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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

A comparison of visitors who contact the Forest Service with those who do not: A case study in Cave Creek Canyon, Arizona

Jensen, Mari Nelms, 1953- January 1996 (has links)
This study investigates characteristics and attitudes of users of Cave Creek Canyon (CCC), a U.S. Forest Service (USFS) recreation site in southeast Arizona, and compares those who contacted the USFS with those who did not. User attitudes and opinions were assessed in 1992 through roadside interviews and a mail survey (278 respondents). Twenty percent of respondents had contacted the USFS regarding CCC management. Contacters and non-contacters do not differ with regard to gender, age, education, or income. A significantly higher proportion of contacters are local residents. Both groups identified a biota-based activity as most important. Contacters visit CCC more frequently and are more likely to pursue nature study or scientific research. For 26 of the 31 attitudes and opinions questions, the majority of contacters agreed with the majority of non-contacters. These results suggest that opinions expressed by the vocal minority may reflect the opinions of the majority of users.
182

Nutritional content of forage in Sonoran pronghorn habitat, Arizona

Fox, Lisa Marie, 1964- January 1997 (has links)
I determined if Sonoran pronghorn (Antilocapra americana sonoriensis) could meet water and mineral requirements through consumption of forage. I sampled vegetation using dry weight rank and comparative yield methods in southwestern Arizona from June 1995 to May 1996 to determine preformed water, nutrient content, mineral content, and vegetation abundance. Water and nutrient content of plants varied between 2 sites and among 5 seasons (P ≤ 0.05). Plants consumed by pronghorn were higher in moisture and nutrients (P ≤ 0.05) than non-forage species. I constructed a model for Sonoran pronghorn diet based on field data. I used the model to describe dietary intake. Water intake predicted by diet models ranged from 1.1 to 6.1 L/animal/day; often exceeding predicted total water requirements (1.8-3.4 L/animal/day). Models predicted that forage provided adequate water for pronghorn during 5 seasons at 1 of 2 study sites and deficiencies for 5 of 11 minerals at both study sites.
183

Potential impacts of rangeland manipulations on desert rodent communities

Fitzgerald, Christopher Stephen, 1972- January 1997 (has links)
I compared vegetation features and rodent communities between manipulated and non-manipulated ranges in southeastern Arizona during summers 1996 and 1997. I also examined the effect of burying traps to determine if this procedure altered trap sensitivity. I used two-way analysis of variance or paired t-tests for all comparisons and identified relationships between rodents and vegetation features with linear regression. There was no difference (P ) in rodent species richness or population size between mechanically treated and reference areas. Rodent species richness and population size were greater on ungrazed compared to grazed areas (P ), but there was no difference in rodent diversity (P = 0.13). Prescribed fire did not have an obvious impact on rodent species richness or population size, though there seemed to be an increase in kangaroo rats following the burn. Buried traps may have demonstrated a reduction in sensitivity because I caught fewer animals in those traps compared to non-buried traps (P = 0.087).
184

Movement and recruitment of flannelmouth suckers in the Paria and Colorado rivers, Arizona

Thieme, Michele Lorraine, 1971- January 1997 (has links)
Sonic-tagged flannelmouth suckers made long distance and local movements; 12.5% of fish moved ≥ 98 km downstream and 40% stayed within Glen Canyon. Motivation for long distance movements could be spawning or food related. A controlled flood of 1,274 m³/sec did not displace flannelmouth suckers downstream or interrupt spawning. The majority (62%) of fish moved into the impounded mouth of the Paria River. Spawning occurred as evidenced by capture of adults over spawning areas and collection of young-of-year (YOY) in spring and summer. From May-September 1996, YOY flannel mouth suckers were captured in the impounded mouth of the Paria River. Successful rearing of YOY fish was attributed to the presence of a warm, slackwater area in the mouth. Formation of this area is dependent upon antecedent Colorado and Paria river flows and their effect on sediment deposition in the mouth of the Paria River.
185

Trichomonas gallinae in avian populations in urban Tucson, Arizona

Hedlund, Charise Ann, 1966- January 1998 (has links)
I studied Trichomonas gallinae, a flagellated protozoan that is the causative agent of the avian disease trichomoniasis. The purpose of my study was to assess (1) the incidence of trichomonads in wild birds, (2) the prevalence of trichomonads in water sources utilized by wild birds, and (3) possible methods to control the transmission of trichomonads in water sources utilized by wild birds. I trapped 403 birds during 1994 and 1995. Approximately 1/3 of these birds tested positive for T. gallinae, however, none exhibited any signs of lesions. I collected water samples from 10 bird baths, isolating flagellated protozoa from 2 of them. I could not identify the species of flagellated protozoa. I determined that high temperatures (50°C), near ultra-violet radiation, and natural sunlight are effective against trichomonads. In addition, the highest effective dilutions of Chlorox, Nolvasan, and distilled white vinegar active against trichomonads were determined.
186

