Joshua trees are the most unique and recognizable plants of the Mojave Desert, but the most amazing thing about them may be their unusual pollination biology. Joshua trees are pollinated exclusively by two species of yucca moths – tiny grey moths that carry pollen to the trees in their mouths. The moths in turn reproduce by laying their eggs inside the Joshua tree flowers. Thus, both the moths and the Joshua trees are dependent on each other for reproduction. The future of this remarkable pollination system is threatened, however, by ongoing global climate change. Computer models predict that within the next 100 years Joshua trees may disappear from much of their current range, and emerging demographic data suggest that many populations in the southern Mojave Desert are already on their way to extinction. It is possible that the species may be able to survive by migrating to more temperate environments further north, but the trees’ capacity to escape warming climates will depend on how quickly they are able to colonize new habitats. A lonely valley in central Nevada, on the northern edge of the Joshua trees’ range, creates a ‘natural laboratory’ for studying how Joshua trees are responding to global climate change. At this site, eastern and western subspecies of Joshua trees, along with their respective yucca moth pollinators, meet and interbreed. By tracking spatial patterns in plant demography at this site, it may be possible to predict which Joshua trees -if any- will win the The Great Race North. During a four-day citizen science program, participants in this course will contribute to ongoing scientific research on the population ecology of this most famous Mojave Desert species.
Food, lodging, gas and supplies are available in Alamo which is approximately 30 miles from the research site. Primitive camping is also available much closer to the research site.
