Scouler's catchfly (Silene scouleri ssp. grandis): COSEWIC assessment and status report: chapter 12

Range of Occurrence in Canada:

British Columbia

extent of occurrence (EO) (km²)

<1 km² remaining

specify trend :

Declining

are there extreme fluctuations in EO (> 1 order of magnitude)?

No

area of occupancy (AO) (km²) :

~ 0.0158 km² (1.58 hectare)

specify trend (decline, stable, increasing, unknown) :

Declining

are there extreme fluctuations in AO (> 1 order magnitude)?

No

number of extant locations :

2

specify trend in # locations (decline, stable, increasing, unknown) :

Decline

are there extreme fluctuations in # locations (>1 order of magnitude)?

No

habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat :

Declining quality and extent

generation time (average age of parents in the population) (indicate years, months, days, etc.) :

uncertain (2 years to flowering ?)

number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values) :

250-350

total population trend:  specify declining, stable, increasing or unknown trend in number of mature individuals :

Decline (loss of one population since 2000 with possibly 1-3 plants lost)

if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period) :

Very small ?

are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?

Unlikely

is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., < 1 successful migrant / year)?

Yes

list each population and the number of mature individuals in each :

• Trial Island sub-popopulation: 5
• Little Trial Island sub-population: 23
• Alpha Islet population  250-300

specify trend in number of populations (decline, stable, increasing, unknown) :

Decline

are there extreme fluctuations in number of populations (>1 order of magnitude)?

No

does species exist elsewhere (in Canada or outside)?

USA

status of the outside population(s)?

Stable

is immigration known or possible?

Unknow

would immigrants be adapted to survive here?

Yes

is there sufficient habitat for immigrants here?

Yes