Fire history and stand structure in the Huachuca Mountains of Southeastern Arizona

Danzer, Shelley Rae, 1951- January 1998 (has links)
Historically, wildfires in mixed conifer forests of Southwestern sky islands were frequent events. Dendrochronological methods were used to reconstruct fire regimes and stand age structures in the Huachuca Mountains of Southeastern Arizona. Pre-settlement (i.e., before ca. 1870) fire intervals ranged from 4 to 10 years, with many fires spreading over the entire sample area. Stand age distributions show an increase in more shade-tolerant tree species. Although ponderosa pine is still the dominant overstory tree species, recent recruitment is predominantly southwestern white pine and Douglas-fir. Establishment of Ft. Huachuca in 1877 was a precursor to extensive use of timber, mineral, range and water resources in the Huachuca Mountains. The fire regime was altered at this time, with only one subsequent widespread surface fire recorded in 1899. Settlement era land-use practices may be responsible for changes in stand structure and composition.
187

Habitat use by endangered masked bobwhites and other quail on the Buenos Aires National Wildlife Refuge, Arizona

King, Nina Monique, 1958- January 1998 (has links)
Masked bobwhites used sites with more structural diversity than what was available on the Buenos Aires National Wildlife Refuge during 1994-96. Selected habitat variables that adequately predicted habitat use by masked bobwhites included percent herbaceous canopy cover, structure at 15 cm and 2 m, forb richness, and season. Masked bobwhite used more structural diversity than Gambel's and scaled quail. Gambel's quail had broader habitat tolerances than either masked bobwhite or scaled quail. Selected habitat variables that revealed differences among masked bobwhites, Gambel's quail, and scaled quail included percent woody canopy cover, structure at 15 cm, forb richness, and season. A historic perspective revealed that masked bobwhites used sacaton grasses that grew along the floodplains as important escape cover. I believe that we need to restore the integrity of the grassland ecosystems including the floodplain if we are to recover masked bobwhite quail.
188

Use of GIS for natural and cultural resource management: A computerized rule-based activity planning system on San Nicolas Island, Point Mugu Naval Air Weapons Station

Casaus, Kevin Ricardo, 1969- January 1998 (has links)
Managing natural and cultural resources on a department of Defense (DoD) facility presents a difficult challenge. Many DoD facilities contain sensitive resources that are protected by a myriad of state and federal laws. Resource protection is complicated further since, while an important endeavor, it often is subjugated to the fulfillment of the military mission. The ability for resource managers to compare, analyze, and integrate complex resource data determines the speed and efficiency in which planning decisions are made. Geographic Information Systems (GIS) can help resource managers make informed accurate resource management decisions in an expedient manner. This project expanded a GIS database for San Nicolas Island (SNI), part of the Point Mugu Naval Air Weapons Station CA, and created prototype computer application to assist in resource management. This application, the Point Mugu Computerized Activity Planning System (PM-CAPS), assists managers in selecting locations on SNI for military activities to occur while minimizing the negative impacts on sensitive cultural and natural resources.
189

Arizona terrestrial vertebrate species richness: An application of Arizona GAP GIS thematic processing

McCarthy, Scott Beach January 1998 (has links)
The National Gap Analysis Program (GAP) is currently developing geographic themes in a Geographic Information System format for statewide analyses of biodiversity issues. This study uses several of the Arizona GAP themes to demonstrate how they might be utilized in resources planning. By overlaying the Arizona GAP vertebrate themes, species richness maps were created. The species richness maps were intersected with the Arizona GAP landcover and land management layers to analyze how the richness areas are distributed across the landscape. Areas of high species richness were then analyzed for how well they are represented within existing conservation areas. The development of vertebrate distribution models is also discussed, since their accuracy greatly influences the species richness maps development.
190

Water use by Emory oak in southeastern Arizona: Estimation by sap-flow measurements

Folkerts, Shaun Hajo, 1972- January 1999 (has links)
Water use by mature and sprout (coppice) forms of Emory oak (Quercus emoryi) was estimated by the sap-flow method. Five standards and five coppice trees were sampled in an area that had been harvested for fuelwood and five mature trees were sampled in an uncut area. Differences were recognized between coppice and standards in the cut area and between coppice trees and mature trees from the uncut area. Regression equations were derived relating estimated annual water use to tree diameter, height, and crown measurements for both cut- and uncut-area trees. Seasonal water use by each tree form showed relationship to precipitation, but little relationship to temperature and relative humidity. Woodland density and tree size measurements facilitate extrapolation of water use from the 15 sampled trees to a per area basis. Water use was approximately 1900 cubic meters per hectare per year, based upon drc measurements, for the uncut area and 3168 cubic meters for the cut area. Estimated water use on a per unit area was approximately 1.67 times greater for the cut area than the uncut area.

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