Ll. Stclair et al., LICHENS OF SOIL CRUST COMMUNITIES IN THE INTERMOUNTAIN AREA OF THE WESTERN UNITED-STATES, The Great Basin naturalist, 53(1), 1993, pp. 5-12
Lichens are common components of microbiotic soil crusts. A total of 3
4 species from 17 genera are reported from soil crust communities thro
ughout the Intermountain Area. Distribution of terricolous lichens is
determined by various physical and biological factors: physical and ch
emical characteristics of the soil, moisture regimes, temperature, ins
olation, and development and composition of the vascular plant communi
ty. Some species demonstrate a broad ecological amplitude while others
have a more restricted distribution. All growth forms are represented
; however, the vast majority of soil crust lichens are squamulose (min
utely foliose). Fruticose species are least abundant. In exposed, midd
le-elevation sites vagrant (detached) species are common. This paper d
escribes and discusses terricolous lichen communities of desert habita
ts of the intermountain western United States. Effects of various huma
n-related activities including grazing, wildfire, air pollution, and r
ecreation vehicles on soil crust lichens are discussed. Gypsoplaca mac
rophylla (Zahlbr.) Timdal, a rare squamulose lichen which occurs on gy
psifersous soils, was recently collected in Emery County, Utah, and is
reported as new to the state.