The IUCN Red List of Threatened Species™ ISSN 2307-8235 (online) IUCN 2019: T70386122A70386125 Scope: Global Language: English Sulcaria isidiifera Assessment by: McMullin, T., Allen, J. & Lendemer, J. View on www.iucnredlist.org Citation: McMullin, T., Allen, J. & Lendemer, J. 2019. Sulcaria isidiifera. The IUCN Red List of Threatened Species 2019: e.T70386122A70386125. https://dx.doi.org/10.2305/IUCN.UK.2019- 3.RLTS.T70386122A70386125.en Copyright: © 2019 International Union for Conservation of Nature and Natural Resources Reproduction of this publication for educational or other non-commercial purposes is authorized without prior written permission from the copyright holder provided the source is fully acknowledged. Reproduction of this publication for resale, reposting or other commercial purposes is prohibited without prior written permission from the copyright holder. For further details see Terms of Use. 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THE IUCN RED LIST OF THREATENED SPECIES™ Taxonomy Kingdom Phylum Class Order Family Fungi Ascomycota Lecanoromycetes Lecanorales Parmeliaceae Taxon Name: Sulcaria isidiifera Brodo Identification Information: From Brodo (1986):Thallus dull yellowishwhite grading into light brown and reddish-brown at the more exposed tips; rarely shades of olive-gray in places ... 3-5 cm long; main branching isotomic to anisotomic-dichotomous, with more-or-less perpendicular spinulose branches developing from splits in the thallus; branches splitting lengthwise and opening into rather wide linear soralia filled with spinulose isidia and spinules, often with brown tips; main branches 0.3 - 0.5mm wide ... very brittle ... .Apothecia and pycnidia not seen. Assessment Information Red List Category & Criteria: Critically Endangered B2ab(i,ii,iii,iv,v) ver 3.1 Year Published: 2019 Date Assessed: August 30, 2017 Justification: This species is assessed as Critically Endangered (CR) on the basis of it having a very narrow distribution (10 km diameter area), correlating to an extent of occurrence of less than 100 km², and an area of occupancy of just 8 km². A continuing decline in the extent of occurrence, and the number of mature individuals is reported, and it is considered that this species severely fragmented and found in 1-4 locations based on the threats of development and changes to the fire regimes. Geographic Range Range Description: This species is narrowly restricted to a small area of old-growth coastal chaparral scrub on stable sand dunes in San Luis Obispo County, California, U.S.A. Country Occurrence: Native: United States (California) © The IUCN Red List of Threatened Species: Sulcaria isidiifera – published in 2019. 1 https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T70386122A70386125.en Distribution Map Sulcaria isidiifera © The IUCN Red List of Threatened Species: Sulcaria isidiifera – published in 2019. 2 https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T70386122A70386125.en Population Sulcaria isidiifera was first discovered in 1984 and was formally described in 1986 (Brodo 1986). It is only known to inhabit an area that is 7 miles across at its widest point (Carlberg and Knudsen 2007). Repeated visits in recent years, including a 2012 visit from C. Bratt (one of the original two people that discovered it), documented significant observed decline in the population and habitat fragmentation (C. Bratt pers. comm., Carlberg and Knudsen 2007). Most known occurrences are within three state parks: Montana de Oro State Park, Morro Bay State Park, and Los Osos Oaks State Reserve, with the highest abundance at Montana de Oro (Reifner 1995). The rest of the population is on private or unregulated land (Carlberg and Knudsen 2007). Current Population Trend: Decreasing Habitat and Ecology (see Appendix for additional information) This is a corticolous species that is restricted to old-growth coastal chaparral scrub (Carlberg and Knudsen 2007). It occurs on the branches of trees and shrubs such as: Adenostoma fasciculatum, Quercus dumosa, Q. agrifolia, and Ceanothus ramulosus (Brodo 1986, Carlberg and Knudsen 2007). Systems: Terrestrial Threats (see Appendix for additional information) This species is threatened by residential development and changes in fire regimes. Development is the biggest threat to this species. Two communities, Los Osos and Baywood, have grown substantially in the last thirty years since Sulcaria isidiifera was discovered. They are within the range of this species and new