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ContributorsDarton, Nelson Horatio (Author) / Fred Harvey (Publisher)
Created1917
DescriptionBooklet describing a geological survey of the Grand Canyon. Four editions: 1917, 1929, 1936, 1950.
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ContributorsBiggs, Thomas H. (Author) / Arizona Geological Survey (Publisher)
Created2006-06
Description

Throughout the southwestern United States, vegetation in what historically was grassland has changed to a mixture of trees and shrubs; exotic grass species and undesirable shrubs have also invaded the grasslands at the expense of native grasses. The availability and amount of soil nutrients influence the relative success of plants,

Throughout the southwestern United States, vegetation in what historically was grassland has changed to a mixture of trees and shrubs; exotic grass species and undesirable shrubs have also invaded the grasslands at the expense of native grasses. The availability and amount of soil nutrients influence the relative success of plants, but few studies have examined fire effects on soil characteristics in a temporal, spatial, and species group-specific fashion. Likewise, few studies have tied fire effects and ecological aspects to the underlying geology. Our research investigates the effects of fire events on selected soil characteristics pH, nitrate (NO3-), plant-available phosphorus (PO4-3), and total organic carbon (TOC) on native grass-, exotic grass-, and mixed grass-dominated plots distributed on four different geological surfaces. Treated and control plots were sampled prior to burn treatment and at intervals after the burns. In addition to new geologic mapping of the study areas, results indicate the geologic substrate is the most important variable for explaining pH, NO3- and PO4-3 values in the soils. Dominant grass type – native, non-native, or mixed – had little effect on the response of soil geochemistry to fire events: post-burn results indicate vegetation was a significant factor only for TOC. Recovery to pre-burn levels varies with characteristic: there were no significant initial differences between vegetation types, but significant differences in NO3-, PO4-3, and TOC amounts occur as a result of fire events, geological characteristics, and time. The research helps identify the soil response to fire and the recovery times of soil characteristics, further defines which fire frequency is optimal as a management strategy to maximize soil macronutrient contents, and illustrates the important role geology plays in grassland ecosystems.

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ContributorsAustin, Diane E. (Author) / Wolf, Barbara (Author) / The Pride Publishing Company (Publisher)
Created2001-10
Description

The research presented here documents institutional and organizational factors affecting fire management on tribal lands. Two case studies of fires occurring on tribal lands in Arizona provide insights into how these factors converged to influence the course of events. This study considers historic as well as current conditions and events

The research presented here documents institutional and organizational factors affecting fire management on tribal lands. Two case studies of fires occurring on tribal lands in Arizona provide insights into how these factors converged to influence the course of events. This study considers historic as well as current conditions and events because these affect whether or not people are receptive to information, to planning, and to working together. Though it focuses on decision making within tribes and agencies responsible for tribal lands, its findings are relevant for other locations as well.

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ContributorsAustin, Diane E. (Author) / Gerlak, Sherri (Author) / Smith, Carolyn (Author) / The Pride Publishing Company (Publisher)
Created2000-11-25
Description

Tribes have a direct government-to-government relationship with the U.S. government wherein no decisions about their lands and people are made without their consent. In Arizona, for example, American Indian reservations occupy nearly 30 percent of the land. Native Americans have a legal and moral claim to significant quantities of water

Tribes have a direct government-to-government relationship with the U.S. government wherein no decisions about their lands and people are made without their consent. In Arizona, for example, American Indian reservations occupy nearly 30 percent of the land. Native Americans have a legal and moral claim to significant quantities of water as well. Because of their special legal standing in the United States, tribes are not just another group of stakeholders to be considered in the research and policy process. The purpose of this paper is to provide a legal and political background for interactions between the United States and tribal governments and provide models for those interactions, with special attention to research and outreach.

ContributorsWitcher, James (Author) / The Pride Publishing Company (Client)
Created1994
Description

This summary report overviews a State of Arizona and U. S. Department of Energy funded drilling project to determine if near-term hot dry rock (HDR) geothermal potential exists in the eastern portion of the White Mountains region of Arizona. A 4,505 feet deep slim-hole exploratory well, Alpine1/Federal, was drilled within

This summary report overviews a State of Arizona and U. S. Department of Energy funded drilling project to determine if near-term hot dry rock (HDR) geothermal potential exists in the eastern portion of the White Mountains region of Arizona. A 4,505 feet deep slim-hole exploratory well, Alpine1/Federal, was drilled within the Apache-Sitgreaves National Forest at Alpine Divide near the Alpine Divide camp ground about 5 miles north of Alpine, Arizona in Apache County (Figure 1). A comprehensive technical report, in two parts, details the results of the project. Part 1, Alpine1/Federal, Drilling Report, discusses the drilling operations,
logging program, permitting and site selection for the hole. Part 2, Temperature Gradients, Geothermal Potential, and Geology, summarizes the temperature gradients, heat flow, geothermal potential, and subsurface geology.