Population Decline of Endangered Lichen Erioderma pedicellatum in Nova Scotia, Canada

Erioderma pedicellatum (Hue) P.M. Jorg. (1972) is a globally endangered lichen known from only four countries worldwide. The Atlantic population in Nova Scotia, Canada, has been declining for at least the last few decades. The population was closely monitored between 2003 and 2012 to determine mortality rates by life stage and population growth. A population viability model was created to assess the future viability of this population. The population declined by 12.8% over the 10 year monitoring period. Mortality rates for juveniles were significantly lower than for adults. The population viability model suggests the population in Nova Scotia will decline by 49% within 25 years. Conservation measures aimed at prolonging adult survival or increasing juvenile survival is, according to the model, the best way to maintain the population.