Present distribution
| This weed is not known to be naturalised in Victoria | ||||
Habitat: “Invasive plant of…open savannas…Hardy and adaptable plant, establishes itself well in a variety of vegetation types and habitats…[It] seems to flourish and establish under good rainfall conditions…Pompom weed threatens rangelands…It drastically lowers grazing capacity of invaded veld” (Krynauw 2008). “Recently become a major invader of roadsides, grassland, savanna and wetland ecosystems in South Africa…Occurs from the KwaZulu-Natal coast to the central interior of the Highveld” (Goodall et al. 2010). “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands…[It] originated in the Tropical Americas, in Argentina and Honduras, as well as in Mexico… During winter the plant is protected from fires and frost due to its living parts being safely underground. During summer droughts C. macrocephalum can revert to a dormant state”. Studies took place at a location with a semi-arid climate (Dixon 2008). Pompom weed at ‘The Downs’ is a huge seed source for invasion of the pristine higher altitude grasslands of the Woldberg…At altitudes or 0- 1900m or more” (ARC 2006). “Along roads, in fields, on hillsides and valleys” also in urban open space (SAPIA news 2007). |
Map Overlays Used Land Use: Broadacre cropping; horticulture perennial; horticulture seasonal; pasture dryland; pasture irrigation; water Ecological Vegetation Divisions Coastal; heathland; grassy/heathy dry forest; freshwater wetland (permanent); treed swampy wetland; lowland forest; foothills forest; forby forest; granitic hillslopes; rocky outcrop shrubland; western plains woodland; basalt grassland; alluvial plains grassland; semi-arid woodland; alluvial plains woodland; ironbark/box; riverine woodland/forest; freshwater wetland (ephemeral); chenopod shrubland; chenopod mallee; hummock-grass mallee; lowan mallee Colours indicate possibility of Campuloclinium macrocephalum 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? | “Pompom weed is a perennial, erect herb up to 1.5m high … Pompom weed forms extensive stands … Covered with rough, bristly hairs” (ARC 2006). “Gloves should be worn at all times while handling the plant as it can cause skin irritation” (Dixon 2008). “A densely bristly plant” (Goodall et al. 2010). High nuisance value. People and/or vehicles access with difficulty. | MH | M |
2. Reduce tourism? | “Infestations become conspicuous when the plants are in flower between December and March, transforming the veld from green to pink … Pompom weed is a perennial, erect herb up to 1.5m high … Pompom weed forms extensive stands … Covered with rough, bristly hairs” (ARC 2006). “Gloves should be worn at all times while handling the plant as it can cause skin irritation” (Dixon 2008). “A densely bristly plant” (Goodall et al. 2010). May cause major impact on recreation. Weeds obvious to most visitors, with visitor response complaints and a major reduction in visitors. | H | ML |
3. Injurious to people? | “Gloves should be worn at all times while handling the plant as it can cause skin irritation” (Dixon 2008). “Covered with rough, bristly hairs” (ARC 2006). “A densely bristly plant” (Goodall et al. 2010). Spines, burrs or toxic properties at most times of the year, or may be a major component in allergies, hayfever and/or asthma. | MH | MH |
4. Damage to cultural sites? | “Rhizomes can spread laterally under native vegetation … Nodes on the rhizomes can give rise to flowering stalks, thus increasing efficacy of the plant’s overall growth” (Dixon 2008). “Infestations become conspicuous when the plants are in flower between December and March, transforming the veld from green to pink … Pompom weed forms extensive stands” (ARC 2006). May cause moderate structural effect. | MH | ML |
Abiotic | |||
5. Impact flow? | “Campuloclinium macrocephalum has put great investment into its underground rootstock and tubers- the annual visible shoots and leaves only account for 30% of the plant’s total biomass” (Dixon 2008). Stands of pompom were almost equally divided in highly disturbed sites (around habitation and adjacent to roadsides), dryland sites (grassland, savannah), and wetland or bottomland sites” (ARC 2006). Little or negligible affect on water flow. | L | M |
6. Impact water quality? | Stands of pompom were almost equally divided in highly disturbed sites (around habitation and adjacent to roadsides), dryland sites (grassland, savannah), and wetland or bottomland sites” (ARC 2006). “During winter the plant is protected from fires and frost due to its living parts being safely underground” (Dixon 2008). Probably no noticeable effect on dissolved 02 or light levels. | L | M |
