The taxon is accepted at species level: Lecanora conizaeoides
A well-known species that reflects major effects of past and present air-pollution (acid rain and nitrogen) on the lichen flora in Western Europe.
Native to lowland temperate Europe, rare in submontane Mediterranean Europe. Introduced in parts of North America, Australia and Asia (not on the map).
The species used to cover large parts of tree trunks in the West-European lowland. It is now rare and mainly occurs in natural areas. The decline in Europe is estimated as 75% over the past 20 years. The species is introduced in N America, but rarely reported and not present in large quantities.
Population Trend: Decreasing
Lecanora conizaeoides is a widespread lichen species that occurred in acid rain affected areas in entire Europe. The species has very much suffered from the decline of acid rain as a result of cleaner power plants and fuels since 1990. The species is also extremely sensitive to ammonia (nitrogen deposition), which caused a further decline. Both the decrease in acid rain and the increase of ammonia cause an increase in bark pH, the main factor causing the decline. Nowadays confined to coniferous trees and mature oak trees in (semi) open areas.
The main current threat is the high levels of ammonia (and other nitrogen compounds) from agro-industry and transportation. Major ammonia reduction measures were not able to stop the decline of this species and other acidophytes with a similar ecology.
Although the decline due to acid rain is not something we want to restore, reducing the widespread nitrogen deposition is still something that can help improve the situation of lichens growing on acid bark.
Continuation of existing monitoring schemes to estimate the population trend of this species and trends of other acidophytic and nitrophytic epiphytes.
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