Abstract Detail

Bryological and Lichenological Section/ABLS

Proulx, Monica W. [1], St. Clair, Larry [2].

Patterns influencing development of Mojave Desert lichen communities.

The Spring Mountains are a sky island mountain range in the northeast portion of the Mojave Desert located 25 km northwest of Las Vegas.  A comparison of the lichen flora of the Spring Mountains National Recreation Area with other lichen floras reported for the Mojave Desert reveals several interesting trends related to species diversity and substrate, and growth form distribution patterns that appear to be influenced by two environmental factors: General microhabitat conditions and available substrates.  These factors are further defined by differences in geological substrates, occurrence and development of woody plant communities, and a combination of environmental factors including – elevation, temperature, precipitation, and insolation. Drier and warmer habitats are typically dominated by crustose species with some, mostly smaller, foliose taxa limited to protected microhabitats usually on steep north-facing aspects. Fruticose species reported from Mojave Desert sites are extremely rare with very small thalli. Generally, larger foliose and fruticose species, with more complex thalli and thus greater surface area, are more susceptible to higher rates of water loss under arid conditions. Lichen communities in the Mojave Desert appear to respond to sharp contrasts in microhabitats with exposed, lower elevation sites generally having lower species diversity along with more drought resistant growth forms – crustose and squamulose species.
The Spring Mountains NRA, with high elevation mountains and diverse, well developed woody plant communities, accommodates a large variety of microhabitat conditions distributed over complex temperature and moisture gradients. These conditions resulted in higher species diversity (124 species in 48 genera) and higher numbers of foliose and corticolous species when compared with other more arid Mojave Desert lichen floras. The only Mojave lichen flora with higher species numbers (145 species in 53 genera) was based on an extensive survey of Joshua Tree National Park by Knudsen et al., in 2013.

1 - Brigham Young University, M.L. Bean Life Science Museum, 1115 M.L. Bean Life Science Museum, Provo, UT, 84602, USA
2 - Brigham Young University, M. L. Bean Museum, 2103C ML Bean Museum, Provo, UT, 84602, USA

Keywords:
Mojave Desert
desert
patterns
development
distribution
precipitation
insolation
temperature
elevation
microhabitat conditions
species distribution
environmental factors
available substrate
lichen communities
geological substrates
development of woody plant communities.

Presentation Type: Oral Paper:Papers for Sections
Session: 23
Location: River Fork/Grove
Date: Tuesday, July 29th, 2014
Time: 11:00 AM
Number: 23008
Abstract ID:637
Candidate for Awards:None