7. Increase soil erosion? | “Pompom weed may be considered a pioneer species…Plants were growing in exposed subsoil resulting from soil erosion” (Goodall et al. 2010). “Pompom weed also seems to flourish and establish under good rainfall conditions” (Krynauw 2008). “Pompom weed forms extensive stands…Stands of pompom were almost equally divided in highly disturbed sites (around habitation and adjacent to roadsides), dryland sites (grassland, savannah), and wetland or bottomland sites” (ARC 2006). “Campuloclinium macrocephalum has put great investment into its underground rootstock and tubers- the annual visible shoots and leaves only account for 30% of the plant’s total biomass… Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodland” (Dixon 2008). High probability of large scale soil movement with major off-site implications. | H | M |
8. Reduce biomass? | “Campuloclinium macrocephalum has put great investment into its underground rootstock and tubers- the annual visible shoots and leaves only account for 30% of the plant’s total biomass… Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodland” (Dixon 2008). “Pompom weed is a perennial, erect herb up to 1.5m high… Pompom weed forms extensive stands…Initially establishes itself in disturbed sites such as roadsides, but then invades natural grasslands, open savannah and wetlands” (ARC 2006). Biomass may increase. | L | M |
9. Change fire regime? | “Campuloclinium macrocephalum has put great investment into its underground rootstock and tubers- the annual visible shoots and leaves only account for 30% of the plant’s total biomass… Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodland” (Dixon 2008). “Pompom weed is a perennial, erect herb up to 1.5m high… Pompom weed forms extensive stands…Initially establishes itself in disturbed sites such as roadsides, but then invades natural grasslands, open savannah and wetlands” (ARC 2006). Small or negligible effect on fire risk. | L | ML |
Community Habitat | |||
10. Impact on composition (a) high value EVC | EVC = Montane Grassy Woodland (V); CMA = East Gippsland; Bioregion = Monaro Tablelands; L CLIMATE potential. “Has a serious impact on the biodiversity of veld, as it out-competes and replaces many indigenous plants [in South Africa and] drastically lowers the grazing capacity of invaded veld, where it often becomes the dominant plant” (Krynauw 2008). “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands leaving detrimental effects to the country’s plant biodiversity in its wake … It has detrimental effects on the growth and well-being of the natural vegetation and animal life …The dense rosette formation of leaves at the base of stems prevents native plant germination and growth … “Rhizomes can spread laterally under native vegetation, increasing growth of C. macrocephalum and diminishing the native species in the area … With both competition and allelopathy in its arsenal the weed is likely to interfere strongly with both grass establishment form seed and with regrowth from dormant tufts … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … These results show that the weed could negatively affect the establishment of desirable grass species” (Dixon 2008). “This weed displaces native species, reducing both the biological diversity and carrying capacity of vleis and veld… Pompom weed forms extensive stands … Dense stands, exceeding a cover of 25%, were recorded in 6.3% of the squares” (ARC 2006). Major displacement of some dominant species within a strata/layer (or some dominant species within different layers). | MH | MH |
(b) medium value EVC | EVC = Valley Grassy Forest (D/R); CMA =East Gippsland; Bioregion =East Gippsland Uplands; L CLIMATE potential. “Has a serious impact on the biodiversity of veld, as it out-competes and replaces many indigenous plants [in South Africa and] drastically lowers the grazing capacity of invaded veld, where it often becomes the dominant plant” (Krynauw 2008). “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands leaving detrimental effects to the country’s plant biodiversity in its wake … It has detrimental effects on the growth and well-being of the natural vegetation and animal life …The dense rosette formation of leaves at the base of stems prevents native plant germination and growth … “Rhizomes can spread laterally under native vegetation, increasing growth of C. macrocephalum and diminishing the native species in the area … With both competition and allelopathy in its arsenal the weed is likely to interfere strongly with both grass establishment form seed and with regrowth from dormant tufts … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … These results show that the weed could negatively affect the establishment of desirable grass species” (Dixon 2008). “This weed displaces native species, reducing both the biological diversity and carrying capacity of vleis and veld… Pompom weed forms extensive stands … Dense stands, exceeding a cover of 25%, were recorded in 6.3% of the squares” (ARC 2006). Major displacement of some dominant species within a strata/layer (or some dominant species within different layers). | MH | MH |
