9870201 Johansen Microbiotic soil crusts are assemblages of cyanobacteria, eukaryotic algae, fungi, lichens, and bryophytes that play an important role in healthy semiarid and arid ecosystems. Despite their prominant ecological role, a clear understanding of the species composition of microbiotic crusts is lacking. Over the course of a 36-month period, thirty locations with known mature microbiotic crust communities throughout intermountain western North America, and representing diverse climatic and geological regions, will be sampled in order to: (1) characterize the species composition of the microbiotic crust organisms. This includes an inventory of the species of cyanobacteria, eukaryotic algae, lichens, and mosses found in the sampled microbiotic crusts and descriptions of new species that may be encountered; (2) produce a data base that includes species lists, descriptions, images, and information on the physical and chemical characteristics of the soils at each locality; (3) produce an electronic version of the data base that will be accessible on the World Wide Web; (4) archive soil samples that will serve as a resource to biologists interested in organisms not included in the survey; (5) identify locations of high diversity that should be targeted for more in-depth study. This project is the first comprehensive study of microbiotic crust organisms, and as such it will provide a resource and database that potentially will be of use to ecologists, systematists, and rangeland managers for many years after the completion of the project.
