Frosted glass-whiskers (Sclerophora peronella) COSEWIC assessment and status report: chapter 13
Technical Summary (Nova Scotia)
Sclerophora peronella
Frosted glass-whiskers (Nova Scotia population) – sclérophore givré (population de la Nouvelle-Écosse)
Range of Occurrence in Canada:
Nova Scotia
Extent and Area information
extent of occurrence (EO)(km²)
Estimated to be <100 km²
specify trend (decline, stable, increasing, unknown)
Historical decline of mature and old-growth forests in Canada has occurred
are there extreme fluctuations in EO (>1 order of magnitude)?
Unlikely
area of occupancy (AO) (km²)
about 3 km² of habitat available where species was found but actual area occupied was <1 m²
specify trend (decline, stable, increasing, unknown)
Unknown
are there extreme fluctuations in AO (>1 order magnitude)?
Unknown
number of extant locations
2
specify trend in # locations (decline, stable, increasing, unknown)
Stable
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
Extent of potential habitat declining
Population information
generation time (average age of parents in the population) (indicate years, months, days, etc.)
Unknown
number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values)
Approx. 75% of apothecia at each of the 2 sites were mature
total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals
Unknown
if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period)
are there extreme fluctuations in number of mature individuals (>1 order of magnitude)?
Unknown
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)?
Total worldwide population is severely fragmented
list each population and the number of mature individuals in each
Nova Scotia, Cape Breton Island, Inverness County
- Sugarloaf Mountain Wilderness Area
- Margaree River Wilderness Area
specify trend in number of populations (decline, stable, increasing, unknown)
Unknown
are there extreme fluctuations in number of populations (>1 order of magnitude)?
Unlikely
Threats (actual or imminent threats to populations or habitats
- Given the available data, Sclerophora peronella seems to prefer the ecological stability associated with mature and old-growth forests. These ecosystems are under threat worldwide from habitat loss and degradation. No specific threats in this regard were noted for the collection localities.
- Like certain other groups of lichens, this species is sensitive to acid rain and other atmospheric pollutants that affect lichens generally.
Rescue Effect (immigration from an outside source)
Unlikely
does species exist elsewhere (in Canada or outside)?
Several small populations exist in Oregon and others in Europe
status of the outside population(s)?
Unknown
is immigration known or possible?
Immigration is possible but unlikely
would immigrants be adapted to survive here?
Possibly
is there sufficient habitat for immigrants here?
Yes, but it is declining
Quantitative Analysis
Not applicable
Status and Reasons for Designation
Status: Special Concern
Alpha-numeric code: Not applicable
Reasons for Designation: This tiny cryptic stubble lichen is very rare or threatened over much of its global range. Two of the three known locations of this species in Canada are in Nova Scotia. Despite considerable efforts to locate this and other rare calicioid lichens in the province, this lichen is known only from the exposed heartwood of red maple trees in mature/old-growth hardwood forest. Threats include potential habitat loss and degradation associated with the decline of old-growth forest ecosystems. However, in Nova Scotia of the two populations appear healthy and are situated within large protected areas on Cape Breton Island.
Applicability of Criteria
- Criterion A (Declining Total Population): Population decline not documented.
- Criterion B (Small Distribution, and Decline or Fluctuation): May meet criterion for Endangered B1+2 (AO <500 km²), a (2 of the 3 locations, Canadian population is severely fragmented), b(iii) (inferred decline habitat based loss of old growth forest).
- Criterion C (Small Total Population Size and Decline): Not applicable since we do not know the number of individuals.
- Criterion D (Very Small Population or Restricted Distribution): May meet criterion for Threatened D2, based on small AO and small number of locations (2). However both Nova Scotia populations are within large protected areas where potential threats are mitigated.
- Criterion E (Quantitative Analysis): Not applicable.
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