(c) low value EVC | EVC = Tableland Damp Forest (LC); CMA =East Gippsland; Bioregion = Monaro Tablelands; L CLIMATE potential. “Has a serious impact on the biodiversity of veld, as it out-competes and replaces many indigenous plants [in South Africa and] drastically lowers the grazing capacity of invaded veld, where it often becomes the dominant plant” (Krynauw 2008). “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands leaving detrimental effects to the country’s plant biodiversity in its wake … It has detrimental effects on the growth and well-being of the natural vegetation and animal life …The dense rosette formation of leaves at the base of stems prevents native plant germination and growth … “Rhizomes can spread laterally under native vegetation, increasing growth of C. macrocephalum and diminishing the native species in the area … With both competition and allelopathy in its arsenal the weed is likely to interfere strongly with both grass establishment form seed and with regrowth from dormant tufts … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … These results show that the weed could negatively affect the establishment of desirable grass species” (Dixon 2008). “This weed displaces native species, reducing both the biological diversity and carrying capacity of vleis and veld… Pompom weed forms extensive stands … Dense stands, exceeding a cover of 25%, were recorded in 6.3% of the squares” (ARC 2006). Major displacement of some dominant species within a strata/layer (or some dominant species within different layers). | MH | MH |
11. Impact on structure? | “Has a serious impact on the biodiversity of veld, as it out-competes and replaces many indigenous plants [in South Africa and] drastically lowers the grazing capacity of invaded veld, where it often becomes the dominant plant” (Krynauw 2008). “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands leaving detrimental effects to the country’s plant biodiversity in its wake … It has detrimental effects on the growth and well-being of the natural vegetation and animal life …The dense rosette formation of leaves at the base of stems prevents native plant germination and growth … “Rhizomes can spread laterally under native vegetation, increasing growth of C. macrocephalum and diminishing the native species in the area … With both competition and allelopathy in its arsenal the weed is likely to interfere strongly with both grass establishment form seed and with regrowth from dormant tufts … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … These results show that the weed could negatively affect the establishment of desirable grass species” (Dixon 2008). “This weed displaces native species, reducing both the biological diversity and carrying capacity of vleis and veld… Pompom weed forms extensive stands … Dense stands, exceeding a cover of 25%, were recorded in 6.3% of the squares” (ARC 2006). Minor effect on >60% of the layers or major effect on < 60% of the floral strata. | MH | MH |
12. Effect on threatened flora? | “Poses a huge threat to South Africa’s endangered grasslands” (Hartebeestfontein Conservancy 2010). Unknown what effect it has on Victorian threatened flora. More information needed. | MH | L |
Fauna | |||
13. Effect on threatened fauna? | No information found. | MH | L |
14. Effect on non-threatened fauna? | “Has a serious impact on the biodiversity of veld, as it out-competes and replaces many indigenous plants [in South Africa and] drastically lowers the grazing capacity of invaded veld, where it often becomes the dominant plant” (Krynauw 2008). “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands leaving detrimental effects to the country’s plant biodiversity in its wake … It has detrimental effects on the growth and well-being of the natural vegetation and animal life … The dense rosette formation of leaves at the base of stems prevents native plant germination and growth … “Rhizomes can spread laterally under native vegetation, increasing growth of C. macrocephalum and diminishing the native species in the area … With both competition and allelopathy in its arsenal the weed is likely to interfere strongly with both grass establishment form seed and with regrowth from dormant tufts … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country…These results show that the weed could negatively affect the establishment of desirable grass species” (Dixon 2008). “This weed displaces native species, reducing both the biological diversity and carrying capacity of vleis and veld … Pompom weed forms extensive stands … Dense stands, exceeding a cover of 25%, were recorded in 6.3% of the squares” (ARC 2006). Reduction in habitat for fauna species, leading to reduction in numbers of individuals, but not to local extinction. | MH | M |
