Present distribution
| Map showing the present distribution of this weed. | ||||
Habitat: Native to North America. Reported in Grassland and desert including at elevation. |
Map Overlays Used Land Use: Pasture dryland Broad vegetation types Coastal scrubs and grassland; coastal grassy woodland; heathy woodland; 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; rainshadow woodland; mallee; boinka-raak; ; mallee woodland; wimmera / mallee woodland Colours indicate possibility of Opuntia lindheimeri 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 form large thickets and spines would hinder clearance (Benson 1982). | mh | m |
2. Reduce tourism? | Probable negative influence of aesthetics. | ml | ml |
3. Injurious to people? | Does have spines (Benson 1982). | mh | m |
4. Damage to cultural sites? | No structural damage reported may have a negative influence on aesthetics. | ml | ml |
Abiotic | |||
5. Impact flow? | Terrestrial species | l | m |
6. Impact water quality? | Terrestrial species | l | m |
7. Increase soil erosion? | I has been reported a spiny cactus species can prevent up to 50% of the herbage cover immediately surrounding it being removed by grazing pressure, therefore limiting over grazing, therefore maintaining ground cover and reducing soil exposure (Mueller, Shoop & Laycock 1994). | l | m |
8. Reduce biomass? | Invading grassland, would cause an increase in biomass, also if grazing pressure is restricted there would be a net increase in biomass (Mueller, Shoop & Laycock 1994). | l | m |
9. Change fire regime? | Due to high water content cacti species do not easily burn themselves, however if the presence of O. lindheimeri does maintain a higher grass biomass by restricting grazing, this would increase the fuel load of the area (Mueller, Shoop & Laycock 1994). | m | m |
Community Habitat | |||
10. Impact on composition (a) high value EVC | EVC= Plains Savannah (E); CMA= Mallee; Bioreg= Lowan Mallee; VH CLIMATE potential. Competitive in the shrub layer and alters species composition of ground layer. Major displacement of species. | mh | mh |
(b) medium value EVC | EVC= Semi-arid Woodland (D); CMA= Mallee; Bioreg= Lowan Mallee; VH CLIMATE potential. Competitive in the shrub layer and alters species composition of ground layer. Major displacement of species. | mh | mh |
(c) low value EVC | EVC= Red Swale Mallee (LC); CMA= Mallee; Bioreg= Lowan Mallee; VH CLIMATE potential. Competitive in the shrub layer and alters species composition of ground layer. Major displacement of species. | mh | mh |
11. Impact on structure? | Invading grassland it creates a shrub layer, also by altering grazing pressure and potentially fire regimes may alter grass/herb composition. | ml | m |
12. Effect on threatened flora? | No specific data, however they are noted for protecting species sensitive of grazing. | m | ml |
Fauna | |||
13. Effect on threatened fauna? | No Australian data, found to be an important food source for desert big horn sheep and white-tailed deer in native range (Arnold & Drawe 1979). | m | m |
14. Effect on non-threatened fauna? | In grassland its presence adds a layer that previously didn't exist, while not having a major impact on the grass/herb layer. | l | m |
15. Benefits fauna? | Has been seen as an important alternate food source in its native range, especially during the dry season (Arnold & Drawe 1979). | ml | m |
16. Injurious to fauna? | Does have spines (Benson 1982). | mh | m |
Pest Animal | |||
17. Food source to pests? | Eaten by goats (Ramirez, Haenlein & Nunez-Gonzalez 2001). | ml | m |
18. Provides harbor? | No specific data, may provide shelter in a grassland where there previously wasn't any. | m | m |
Agriculture | |||
19. Impact yield? | Can invade grassland and reduce net grazing area (Benson 1982), however in a rangeland situation also seen as an additional fodder source (Mueller, Shoop & Laycock 1994, Potter, Peterson & Ueckert 1984 and Ramirez etal 2000). | ml | mh |
20. Impact quality? | Small reduction in quantity of fodder may have ill effect on stock, however a high water content feed during dry times may be beneficial (Ramirez etal 2000). | l | m |
21. Affect land value? | If control viewed as necessary may have negative impact on land value. | m | l |
22. Change land use? | May reduce stocking rates but wouldn't alter system from grazing. | l | ml |
23. Increase harvest costs? | If restrict the movement of stock may increase mustering times. | mh | m |
24. Disease host/vector? | No specific data. | l | m |
QUESTION | COMMENTS | RATING | CONFIDENCE |
Establishment | |||
1. Germination requirements? | In their natural range, germination occurs during the summer rainy season, requiring 43mm or more of rain in 2 weeks or less (Bowers 2005). Vegetative growth can also occur from a broken segment (Benson 1982). | h | mh |
2. Establishment requirements? | Reported to inhabit grassland and brushlands (Benson 1982), establishment of seedlings infrequent requiring sufficient water over a period of time plains. Journal of Range Management. 32: 175-178. (Bowers 2005). | mh | m |
3. How much disturbance is required? | Reported in grasslands (Benson 1982). | mh | m |
Growth/Competitive | |||
4. Life form? | Shrubby cactus (Benson 1982). | l | mh |
5. Allelopathic properties? | None described. | l | m |
6. Tolerates herb pressure? | Has spines but is reportadly eaten, by big horn sheep, goats, white-tailed deer and cattle (Arnold & Drawe 1979, Ramirez, Haenlein & Nunez-Gonzalez 2001 and Tarango etal 2002). Short term intensive grazing can increase the population by breaking segments but not consuming them allowing for increased vegetative dispersal (Taylor & Merrill 1975). | ml | m |
7. Normal growth rate? | Time to reproductive maturity from seed has been reported to be between 9-11 years, it may be faster from vegetative growth however this is slow in comparison to other cactus species (Bowers 2005). | ml | m |
8. Stress tolerance to frost, drought, w/logg, sal. etc? | Desert Cactus (Drought tolerant) (Bowers 2005). A single burn in Arizona killed 25% in a population, fire is also used a a way of de-thorning cactus so that it will be more readily eaten by cattle (Reynolds & Bohning 1956). Described as cold hardy and used as a hybrid parent to increase frost tolerance in other opuntia species (Wang, Felker & Paterson 1997). | mh | m |
Reproduction | |||
9. Reproductive system | Produces seed, and can spread vegetatively from broken segments (Bowers 2005). | h | mh |
10. Number of propagules produced? | Is in cultivation for its fruit crop, fruit contain numerous seeds (Benson 1982). | h | m |
11. Propagule longevity? | Seeds can persist in the soil for at least 19 months and potentially longer (Bowers 2005). | l | m |
12. Reproductive period? | Individuals can live up to 30 years, while it takes 9-11 years to reach reproductive maturity from seed, plants can spread vegetatively during this time (Bowers 2005). | h | h |
13. Time to reproductive maturity? | From seed plants take 9-11 years to reach reproductive maturity, however from vegetative dispersal faster growth rates have been recorded and may produce more vegetative propagules within a year (Bowers 2005). | h | m |
Dispersal | |||
14. Number of mechanisms? | Fruit produced which have been noted to be eaten by a number of animal species (Mosallum 1996 and Potter, Peterson & Ueckert 1984). | mh | m |
15. How far do they disperse? | If fruits eaten by cattle may be seeds may be dispersed kilometres (Potter, Peterson & Ueckert 1984). | h | mh |