Dwarf woolly-heads, specific populations, COSEWIC assessment status report: chapter 12
Technical Summary - Prairie population
Psilocarphus brevissimus: Prairie population
Dwarf woolly-heads (Prairie population) – psilocarphe nain (Population des Prairies)
Occurrence:
Alberta, Saskatchewan
Extent and Area information
Extent of occurrence (EO)
[estimated using OziExplorer mapware area calculation] : 23,760 km²
Specify trend :
unknown
Are there extreme fluctuations in EO :
probably, unless seed banks are considered
Area of occupancy (AO)
[estimated from summing up area occupied by individual occurrences and estimating missing values] <40 ha
Specify trend in AO :
unknown
Are there extreme fluctuations in AO :
yes
Number of known or inferred current locations :
41
Specify trend in # :
unknown
Are there extreme fluctuations in number of locations?
yes
Specify trend in area, extent or quality of habitat :
unknown
Population information
Generation time (average age of parents in the population) :
4 months
Number of mature individuals :
2,000 – 27,000 depending on the year
Total population trend :
unknown
% decline over the last/next 10 years or 3 generations :
n/a
Are there extreme fluctuations in number of mature individuals?
yes
Is the total population severely fragmented?
perhaps not severely
Specify trend in number of populations :
unknown
Are there extreme fluctuations in number of populations?
Probably
List populations with number of mature individuals in each:
- Prairie 1: 0? – several hundred
- Prairie 2: 0? – 50
- Prairie 3: 0? – 100
- Prairie 4: 0? – 1,000
- Prairie 5: 0? - >2,700
- Prairie 6: 0? – 1,000
- Prairie 7: 0? – 1,000
- Prairie 8: 0? – 1,000
- Prairie 9: 0? – 1,000
- Prairie 10: 0? – 1,000
- Prairie 11: 0? – 1,000
- Prairie 12: 0? – 1,000
- Prairie 13: 0? – 1,000
- Prairie 14: unknown
- Prairie 15: 0? – 1,000
- Prairie 16: 0? – 1,000
- Prairie 17: 0? – 1,000
- Prairie 18: 0? – 1,000
- Prairie 19: 0? – 1,000
- Prairie 20: 0? – 1,000
- Prairie 21: 0? – 1,000
- Prairie 22: 0? – 1,000
- Prairie 23: 0? – 1,000
- Prairie 24: 0? – 1,000
- Prairie 25: 0? – 1,000
- Prairie 26: unknown
- Prairie 27: 1,000
- Prairie 28: locally abundant
- Prairie 29: scarce
- Prairie 30: small amount
- Prairie 31: 0? - 200
- Prairie 32: 0? - 1,000
- Prairie 33: 0? - 50
- Prairie 34: 0? – 1,000
- Prairie 35: 0? - 200
- Prairie 36: 0? - 200
- Prairie 37: 0? - 500
- Prairie 38: 0? - 10
- Prairie 39: 0? - 50
- Prairie 40: 0? - 75
- Prairie 41: 0? - 10
Threats (actual or imminent threats to populations or habitats)
- Actual threats - agricultural expansion, oil and gas exploration
- Potential threats - changes in hydrology, changes in grazing practices, weed control measures
Rescue Effect (immigration from an outside source)
Status of outside population(s)?
The species is not ranked in Washingtonbut S2 in Idaho and Montana.
Is immigration known or possible?
Immigration is possible but probably occurs so rarely that it has no significance to rescue over periods of less than at least a few decades
Would immigrants be adapted to survive in Canada?
unknown
Is their sufficient habitat for immigrants in Canada?
yes
Is rescue from outside populations likely?
no
Quantitative Analysis
Not available
Current Status
COSEWIC: Special Concern (2006)
Status and Reasons for Designation
Status: Special Concern
Alpha-numeric code: not applicable
Reasons for Designation: This population is widely distributed in Saskatchewan and Alberta at more than 40 sites with large among-year fluctuations in numbers of mature individuals and with concerns over potentially significant future impacts. These pertain to potential future development of coal-bed methane gas extraction in a significant part of the range of the population and disruptions from pipeline construction.
Applicability of Criteria
- Criterion A: (Declining Total Population): Not available. No data for significant decline.
- Criterion B: (Small Distribution, and Decline or Fluctuation): Although having a small total area of occupancy, this criterion is not applicable because the population comprises many sites that likely are not extremely fragmented and have not shown significant declines in numbers of plants.
- Criterion C: (Small Total Population Size and Decline): Not applicable. Total numbers of plants may be sufficiently low to consider the species at risk during years of drought, but continued or inferred declines cannot be adequately rationalized to assess status under this criterion.
- Criterion D: (Very Small Population or Restricted Distribution): Not applicable. Although having an area of occupancy < 20 km², threatened D2 likely does not apply since it is uncertain as to the actual extent of impact of the various threats such as oil and gas exploitation and development and agricultural expansion on the naturally fragmented habitats and populations.
- Criterion E: (Quantitative Analysis): Not available.
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