Impact Assessment - Japanese privet (Ligustrum ovalifolium) in Victoria
Back | Table | Feedback
Assessment of plant invasiveness is done by evaluating biological and ecological characteristics such as germination requirements, growth rate, competitive ability, reproduction methods and dispersal mechanisms. Assessment of plant impacts, however, is determined by the extent to which a plant affects a land manager’s environmental, economic and social resources.
The relative importance of these resources varies depending upon the value people place on them and, as such, the assessment process is subjective. For example, a farmer is likely to place a higher emphasis on the impact of a plant on production (economic resource) than its impact on areas of natural vegetation occurring on the farm. Conversely, a Landcare or Friends group would value environmental or social resources more than economic resources.
Recognising that the value of resources vary between different land tenures, plant impact assessments allow a prioritisation of resources by land managers. Assessments can apply at a local, regional or state level, and the relative values of each resource identified may differ at each level.
The impact assessment method used in the Victorian Pest Plant Prioritisation Process uses three broad resource categories: social, environmental and agricultural, each with a number of related attributes. For example, social resources include such attributes as how the plant affects human access for recreation, or if it creates a health risk due to toxicity or by producing allergens.
| Each resource attribute, or criterion, is assessed relative to a list of intensity ratings. Depending upon information found in relation to each criterion, a rating of Low, Medium Low, Medium High or High is assigned. Descriptions of the impact criteria and intensity ratings used in this process can be viewed here. |
The following table provides information on the impact of Japanese privet.
A more detailed description of the methodology of the Victorian Weed Risk Assessment (WRA) method can be viewed below:
A more detailed description of the methodology of the Victorian Weed Risk Assessment (WRA) method can be viewed below:
Victorian Weed Risk Assessment (WRA) method (PDF - 630 KB)
Victorian Weed Risk Assessment (WRA) method (DOC - 1 MB)
To view the information PDF requires the use of a PDF reader. This can be installed for free from the Adobe website (external link).
Common Name: Japanese privet
Scientific name: Ligustrum ovalifolium
| Question | Comments | Rating | Confidence |
| Recreation | |||
| 1. Restrict human access? | The species is used for hedging and can grow to 5 m (Webb, Sykes & Garnock-Jones 1988). Therefore the species could form a barrier that would be of nuisance, it is unknown however if this occurs in the wild. | M | L |
| 2. Reduce tourism? | Unknown; the species is a large ornamental shrub, that has some toxic properties and may restrict access (Shepherd 2004; Webb, Sykes & Garnock-Jones 1988). The species has not however been reported to impact on recreation. | M | L |
| 3. Injurious to people? | Suspected to cause allergy (D’Amato & Liccardi 2002). The fruit and leaves of Ligustrum species are reported to be potentially fatal (Shepherd 2004). | H | M |
| 4. Damage to cultural sites? | The species is a large ornamental shrub (Webb, Sykes & Garnock-Jones 1988). The species may therefore have some impact upon aesthetics, this has not however been reported. | ML | L |
| Abiotic | |||
| 5. Impact flow? | Unknown; a similar species can reportedly impact on the flow of water along drainage lines (Blood 2001, Muyt 2001). | M | L |
| 6. Impact water quality? | Chemicals released from the leaves of the similar species L. sinense have been reported to impact on aquatic macro invertebrates (Llewellyn 2005). The species does occur in riparian areas, and could have some impact on water quality by changing light levels and nutrient imputes. There has been however no quantifiable reports of this species impacting upon water quality. | M | L |
| 7. Increase soil erosion? | This is not specifically known, however as Webb et al (1988) describes the plant as a large shrub it is thought to pose some resistance to erosion. | ML | M |
| 8. Reduce biomass? | Unknown. | M | L |
| 9. Change fire regime? | Unknown. | M | L |
| Community Habitat | |||
| 10. Impact on composition (a) high value EVC | EVC= Damp Forest (E); CMA= West Gippsland; Bioreg= Strzelecki Ranges; VH CLIMATE potential. The impact this species could potentially have on a specific strata is not known. The species has been reported to invade similar habitats to L. sinense, the impact of this has not been reported however (Roy et al 2004). | M | L |
