Spirirestris rafaelensis Flechtner et Johansen

This site is in Meigs Creek, a tributary of the Little River in the Great Smoky Mountains. This stream is bordered by a mixed mesic hardwood forest and flows through the Thunderhead Sandstone Formation. The specific site was located on the county line between Blount and Sevier Counties, and was also just at the point where the stream flows from the Thunderhead Sandstone into the Metcalf Phylite Formation.

This arid hot desert site is located in the Sevilleta Long-Term Ecological Research Project area. The soil is a sandy loam with low organic matter (0.51%), slightly alkaline pH (7.45), and low electrical conductivity (0.5 mS.cm-1). This site is located in the Chihuahuan Desert near the intersection of several biomes.

This arid hot desert site is located near the Montana Mine in an upland bajada site in the Paradise Range. The soil at the site is a gravelly silt loam with a surface covering of gravels and coarse sands. It is low in organic matter (0.7% OM), neutral (pH 7.12), and low in electrical conductivity (0.5 mS.cm-1). It has been characterized thoroughly in another paper (Johansen et al. 2001) under the site name PR1. This typical Mojave Desert site is dominated by the following shrubs: Ambrosia dumosa, Atriplex canescens, Larrea tridentata, Krameria erecta, Lycium andersonii, Mirabilis bigelowii, Haplopappus cooperi, Xylorhiza tortifolia, Encelia actonii, and Yucca brevifolia. The soil has a very patchy microbiotic crust cover, and the samples used for isolation of strains were essentially uncrusted.

This semi-arid site is located in a nearly inaccessible perched shelf located below the Wedge Overlook area of the San Rafael Swell. The soil at the site is a reddish loam with very low organic matter (0.17% OM), slightly alkaline pH (7.6), electrical conductivity of 2.4 mS.cm-1, sodium absorption ratio of 0.11, 2.9 ppm nitrate-N, 5.7 ppm phosphate - P, 134 ppm exchangeable K, 613 ppm soluble Ca, 39 ppm soluble Mg, and 55 ppm soluble Na. Soils are very shallow (0.2-1.5 m to slickrock base) and support a sparse vascular plant community dominated by widely spaced Juniperus osteosperma. The soil is covered with a well-developed pedicled microbiotic crust. This site is located in the Colorado Plateau, a large geological province that supports microbiotic crusts in much of its range.