Great Basin Naturalist Memoirs


This study was done to document the variability in time of phenological events at different locations on the Nevada Test Site. Phenological events for desert shrubs were recorded, and rainfall and temperature data were gathered for four to six years at eight sites that are located within the northern Mojave Desert, the southern Great Basin Desert, and the transitional zone between them. Results have been graphically displayed to show the variability in phenological activity encountered during the study period and also to show the general correlation between these events and the environmental regime that triggered a particular phenological stage among different species. For a given location a four-to-six-week range in beginning events from year to year was common. In addition to the usual spring activity that normally followed winter rain and snow, most shrub species resumed new growth, and six species were observed to flower and fruit following rare summer or early fall rains. In comparison to surrounding locations, the closed drainage basins within the study area have lower temperatures at night that result in a delay of phenological events in most shrubs.