| (b) medium value EVC | EVC=Wet Forest (D); CMA= West Gippsland; Bioreg= Strzelecki Ranges; VH CLIMATE potential. The impact this species could potentially have on a specific strata is not known. The species has been reported to invade similar habitats to L. sinense, the impact of this has not been reported however (Roy et al 2004). | M | L |
| (c) low value EVC | EVC= Wet Forest (LC); CMA= West Gippsland; Bioreg= Wilsons Promontory; VH CLIMATE potential. The impact this species could potentially have on a specific strata is not known. The species has been reported to invade similar habitats to L. sinense, the impact of this has not been reported however (Roy et al 2004). | M | L |
| 11. Impact on structure? | The impact this species could potentially have on a the vegetation structure is not known. The species has been reported to invade similar habitats to L. sinense, the impact of this has not been reported however (Roy et al 2004). | M | L |
| 12. Effect on threatened flora? | Unknown. | MH | L |
| Fauna | |||
| 13. Effect on threatened fauna? | The increased food privet species provide through the fruit load, supports increased populations of aggressive bird species such as currowongs (Blood 2001; Swarbrick, Timmins & Bullen 1999). This then has the potential to impact on other bird species populations, it has not however been reported to specifically impact upon a threatened species. | MH | L |
| 14. Effect on non-threatened fauna? | The increased food privet species provide through the fruit load, supports increased populations of aggressive bird species such as currowongs (Blood 2001; Swarbrick, Timmins & Bullen 1999). This then has the potential to impact on other bird species populations, quantitative evidence of the impact on such species has not been reported however | M | L |
| 15. Benefits fauna? | Being a large fruit producing shrub, the species is likely to provide some assistance in either food or shelter to desirable species (Webb, Sykes & Garnock-Jones 1988). | MH | MH |
| 16. Injurious to fauna? | The leaves and fruit of Ligustrum sp. are considered toxic (Shepherd 2004). There has been no evidence reported on if this species is toxic to native fauna and if so to what extent it impacts on them. | M | L |
| Pest Animal | |||
| 17. Food source to pests? | Blackbirds and starlings are also reported to eat fruit of other Ligustrum species (Swarbrick, Timmins & Bullen 1999). | ML | M |
| 18. Provides harbor? | Unknown. | M | L |
| Agriculture | |||
| 19. Impact yield? | Not reported as an agricultural weed. The species however is considered toxic and the similar species L. vulgare has been linked to cases of stock death (Everist 1974; Connor 1977; Shepherd 2004). | M | L |
| 20. Impact quality? | Honey collected from privet species is reported to smell like fish (Swarbrick, Timmins & Bullen 1999). | M | L |
| 21. Affect land value? | The species has been used as an ornamental (Webb, Sykes & Garnock-Jones 1988). It is therefore unlikely to have any significant impact upon land values. | L | MH |
| 22. Change land use? | Unknown however as the species is considered to be largely an environmental weed this is unlikely. | L | M |
| 23. Increase harvest costs? | Unknown however as the species is considered to be largely an environmental weed this is unlikely. | L | M |
| 24. Disease host/vector? | Unknown. | M | L |
Impact Assessment Record - Japanese privet (PDF - 77KB)
Impact Assessment Record - Japanese privet (PDF - 54KB)
To view the information PDF requires the use of a PDF reader. This can be installed for free from the Adobe website (external link).
Feedback
Do you have additional information about this plant that will improve the quality of the assessment?
If so, we would value your contribution. Click on the link to go to the feedback form.
© State of Victoria (Agriculture Victoria) 1996 - .
This work, Victorian Resources Online, is licensed under a Creative Commons Attribution 4.0 licence. You are free to re-use the work under that licence, on the condition that you credit the State of Victoria (Agriculture Victoria) as author, indicate if changes were made and comply with the other licence terms.
The licence does not apply to ‘branding’ or some ‘images or photographs’ that may be owned by third parties. We ask you to seek prior approval to use images using the VRO feedback form. Access to higher quality images can also be provided on request.
This page was last updated on .