Present distribution
| Map Overlays Used Land Use: Pasture dryland; pasture irrigation. Broad vegetation types Coastal scrubs and grassland; coastal grassy woodland; heathy woodland; inland slopes woodland; sedge-rich woodland; grassland; plains grassy woodland; herb-rich woodland; riverine grassy woodland; rainshadow woodland; mallee woodland; wimmera/mallee woodland. Colours indicate possibility of Achnatherum caudatum infesting these areas. In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable. |
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QUESTION | COMMENTS | RATING | CONFIDENCE |
| Social | |||
| 1. Restrict human access? | Tussock-forming perennial grass up to 100cm (Parsons & Cuthbertson 1992). Weed unlikely to restrict human access. | L | MH |
| 2. Reduce tourism? | Flowers throughout summer (Parsons & Cuthbertson 1992). Has purplish-brown flowers (CCC 2005). ‘Tall, stout, bright green perennial’ (Edgar & Connor 2000). Found in grasslands and open areas. May have minor effect on aesthetics of area, particularly when flowering. | ML | MH |
| 3. Injurious to people? | ‘Blades to 30cm long ..scabrous near the tip, the upper surface scabrous, somewhat sharp, the tip somewhat sharp (USU 2001). Leaf-blade ‘…with many small prickles on ribs’ (Edgar & Connor 2000). May cause some minor irritations. | ML | MH |
| 4. Damage to cultural sites? | Dense patches of tussocks likely to create a negative visual impact on cultural sites. | ML | MH |
| Abiotic | |||
| 5. Impact flow? | Terrestrial species (Parsons & Cuthbertson 1992). | L | MH |
| 6. Impact water quality? | Terrestrial species (Parsons & Cuthbertson 1992). | L | MH |
| 7. Increase soil erosion? | Fibrous root system (CCC 2005). Found in open areas and form tussocks which persist for many years. Low probability of large-scale soil movement. | ML | MH |
| 8. Reduce biomass? | Tussock-forming perennial grass up to 100cm. Usually found in waste places or open areas (Parsons & Cuthbertson 1992). Biomass likely to increase. | L | MH |
| 9. Change fire regime? | Tussock-forming perennial grass up to 100cm. Usually found in waste places or open areas (Parsons & Cuthbertson 1992). Moderate change to both frequency and intensity of fire risk. | MH | MH |
| Community Habitat | |||
| 10. Impact on composition (a) high value EVC | EVC=Coastal dune scrub (BCS =V); CMA=Glenelg Hopkins; Bioreg=Warrnambool Plain; CLIMATE potential=VH. Tussock-forming perennial grass which is a weed of grasslands, riparian vegetation, waste areas and roadsides (Parsons & Cuthbertson 1992). May cause a minor displacement of some dominant species within the lower strata. | ML | MH |
| (b) medium value EVC | EVC=Coastal alkaline scrub (BCS =D); CMA=West Gippsland; Bioreg=Gippsland Plain; CLIMATE potential=VH. Tussock-forming perennial grass which is a weed of grasslands, riparian vegetation, waste areas and roadsides (Parsons & Cuthbertson 1992). May cause a minor displacement of some dominant species within the lower strata. | ML | MH |
| (c) low value EVC | EVC=Heathy woodland (BCS =LC); CMA=Glenelg Hopkins; Bioreg=Glenelg Plain; CLIMATE potential=VH. Tussock-forming perennial grass which is a weed of grasslands, riparian vegetation, waste areas and roadsides (Parsons & Cuthbertson 1992). May cause a minor displacement of some dominant species within the lower strata. | ML | MH |
| 11. Impact on structure? | Tussock-forming perennial grass which is a weed of grasslands, riparian vegetation, waste areas and roadsides (Parsons & Cuthbertson 1992). Minor effect on the lower strata. | ML | MH |
| 12. Effect on threatened flora? | ‘Threatening the vulnerable hairy anchor plant (Discaria pubescens) at Creswick Creek (McPhee & May 1992, cited in McLaren et al 1998). | MH | MH |
| Fauna | |||
| 13. Effect on threatened fauna? | This species is not documented as posing an additional risk to threatened fauna. | MH | L |
| 14. Effect on non-threatened fauna? | ‘Palatable when young, but mature leaves are tough and rarely grazed by stock’ (Parsons & Cuthbertson 1992). Possible that this species will replace other native palatable species thereby reducing food for non-threatened fauna species. | ML | MH |
