Ability to Respond Total:17 / 25Ability to Respond = ( Ease of Response + Tools in Place )
Confidence:High
Confidence Notes:
Impact
Spread
Notes
Score
Spread Rate
After having discovered in Newport Bay about 35 years previously, where it's spread has been slow, it has recently spread to more favorable habitat and is spreading rapidly in arid and semi-arid areas of Southern California
5
Spread Amount
Occurs throughout the Mediterranean and North Africa, also invasive in Chile, it should be able to occupy large parts of southern, coastal and central California if it reaches its full extent.
4
Damage
Notes
Score
Ecological
Dense stands crowd out native plants, it is not palatable, and few, if any, animals seem to graze on the forage. Dense stands could add fuels and lead to increased fires in desert areas.
4
Agricultural
A weed in agricultural systems, it can grow in disturbed areas and agricultural areas in its native range. Unknown how severe effects will be in agriculture in California. Other knapweeds are persistent pests of rangelands and reduce quality
2
Infrastructure
0
Cultural
0
Health
Plant has strongly bitter taste, closely related species are toxic. Likely also toxic, unknown as to how toxic species is.
1
Benefit
Notes
Score
Ecological
0
Agricultural
0
Infrastructure
0
Cultural
0
Health
0
Total
16
Ability to Respond
Ease of Response
Notes
Score
Detection
Moderate to difficult to detect. Plants grow as a rosette during fall and winter and can be easily overlooked, when flowering easier to detect tall stems. In dry years, poor locations, or late germinating individuals can flower when only a few inches tall
2
Control
Moderately difficult to control. While individual plants can be controlled with herbicides or pulled before flowering, the seed bank appears to persist for at least 5 years based on current observations in California and Chile.
3
Tools in Place
Notes
Score
Entry
A-rated pest, seeds would be difficult to detect in shipments or as contaniment on vehicles (i.e. mud on vehicle)
4
Control
A-rated pest
5
Outreach
Outreach occurs in several areas in San Diego, Riverside and Orange Counties, where Volutaria currently occurs. Less frequent outside known areas.
