Present distribution
| Map showing the present distribution of this weed. | ||||
Habitat: Native to North America. Reported in various grasslands and woodlands to 2200m. |
Map Overlays Used Land Use: Pasture dryland Broad vegetation types Coastal scrubs and grassland; coastal grassy woodland; lowland forest; box ironbark forest; inland slopes and plains; sedge rich woodland; dry foothills forest; montane dry woodland; sub-alpine woodland; grassland; plains grassy woodland; herb-rich woodland; sub-alpine grassy woodland; montane grassy woodland; riverine grassy woodland; rainshadow woodland; mallee; mallee heath; boinka-raak; mallee woodland; wimmera / mallee woodland Colours indicate possibility of Cylindropuntia imbricata 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? | Can grow to 3m and has spines (Hubert 1980), would be an impediment. | m | m |
2. Reduce tourism? | May have some negative influence on the aesthetics of an area. | ml | m |
3. Injurious to people? | Does have spines (Hubert 1980). | mh | mh |
4. Damage to cultural sites? | No reported structural damage may have a negative influence on the aesthetics. | ml | m |
Abiotic | |||
5. Impact flow? | Terrestrial species | l | m |
6. Impact water quality? | Terrestrial species | l | m |
7. Increase soil erosion? | Reduces grazing pressure on an area, by restricting the movement of grazing species, and protecting the grasses/herbs in the immediate vacinity of its spines (Pieper 1971), therefore increasing the ground cover and reducing soil exposed to erosion. | l | m |
8. Reduce biomass? | Apparent lack of competition between it and the grasses has been reported also that C.imbricata, may improve the microclimate for grasses, while also protecting them from over grazing increasing net biomass (Mueller, Shoop & Laycock 1994 and Pieper 1971). | l | m |
9. Change fire regime? | If an increase in biomass does eventuate from the presence of C.imbricata, this increase in fire intensity would not be persistent as the cactus population left exposed after the fire would be reduced by herbiovry due to its now lack of spines (Bunting, Wright & Neuenschwander 1980). | l | m |
Community Habitat | |||
10. Impact on composition (a) high value EVC | EVC= Plains Savannah (E); CMA= Wimmera; Bioreg= Lowan Mallee; VH CLIMATE potential. Competitive species in shrub layer, can alter conditions for grass/herb layer Major displacement of dominant sp. within a layer, and alter species composition of another layer. | mh | mh |
(b) medium value EVC | EVC= Semi-arid Woodland (D); CMA= Wimmera; Bioreg= Lowan Mallee; VH CLIMATE potential. Competitive species in shrub layer, can alter conditions for grass/herb layer Major displacement of dominant sp. within a layer, and alter species composition of another layer. | mh | mh |
(c) low value EVC | EVC= Lowan Sands Mallee (LC); CMA= Wimmera; Bioreg= Lowan Mallee; VH CLIMATE potential. Competitive species in shrub layer, can alter conditions for grass/herb layer Major displacement of dominant sp. within a layer, and alter species composition of another layer. | mh | mh |
11. Impact on structure? | In a grassland it creates a shrub layer and reportedly may alter the microclimate for the grass and herb layer (Pieper 1971). | ml | m |
12. Effect on threatened flora? | No specific data, may protect species sensitive to grazing. | m | ml |
Fauna | |||
13. Effect on threatened fauna? | No specific data. | mh | l |
14. Effect on non-threatened fauna? | If invades grassland creates a vegetation layer that previously didn't exist. | l | m |
15. Benefits fauna? | May be a food source during drought (Endecott etal 2005). | mh | m |
16. Injurious to fauna? | Does have spines (Hubert 1980). | mh | m |
Pest Animal | |||
17. Food source to pests? | Cactus species reportadly eaten by goats. | ml | m |
18. Provides harbor? | No more than another shrub species. | m | ml |
Agriculture | |||
19. Impact yield? | Conflicting data on its impact on the net herbage yield of an area as fodder for stock. Also may be used itself as a fodder source during drought, but its use is cautioned (Endecott etal 2005, Pieper 1971 and Pieper, Rea & Fraser 1974). | ml | m |
20. Impact quality? | No specific data however if used as a fodder source may have a negative effect on stock (Endecott etal 2005). | l | m |
21. Affect land value? | If control viewed as necessary, may have negative effect on land value. | m | ml |
22. Change land use? | A pest of pastoral country can't really be further downgraded. | ml | m |
23. Increase harvest costs? | If restrict the movement of stock may increase mustering times. | mh | m |
24. Disease host/vector? | Not reported. | l | m |
QUESTION | COMMENTS | RATING | CONFIDENCE |
Establishment | |||
1. Germination requirements? | No data specified for seed germination of this species, presumed like other opuntia species requiring a sufficient quantity of water in the growing season, also vegetative propagules of opuntia sp. only require sufficient water to set root | h | ml |
2. Establishment requirements? | Passive dispersal by stock and wildlife is that gaps and open spaces are created for the species to fill, therefore may require bare ground for establishment (Allen etal 1991). | ml | m |
3. How much disturbance is required? | Invades grassland | mh | m |
Growth/Competitive | |||
4. Life form? | Tree-like cactus, growing to 3m (other) (Hubert 1980). | l | m |
5. Allelopathic properties? | None described. | l | m |
6. Tolerates herb pressure? | Has been used as emergency stock feed in New Mexico for more than 100 years. However due to its spines it first required to be singed (Endecott etal 2005). | mh | mh |
7. Normal growth rate? | No specific data but being tree like would at least be average for opuntia species. | mh | m |
8. Stress tolerance to frost, drought, w/logg, sal. etc? | Can survive fire but is left exposed to herbivory post-fire leading to up to 100% mortality (Bunting, Wright & Neuenschwander 1980). Reportadly its native range includes areas that experience an average January temperature of -1C, therefore it can withstand temperature below 0C (Frost tolerant) (Kinraide 1978). Used as emergency feed during a drought can therefore tolerate of drought (Endecott etal 2005). | mh | mh |
Reproduction | |||
9. Reproductive system | Produces fruit that contain seeds, broken segments can also reproduce vegetatively (Allen etal 1991). | h | mh |
10. Number of propagules produced? | Reported to set numerous seeds, also a 3m tall plant with branches could be broken up into many viable propagules (McFarland, Kevan & Lane 1989). | mh | m |
11. Propagule longevity? | Not specified. | m | l |
12. Reproductive period? | No specific data for this species, however the majority of other cactace sp. live longer than 10 years, and can reproduce vegetatively during this time. | h | m |
13. Time to reproductive maturity? | Can reproduce vegetatively within its first year of growth. | h | m |
Dispersal | |||
14. Number of mechanisms? | More than just passive dispersal (McFarland, Kevan & Lane 1989). | m | m |
15. How far do they disperse? | Unknown | m | l |