Hypogeous fungi (truffles and false truffles) are ideal organisms for studying the relationships of fungi and their plant hosts. These fungi form obligate, ectomycorrhizal associations with trees and are also dependent on rodents for spore dispersal. The Great Basin is an ideal setting for such studies because hypogeous fungi are found in widely scattered forest "islands" separated by inhospitable desert lacking appropriate ectomycorrhizal hosts to serve as "stepping-stones" for dispersal between islands. A survey on hypogeous fungi on forest islands in the Great Basin, an area of 714,854 sq. km., is proposed to supplement the 1500 collections, virtually, the only collections from most of the Great Basin, that have been amassed from limited collecting in the area. Data from the collections will be used to expand an existing database, produce a hypogeous mycoflora of the region, and test several theories of biogeography and evolutionary biology. In addition, information from the specimens will be valuable in selecting fungi for artificial inoculation of tree seedlings for reforestation in the Great Basin. The data will also be useful to wildlife managers interested in the dietary items available to small mammals. The specimens themselves will provide DNA for testing phylogenetic relationships, factors controlling macrospeciation, and the genetic structure of isolated populations of hypogeous fungi.
