ASSESSMENT FROM NEW YORK WORKSHOP
Proposed Author: James Lendemer, Jessica Allen, Troy McMullin, Christoph Scheidegger
Common Name: Back of the Bay
Current Scientific Name: Loxospora assateaguensis Lendemer
Proposed Status: Critically Endangered: B2a,biii; C2aii; E
EOO: 0 km2
AOO: 3.000 km2
# of Documented populations: 1 (presumed extant)
Assessment Synopsis. – Loxospora assateaguensis is a crustose lichen known from a single location on the Virginian Barrier Islands of the Mid-Atlantic Coastal Plain of southeastern North America. Suitable habitat for this species is severely fragmented and has been degraded by anthropogenic forces. The threats to L. assateaguensis stem from continued degradation of suitable habitat and projected impacts from sea-level rise.
Distinguishing Traits. – This crustose lichen can be recognized by its occurrence on bark, blue-gray color, large pustulose soralia and the production of 2-O-methylperlatolic acid.
Distribution and Ecology. – Loxospora assateaguensis is a recently described species known only from a single remnant mature maritime forest off the coast of Delmarva in the Virginian Barrier Islands of eastern North America. It occurred only on the bark of mature American holly (Ilex opaca) at this site, and was encountered as part of a large scale biodiversity inventory of the Mid-Atlantic Coastal Plain (New Jersey south to Florida; Lendemer & Allen 2014) that inventoried 300+ sites and generated 17,000+ specimens. Remnant mature maritime forests are rare in the Virginian Barrier Islands (see Lendemer 2013), and other endemic lichen species have been found in comparable habitats further south in the Carolinian Barrier Islands.
Despite extensive inventories by multiple specialists of suitable habitats elsewhere in the Coastal Plain over a period spanning +20 years (e.g., Florida: W.R. Buck, R. Commons, R.C. Harris, F.&J. Seavey; Georgia: S.Q. Beeching, M.F. Hodges, J.C. Lendemer), no additional populations have been located.
Status of Populations – The sole know location is within a protected management unit (Assateague Island National Seashore). At this location the species occurs as less than approximately100 mature individuals growing in scattered patches on the trunks of a group of ten Ilex opaca.
Protected Status. – None.
Threats. – Maritime forests, particularly mature communities, are threatened throughout eastern North America and have been greatly impacted by habitat loss and degradation, particularly post-1960 (e.g., Bellis 1995, Berman & Berquist. 2007). Now these coastal habitats are further threatened by climate change, particularly sea-level rise (Lendemer & Allen 2014, Sallenger et al. 2012) and increasing frequency and intensity of storms including hurricanes (U.S. Army Corps of Engineers 2015, Villarini & Vecchi 2012).
Explanation of Proposed Rank. – This species merits ranking as Critically Endangered: B2a,biii based on the single known location, and the documented declines in habitat quality historically, at present, and projected into the future. It also ranks as Critically Endangered C2aii and E based on the inferred near 100% probability that 100% of the population, which lies at ~0.3 meters above sea level (well below the 1.5 meter conservative estimate for sea-level rise by 2100; see Lendemer & Allen 2014, Sallenger et al. 2012, U.S. Army Corps of Engineers 2015) will be flooded within the next three generations as a result of sea-level rise and/or intense storm damage. It would also meet Endangered D based on the small number of mature individuals (ca.
Conservation Recommendations. – In addition to formal listing as an endangered species, given the threats posed by sea-level rise, monitoring is warranted and translocation is needed.
Bellis, V.J. 1995. Ecology of Maritime Forests of the Southern Atlantic Coast: A Community Profile. Biological Report 30: 1-90.
Berman, M. & H. Berquist. 2007. Coastal Maritime Forests in Virginia – Delineation and Distribution.
Lendemer, J.C./ Allen, J.L. 2014: Lichen Biodiversity under threat from Sea-Level Rise in the Atlantic Coastal Plain. - BioScience 64: 923-931.
Lendemer, J.C. 2013: Two New Sterile Species of Loxospora (Sarrameanaceae: Lichenized Ascomycetes) from the Mid-Atlantic Coastal Plain. - Journal of the North Carolina Academy of Science 129: 71-81.
Sallenger A.H. Jr., K.S. Doran & P.A. Howd. 2012. Hotspot of accelerated sea-level rise on the Atlantic Coast of North America. Nature Climate Change 2: 884–888.
United States Army Corps of Engineers. 2015. North Atlantic Coast Comprehensive Study: Resilient Adaptation to Increasing Risk. http://www.nad.usace.army.mil/Portals/40/docs/NACCS/NACCS_main_report.pdf
Villarini, G. & G.A. Vecchi. 2012. Projected Increases in North Atlantic Tropical Cyclone Intensity from CMIP5 Models. Journal of Climate, 2012; 121116142835009 DOI: 10.1175/JCLI-D-12-00441.1
Loxospora assateaguensis is known only from a single island along the Atlantic Coast of the United States where it is restricted to remnant mature maritime forest habitats. These habitats have been significantly impacted by past human activities and now are imperiled by climate change and associated sea-level rise.
The species is known only from a single remnant mature maritime forest on an island off the Atlantic Coast in the Virginian Barrier Islands Ecoregion of the eastern United States.
Demographic studies are needed to assess and monitor populations sizes. Our current knowledge of the species suggests that the population is stable.
Population Trend: Stable
Loxospora assateaguensis occurs on the bark of mature individuals of hardwoods, particularly American holly (Ilex opaca), in mature maritime forests.
This species may have been more widespread in the Virginian Barrier Islands Ecoregion before the historical large scale deforestation that occurred in the Mid-Atlantic Region of the eastern United States. Mature maritime forests are a naturally rare habitat extent because they occur on transient and ever changing barrier islands and in coastal areas that are subject to frequent changes with erosion and sea-level. These already rare habitats have been significantly impacted and reduced in extent as a result of large scale development along the Atlantic Coast. The remnant forest where this species occurs is protected within a national park, however it is imperiled by sea-level rise (site will be inundated under most conservative estimates for sea-level rise by 2100).
There are many conservation actions that can be taken including monitoring for the presence of laurel wilt which if introduced would impact a dominant tree in the forest and potentially change microhabitats thus imapcting the species, educating and training land managers and local botanists to identify the species so we can monitor its health, federally listing the species as endangered in the United States, and improving air quality regulation, monitoring changes associated with sea-level rise. Policy and legislation considering biodiversity threatened by sea-level rise is also needed.
This species is well documented not to occur north and south of the Virginian Barrier Islands, however further inventories of remote/difficult to access islands in the ecoregion are needed. Further research that will aid in the conservation of this species includes population assessments and monitoring, population genetics studies, and ecological studies that incorporate threats to the species. Additionally, a species recovery plan needs to be written.
Lendemer, J.C. and J. Allen. 2014. Lichen Biodiversity under threat from Sea-Level Rise in the Atlantic Coastal Plain. BioScience 64: 923-931.
Lendemer, J.C. 2013. Two New Sterile Species of Loxospora (Sarrameanaceae: Lichenized Ascomycetes) from the Mid-Atlantic Coastal Plain. Journal of North Carolina Academy of Sciences 129(3): 71-81.