Publications

No abstract available.

In the spring of 1996, a nine-day test flood from Glen Canyon Dam involved the deepest and largest hypolimnetic withdrawals from the penstocks and the river outlet works (ROW) since 1986, interacting with ongoing hydrodynamic and stratification patterns to enhance freshening of the hypolimnion of Lake Powell reservoir and its tailwaters. Prior to the test flood, a six-year drought had...

No abstract available.

Bromus tectorum is an exotic annual grass that currently dominates many western U.S. semi-arid ecosystems, and the effects of this grass on ecosystems in general, and soil biota specifically, are unknown. Bromus recently invaded two ungrazed and unburned perennial bunchgrass communities in southeastern Utah. This study compared the soil food-web structure of the two native grassland...

The introduction of nonnative plant species may decrease ecosystem stability by altering the availability of nitrogen (N) for plant growth. Invasive species can impact N availability by changing litter quantity and quality, rates of N2-fixation, or rates of N loss. We quantified the effects of invasion by the annual grass Bromus tectorum on N cycling in an arid grassland on the Colorado...

No abstract available.

A release from Glen Canyon Dam during March-April 1996 was designed to test the effectiveness with which the riparian environment could be renewed with discharges greatly in excess of the normal powerplant-restricted maximum. Of primary concern was the rebuilding of sand deposits along the channel sides that are important to the flora and fauna along the river corridor and that provide...

The papers in this volume are contributions from federal, state, and private sector researchers, who have come together to share scientific information with land managers on the Colorado Plateau. This Proceedings is the third in a series of publications that focuses on providing information to land managers on baseline scientific information pertaining to physical, cultural and...

Lava Falls Rapid is the most formidable reach of whitewater on the Colorado River in Grand Canyon and is one of the most famous rapids in the world. Although the rapid was once thought to be controlled by the remnants of lava dams of Pleistocene age, Lava Falls was created and is maintained by frequent debris flows from Prospect Canyon. We used 232 historical photographs, of which 121...

On 25-28 October 1993 in Flagstaff, Arizona, the National Biological Service Colorado Plateau Research Station (formerly National Park Service Cooperative Park Studies Unit) and Northern Arizona University hosted the Second Biennial Conference of Research on the Colorado Plateau. The conference theme focused on research, inventory, and monitoring on the federal, state, and private lands...

The 19 papers in this volume were selected from the 46 presentations given at the First Biennial Conference on Research in Colorado Plateau National Parks. The overall theme for this meeting was research, inventory, and monitoring in National Park Service units on the Colorado Plateau. The conference, held in Flagstaff Arizona, on 22-25 July 1991, was sponsored by the National Park...

With continued exploitation of the Cerro Prieto, Mexico, geothermal field, there is increasing evidence that the hydrogeologic model developed by Halfman and co-workers presents the basic features controlling the movement of geothermal fluids in the system. In mid–1987 the total installed capacity at Cerro Prieto reached 620 MWc, requiring a large rate of fluid production (more than 10...