The generation time of Erioderma pedicellatum is roughly estimated to about 30 years. This is based onseveral hundred permanent plots established in Newfoundland where single thalli were observed over four years. For the assessment of the Red List status we therefore considered a period of about 100 years (three generations). During this period E. pedicellatum has completely disappeared from NewBrunswick (Canada), Norway and Sweden. Populations in Nova Scotia have suffered a major decline (>95% of the regional population size). Only in Newfoundland has a considerable regional population survived and is under permanent observation by regional forest and conservation authorities, and the Lichen Specialist Group of IUCN. A recent assessment of the Newfoundland population has suggested that this species is threatened based on thallus counts and a documented decline in the regional distribution (local subpopulations and habitat range). The major threats to this species are habitat destruction through logging and air pollution. The decline (considered irreversible) of the global population (i.e., loss of local subpopulations) is > 80%. The area ofoccupancy for the Newfoundland population is 23.35 km². The number of individuals in the Canadian subpopulation (based on thallus counts during the past five years) is about 5,074 thalli.
Assessor/s: Scheidegger, C.; Reviewer/s: Wolseley, P.A. & Smith, C.
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