Branched phacelia (Phacelia ramosissima) COSEWIC assessment and status report: chapter 11
Technical Summary
Phacelia ramosissima
Branched phacelia – phacélie rameuse
Range of Occurrence in Canada:
British Columbia
Extent and Area Information
Extent of occurrence (EO) (km²)
[area encompassed by all sites on Mt Kruger] 8-15 km²
Specify trend in EO:
Unknown
Are there extreme fluctuations in EO?
No
Area of occupancy (AO) (km²)
[narrow band of habitat occupied by the populations] <<1km² (0.0008 – 0.001 km²)
Specify trend in AO:
Unknown
Are there extreme fluctuations in AO?
No
Number of known or inferred current locations:
3
Specify trend in #:
Decline
Are there extreme fluctuations in number of locations?
No
Specify trend in area, extent or quality of habitat:
Decline
Population Information
Generation time (average age of parents in the population):
Unknown
Number of mature individuals:
500-700
Total population trend:
Unknown
% decline over the last/next 10 years or 3 generations.
Not Applicable (N/A)
Are there extreme fluctuations in number of mature individuals?
Unknown
Is the total population severely fragmented?
No
Specify trend in number of populations:
Unknown but two subpopulations have been extirpated
Are there extreme fluctuations in number of populations?
Unknown but unlikely
List populations with number of mature individuals in each:
Mt. Kruger:
- West slope – 6
- North slope – unknown
- East slope – 500 to 700
Threats (actual or imminent threats to populations or habitats)
- actual and imminent: mineral exploration and mining activity, urban development
Rescue Effect (immigration from an outside source)
Status of outside population(s)?
USA : Unknown or Not at Risk
Is immigration known or possible?
Unknown but not likely due to the considerable distance to nearest US population in Washington (175 km)
Would immigrants be adapted to survive in Canada?
Yes
Is there sufficient habitat for immigrants in Canada?
Yes
Is rescue from outside populations likely?
Unlikely
Quantitative Analysis
Not applicable
Current Status
COSEWIC: Endangered (May 2005)
Status and Reasons for Designation
Status: Endangered
Alpha-numeric code: B1ab (ii,iii,iv,v) + 2ab (ii,iii,iv,v)
Reasons for Designation: A geographically highly restricted perennial known only from three small populations numbering fewer than 1000 plants subject to continued habitat loss and population decline from urban expansion and mining activities.
Applicability of Criteria
- Criterion A (Declining Total Population): Not applicable.
- Criterion B (Small Distribution, and Decline or Fluctuation): Meets Endangered B1ab (ii,iii,iv,v) + 2ab (ii,iii,iv,v) based on the small extent of occurrence and area of occupancy that are below threshold values, presence of only three populations and recent losses of two subpopulations resulting in declines in area of occupancy and number of mature individuals. Extent and quality of habitat has also declined as a result of urban expansion and mining activities.
- Criterion C (Small Total Population Size and Decline): Uncertain of applicability but may meet Endangered C2a(ii) based on a total population <<2500 plants and possibly 95% of all mature plants in one population on the east slope of Mt. Kruger. Unfortunately no counts are available for the north slope population.
- Criterion D (Very Small Population or Restricted Distribution): The species qualifies as threatened D2 based on the occurrence of only three populations at continued risk from habitat loss as result of urban expansion and mining activities.
- Criterion E (Quantitative Analysis): Not applicable.
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