15. Benefits fauna? | “Pompom weed is not utilised by large herbivores, and therefore causes a drastic decline in the feed value of invaded veld” (Krynauw 2008). “The plant initially establishes itself in disturbed sites, such as roadsides, overgrazed areas and then invades grasslands, open savannah and wetlands” (Matloko, undated). “Campuloclinium macrocephalum has put great investment into its underground rootstock and tubers- the annual visible shoots and leaves only account for 30% of the plant’s total biomass” (Dixon 2008). Provides very little support to desirable species. | H | M |
16. Injurious to fauna? | “Covered with rough, bristly hairs” (ARC 2006). “A densely bristly plant” (Goodall et al. 2010). “Gloves should be worn at all times while handling the plant as it can cause skin irritation” (Dixon 2008). Unknown effect on animals. | M | L |
Pest Animal | |||
17. Food source to pests? | “Pompom weed is not utilised by large herbivores, and therefore causes a drastic decline in the feed value of invaded veld” (Krynauw 2008). Probably provides minimal food for pest animals. | L | ML |
18. Provides harbour? | “Erect herb up to 1.5m high … Pompom weed forms extensive stands … Dense stands, exceeding a cover of 25%, were recorded in 6.3% of the squares” (ARC 2006). “Campuloclinium macrocephalum has put great investment into its underground rootstock and tubers - the annual visible shoots and leaves only account for 30% of the plant’s total biomass” (Dixon 2008). Doesn’t provide harbour for serious pest species, but may provide for minor pest species. | ML | ML |
Agriculture | |||
19. Impact yield? | “Pompom weed forms extensive stands on ‘The Downs’, a grassy plateau at the top of the Orrie Baragwanath Pass - an area previously inhabited and under potato cultivation … In general, physical methods of control, such as uprooting or hoeing, are ineffective and make the problem worse through disturbance. It is not advisable to plough lands with pompom weed as this will damage the rootstock, stimulating further vegetative growth and denser stands” (ARC 2006). “Expanding at such a rate that chemical control will soon become unpractical and unaffordable” (Matloko, undated). “Pompom weed is not utilised by large herbivores, and therefore causes a drastic decline in the feed value of invaded veld” (Krynauw 2008). “This is becoming a problem for farmers as the plant is taking up valuable space needed for palatable grasses to be used by grazing animals … In terms of C. macrocephalum invasion in South Africa it can be seen that prominent economic grass species and their habitats could be seriously affected by the weed … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … If more research is not done soon on how to control and eradicate the plant the country [South Africa] could suffer grave economic losses” (Dixon 2008). Serious impacts on quantity (eg >20% reduction). unviable to harvest crop/ stock. | H | MH |
20. Impact quality? | “Pompom weed forms extensive stands on ‘The Downs’, a grassy plateau at the top of the Orrie Baragwanath Pass - an area previously inhabited and under potato cultivation … In general, physical methods of control, such as uprooting or hoeing, are ineffective and make the problem worse through disturbance. It is not advisable to plough lands with pompom weed as this will damage the rootstock, stimulating further vegetative growth and denser stands” (ARC 2006). “Expanding at such a rate that chemical control will soon become unpractical and unaffordable” (Matloko, undated). “Pompom weed is not utilised by large herbivores, and therefore causes a drastic decline in the feed value of invaded veld” (Krynauw 2008). “This is becoming a problem for farmers as the plant is taking up valuable space needed for palatable grasses to be used by grazing animals … In terms of C. macrocephalum invasion in South Africa it can be seen that prominent economic grass species and their habitats could be seriously affected by the weed … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … If more research is not done soon on how to control and eradicate the plant the country [South Africa] could suffer grave economic losses” (Dixon 2008). Serious impacts on quality (e.g. >20% reduction). unviable to harvest crop/stock. | H | MH |
