmartin 1982 in Howard & Winkler 1994) enabling seeds to disperse a considerable distance. Few propagules will disperse greater than 1kilometre but many likely to reach >200m.	MH	MH

References

Andersen MR, Depuit EJ, Abernethy RH & Kleinman LH 1992, ‘Value of mountain rye for suppression of annual bromegrasses on semiarid mined lands’, Journal of Range Management, vol. 45, no. 4, pp. 345-351.

Baskin JM & Baskin CC 1981, ‘Ecology of germination and flowering in the weedy winter annual grass Bromus japonicus’, Journal of Range Management, vol. 34, no. 5, pp. 369-372.

Bates JD, Miller RF & Svejcar TJ 2000, ‘Understorey dynamics in cut and uncut western juniper woodlands’, Journal of Range Management, vol. 53, no. 1, pp. 119-126.

Finnerty DW & Klingman DL 1962, ‘Lifecycles and control studies of some weedy brome grasses’, Weeds, vol. 10, pp. 40-47.

Fleharty ED & Olson LE 1969, ‘Summer food habits of Microtus ochrogaster and Sigmodon hispidus’, J. Mammal., vol. 50, pp. 475-486.

Haferkamp MR & Karl MG 1999, ‘Clipping effects on growth dynamics of Japanese brome’, Journal of Range Management, vol. 52, no. 4, pp. 339-345.

Haferkamp MR, Grings EE, Heitschmidt RK, McNeil MD & Karl MG 2001, ‘Suppression of annual bromes impacts rangeland: animal responses’, Journal of Range Management, vol. 54, no. 6, pp. 663-668.

Haferkamp MR, Palmquist D, Young JA & McNeil MD 1995, ‘Influence of temperature on germination of Japanese brome seed’, Journal of Range Management, vol. 48, no. 3, pp. 264-266.

Harmoney K 2006, Western Kansas Agricultural Research Centre: Rangeland Research, ‘Publications & Current Projects: Grazing & burning Japanese Brome (Bromus japonicus) on Mixed Grass Rangelands’, Kansas State University, viewed 28th December 2006, http://www.wkarc.org/Arch/Research/Range/JapBromeBurnGraze06.pdf

Heidel B, Christy EJ & Gilmartin AJ 1982, ‘Numerical phenetic analysis of variation on populations of Poa secunda Presl. and Bromus japonicus Thunb. (Poaceae)’. Northwest Science, vol. 56, pp. 108-120.

Howard JL & Winkler G 1994, Bromus japonicus. In: Fire Effects Information System, United States Department of Agriculture Forest Service, Washington, viewed: 28th December 2006, http://www.fs.fed.us/database/feis/plants/graminoid/brojap/all.html

Hussey BMJ, Keighery GJ, Cousens RD, Dodd J & Lloyd SG 1997, Western Weeds: A guide to the weeds of Western Australia, The Plant Protection Society of Western Australia (Inc.), Victoria Park, WA. Karl MG, Heitschmidt RK & Haferkamp MR 1999, ‘Vegetation biomass dynamics and patterns of sexual reproduction in a northern mixed-grass prairie’, American Midland Naturalist, vol. 141, no. 2, pp. 227-237.

McKinney HH & Fellows H 1951, ‘Wild and forage grasses found to be susceptible to the wheat streak mosaic virus’, Plant Dis. Reptr., vol. 35, no. 10, pp. 441-442.

McNeil WK & Peeper TF 1978, ‘Correction of wheat yield data for Bromus or Avena spp. content’, Proceedings of the 31st Annual meeting of the Southern Weed Science Society, no. 69.

Mehner S, Manurung B, Gruntzig M, Habekuss A, Witsack W & Fuchs E (2003) ‘Investigations into the ecology of the Wheat dwarf virus (WDV) in Saxony-Anhalt, Germany’, Zeitschrift fur Pflanzenkrankheiten und Pflanzenschutz, vol. 110, no. 4, pp. 313-323.

Ogle SM & Reiners WA 2002, ‘A phytosociological study of exotic annual brome grasses in a mixed grass prairie/ ponderosa pine forest ecotone’, American Midland Naturalist, vol. 147, no. 1, pp. 25-31.

PFAF: Plants for a Future 2006. Edible, medicinal and useful plants for a healthier world. viewed: 28th December 2006, http://www.pfaf.org/database/plants.php?Bromus+japonicus.

Silzer T 2006, Rangeland Ecosystems & Plants Fact Sheet: Bromus japonicus, Department of Plant Sciences, University of Saskatchewan, viewed: 28th December 2006, http://www.usask.ca/agriculture/plantsci/classes/range/bromusjaponicus.html.

Stewart H & Hebda RJ (2000), Working Paper 45: Grasses of the Columbia Basin of British Columbia, Ministry of Forests Research Program, Royal British Columbia Museum, Natural History Section, Victoria, BC, viewed: 30th January 2007, www.for.gov.bc.ca/hfd/pubs/docs/wp/Wp45/Wp45-g.pdf

Wells MJ, Balsinhas AA, Joffe H, Engelbrecht VM, Harding G & Stirton CH 1986, ‘A catalogue of problem plants in southern Africa incorporating the National Weeds list of southern Africa,’ Memoirs of the Botanical Survey of South Africa, vol. 53.

Whisenant SG 1990, ‘Postfire Population Dynamics of Bromus japonicus’, American Midland Naturalist, vol. 123, no. 2, pp. 301-308.

Whitson TD, Burrill LC, Dewey SA, Cudney DW, Nelson BE, Richard DL & Parker R 1992, Weeds of the West, Western Society of Weed Science, CA, USA.

Global present distribution data references

Australian National Herbarium (ANH) 2006, Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, viewed 24th October 2006, http://www.anbg.gov.au/avh/

Global Biodiversity Information Facility (GBIF) 2006, Global biodiversity information facility: Prototype data portal, viewed 28th December 2006, http://www.gbif.org/

Missouri Botanical Gardens (MBG) 2006, w³TROPICOS, Missouri Botanical Gardens Database, viewed 28th December 2006, http://mobot.mobot.org/W3T/Search/vast.html

National Biodiversity Network (NBN) 2004, National Biodiversity Network Gateway, NBN, United Kingdom, viewed: 24th October 2006, http://www.searchnbn.net/index_homepage/index.jsp

Western Australian Herbarium (WAH) 2006, Florabase- the Western Australian Flora, Department of Environment & Conservation, WAH, Government of Western Australia, viewed: 24th October 2006, http://florabase.calm.wa.gov.au/search/advanced.

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