Biodiversity and Conservation

, Volume 21, Issue 4, pp 1015–1031 | Cite as

Late-successional biological soil crusts in a biodiversity hotspot: an example of congruency in species richness

  • Rebecca R. Hernandez
  • Kerry Knudsen
Original Paper


Understanding the biodiversity of functionally important communities in Earth’s ecosystems is vital in the apportionment of limited ecosystem management funds and efforts. In southern California shrublands, which lie in a global biodiversity hotspot, biological soil crusts (BSCs) confer critical ecosystem services; however, their biodiversity remains unknown. In this study, six sites (n = 4 each, 25 m2) were established along a mediterranean shrubland environmental gradient in southern California. Here, the biodiversity of all BSC-forming lichens and bryophytes was evaluated, related to environmental traits along the gradient, and compared to species richness among North American ecosystems supporting BSCs (data from previous studies). In total, 59 BSC-forming lichens and bryophytes were observed, including the very rare Sarcogyne crustacea, a rare moss, and five endemic lichen species. Over half (61%) of the species observed were found at a single site. Along the gradient, species evenness of late-successional BSC was related to dew point and elevation, and both evenness and richness were related to distance to coast. Using an ordination analysis, five distinct late-successional BSC communities were identified: Riversidian, Spike moss, Casperian, Alisian, and Lagunian. Twenty-five lichens and 19 bryophytes are newly reported for North American BSC-forming organisms, now comprising ~1/2 of the North American total. BSCs in North American hot and cold deserts were approximately 4.0 and 2.4 times less species rich than BSCs found in southern California shrublands, respectively. Given the anthropogenic impacts on quality and distribution of California mediterranean shrublands, our results show that these sites represent important refugia of BSC species in this globally important region.


California sage scrub Chaparral Lichens Mediterranean Mosses Shrubland 



We thank P. Wilson and R.H. Zander for help in identifying bryophyte specimens. We also thank E.B. Allen, R. Medina, R. Johnson, B. Payne, and R.C. Ochoa-Hueso who contributed greatly to this project. R.R.H. was supported by grants from Orange County Chapter of the California Native Plant Society, the Department of Botany and Plant Sciences, and the Center for Conservation at UC Riverside.

Supplementary material

10531_2012_236_MOESM1_ESM.doc (32 kb)
Supplementary material 1 (DOC 33 kb)
10531_2012_236_MOESM2_ESM.doc (35 kb)
Supplementary material 2 (DOC 35 kb)
10531_2012_236_MOESM3_ESM.doc (45 kb)
Supplementary material 3 (DOC 45 kb)
10531_2012_236_MOESM4_ESM.doc (32 kb)
Supplementary material 4 (DOC 32 kb)
10531_2012_236_MOESM5_ESM.doc (236 kb)
Supplementary material 5 (DOC 236 kb)