21. Affect land value? | “Expanding at such a rate that chemical control will soon become unpractical and unaffordable” (Matloko, undated). “Pompom weed forms extensive stands on ‘The Downs’, a grassy plateau at the top of the Orrie Baragwanath Pass - an area previously inhabited and under potato cultivation…In general, physical methods of control, such as uprooting or hoeing, are ineffective and make the problem worse through disturbance. It is not advisable to plough lands with pompom weed as this will damage the rootstock, stimulating further vegetative growth and denser stands” (ARC 2006). “Pompom weed is not utilised by large herbivores, and therefore causes a drastic decline in the feed value of invaded veld” (Krynauw 2008). “This is becoming a problem for farmers as the plant is taking up valuable space needed for palatable grasses to be used by grazing animals … In terms of C. macrocephalum invasion in South Africa it can be seen that prominent economic grass species and their habitats could be seriously affected by the weed … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … If more research is not done soon on how to control and eradicate the plant the country [South Africa] could suffer grave economic losses” (Dixon 2008). May be of major significance > 10%. | H | M |
22. Change land use? | “Pompom weed forms extensive stands on ‘The Downs’, a grassy plateau at the top of the Orrie Baragwanath Pass - an area previously inhabited and under potato cultivation … In general, physical methods of control, such as uprooting or hoeing, are ineffective and make the problem worse through disturbance. It is not advisable to plough lands with pompom weed as this will damage the rootstock, stimulating further vegetative growth and denser stands” (ARC 2006). “Expanding at such a rate that chemical control will soon become unpractical and unaffordable” (Matloko, undated). “Pompom weed is not utilised by large herbivores, and therefore causes a drastic decline in the feed value of invaded veld” (Krynauw 2008). “This is becoming a problem for farmers as the plant is taking up valuable space needed for palatable grasses to be used by grazing animals … In terms of C. macrocephalum invasion in South Africa it can be seen that prominent economic grass species and their habitats could be seriously affected by the weed … From the results obtained it is clear that C. macrocephalum leaf infusions affect the root growth of three prominent grasses. When applied to a grassland situation this could mean the C. macrocephalum could affect the roots of grasses in the field depleting their winter reserves and slowing their growth in the spring. With C. macrocephalum’s extensive root system and the probable inhibition of grass root growth, C. macrocphalum will easily take over open grassland causing great economic and livestock food losses for the country … If more research is not done soon on how to control and eradicate the plant the country [South Africa] could suffer grave economic losses” (Dixon 2008). May cause major detrimental change and significant loss for agricultural usage (e.g. complete change to different ag use e.g. farm forestry.) | H | MH |
23. Increase harvest costs? | “Pompom weed forms extensive stands on ‘The Downs’, a grassy plateau at the top of the Orrie Baragwanath Pass - an area previously inhabited and under potato cultivation … In general, physical methods of control, such as uprooting or hoeing, are ineffective and make the problem worse through disturbance. It is not advisable to plough lands with pompom weed as this will damage the rootstock, stimulating further vegetative growth and denser stands” (ARC 2006). “Expanding at such a rate that chemical control will soon become unpractical and unaffordable” (Matloko, undated). Major increase in time or labour, or machinery in harvesting. | H | M |
24. Disease host/vector? | “In February 2006 a rust fungus was found to have caused considerable die-back of pom-pom weed plants in various localities within the Pretoria area … The plants die back to the rootstock. Seedlings are killed by the fungus. The identity of this fungus is currently being investigated” (SAPIA news 2007). “The stem-boring, Zeale (=Adesmus nigromaculatus (Coleoptera: Cerambycidae), was found feeding on C. macrocephalum… Z. migromaculatus is known to use other Asteraceae as host plants in Argentina … It has also been reported as a pest in cultures of mint, Mentha arvensis var. piperascens. Given the broad host range of this insect, its consideration as a biocontrol agent will depend on the risk this beetle could pose on the South African indigenous Asteraceae species … Carmenta n. sp. (Lepidoptera: Sesiidae). A clearwing moth was found boring plants of C. macrocephalum … A thrip was found damaging leaves and stem tips of C. macrocephalum … This thrip is a slightly unusual member of the worldwide “Liothrips-linerage”… Found damaging the flower heads of Campuloclinium macrocephalum, a Gelechiidae and a Pterophoridae moth … Large numbers of a tephritid fly, Trupanea sp. Were also obtained” (Mc Kay and Oleiro, undated). May provide host to minor (or common) pests, or diseases. | M | M |
