Frosted glass-whiskers (Sclerophora peronella) COSEWIC assessment and status report: chapter 2

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Executive Summary

Species information

Frosted glass-whiskers (Sclerophora peronella) belongs to a group of lichenized fungi known, colloquially, as calicioid or “stubble” lichens because of their tiny stalked spore-bearing structures. The species has been found on the bark and wood of old trees and can be recognized by the pale colour of its spore-bearing apothecia that are raised on stalks 0.5 to 0.8 mm above the substrate. The main body (thallus) of the lichen is imbedded in the substrate.

Distribution

Sclerophora peronella is known from only three locations in Canada and is rare to extremely rare throughout its range. The current known global distribution includes Europe (Scotland, Germany, Moravia, Denmark, Sweden, Finland, Norway, France, Austria, Italy, and Estonia), where it had previously been considered endemic, the Caucases in Russia, western Oregon in the United States, and from British Columbia and Nova Scotia in Canada.

Habitat

Sclerophora peronella occurs on hardwoods, usually on exposed heartwood of living trunks, and more rarely on bark. It is often associated with mature and old-growth coniferous and deciduous forests, but also occurs in savannas and parklands. In Canada, the specimen from British Columbia was collected on bark at the base of a large black cottonwood in a rich, shady cottonwood stand. Both of the collections from Nova Scotia were on exposed heartwood of living red maple trees growing in old-growth northern hardwood stands.

Biology

Found exclusively on the wood and bark of older trees, S. peronella seems to prefer stable humidity and small temperature fluctuations in microhabitats of intermediate light. Despite their small size, S. peronella thalli in Canada appear to be healthy, with apothecia containing mature spores. These spores are distributed by wind, rain, and probably by invertebrates.

Population sizes and trends

The entire known physical area of coverage for S. peronella in the three known Canadian locations is probably no more than one square metre. It is not possible to determine whether these populations are increasing, remaining stable, or are declining in size.

Limiting factors and threats

The available data suggests that S. peronella prefers the environmental stability associated with old-growth forests. Unfortunately, such habitat has been in decline across Canada and throughout most of the world. Habitat destruction from logging of old forests is a threat in parts of the species range. The threat to the habitat continues to be a problem by atmospheric pollutants in much of the worldwide range. Pollutants threaten both the tree and the lichen growing on the tree.

Special significance of the species

Sclerophora peronella is currently known from only three collections in Canada and from just a few locations in the United States, Russia and several European countries. The ecological significance is that the species is recognized as an old-growth forest indicator species. Calicioid lichens and fungi are considered our most sensitive biomonitors of forest ecosystem health.

Existing protection or other status designations

Besides being redlisted in several European countries, S. peronella is not explicitly protected by any federal laws or any state/provincial/territorial wildlife acts or endangered species acts, nor is it protected by any international agreements or conventions. It is protected in Nova Scotia, however, by the Wilderness Areas Act that governs collecting and habitat destruction in Crown Lands Wilderness Areas, within which it is known to occur. No such protection is provided in the recreation area where S. peronella is found in British Columbia.

COSEWIC History

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC Secretariat as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership

COSEWIC Secretariat comprises members from each provincial and territorial government wildlife agency, four federal agencies (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government members and the co-chairs of the species specialist and the Aboriginal Traditional Knowledge subcommittees. The Committee meets to consider status reports on candidate species.

Definitions (November 2004)

Wildlife Species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and it is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)

A wildlife species that no longer exists.

Extirpated (XT)

A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A wildlife species facing imminent extirpation or extinction.

Threatened (T)

A wildlife species likely to become endangered if limiting factors are not reversed.

Special Concern (SC) ^Footnotea

A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at Risk (NAR) ^Footnoteb

A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data Deficient (DD) ^Footnotec

A wildlife species for which there is inadequate information to make a direct, or indirect, assessment of its risk of extinction.

Canadian Wildlife Service

The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.