Concentric Boulder Lichen
VU

Concentric Boulder Lichen

Porpidia crustulata

Unknown

Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Porpidia_crustulata

Overview

Porpidia crustulata is a species of crustose lichen in the genus Porpidia, commonly known as the concentric boulder lichen.

Concentric Boulder Lichen faces significant threats from air pollution, particularly acid rain and nitrogen deposition, which alter the chemical composition of its rocky substrates and disrupt its slow-growing crustose structure. Climate change poses additional risks through altered precipitation patterns and temperature fluctuations that affect the delicate moisture balance required for photosynthesis and growth. Habitat degradation from quarrying, construction activities, and recreational disturbance further threatens the stable rock surfaces this species depends upon.

Threat summary

Habitat

This crustose lichen grows on siliceous rocks, boulders, and stone surfaces in exposed to semi-shaded locations, typically in montane and subalpine environments. It forms thin, crusty patches on hard rock substrates, particularly favoring acidic stone surfaces in areas with clean air and stable moisture conditions.

TERRESTRIAL· major

Other threatened species in Lecideaceae

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rosskivlav

Lecidea roseotincta

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VU

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Porpidia hydrophila

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Porpidia ochrolemma

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Lecidea altissima

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Frequently asked questions

Why is Concentric Boulder Lichen classified as Vulnerable?
Concentric Boulder Lichen is classified as Vulnerable because the population is declining and the species faces a high risk of extinction in the medium-term future if current pressures continue. Concentric Boulder Lichen faces significant threats from air pollution, particularly acid rain and nitrogen deposition, which alter the chemical composition of its rocky substrates and disrupt its slow-growing crustose structure. Climate change poses additional risks through altered precipitation patterns and temperature fluctuations that affect the delicate moisture balance required for photosynthesis and growth. Habitat degradation from quarrying, construction activities, and recreational disturbance further threatens the stable rock surfaces this species depends upon.
Where does Concentric Boulder Lichen live?
Concentric Boulder Lichen occurs in across multiple regions. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Concentric Boulder Lichen?
The main threats to Concentric Boulder Lichen are ai-1, ai-2, ai-3, and ai-4. The full IUCN-classified threat record for this species is detailed on the species page.

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