Impact Assessment - Rubber Vine (Cryptostegia grandiflora) in Victoria (Nox)
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 Rubber vine
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: Rubber vine
Scientific name: Cryptostegia grandiflora
| Question | Comments | Rating | Confidence |
| Recreation | |||
| 1. Restrict human access? | “The important properties of rubber vine are its ability to climb over and smother tall trees and to extend into rundown pastures. In such situations it forms dense thickets, particularly along waterways which, being impenetrable to man and beast, restrict access to water” (Parsons & Cuthbertson 2001). Major impediment to access waterways. | H | MH |
| 2. Reduce tourism? | “…it is a twining vine, smothering vegetation. The Undarra Volcanic National Park in Queensland was affected when rubber vine covered the entrance of the volcanic lava tubes, thus decreasing the appeal of this attraction” (ARMCANZ 2001). | H | MH |
| 3. Injurious to people? | “Extracts of the stems are…toxic and the plant has been implicated in human as well as animal deaths. Fortunately rubber vine is unpalatable and seldom eaten, so deaths are few” (Tomley 1998). Potentially fatal for humans. | H | MH |
| 4. Damage to cultural sites? | “In thickets or supported by other vegetation it forms a dense tangled mass, smothering vegetation up to 40 m above the ground” (Tomley 1998). With the smothering habit of rubber vine, infestations on culturally significant vegetation (e.g. historical trees) could have a major impact. | H | MH |
| Abiotic | |||
| 5. Impact flow? | Terrestrial species (Tomley 1998). | L | MH |
| 6. Impact water quality? | ‘.. severely threatens riverine vegetation, and can potentially displace the plants and animals that inhabit riverbanks, thereby affecting the water quality of streams’ (CRC for Australian Weed Management 2003). Potential to have minor effects in dissolved O2. | ML | M |
| 7. Increase soil erosion? | Rubber vine increases soil erosion due to, “…loss of grasses and other ground covers” (ARMCANZ 2001). It commonly occurs along watercourses (Parsons & Cuthbertson 2001), thus there is a high probability for large scale soil movement. | MH | MH |
| 8. Reduce biomass? | “Rubber vine invades and dominates…riverine forest, eucalypt woodland and vine thickets” (Tomley 1998). The smothering nature of rubber vine suggests biomass would increase. | L | MH |
| 9. Change fire regime? | “Heavy grazing and drought reduced the amount of available fuel, and so reduced the frequency and intensity of fires” (Mackey 1996). Although the plant burns vigorously, it requires a significant dry fuel load to cause ignition (Parsons & Cuthbertson 2001). Minor change to frequency of fire. | ML | MH |
| Community Habitat | |||
| 10. Impact on composition (a) high value EVC | The potential for C. grandiflora to establish and naturalise in Victoria is highly unlikely due to ecoclimatic limitations (Mackey 1996). No impact on EVCs in Victoria. | L | M |
| (b) medium value EVC | The potential for C. grandiflora to establish and naturalise in Victoria is highly unlikely due to ecoclimatic limitations (Mackey 1996). No impact on EVCs in Victoria. | L | M |
| (c) low value EVC | The potential for C. grandiflora to establish and naturalise in Victoria is highly unlikely due to ecoclimatic limitations (Mackey 1996). No impact on EVCs in Victoria. | L | M |
| 11. Impact on structure? | “Rubber vine invades and dominates…riverine forest, eucalypt woodland and vine thickets. As a result some of these communities could be largely degraded” (Tomley 1998). “It is a vigorous climber which will smother and kill plants and shade out the ground layer; potential to destroy all deciduous vine thickets in Queensland” (ARMCANZ 2001). Major impact on <60% of the floral strata. | MH | MH |
| 12. Effect on threatened flora? | The potential for C. grandiflora to establish and naturalise in Victoria is highly unlikely due to ecoclimatic limitations (Mackey 1996). No impact on threatened flora in Victoria. | L | M |
| Fauna | |||
| 13. Effect on threatened fauna? | The potential for C. grandiflora to establish and naturalise in Victoria is highly unlikely due to ecoclimatic limitations (Mackey 1996). No impact on threatened fauna in Victoria | L | M |
| 14. Effect on non-threatened fauna? | See comment in 11 above. “Fauna living in such communities are also threatened. Rubber vine destroys the habitat of the greater glider Petauroides volans Kerr and the squirrel glider Petaurus norfolcensis Kerr” (Tomley 1998). Reduction in habitat leading to reduced numbers but not local extinction. | MH | MH |
| 15. Benefits fauna? | No known benefits. | H | MH |
| 16. Injurious to fauna? | “The plant is highly toxic to cattle, goats, sheep and, especially, horses” (Parsons & Cuthbertson 2001). Potentially injurious to native herbivores. | H | MH |
| Pest Animal | |||
| 17. Food source to pests? | Not known as a food source to pest animals. | L | MH |
| 18. Provides harbour? | ‘Its effects include … harbouring feral animals such as wild pigs’ (DNRME 2004). Can provide harbour for minor pest spp. | ML | M |
| Agriculture | |||
| 19. Impact yield? | “…there is a direct loss of pasture on better soils where rubber vine competes directly with pasture grasses, [with] dense infestations reducing carrying capacity by nearly 100%” (Tomley 1998). Serious impact on yield. | H | MH |
| 20. Impact quality? | Not a weed of cropping. Not known to affect the quality of other agricultural produce. | L | MH |
| 21. Affect land value? | “Chippendale (1991) reported that landholders perceived that property values…had dropped …due to infestation by rubber vine. …landholders recognise that rubber vine is a serious enough problem to affect their capital investment” (Tomley 1998). | H | MH |
| 22. Change land use? | Rubber vine is toxic, it seriously hinders day-to-day stock management of cattle and increases mustering costs (Tomley 1998). With such a serious impact on grazing activities, land may no longer be viable for grazing purposes. | H | MH |
| 23. Increase harvest costs? | “Mustering costs are almost doubled” (Tomley 1998). Major increase in time and labour to muster animals. | H | MH |
| 24. Disease host/vector? | None evident. | L | MH |
Impact Assessment Record - Rubber vine (PDF - 72KB)
Impact Assessment Record - Rubber vine (DOC - 71KB)
This table can also be viewed as a PDF document (printer friendly). 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 .