Your gateway to a wide range of natural resources information and associated maps

Victorian Resources Online

Impact Assessment - Kochia scorpia (Bassia spp.) in Victoria

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 Kochia scorpia

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: Kochia scorpia
Scientific name: Bassia scoparia (syn. B. sieversiana, Kochia alata, K. scoparia var. culta, K. scoparia var. pubsecens, K. scoparia var. subvillosa, K. scoparia var. trichophilla, K. sieversiana, K. trichophila

Question
Comments
Rating
Confidence
Recreation
1. Restrict human access?Erect, much-branched stems from one to two metres long. Bush can grow up to 150 cm in height (Noxious Weed Control Board 1999). May have a low nuisance value which impedes individual access.
ML
MH
2. Reduce tourism?Possible that the weed will have a minor effect on aesthetics.
ML
MH
3. Injurious to people?Causes ‘ asthma, hayfever and allergic rhinitis.’ ‘Common cause of sensitisation ..’ (All Allergy 1998). Mildly toxic at certain times of year.
ML
M
4. Damage to cultural sites?Little or negligible effect on aesthetics or structure of cultural sites.
L
MH
Abiotic
5. Impact flow?Terrestrial species.
L
MH
6. Impact water quality?Terrestrial species.
L
MH
7. Increase soil erosion?‘Has a main taproot [which can grow up to 5 metres] and network of finer roots.’ ‘Dead plants break off at the base and are blown by the wind as tumbleweeds (CRC for Australian Weed Management 2003). Although, ‘can be used in revegetation programs for erosion control’ as it can out compete perennial species, chance of bare ground open to soil erosion is increased (Undersander et al 1990). Only low probability of large scale soil movement.
ML
H
8. Reduce biomass?‘Dense infestations could suppress recruitment of native ground cover plants and alter natural fire regime’ (Csurhes & Edwards 1998). As replacing grasses, biomass may slightly increase.
L
MH
9. Change fire regime?‘Dense infestations could suppress recruitment of native ground cover plants and alter natural fire regime’ (Csurhes & Edwards 1998). Plants die off during dry season. May have minor effect on intensity of fire.
ML
MH
Community Habitat
10. Impact on composition
(a) high value EVC
EVC= Parilla mallee (E); CMA=Mallee; Bioreg=Murray Mallee; CLIMATE potential=VH.
‘Dense infestations could suppress recruitment of native ground cover plants and alter natural fire regime’ (Csurhes & Edwards 1998). Monoculture within the groundcover layer.
H
MH
(b) medium value EVCEVC= Parilla mallee (E); CMA=Mallee; Bioreg=Murray Mallee; CLIMATE potential=VH.
‘Dense infestations could suppress recruitment of native ground cover plants and alter natural fire regime’ (Csurhes & Edwards 1998). Monoculture within the groundcover layer.
H
MH
(c) low value EVCEVC= Grassy dry forest (D); CMA=Corangamite; Bioreg=Victorian Volcanic Plain; CLIMATE potential=VH.
‘Dense infestations could suppress recruitment of native ground cover plants and alter natural fire regime’ (Csurhes & Edwards 1998). Monoculture within the groundcover layer.
H
MH
11. Impact on structure?‘Dense infestations could suppress recruitment of native ground cover plants and alter natural fire regime’ (Csurhes & Edwards 1998). Major effect on less than 60% of floral strata.
MH
MH
12. Effect on threatened flora?No information available.
MH
L
Fauna
13. Effect on threatened fauna?No information available.
MH
L
14. Effect on non-threatened fauna?No documented effect on non-threatened fauna spp.
L
MH
15. Benefits fauna?Weed not known to provide benefits to indigenous fauna.
H
MH
16. Injurious to fauna?‘Contains high levels of oxlates, alkaloids and nitrates that can be toxic to a variety of grazing animals if large amounts are consumed’ (CRC for Australian Weed Management 2003). Toxic properties at certain times of the year.
MH
M
Pest Animal
17. Food source to pests?Not known to be a food source to pests.
L
MH
18. Provides harbor?Not known to provide harbour to pests.
L
MH
Agriculture
19. Impact yield?Serious pest of late-maturing crops such as sorghum, soybeans and sugarbeets .. an effective competitor for light, nutrients and soil moisture, and can reduce crop yield’ (Noxious Weed Control Board 1999). ‘A weed that infests cereal crops in the Great Plains of the USA, often severely reducing yields’ (Fischer et al 2000). Assume greater than 20% reduction
H
H
20. Impact quality?Not documented to impact upon quality of yield.
L
MH
21. Affect land value?Not documented to affect land value.
L
MH
22. Change land use?Unlikely that the weed would cause a change in priority of land use.
L
MH
23. Increase harvest costs?Possible that there will be a minor increase in time and labour required in harvesting.
M
MH
24. Disease host/vector?‘Resistance to diseases’ (Undersander et al 1990). Not a known host or vector for diseases.
L
H

Impact Assessment Record - Kochia (PDF - 27KB)
Impact Assessment Record - Kochia (PDF - 68KB)
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.
Page top