development is reducing the already small area of suitable habitat. Conservation Actions (see Appendix for additional information) This species needs to be listed as an endangered species in the United States. Additionally, efforts need to be made to protect populations from residential development. Because of the small population size of this species and significant loss of habitat, reintroduction to areas where it has been lost should be attempted. Monitoring the abundance and health of this species needs to begin immediately. Also, the viability of reintroduction should be explored. Credits Assessor(s): McMullin, T., Allen, J. & Lendemer, J. Reviewer(s): Scheidegger, C. Contributor(s): Aptroot, A., Dahlberg, A., Weerakoon, G., Perez-Ortega, S & Spribille, T. © The IUCN Red List of Threatened Species: Sulcaria isidiifera – published in 2019. 3 https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T70386122A70386125.en Bibliography Brodo, IM. 1986. A new species of the lichen genus Sulcaria (Ascomycotina, Alectoriaceae) from California. Mycotaxon 27: 113-117. IUCN. 2019. The IUCN Red List of Threatened Species. Version 2019-3. Available at: www.iucnredlist.org. (Accessed: 10 December 2019). T. Carlberg and K. Knudsen. 2007. Sulcaria isidiifera, sponsorship for the CALS Conservation Committee. Bulletin of the California Lichen Society 14(2): 45-47. Citation McMullin, T., Allen, J. & Lendemer, J. 2019. Sulcaria isidiifera. The IUCN Red List of Threatened Species 2019: e.T70386122A70386125. https://dx.doi.org/10.2305/IUCN.UK.2019- 3.RLTS.T70386122A70386125.en Disclaimer To make use of this information, please check the Terms of Use. External Resources For Images and External Links to Additional Information, please see the Red List website. © The IUCN Red List of Threatened Species: Sulcaria isidiifera – published in 2019. 4 https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T70386122A70386125.en Appendix Habitats (http://www.iucnredlist.org/technical-documents/classification-schemes) Major Season Suitability Habitat Importance? 3. Shrubland -> 3.8. Shrubland - Mediterranean-type Shrubby Vegetation Resident Suitable Yes Plant Growth Forms (http://www.iucnredlist.org/technical-documents/classification-schemes) Plant Growth Forms Lichen Epiphyte Threats (http://www.iucnredlist.org/technical-documents/classification-schemes) Threat Timing Scope Severity Impact Score 1. Residential & commercial development -> 1.1. Ongoing Majority (50- Rapid declines Medium Housing & urban areas 90%) impact: 7 Stresses: 2. Species Stresses -> 2.1. Species mortality 2. Species Stresses -> 2.2. Species disturbance 11. Climate change & severe weather -> 11.2. Ongoing Minority (50%) Causing/could Low impact: 5 Droughts cause fluctuations Stresses: 2. Species Stresses -> 2.2. Species disturbance 7. Natural system modifications -> 7.1. Fire & fire Ongoing Minority (50%) Slow, significant Low impact: 5 suppression -> 7.1.1. Increase in fire declines frequency/intensity Stresses: 2. Species Stresses -> 2.1. Species mortality 2. Species Stresses -> 2.2. Species disturbance Conservation Actions in Place (http://www.iucnredlist.org/technical-documents/classification-schemes) Conservation Actions in Place In-Place Research, Monitoring and Planning Action Recovery plan: No Systematic monitoring scheme: No In-Place Land/Water Protection and Management © The IUCN Red List of Threatened Species: Sulcaria isidiifera – published in 2019. 5 https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T70386122A70386125.en Conservation Actions in Place Conservation sites identified: No Occur in at least one PA: Yes Percentage of population protected by PAs (0-100): 71-80 Area based regional management plan: No Invasive species control or prevention: Not Applicable In-Place Species Management Harvest management plan: No Successfully reintroduced or introduced beningly: No Subject to ex-situ conservation: No In-Place Education Subject to recent education and awareness programmes: No Included in international legislation: No Subject to any international management/trade controls: No Conservation Actions Needed (http://www.iucnredlist.org/technical-documents/classification-schemes) Conservation Actions Needed 1. Land/water protection -> 1.1. Site/area protection 2. Land/water management -> 2.1. Site/area management 3. Species management -> 3.2. Species recovery 3. Species management -> 3.3. Species re-introduction -> 3.3.1. Reintroduction 4. Education & awareness -> 4.1. Formal education