Assessed as Endangered B2ab(i,ii,iii,iv,v), ver 3.1; date assessed: August 4, 2020

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Common name(s): English: Golden Spruce Dots

ASSESSMENT JUSTIFICATION [criteria: B2ab(i,ii,iii,iv,v)]

Arthonia cupressina (Golden Spruce Dots) is endemic to the Appalachian Mountains of eastern North America. It is known from a small number of scattered occurrences in remnant old-growth forests, withthe majority of the population occurring in Great Smoky Mountains National Park in the eastern United States. Despite its small size, the species has been searched for extensively in suitable habitat throughout the southern Appalachian and central Appalachian Mountains. In addition to being restricted to old-growth forests, the species occurs on mature trees of specific conifer host species. The overall rarity and spatial dispersion of the population make the species particularly susceptible to stochastic events, such as wildfires and storms, which are increasing in much of the area where it occurs. Host trees are being impacted directly by invasive species, and indirectly through the loss of co-occurring dominant tree species. The southern Appalachian spruce-fir forests where much of the population occurs are considered endangered and likely to be greatly impacted by climate change in the near-term future. The species has an extent of occurrence (EOO) of 262,493 km2 and and Area of Occupancy (AOO) of 52 km2, the population is severely fragmented, there is a small number of extant locations (4), and there are inferred continuing declines in EOO, AOO, habitat quality, number of locations/subpopulations, and number of mature individuals. Therefore, it is listed as Endangered under criterion B2ab(i,ii,iii,iv,v).

Assessor/s: Lendemer, J.; Reviewer/s: McMullin, T.; Facilitator(s) and Compiler(s): Allen, J., Bishop, G. & Chandler, A.

Bibliography:

Allen, J.L. & Lendemer, J.C. (2016) Climate change impacts on endemic, high-elevation lichens in abiodiversity hotspot. Biodiversity and Conservation 25(3): 555-568.

Bachman, S., Moat, J., Hill, A.W., de la Torre, J. & Scott, B. 2011. Supporting Red List threat assessments with GeoCAT: geospatial conservation assessment tool. In: V. Smith and L. Penev (eds) e-Infrastructures for data publishing in biodiversity science. Zookeys 150: 117–126.

Ellison, A.M., Orwig, D.A., Fitzpatrick, M.C. and Preisser, E.L. (2018) The past, present, and future of the Hemlock Woolly Adelgid (Adelges tsugae) and its ecological interactions with Eastern Hemlock (Tsuga canadensis) forests. Insects 9(172): 1-18.

IUCN. 2020. The IUCN Red List of Threatened Species. Version 2020-3. Available at: www.iucnredlist.org. (Accessed: 10 December 2020).

James, N.A., Abt, K.L., Frey, G.E., Han, X. & Prestemon, J.P. (2020) Fire in the Southern Appalachians: Understanding Impacts, Interventions, and Future Fire Events. e-General Technical Report. Departmentof Agriculture Forest Service, Southern Research Station, Asheville, NC.

Jenkins, J.C., Aber, J.D. & Canham, C.D. 1999. Hemlock Woolly Adelgid impacts on community structure and N cycling rates in Eastern Hemlock forests. Canadian Journal of Forestry Research 29(5): 630-645.

Kenis, M., Auger-Rozenberg, M.A., Roques, A., Timms, L., Péré, C., Cock, M.J.W., Settele, J., Augustin, S. & Lopez-Vaamonde, C. (2009) Ecological effects of invasive alien insects. Biological Invasions 11: 21-45.

Lendemer, J.C., Anderson Stewart, C.R., Besal, B., Goldsmith, J., Griffith, H., Hoffman, J.R., Kraus, B.,LaPoint, P., Li, L. Muscavitch, Z., Schultz, J., Schultz, R. & Allen, J.L. (2017) The lichens and allied fungi of Mount Mitchell State Park, North Carolina: A first checklist with comprehensive keys and comparison to historical data. Castnea 82: 69-97.

Noss, R.F., LaRoe, E.T. & Scott, J.M. (1995) Endangered Ecosystems of the United States: A Preliminary Assessment of Loss and Degradation. National Biological Service, Flagstaff, Arizona.

Rollins, A.W., Adams, H.S. & Stephenson, S.L. (2010) Changes in forest composition and structure across the red spruce-hardwood ecotone in the central Appalachians. Castanea 75: 303–314.

White, P.B., S.L. van de Gevel, & P. T. Soulé (2012) Succession and disturbance in an endangered redspruce-Fraser fir forest in the southern Appalachian Mountains, North Carolina, USA. Endangered Species Research 18: 17-25.

Find out more about the IUCN Red List Categories and Criteria here.

MB#376438

TYPE. UNITED STATES. MASSACHUSETTS, [Bristol County], New Bedford, on White Cedar, 1862-1898, H. Willey s.n. (F C0303102F, possible isotype; MICH 62525, isotype; NY 1217558, 03719699, 03719700, 1217558, isotypes and possible isotypes; US 00067757, isotype).

Description. Lichenized fungus.

Thallus crustose, thin, whitish, smooth to granular. Ascomata arthonioid apothecia, round, immersed to sessile, 0.2-0.6 mm diam.; disk flat to convex, pale brown to black, or grayish pruinose; hymenium pale brownish; hypothecium dark brown. Asci clavate, 8-spored; ascospores hyaline, slipper-shaped, 3-septate, one end cell larger, 16-22 x 5-7 μm.

Chemistry. Secondary compounds not detected by TLC.

Substrate and Habitat. Corticolous on mature conifers in spruce-fir forests.

Distribution. Eastern North America; in North Carolina restricted to the southern Appalachians.

Literature

Fink, B. (1935) The Lichen Flora of the United States. University of Michigan Press, Ann Arbor.

Tuckerman, E. (1872) Genera Lichenum: An arrangement of the North America lichens. Amherst, 281 pp (original description).