This species was described by Lendemer (2009) as Pertusaria andersoniae and subsequently transferred to Lepra by Lendemer & Harris (2017).
Why suggested for a Global Red List Assessment?
Lepra andersoniae is narrowly endemic to the Appalachian Mountains where it is known from three subpopulations and four sites. Extensive study of suitable habitat throughout the region during the last decade has failed to locate any occurrences at sites outside of the three subpopulations that are currently known (see Allen & Lendemer 2016, Lendemer et al. 2017).
The EOO is 4313 km2 and the AOO is 16km2.
Population and Trends
The total population is distributed across four sites comprising three geographically restricted subpopulations. The Virginia subpopulation was located in 1936 and confirmed extant in 2016 (estimate, 20 functional individuals). The Roan (North Carolina) subpopulation was located in 1993, relocated in 1994, and confirmed extant in 2019 (estimate, 50-100 functional individuals). The Grandfather (North Carolina) subpopulation was located in 1935, however has not been subjected to targeted search efforts and cannot be confirmed as extant or given a size estimate.
ASSESSMENT: Endangered B1a,b & B2a,b.
This species meets the thresholds for Endangered status under the B1 criterion EOO (4313 km2) and B2 criterion for AOO (16 km2). The small EOO and AOO are further supported by the small number of locations (4 total) and the continuing decline in habitat quality due to changes in environmental conditions and climate.
Population Trend: Uncertain
Habitat and Ecology
This species is restricted to sheltered and vertical faces of high elevation rock outcrops and talus slopes in spruce-fir forests.
Damage to colonies of this species from recreational use of the habitat poses a threat to the two known extant subpopulations, each of which is located in fragile natural communities in highly visited areas. The third subpopulation, if extant, would be subjected to the same threat. Across its range the species is threatened by changing climate and environmental conditions (see Keyser et al. 2014), including from changes in cloud cover and humidity in high-elevation rock outcrops (Cullata and Horton 2014), and loss of shade from mature, healthy spruce-fir forest due to the balsam wooly adelgid (Rose and Nicholas 2008, Rollins et al. 2010, White et al. 2012). Logging or other land use change would also result in major declines to the population of this species.
Tourism & recreation areasUnintentional effects: subsistence/small scale (species being assessed is not the target) [harvest]Recreational activitiesNamed speciesHabitat shifting & alterationTemperature extremesOther impacts
The species occurs on existing public lands, with one subpopulation protected within a National Park. The other sites could be subjected to resource extraction or other impacts in the future if current management polices are changed. Increased education about the species and its threatened status is needed. Inclusion in local and national conservation policy is needed.
Site/area protectionFormal educationTrainingAwareness & communicationsNational levelSub-national levelPolicies and regulations
Location level demographic data are needed, as are long term monitoring of the population and its habitat. Targeted efforts to relocate the Grandfather (NC) subpopulation are needed. A monitoring and recovery plan needs to be developed.
Life history & ecologySpecies Action/Recovery PlanPopulation trendsHabitat trends