We currently are funded through the Biotic Surveys and Inventories Program of the National Science Foundation to conduct studies on the species composition of microbiotic crusts throughout western North America (NSF Proposal reference: DEB-9870201, amount: $377,000, period of support: 10/1/1998-9/30/2001). The principal investigators of the study are Jeffrey R. Johansen (John Carroll University), Valerie R. Flechtner (John Carroll University), Louise A. Lewis (University of Connecticut) and Larry L. St. Clair (Brigham Young University). The project includes funding for undergraduate summer fellowships and graduate student support. Interested students should contact any one of the principal investigators if interested in becoming involved in the project. Below is the project summary for this grant.

Microbiotic soil crusts are assemblages of cyanobacteria, eukaryotic algae, fungi, lichens, and bryophytes that occur in many semiarid and arid sites world-wide. Microbiotic crusts are considered to be essential components of healthy desert ecosystems. Current evidence suggests that microbiotic crusts stabilize soil surfaces, reducing the incidence of erosion from wind and rain. Nitrogen fixation by cyanobacteria and free-living heterotrophic bacteria in desert soils is elevated when a well established crust is present. Microbiotic crusts are most conspicuous in undisturbed soils of semi-arid regions, but occur in selected sites in hot deserts as well. These crusts are negatively impacted by grazing livestock, offroad vehicles, human foot-traffic, and rangefire. Many arid and semi-arid lands in the United States are under pressure of human activity, expansion, and development. Furthermore, introduction of exotic species, such as cheatgrass, have increased the periodicity of rangefire. Study of the taxonomic composition, distribution, and ecological roles of crusts is urgently needed.

The objectives of the present study are several. 1) Characterize the species composition of the cyanobacteria, eukaryotic algae, lichens, and bryophytes of microbiotic crusts from 30 sites throughout intermountain western North America. 2) Establish an extensive set of collections that can be used to conduct taxonomic and systematic studies in the upcoming decades. These collections will be housed in established, funded, curated herbaria (Herbarium for Nonvascular Cryptogams, BYU, and Hanna Diatom Herbarium, CAS). Soil samples to be reserved for study of other taxonomic groups beyond the scope of this project (bacteria, fungi, protozoans, etc.) will also be curated at BYU. Isolates of new algal taxa will be deposited in the UTEX Culture Collection. 3) Create an electronic database in BIOTA and a web-site for the project. The database will be searchable by species, genus, other taxonomic group, or location. It will contain accession numbers for all isolates and specimens curated in one of the two sites. Images and descriptions of all taxa will accessible through the web-site.

All sites will be visited during the first two years of the three-year project. Selected sites will be sampled more than once during different seasons. Cyanobacteria, chlorophytes, and xanthophytes will be isolated from dilution plate culture, and identified primarily based on a morphological species concept using morphology and life history. Lichens will be analyzed using a combination of morphological and chemotaxonomic characters. Bryophytes identification will be based on morphology.