Ability to Respond Total:10 / 25Ability to Respond = ( Ease of Response + Tools in Place )
Confidence:High
Confidence Notes:
Impact
Spread
Notes
Score
Spread Rate
Can spread very rapidly once it gets a foothold. Populations can double in far less than 10 years.
5
Spread Amount
Most widespread in the grassland and scrubland of the Great Basin region, but can be found in southern California. Mainly a rangeland problem, but also found in forests, woodlands, and open fields.
4
Damage
Notes
Score
Ecological
The dense litter cover enhances medusahead germination, may exclude native species, ties up soil nutrients, and contributes to fire danger in the summer.
5
Agricultural
Dense stands displace desirable vegetation and wildlife and lower livestock carrying capacity on rangeland.
4
Infrastructure
2
Cultural
Impacts recreational areas and other historical sites. Reduced the aesthetics of many wildland areas.
4
Health
The stiff awns and hard florets can injure eyes, nostrils, and mouths of grazing animals. Seed-eating birds usually avoid feeding on the seeds.
2
Benefit
Notes
Score
Ecological
0
Agricultural
Animals can graze medusahead in before seehead production, but weight gains are minimal due to low nutritive value.
1
Infrastructure
0
Cultural
0
Health
0
Total
25
Ability to Respond
Ease of Response
Notes
Score
Detection
Previous years stands are generally easy to detect. Seedlings are difficult to identify but because plant contains so much silica it takes more than one year to decay and seedheads from previous year are visible.
4
Control
Difficult to control economically. Can be controlled with herbicides and with prescribed fire. Difficult to do in most areas, due to remoteness.
3
Tools in Place
Notes
Score
Entry
None in place
0
Control
Some local control.
1
Outreach
Minimal outreach due to extension publications and listing on CDFA and Cal-IPC lists.
