Assessment Notes

Justification

Bergerella atrofusca is a pathogen of common, widespread lichen species. Though it has not been frequently described, it is likely to be widespread within its host range and occurs in temperate forests with no recorded decline. This species is categorised as Least Concern (LC).

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Geographic range

This species was recently described from two Alpine locations in Osttirol, Austria (Lawrey et al. 2020), and there is another report of it in Mt. Egginer, Switzerland (Kray and Weber 2020). However, considering this is an overlooked and recently described species with common and widespread host species, it is very likely that it occurs across a much wider range within the Alps (Lawrey et al. 2020).

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Population and Trends

There is currently no specific information on the population size and trend of this species. However, its host species is common and widespread (Lawrey et al. 2020), and it is suspected that Bergerella atrofusca is also common and widespread within its host range. Although this species should be easy to detect through its dense agglomerations of dark brown bulbils (Lawrey et al. 2020), it has likely been overlooked since it was just recently described, and its host species are not a high priority for collection.

Population Trend: Unknown

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Habitat and Ecology

This species is a virulent pathogen of Physcia species, which produces tightly coiled hyphal masses, called bulbils, on the surface of the host lichen or within its tissues (Lawrey et al. 2020). It is known to grow on Physcia aipolia, P. stellaris (Lawrey et al. 2020) and Lecanora (Kray and Weber 2020) hosts, on shaded, cool, and humid areas on Larix or Salix trees (Lawrey et al. 2020).

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Threats

No significant threats to the species are known.

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Conservation Actions

Surveys to document the species' distribution, ecology and population trends are needed.

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Use and Trade

There is no use of this species.

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Source and Citation

Canteiro, C. & Whitacre, G. 2026. Bergerella atrofusca. The IUCN Red List of Threatened Species 2026: e.T290320613A290321342. Accessed on 10 July 2026.

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• Country occurrence