QUESTION | COMMENTS | RATING | CONFIDENCE |
Establishment | |||
1. Germination requirements? | “Achenes were collected from C. macrocephalum infestations and refrigerated at 5°C for 1 week to break a potential physiological dormancy. Seeds were than stored under dry ambient conditions at room temperature for 6 months. Achenes with pappus attached were germinated in Petri dishes in a growth chamber at 12h dark/light (spectral irradiance 11 Wm-²) and 15/28°C, respectively Germination was first observed after 6 days” (Goodall et al. 2010). Potentially requires natural seasonal disturbances such as seasonal rainfall, spring/summer temperatures for germination. | MH | MH |
2. Establishment requirements? | “It colonizes disturbed sites such as roadsides and has the potential to invade native grasslands and wetlands, displacing native vegetation” (Brown 2006). “Pompom weed also seems to flourish and establish under good rainfall conditions… Invasive plant of grasslands and open savannas… Pompom weed threatens rangelands… It drastically lowers grazing capacity of invaded veld” (Krynauw 2008). “Recently become a major invader of roadsides, grassland, savanna and wetland ecosystems in South Africa…Pompom weed occurs from the KwaZulu-Natal coast to the central interior of the Highveld” (Goodall et al. 2010). “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands …Its ability to establish on disturbed areas, for example roadsides, and abandoned fields and open savannahs are equal” (Dixon 2008). Pompom weed at ‘The Downs’ is a huge seed source for invasion of the pristine higher altitude grasslands of the Woldberg... Stands of pompom were almost equally divided in highly disturbed sites (around habitation and adjacent to roadsides), dryland sites (grassland, savanna), and wetland or bottomland sites” (ARC 2006). Also in urban open space (SAPIA news 2007). Requires more specific requirements to establish (eg. open space or bare ground with access to light and direct rainfall). | ML | MH |
3. How much disturbance is required? | “Becoming a major problem in South Africa as it invades savannahs, roadsides, grasslands and open woodlands leaving detrimental effects to the country’s plant biodiversity in its wake… Its ability to establish on disturbed areas, for example roadsides, and abandoned fields and open savannahs are equal” (Dixon 2008). “Initially establishes itself in disturbed sites such as roadsides, but then invades natural grasslands, open savanna and wetlands…Pompom weed at ‘The Downs’ is a huge seed source for invasion of the pristine higher altitude grasslands of the Woldberg. Already in 2004 pompom weed, which is wind-dispersed, was reported by a hiker in the remote Trichardt’s Pass area of this reserve” (ARC 2006). Establishes in relatively intact or only minor disturbed natural ecosystems (eg. wetlands, riparian, riverine, grasslands, open woodlands); in vigorously growing crops or in well-established pastures. | MH | MH |
Growth/Competitive | |||
4. Life form? | “Rhizomes can spread laterally under native vegetation…Nodes on the rhizomes can give rise to flowering stalks, thus increasing efficacy of the plant’s overall growth” (Dixon 2008). Geophyte. | ML | MH |
5. Allelopathic properties? | “Results suggest the C. macrocephalum does have significant allelopathic potential…All three grass species assayed were negatively affected by the allelochemicals contained in the C. macrocephalum leaf infusions … With both competition and allelopathy in its arsenal the weed is likely to interfere strongly with both grass establishment from seed and with regrowth from dormant tufts” (Dixon 2008). Allelopathic properties seriously affecting some plants. | MH | MH |
6. Tolerates herb pressure? | “Pompom weed is not utilised by large herbivores, and therefore causes a drastic decline in the feed value of invaded veld” (Krynauw 2008). “The plant initially establishes itself in disturbed sites, such as roadsides, overgrazed areas and then invades grasslands, open savanna and wetlands” (Matloko, undated). “At least two clear wing moths have been studied as weed biological control agents: the argentine root-boring moth Carmenta haematica (Ureta), considered a potential biological agent against snakeweeds (Gutierrezia spp.) in the U.S. and Carmenta mimosa Eichlin and Passoa, released in Australia as a biocontrol agent against Mimosa pigra (Leguminosae)” (Mc Kay and Oleiro, undated). Although information indicates that there may already be a biological control agent in Australia, C. macrocephalum is not currently under a biocontrol program in Australia and not known to be in New Zealand. Favoured by heavy grazing pressure as not eaten by animals/insects and not under a biological control program in Australia/New Zealand. | H | MH |