  1. Armstrong RA (1987) Dispersal in a population of the lichen Hypogymnia physodes. Environ Exp Bot 27:357–363CrossRefGoogle Scholar
  2. Bates ST, Nash TH III, Sweat KG, Garcia-Pichel F (2010) Fungal communities of lichen-dominated biological soil crusts: diversity, relative microbial biomass, and their relationship to disturbance and crust cover. J Arid Environ 74:1192–1199CrossRefGoogle Scholar
  3. Belnap J, Lange OL (2001) Biological soil crusts: structure, function, and management, 2nd edn. Springer-Verlag, BerlinCrossRefGoogle Scholar
  4. Belnap J, Büdel B, Lange OL (2001) Biological soil crusts: characteristics and distribution. In: Belnap J, Lange OL (eds) Biological soil crusts: structure, function, and management, 2nd edn. Springer-Verlag, Berlin, pp 3–30CrossRefGoogle Scholar
  5. Belnap J, Phillips SL, Miller ME (2004) Response of desert biological soil crusts to alterations in precipitation frequency. Oecologia 141:306–316PubMedCrossRefGoogle Scholar
  6. Belnap J, Phillips SL, Flint S, Money J, Caldwell M (2008) Global change and biological soil crusts: effects of ultraviolet augmentation under altered precipitation regimes and nitrogen additions. Glob Chang Biol 14:670–686CrossRefGoogle Scholar
  7. Bowker MA, Belnap J (2008) A simple classification of soil types as habitats of biological soil crusts on the Colorado Plateau, USA. J Veg Sci 19:831–840CrossRefGoogle Scholar
  8. Bowker MA, Belnap J, Davidson DW, Phillips SL (2005) Evidence for micronutrient limitation of biological soil crusts: importance to arid-lands restoration. Ecol Appl 15:1941–1951CrossRefGoogle Scholar
  9. Bowker MA, Mau RL, Maestre FT, Escolar C, Castillo-Monroy AP (2008) Functional profiles reveal unique ecological roles of various biological soil crust organisms. Funct Ecol 25:787–795CrossRefGoogle Scholar
  10. Büdel B (2001) Synopsis: comparative biogeography of soil-crust biota. In: Belnap J, Lange OL (eds) Biological soil crusts: structure, function, and management, 2nd edn. Springer-Verlag, Berlin, pp 141–152Google Scholar
  11. Burk JH, Jones CE, Ryan WA, Wheeler JA (2007) Floodplain vegetation and soils along the upper Santa Ana River, San Bernardino County, California. Madroño 54:126–137CrossRefGoogle Scholar
  12. Chao A, Chazdon RL, Colwell RK, Shen T-J (2005) A new statistical approach for assessing similarity of species composition with incidence and abundance data. Ecol Lett 8:148–159CrossRefGoogle Scholar
  13. Chaudhary VB, Bowker MA, O’Dell TE, Grace JB, Redman AE, Rillig MC, Johnson NC (2009) Untangling the biological contributions to soil stability in semiarid shrublands. Ecol Appl 19:110–122PubMedCrossRefGoogle Scholar
  14. Clavel J, Julliard R, Devictor V (2011) Worldwide decline of specialist species: toward a global functional homogenization? Front Ecol Environ 9:222–228CrossRefGoogle Scholar
  15. Colwell RK (2005) EstimateS: statistical estimation of species richness and shared species from samples. Version 7.5. User’s guide and application. Accessed 01 June 2010
  16. Colwell RK, Coddington JA (1994) Estimating terrestrial biodiversity through extrapolation. Philos Trans R Soc (Ser B) 354:101–118CrossRefGoogle Scholar
  17. Cowling RM, Rundel PW, Lamont BB, Arroyo MK, Arianoutsou M (1996) Plant diversity in mediterranean-climate regions. Trends Ecol Evol 11:362–366PubMedCrossRefGoogle Scholar
  18. Días S, Cabido M (2001) Vive la différence: plant functional diversity matters to ecosystem processes. Trends Ecol Evol 16:646–655Google Scholar
  19. Doyle WT, Stotler RE (2006) Contributions toward a bryoflora of California III: keys and annotated species catalogue for liverworts and hornworts. Madroño 53:89–197CrossRefGoogle Scholar
  20. During HJ, Van Tooren BF (1990) Bryophyte interactions with other plants. Bot J Linn Soc 104:79–98CrossRefGoogle Scholar
  21. Evans RD, Belnap J, Garcia-Pichel F, Phillips SL (2001) Global change and the future of biological soil crusts. In: Belnap J, Lange OL (eds) Biological soil crusts: structure, function, and management, 2nd edn. Springer-Verlag, Berlin, pp 417–429Google Scholar
  22. Fierer NG, Gabet EJ (2002) Carbon and nitrogen losses by surface runoff following changes in vegetation. J Environ Qual 31:1207–1213PubMedCrossRefGoogle Scholar
  23. Harrison AT, Small E, Mooney HA (1971) Drought relationships and distribution of two mediterranean-climate California plant communities. Ecology 52:869–875Google Scholar
  24. Harthill MP, Long DM, Mishler BD (1979) Preliminary list of southern California mosses. Bryologist 82:260–267CrossRefGoogle Scholar
  25. Hasse HE (1913) The lichen flora of southern California. Contrib U.S. Natl Herb 17:1–32Google Scholar
  26. Hawkes CV, Menges ES (2003) Effects of lichens on seedling emergence in a xeric Florida shrubland. Southeast Nat 2:223–234CrossRefGoogle Scholar
  27. Hernandez RR, Sandquist DR (2011) Disturbance of biological soil crust increases emergence of exotic vascular plants in California sage scrub. Plant Ecol 212:1709–1721Google Scholar
  28. Kelly AE, Goulden ML (2008) Rapid shifts in plant distribution with recent climate change. Proc Natl Acad Sci 105:11823–11826PubMedCrossRefGoogle Scholar
  29. Knudsen K (2003) Texosporium sancti-jacobi (Ascomycetes: Caliciales: Caliciaceae). New finds and general observations. Crossosoma 28:9–12Google Scholar
