Differences in soil physical, chemical and mineralogical properties between inhabited and uninhabited Arctomecon californica habitats

Vascular plant endemism to gypsum soils in arid environments is fairly rare; in southern Nevada few plant species are known to exist solely on gypsum soils and the explanation for why they exist on these soils is even less understood. One such species, commonly known as Las Vegas Bearpoppy (Arctomecon californica), is believed to be a gypsophile endemic occurring on substrates derived from the Moenkopi and Horse springs geological formations in southeastern Nevada and northwestern Arizona. During the past two decades, populations of A. californica have been declining mostly around the rapidly developing urban areas on public lands on the outskirts of the Las Vegas Valley. This research was conducted in order to assess the relationship between A. californica and the soils it inhabits. Soils from the Tule Springs area in North Las Vegas were analyzed for physical, chemical and the mineralogical properties in areas inhabited and uninhabited by A. californica. Results show that soil surficial characteristics significantly differ between populated and unpopulated A. californica sites. (Abstract shortened by UMI.)