Chapter D. Summary and conclusions.

Abstract/Summary

Hydrological and biological investigations were done during 2005 and 2006 in cooperation with the U.S. National Park Service at Darwin Falls in Death Valley National Park, Piute Spring in Mojave National Preserve, and Fortynine Palms Oasis in Joshua Tree National Park where discharge from springs or groundwater seeps sustains rare perennial streams in the otherwise arid environment of the Mojave Desert in which surface water is scarce and usually ephemeral. The study collected data on water quantity (discharge), temperature, water quality, and endemic anuran (frog and toad) populations and their health. In addition, a single survey of endemic anuran populations and their health was completed at Rattlesnake Canyon in the Joshua Tree National Park. Results from this study were compared to historical data, and can provide a baseline for future hydrological and biological investigations to evaluate health and sustainability of the resource as well as its response to changing climate and increases in human use.