• Proposed
  • Under Assessment
  • Preliminary Assessed
  • Assessed
  • CRPublished

Loxospora assateaguensis Lendemer

Search for another species...

Scientific name
Loxospora assateaguensis
Author
Lendemer
Common names
 
IUCN Specialist Group
Lichens
Kingdom
Fungi
Phylum
Ascomycota
Class
Lecanoromycetes
Order
Lecanorales
Family
Sarrameanaceae
Assessment status
Published
Assessment date
2017-08-31
IUCN Red List Category
CR
IUCN Red List Criteria
A3c; B1ab(iii)+2ab(iii)
Assessors
Lendemer, J., Allen, J. & McMullin, T.
Reviewers
Scheidegger, C.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/80702946/80702949

Justification

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 significantly 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.

This species is assessed here as Critically Endangered (CR) based on the single known location, small area of occupancy, and extent of occurrence, and the documented declines in habitat quality historically, at present, and projected into the future. It also ranks as CR based on the inferred future decline which estimates that even under the most conservative estimates, 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.<100).


Geographic range

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.

Population and Trends

The sole know location is within a protected management unit (Assateague Island National Seashore). At this location the species occurs as less than approximately 100 mature individuals growing in scattered patches on the trunks of a group of ten Ilex opaca.

Population Trend: stable


Habitat 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.

Threats

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).

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).


Conservation Actions

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 impacting 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.
In addition to formal listing as an endangered species, given the threats posed by sea-level rise, monitoring is warranted and translocation is needed.

 


Source and Citation

Lendemer, J., Allen, J. & McMullin, T. 2018. Loxospora assateaguensis. The IUCN Red List of Threatened Species 2018: e.T80702946A80702949. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T80702946A80702949.en .Accessed on 31 January 2022

Country occurrence