| 15. Benefits fauna? | ‘Palatable when young, but mature leaves are tough and rarely grazed by stock’ (Parsons & Cuthbertson 1992). Provides very little support to desirable species. | H | MH |
| 16. Injurious to fauna? | Weed not documented to be injurious to fauna. | L | MH |
| Pest Animal | |||
| 17. Food source to pests? | Not documented as a food source to pest species. | L | MH |
| 18. Provides harbor? | Not known to provide harbour for pest species. | L | MH |
| Agriculture | |||
| 19. Impact yield? | Problem in lucerne in Argentina and California ‘reducing yield and interfering with mowing’ (Parsons & Cuthbertson 1992). Major impact (5-20%) on quantity of produce. | MH | MH |
| 20. Impact quality? | Weed not documented to impact on quality of produce. | L | MH |
| 21. Affect land value? | Weed not documented to affect value of land. | L | MH |
| 22. Change land use? | ‘In pasture and lucerne paddocks, control is more difficult (Parsons & Cuthbertson 1992). Not documented but possible that there may be some change to use of land. | ML | M |
| 23. Increase harvest costs? | Problem in lucerne in Argentina and California … ‘interfering with mowing’ (Parsons & Cuthbertson 1992). Increase in time and labour to eradicate weed from paddocks. | M | MH |
| 24. Disease host/vector? | Weed not known as an alternative host or vector for disease of agriculture. | L | MH |
QUESTION | COMMENTS | RATING | CONFIDENCE |
| Establishment | |||
| 1. Germination requirements? | Seeds germinate in autumn (Parsons & Cuthbertson 1992). Requires natural seasonal conditions for germination. | MH | MH |
| 2. Establishment requirements? | Habitat is primarily ‘open’ areas e.g. grasslands, roadside and pastures (Parsons & Cuthbertson 1992). Requires more specific requirements to establish. | ML | MH |
| 3. How much disturbance is required? | Established in ‘disturbed soils along roadsides, streambanks and waste places from which it invades run-down pastures’ (Parsons & Cuthbertson 1992). Establishes in highly disturbed natural ecosystems. | ML | MH |
| Growth/Competitive | |||
| 4. Life form? | Grass (in family Poaceae/Gramineae) (GRIN 2000). | MH | MH |
| 5. Allelopathic properties? | None described. | L | MH |
| 6. Tolerates herb pressure? | ‘Palatable when young, but mature leaves are tough and rarely grazed by stock’ (Parsons & Cuthbertson 1992). Consumed but non-preferred. | MH | MH |
| 7. Normal growth rate? | Growth rate is initially slow and also slows/ceases in winter (McLaren et al 1998). Only known to be a threat to one species (Parsons & Cuthbertson 1992). Maximum growth rate less than many species of the same life form. | ML | MH |
| 8. Stress tolerance to frost, drought, w/logg, sal. etc? | Tolerance to fire (Walsh & Entwistle 1994). Insufficient information to determine other tolerances. | M | L |
| Reproduction | |||
| 9. Reproductive system | Sexual reproduction. Two kinds of seed – open pollinated and self-pollinated (Parsons & Cuthbertson 1992). | ML | MH |
| 10. Number of propagules produced? | ‘Produces abundant hard awnless ‘nut-like’ cleistogenes’ (McLaren et al 1998). Well > 2000 possible See picture P & C (1992) p. 134 & 135. | H | MH |
| 11. Propagule longevity? | ‘Seeds often have dormancy mechanisms that allow them to persist for a long time.’ For example, Nassella neesiana and N. trichotoma have known seedbank longevities of 6 and 13 years respectively (Gardener & Sindel 1998). Achnatherum caudatum may exhibit similar longevity. | MH | ML |
| 12. Reproductive period? | Information on the life duration of this species is lacking. A related species Nassella trichotoma is known to be, “…long-lived, though the age which individuals can attain has not been determined.” Individuals may produce propagules for more than 3 years. | M | L |
| 13. Time to reproductive maturity? | Seeds germinate in autumn flowering, commences spring/summer following (Parsons & Cuthbertson 1992). Therefore assumed to produce propagules in less than a year. | H | MH |
| Dispersal | |||
| 14. Number of mechanisms? | Spread by water, stock and machinery (McLaren et al 1998). | MH | MH |
| 15. How far do they disperse? | Floodwaters and stock along stock routes are likely to disperse propagules 200 – 1000 m (McLaren et al 1998). | MH | MH |