干旱区生态环境知识资源中心(Arid): Source, Discharge, and Chemical Characteristics of Selected Springs, and the Abundance and Health of Associated Endemic Anuran Species in the Mojave Network Parks.

Arid

报告编号	PB2017102250
	Source, Discharge, and Chemical Characteristics of Selected Springs, and the Abundance and Health of Associated Endemic Anuran Species in the Mojave Network Parks.
	Martin, P; Schroeder, R. A; Smith, G. A; Flint, L. L; Gallegos, E; Fisher, R. N.
英文摘要	Hydrological and biological investigations were done during 2005 and 2006 in cooperation with the U.S. National Park Service to investigate the source, discharge, and chemical characteristics of selected springs and the abundance and health of endemic anuran (frog and toad) species at Darwin Falls in Death Valley National Park, Piute Spring in Mojave National Preserve, and Fortynine Palms Oasis in Joshua Tree National Park. Discharge from the springs at these sites sustains isolated riparian habitats in the normally dry Mojave Desert. Data were collected on water quantity (discharge) and quality, air and water temperature, and abundance and health of endemic anuran species. In addition, a single survey of the abundance and health of endemic anuran species was completed at Rattlesnake Canyon in Joshua Tree National Park. Results from this study were compared to limited historical data, where they exist, and can provide a baseline for future hydrological and biological investigations to evaluate the health and sustainability of the resource and its response to changing climate and increasing human use. Radiocarbon dating of the water yielded estimated ages of about 7,000 years at Piute Spring and about 3,000 years at Darwin Spring, and tritium-helium-3 dating indicated an age of less than 2 years at Fortynine Palms Oasis. Stable hydrogen-isotope ratios were used to interpret an average altitude of recharge of 2,348 meters for Darwin Spring (about 1,415 meters higher than the altitude of Darwin Spring), 1,668 meters for Piute Spring (about 766 meters higher than the altitude of Piute Spring), and 1,400 meters for the Upper Pool at Fortynine Palms Oasis (about 543 meters higher than the altitude of the Upper Pool). Water-quality data collected for this study did not appear to be sensitive to trends in precipitation or seasonality in the Darwin Falls and Piute Spring study areas; however, it was sensitive to trends in Fortynine Palms Oasis where salinity increased by more than 10 percent during the 2 years of this study. Such a rapid response is consistent with the comparatively short travel time of less than 2 years from recharge to discharge at Fortynine Palms Oasis. Of the 14 trace elements analyzed, only concentrations of uranium at Fortynine Palms Oasis and arsenic at Darwin Spring were above drinking water standards; both constituents are derived from natural sources in the drainage basin and, therefore, are likely to have accumulated as a result of natural processes. Endemic anuran species were surveyed at Darwin Falls for the western toad (Anaxyrus boreas) and the red-spotted toad (Anaxyrus punctatus), at Piute Spring for the red-spotted toad, and at Fortynine Palms Oasis for the red-spotted toad and California treefrog (Pseudacris cadaverina). Historically, red-spotted toads were at the edge of their range at Darwin Falls, but they were not detected during this study and have not been detected since the early 1980s. The 2006 western toad population at Darwin Falls was estimated at 381 adults (95-percent confidence interval [CI] of 314–482). The population of red-spotted toads at Piute Spring was estimated at 1,153 adults (95-percent CI of 935–1,503). However, an elevated rate of abnormalities (approximately 5 percent) was recorded in red-spotted toads as well as the presence of the chytrid fungus, Bactrochochytrium dendrobatidis, at Piute Spring. In Joshua Tree National Park, the California treefrog now occupies only three of the seven historically occupied drainages. Populations of California treefrogs at Fortynine Palms Oasis have declined more than 50 percent from 288 in 1969–71 to 109 in 2006. A similar decline was observed in the populations of red-spotted toads at Fortynine Palms Oasis from 300 adults in 1969–71 to 155 adults (95-percent CI of 90–139) in 2006. The red-spotted
英文关键词	Ground water Flow models Watersheds Basins Arizona Mexico Permeability Groundwater recharge Water wells Evapotranspiration Hydrogeology Hydraulic properties Water levels Gradients Stream flow Computerized simulation Gravity
出版年	2015
语种	英语
国家	United States
来源学科分类	48G - Hydrology & Limnology ; 48B - Natural Resource Management
URL	http://r.cnki.net/KCMS/detail/detail.aspx?DbCode=KJBG&dbname=KJBGW&filename=5a02cb6531c97d1c38a8a5d3
来源机构	United States Geological Survey
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/273998
推荐引用方式 GB/T 7714	Martin, P,Schroeder, R. A,Smith, G. A,et al. Source, Discharge, and Chemical Characteristics of Selected Springs, and the Abundance and Health of Associated Endemic Anuran Species in the Mojave Network Parks.,2015.