Columbian carpet moss (Bryoerythrophyllum columbianum) COSEWIC assessment and status report: chapter 14
Range of Occurrence in Canada: BC
Extent and Area Information
Specify trend in EO
stable to declining
Are there extreme fluctuations in EO ?
Area of occupancy (AO) ( km2 )
> 20 km2 , based on area of Bunchgrass and Purshia communities in which species was found.
Specify trend in AO
Are there extreme fluctuations in AO ?
Number of known or inferred current locations
11 recently confirmed of 18 known/reported
Specify trend in #
1 possibly lost
Are there extreme fluctuations in number of locations?
Specify trend in area, extent or quality of habitat
stable to declining depending on habitat type ( e.g. , Purshia ecosystem is declining) (refer to Table 1 )
Number of mature individuals
Total population trend:
?declining – possible loss of 1 population
% decline over the last/next 10 years or 3 generations.
Are there extreme fluctuations in number of mature individuals?
Is the total population severely fragmented?
Specify trend in number of populations
?declining, based on loss of 1 population
Are there extreme fluctuations in number of populations?
List populations with number of mature individuals in each:
unknown # of mature individuals (refer to Table 1 )
Threats (actual or imminent threats to populations or habitats)
Grazing impacts, vineyard and urban development, road construction, human impacts such as hiking, camping, and general erosion (refer to Table 1)
Rescue Effect (immigration from an outside source)
Is immigration known or possible?
not likely. Spores seldom produced in this species
Would immigrants be adapted to survive in Canada?
Is there sufficient habitat for immigrants in Canada?
Is rescue from outside populations likely?
NatureServe: imperiled to secure (G2G4)
Status and Reasons for Designation
Reasons for Designation: This is a western North American endemic species. It is a small perennial species and in Canada has a restricted distribution in the shrub-steppe in semi-arid regions of British Columbia where recent surveys have confirmed its presence from 11 sites. The species is never abundant in sites where it is found and extensive surveys have provided few new locations. At least one population is believed to have been lost to cultivation (vineyard) or to stochastic events. Threats include agriculture (especially vineyards), impact by grazing animals, urban development, road improvements, and human recreational impacts. Based on known occurrences, the species appears to have a very restricted distribution. However the species is patchily distributed at low densities in large habitats not all of which have been censused.
Applicability of Criteria
Criterion A (Declining Total Population):
does not meet thresholds for decline
Criterion B (Small Distribution, and Decline or Fluctuation):
Does not meet any criterion for ‘a’ (known from 11 sites) or ‘c’ (no fluctuation)
Criterion C (Small Total Population Size and Decline):
no data – number of mature individuals not known.
Criterion D (Very Small Population or Restricted Distribution):
Does not meet criterion: Number of sites > 5 (11 confirmed), and area of occupancy likely > 20 km2
Criterion E (Quantitative Analysis):
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