Ghost Antler Lichen
Scientific Name: Pseudevernia cladonia
Other/Previous Names: Ghost Antler
Taxonomy Group: Lichens
Range: Quebec, New Brunswick, Nova Scotia
Last COSEWIC Assessment: November 2011
Last COSEWIC Designation: Not at Risk
SARA Status: No schedule, No Status
Image of Ghost Antler Lichen
The Ghost Antler is a large, finely branched lichen that grows on trees, mainly on the twigs and branches of young conifers. As its name suggests, it resembles the branches of a deer’s antlers and is therefore conspicuous. The thallus (the main part of the lichen) is evenly and repeatedly branched from the base. Chalky white and matte-textured, this luxuriant lichen can attain a diameter of 12 cm and a thickness of 4 cm. In the largest specimens (which are also the oldest), the branches may be up to 2.5 mm wide at the base. Their channelled lower surfaces become grey (or locally brown) to black-mottled to entirely black, although these dark-pigmented areas sometimes develop a thin, waxy, ash-white, fine-textured “bloom.” Generally, the thallus resembles a small bush. It only very rarely forms apothecia, the small fruiting bodies that produce spores used in reproduction.
Distribution and Population
The Ghost Antler occurs primarily in high-elevation spruce-fir forests in the Appalachian Mountains of eastern North America, from the Great Smoky Mountains, in Tennessee and North Carolina, north to Mount Katahdin, in Maine. In the northernmost regions, it is also present at low elevations, along or near the coast of the Bay of Fundy and the Atlantic Ocean as far as Nova Scotia. A widely disjunct population also occurs in the high mountains of the Dominican Republic. In Canada, the Ghost Antler is known from a small area of the Appalachian Mountains in southeastern Quebec and from scattered localities along the coasts of New Brunswick and Nova Scotia. At least 20 locations are currently known in Canada: three in Quebec, ten in New Brunswick and seven in Nova Scotia. At most of the locations in the Maritime provinces, fewer than 50 thalli have been found. A notable exception is one site in New Brunswick where more than 2000 thalli are present. Three of five Maritime populations first found before 1990 could not be relocated in 2003-2004. Two of these populations have apparently been lost to housing development, and the other was apparently eliminated following a spruce budworm outbreak. In 2004, the discovery of more than 3 000 000 thalli at two locations in Quebec resulted in a dramatic increase in the known population in that province, where the population previously consisted of an unknown number of individuals at one small site, last documented in 1959. It is likely that other high-elevation occurrences will be found in a small mountainous area of southeastern Quebec near the United States border that has not yet been intensively searched. The number of individuals in Quebec is estimated to be more than 10 000 000 and the number of individuals in the Maritime provinces more than 2600. The total Canadian population of the Ghost Antler is probably stable.
In Canada, the Ghost Antler occurs in cool, humid montane or coastal coniferous forests dominated by red spruce and/or balsam fir. Where it occurs near the coast, the Ghost Antler is a species of humid forest interiors. It does not occur on headlands exposed to the wind. A key feature shared by these coastal and high-elevation stands is their frequent and often prolonged immersion in fog or clouds. This lichen has been found growing on balsam fir, red spruce and, in some poorly drained sites, black spruce. It occurs mainly on twigs and branches (less frequently on the trunks) of these tree species or on woody debris on the forest floor. The presence of the Ghost Antler, as well as its relative abundance (at least in Quebec), is clearly a function of stand age and humid conditions. Its restriction to foggy coastal and montane forests suggests a requirement for cool, humid climates. With increasing distance from cool coastal areas, it becomes progressively more restricted, at non-montane elevations, to humid old-growth stands. Overall, the habitat of the Ghost Antler in Canada appears to be stable. Succession and maturation of montane fir forests in areas in southeastern Quebec that were previously logged but are now protected may result in a gradual increase in the population within these areas. However, such gains could be offset by losses resulting from logging of montane forests and from additional telecommunications towers or the further development of alpine skiing at mountaintop sites. In the Maritime provinces, the extent of potential habitats is probably stable.
Like all lichens, the Ghost Antler is not composed of a single organism, but rather two organisms coexisting in a symbiotic relationship (that benefits both). The filaments of a fungus comprise the largest part of the lichen, but green algae cells live among these filaments. Once established in a forest stand, the Ghost Antler appears to be incapable of dispersing quickly or over long distances. This trait can be explained by the fact that this lichen lacks vegetative propagules and only very rarely forms apothecia, small fruiting bodies that produce spores for sexual reproduction. Pycnidia, structures bearing the asexual spores of the fungus, are also rare. This species therefore reproduces mainly by fragmentation. However, its thallus is not particularly brittle, so it appears to have a limited capacity for long-distance dispersal or even for dispersal within a stand. Wind and animals, particularly birds, are the main potential vectors for the dispersal of the Ghost Antler. Since the conifer branches where it grows are acidic, this lichen is probably less affected by acidifying pollutants, particularly sulphur dioxide, than other lichens.
Logging of mature moist spruce-fir forests will likely eliminate the sites most likely to harbour populations. The occurrence making up more than 75% of the known population in the Maritime provinces is in an old-growth stand currently threatened by logging and housing development. In addition, because of its limited capacity for long-distance dispersal, the Ghost Antler is poorly adapted to recover from these types of major disturbances. The natural disturbance dynamics of spruce-fir forests, including periodic outbreaks of spruce budworm, cause populations of the Ghost Antler to fluctuate on a local scale. Novel forest pathogens, such as the introduced brown spruce longhorn beetle, could pose a greater threat. A potential long-term threat to the large population in mountainous southeastern Quebec is ongoing change in the mean height of the cloud base. Research indicates that this elevation has been increasing by approximately 4 m per year over the past 30 years, possibly due to climate warming. If continued, these changes could result in a gradual reduction in the area of moist (cloud-influenced) montane fir forest suitable for the Ghost Antler. In Quebec, the population in Mont-Orford provincial park is threatened by an alpine skiing development. The size of this population may also have been reduced by the erection of several large telecommunications towers.
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
8 record(s) found.
- COSEWIC Status Reports (2 record(s) found.)
- Response Statements (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (2 record(s) found.)
- Consultation Documents (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2006 (2006)2006 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
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