7. Normal growth rate? | “This weed has very prominent root reserves that enable quick regeneration and growth in the spring” (Dixon 2008). Rapid growth rate that will exceed most other species of the same life form. | H | MH |
8. Stress tolerance to frost, drought, w/logg, sal. etc? | “Pompom weed exhibits a greater degree of adaptive plasticity by invading a wider range of soil types, soil moisture gradients and disturbance regimes… Pompom weed occurs from the KwaZulu-Natal coast to the central interior of the Highveld” (Goodall et al. 2010). “During winter the plant is protected from fires and frost due to its living parts being safely underground. During summer droughts C. macrocephalum can revert to a dormant state by transferring nutrients from the above ground parts to the roots” (Dixon 2008). “Ability to establish in disturbed or denuded areas after fires, and to actually benefit from fires… At altitudes or 0 - 1900m or more… Pompom weed at ‘The Downs’ is a huge seed source for invasion of the pristine higher altitude grasslands of the Woldberg ... Stands of pompom were almost equally divided in highly disturbed sites (around habitation and adjacent to roadsides), dryland sites (grassland, savanna), and wetland or bottomland sites” (ARC 2006). Maybe highly resistant to fire, drought and waterlogging and highly tolerant to frost and salinity. Highly resistant to at least two and not susceptible to more than one. | H | MH |
Reproduction | |||
9. Reproductive system | “Removing the flowerhead stops seed dispersal, but vegetative reproduction will still occur” (Dixon 2008). Both vegetative and sexual reproduction (vegetative reproduction may be via cultivation, but not propagation). | H | MH |
10. Number of propagules produced? | “Produce[s] large amounts of seeds, in a manner very similar to that of annual weeds” (Krynauw 2008). “Flowerheads (inflorescences) are produced in dense clusters…Each flowerhead…consists of hundreds of tiny, star-shaped florets…Enormous reproductive potential, enables it to rapidly encroach large areas… Pompom weed is a perennial, erect herb up to 1.5m high” (ARC 2006). “Nodes on the rhizomes can give rise to flowering stalks, thus increasing efficacy of the plant’s overall growth” (Dixon 2008). Given the size of the plant and considering that each flower produces hundreds of tiny florets, if one floret produces 200 seeds x 10 flowerheads potentially on one plant = 2,000 seeds at least. Likely to produce above 2000 seeds. | H | ML |
11. Propagule longevity? | “Annual follow-up spraying will be essential, because of the germination of the seeds in the soil seed banks…Once the root crown has been removed, the roots will apparently not regrow. It is important to cause as little soil disturbance as possible, in order to prevent the mass-germination of pompom seeds. Regular follow-up visits to the site for the next three growing seasons are essential to ensure that all seedlings have been removed” (ARC 2006). Greater than 25% of seeds survive 5 years, or vegetatively reproduces. | L | ML |
12. Reproductive period? | “Vigorous growth from seed to flowering in one growing season… Pompom weed is a perennial, erect herb up to 1.5m high” (ARC 2006). “Nodes on the rhizomes can give rise to flowering stalks, thus increasing efficacy of the plant’s overall growth” (Dixon 2008). Mature plant produces viable propagules for 3 – 10 years. | MH | M |
13. Time to reproductive maturity? | “Vigorous growth from seed to flowering in one growing season” (ARC 2006). “Nodes on the rhizomes can give rise to flowering stalks, thus increasing efficacy of the plant’s overall growth” (Dixon 2008). Reaches maturity and produces viable propagules, or vegetative propagules become separate individuals, in under a year. | H | MH |
Dispersal | |||
14. Number of mechanisms? | “Mature florets each produce a single-seeded dry fruit (achene) with a tuft of brown hairs (pappus) that promote wind dispersal… Pompom weed at ‘The Downs’ is a huge seed source for invasion of the pristine higher altitude grasslands of the Woldberg. Already in 2004 pompom weed, which is wind-dispersed, was reported by a hiker in the remote Trichardt’s Pass area of this reserve” (ARC 2006). Very light, wind dispersed seeds. | H | MH |
15. How far do they disperse? | “Mature florets each produce a single-seeded dry fruit (achene) with a tuft of brown hairs (pappus) that promote wind dispersal… Pompom weed at ‘The Downs’ is a huge seed source for invasion of the pristine higher altitude grasslands of the Woldberg. Already in 2004 pompom weed, which is wind-dispersed, was reported by a hiker in the remote Trichardt’s Pass area of this reserve” (ARC 2006). Very likely that at least one propagule will disperse greater one kilometre. | H | MH |