Contorted-pod evening-primrose (Camissonia contorta) COSEWIC assessment and status report: chapter 11

Technical Summary

Camissonia contorta

Contorted-pod Evening-primrose – onagre à fruits tordus

Range of Occurrence in Canada:

British Columbia

Extent and Area Information

Extent of occurrence (EO)(km²)

Status report: Canadian Range Area enclosing all populations excluding ocean : 750 km²

Specify trend in EO :

stable

Are there extreme fluctuations in EO?

no

Area of occupancy (AO) (km²)

Status report: Table 2 Summary of areas occupied by extant populations <10.0784 km²

Specify trend in AO :

declining

Are there extreme fluctuations in AO?

no

Number of known or inferred current locations :

seven

Specify trend in # :

decreasing

Are there extreme fluctuations in number of locations?

no

Specify trend in area, extent or quality of habitat :

decreasing

Population Information

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

5 months

Number of mature individuals :

3,500-4,500

Total population trend:

declining

 % decline over the last/next 10 years or 3 generations.

Unknown estimated at 35%

Are there extreme fluctuations in number of mature individuals?

unknown

Is the total population severely fragmented?

yes

Specify trend in number of populations:

decline

Are there extreme fluctuations in number of populations?

no

List populations with number of mature individuals in each

  • population 1: 253 mature individuals
  • population 2: 500-1,000 mature individuals
  • population 3: 200-250 mature individuals
  • population 4: 700-750 mature individuals
  • population 5: 2,000 mature individuals
  • population 6: 100 mature individuals
  • population 7: 20 mature individuals

Threats (actual or imminent threats to populations or habitats)

Actual threats: significant recent habitat conversion; recreational activities such as trampling and ATV use; invasive plants; introduced herbivores (Eastern Cottontail).

Potential threats that are likely: altered dune dynamics; demographic collapse due to small size of some populations.

Rescue Effect (immigration from an outside source)

Status of outside population(s)?

USA: NatureServe - secure

Is immigration known or possible?

no

Would immigrants be adapted to survive in Canada?

probably

Is there sufficient habitat for immigrants in Canada?

yes

Is rescue from outside populations likely?

no

Current Status

COSEWIC: Endangered (2006)

British Columbia: Red-listed; S1

Recommended Status and Reasons for Designation

Recommended Status: Endangered

Alpha-numeric code:B1ab(ii, iii, iv,v) + 2ab(ii, iii, iv,v)

Reasons for Designation: An annual herb restricted to several dry, open  and sandy coastal habitats of very small size. The small fragmented populations are impacted by on-going habitat loss, high recreational use and competition with several invasive exotic plants.

Applicability of Criteria

  • Criterion A (Declining Total Population): Meets Threatened A2ce+3c edue to the suspected past and inferred future decline in populations of at least 30% based on habitat loss and decline in habitat quality due to recreational use of the plant’s habitat and expansion of invasive plants over a period of 10 years.
  • Criterion B (Small Distribution, and Decline or Fluctuation): Meets Endangered B1ab(ii, iii, iv,v) + 2ab(ii, iii, iv,v) due to the very small extent of occurrence and area of occupancy, the highly fragmented populations and decline due to a recent population loss,  reduction of area of occupancy, as well as decline in quality of habitat and number of individuals.
  • Criterion C (Small Total Population Size and Decline): Not applicable. Population size is <10,000 but no additional criteria are met to apply criterion C.
  • Criterion D (Very Small Population or Restricted Distribution): Meets Threatened D2 due to an area of occupancy <20km² and on-going threats are present from recreational use of the plant’s habitat and spread of exotic invasive plants.
  • Criterion E (Quantitative Analysis): None available.

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