Ecology and Distribution of Desert Truffles in Western North America

Abstract

The four major deserts of North America are situated in the western USA and northern Mexico: the Great Basin Desert, Mojave Desert, Sonoran Desert, and Chihuahuan Desert. Together they cover about 1,244,000 km2. Two genera of North American desert truffles, Carbomyces with three species and Stouffera with one, are endemics. A third genus, Mattirolomyces with one endemic species in North America, occurs in both northern and southern hemispheres from mesic forests to semiarid and arid habitats in three other continents. The largest and also the coldest of the North American deserts, the Great Basin Desert, and the smallest and hottest Mojave have each produced only one desert truffle collection so far. The Sonoran, also relatively hot, accounts for only two. In contrast, the relatively cold Chihuahuan, which extends from southern New Mexico south into Mexico’s central plateau, has produced 17 truffle collections from New Mexico and about 30 from Chihuahua. Too little data are available on habitat requirements of the North American desert truffles to explain this skewed distribution. However, it likely reflects a concentration of early collecting efforts around the Jornada Basin Long-Term Ecological Research Site, originally established in 1912, that has attracted desert researchers for a century. Ten of the 17 collections in the Jornada vicinity were found by mycologist W. H. Long and his students and associates in 1941. More recently, active collecting in the Chihuahuan Desert of Chihuahua, Mexico, has added about 30 desert truffle collections. Both seem to reflect a convergence of the right people at the right place in a good truffle year.