  30. Knudsen K (2007) Texosporium sancti-jacobi, a rare endemic lichen of western Northern America: is it evanescent under drought conditions? Bull Calif Lichen Soc 14:33–36Google Scholar
  31. Knudsen K (2010) Acarospora orcutti (Acarosporaceae), a rare terricolous lichen from southern California. Bryol 113:713–716CrossRefGoogle Scholar
  32. Knudsen K, Kocourková J (2010a) Lichens, lichenicolous and allied fungi of the Santa Monica Mountains, Part 5: additions and corrections to the annotated checklist. Opusc Philolichenum 8:83–100Google Scholar
  33. Knudsen K, Kocourková J (2010b) Lichenological notes 1: Acarosporaceae. Mycotaxon 112:361–366CrossRefGoogle Scholar
  34. Knudsen K, Magney D (2006) Lichen habitats and rare lichen species of Ventura County, California. Opusc Philolichenum 3:49–52Google Scholar
  35. Maestre FT, Escudero A, Martínez I, Guerrero C, Rubio A (2005) Does spatial pattern matter to ecosystem functioning? Insights from biological soil crusts. Funct Ecol 19:566–573CrossRefGoogle Scholar
  36. Master LL (1991) Assessing threats and setting priorities for conservation. Conserv Biol 5:559–563Google Scholar
  37. Muhs DR, Budahn JR, Reheis M, Beann J, Skipp G, Fisher E (2007) Airborne dust transport to the eastern Pacific Ocean off southern California: evidence from San Clemente Island. J Geophys Res 112:D13203CrossRefGoogle Scholar
  38. Myers N (2003) Biodiversity hotspots revisited. Bioscience 53:916–917CrossRefGoogle Scholar
  39. Myers N, Mittermeier RA, Mittermeier CG, da Fonseca GAB, Kent J (2000) Biodiversity hotspots for conservation priorities. Nature 403:853–858PubMedCrossRefGoogle Scholar
  40. Nagy ML, Pérez A, Garcia-Pichel F (2005) The prokaryotic diversity of biological soil crusts in the Sonoran Desert (Organ Pipe Cactus National Monument, AZ). FEMS Microbiol Ecol 54:233–245PubMedCrossRefGoogle Scholar
  41. Norris DH, Shevock JR (2004) Contributions toward a bryoflora of California: I. A specimen based catalogue of mosses. Madroño 51:1–131Google Scholar
  42. Reyers B, O’Farrell PJ, Cowling RM, Egoh BN, Le Maitre DC, Vlok JHJ (2009) Ecosystem services, land-cover change, and stakeholders: finding a sustainable foothold for a semiarid biodiversity hotspot. Ecol Soc 14:1–23Google Scholar
  43. Riefner RE Jr, Bowler PA (1995) Cushion-like fruticose lichens as Dudleya seed traps and nurseries in coastal communities. Madroño 42:81–82Google Scholar
  44. Rivera-Aguilar V, Montejanob G, Rodríguez-Zaragozaa S, Durán-Díaz A (2006) Distribution and composition of cyanobacteria, mosses and lichens of the biological soil crusts of the Tehuacán Valley, Puebla, México. J Arid Environ 67:208–225CrossRefGoogle Scholar
  45. Rosentreter R, Belnap J (2001) Biological soil crusts of North America. In: Belnap J, Lange OL (eds) Biological soil crusts: structure, function, and management, 2nd edn. Springer-Verlag, Berlin, pp 31–55Google Scholar
  46. Rosentreter R, Eldridge DJ, Kaltenecker JH (2001) Monitoring and management of biological soil crusts. In: Belnap J, Lange OL (eds) Biological soil crusts: structure, function, and management, 2nd edn. Springer-Verlag, Berlin, pp 457–468Google Scholar
  47. Sedia EG, Ehrenfeld JG (2003) Lichens and mosses promote alternate stable plant communities in the New Jersey Pinelands. Oikos 100:447–458CrossRefGoogle Scholar
  48. Shlemon RJ, Riefner RE (2006) The role of tectonic processes in the interaction between geology and ecosystems. In: Zekser IS, Marker B, Ridgway J, Rogachevskaya L, Vartanyan G (eds) Geology and ecosystems, 1st edn. Springer-Verlag, Berlin, pp 49–60CrossRefGoogle Scholar
  49. Soininen J, McDonald R, Hillebrand H (2007) The distance decay of similarity in ecological communities. Ecography 30:3–12Google Scholar
  50. Soule T, Anderson IJ, Johnson SL, Bates ST, Garcia-Pichel F (2009) Archaeal populations in biological soil crusts from arid lands in North America. Soil Biol Biochem 41:2069–2074CrossRefGoogle Scholar
  51. St. Clair LL, Johansen JR, Rushforth SR (1993) Lichens of soil crust communities in the intermountain area of the western United States. Great Basin Nat 53:5–12Google Scholar
  52. St. Clair LL, Johansen JR, St. Clair SB, Knight KB (2007) The influence of grazing and other environmental factors on lichen community structure along an alpine tundra ridge in the Uinta Mountains, Utah, USA. Arct Antarct Alp Res 39:603–613CrossRefGoogle Scholar
  53. Sundberg S (2005) Larger capsules enhance short-range spore dispersal in Sphagnum, but what happens further away? Oikos 108:115–124CrossRefGoogle Scholar
  54. Talluto MV, Suding KN (2008) Historical change in coastal sage scrub in southern California, USA in relation to fire frequency and air pollution. Landsc Ecol 23:803–815CrossRefGoogle Scholar
  55. Tilman D, Knops J, Wedin D, Reich P, Ritchie M, Siemann E (1997) The influence of functional diversity and composition on ecosystem processes. Science 227:1300–1302CrossRefGoogle Scholar
  56. Wilcove DS, Rothstein D, Dubow J, Phillips A, Losos E (1998) Quantifying threats to imperiled species in the United States. Bioscience 48:607–615Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  1. 1.Department of Botany and Plant SciencesUniversity of CaliforniaRiversideUSA
  2. 2.Center for Conservation Biology, University of CaliforniaRiversideUSA
  3. 3.UC Riverside Herbarium, University of CaliforniaRiversideUSA
  4. 4.Department of Environmental Earth System ScienceStanford UniversityStanfordUSA

Personalised recommendations