Lindley’s false silverpuffs (Uropappus lindleyi) COSEWIC assessment and status report: chapter 11

Technical summary

Uropappus lindleyi

Lindley’s false silverpuffs – uropappe deLindley

Range of Occurrence in Canada:

British Columbia

Demographic information

Generation time (average age of parents in the population) :

3-4 months

Population trend and dynamics

Observed percentage of reduction in total number of mature individuals over the last 10 years.

Unknown

Projected percentage of reduction in total number of mature individuals over the next 10 years.

Unknown

Observed percentage reduction in total number of mature individuals over any 10 years period, over a time period including both the past and the future.

Unknown

Are the causes of the decline clearly reversible?

Partially

Are the causes of the decline clearly understood? Habitat loss and degradation have been documented.

No

Observed trend in number of populations.

Decline

Are there extreme fluctuations in number of mature individuals?

No

Are there extreme fluctuations in number of populations?

No

Number of mature individuals in each population

  • Ruxton Island: 800
  • North Pender Island: 20?
  • Galiano Island: 1190
  • Saturna Island (1): 22+
  • Saturna Island (2): 28
  • Grand Total : 2000

Extent and area information

Estimated extent of occurrence (km²) based on a convex polygon :

150 km²

Observed trend in extent of occurrence historic loss :

Decline

Are there extreme fluctuations in extent of occurrence?

No

Estimated area of occupancy (km²)

Actual area of habitat occupied is 0.01 km² but the area of occupancy for the 5 sites, based on a 1x1 km grid is 5 km² or 20 km² using a 2x2 km grid overlay: 20 km²

Observed trend in area of occupancy :

Decline

Are there extreme fluctuations in area of occupancy?

No

Is the total population severely fragmented?

Yes

Number of current locations:

5

Trend in number of locations:

Decline

Are there extreme fluctuations in number of locations?

No

Observed trend in quality of habitat:

Decline

Quantitative analysis

[<0.00% probability of extirpation in years]

Threats (actual or imminent, to populations or habitats)

  1. habitat destruction through housing development on private property
  2. habitat fragmentation
  3. invasion of alien plant species

Rescue effect (immigration from an outside source)

Status of outside population(s)?

USA: secure

Is immigration known or possible?

Unknown

Would immigrants be adapted to survive in Canada?

Likely

Is there sufficient habitat for immigrants in Canada?

Yes

Is rescue from outside populations likely?

No

Current status

COSEWIC: endangered 2008

Status and reasons for designation

Status: endangered

Alpha-numeric code: B1ab(iii)+2ab(iii)

Reasons for designation: An annual flowering plant of British Columbia restricted to only five extant locations in the Gulf Islands. The species is no longer known to occur on Vancouver Island. There are extremely small numbers of individuals known in Canada. The species is also at continued risk from habitat loss and degradation from such factors as home building and spread of invasive plants.

Applicability of criteria

  • Criterion A: (Decline in total number of mature individuals): Not applicable; no decline data available
  • Criterion B: (Small distribution range and decline or fluctuation): Endangered B1ab(iii)+2ab(iii) with EO and AO below maximum limits for endangered and only 5 severely fragmented localities with loss in AO and mature individuals due to recent extirpation of 1 population and continued impact on habitat inferred due to spread of invasive plants and development.
  • Criterion C: (Small and declining number of mature individuals): Population size is below maximum limit for endangered and continuing decline can be inferrred due to spread of invasives and pressures for land development but population structure under this criterion is not met
  • Criterion D: (Very small population or restricted distribution): Threatened D2; only 5 populations with a maximum AO of 20 km²
  • Criterion E: (Quantitative analysis): None available

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