Thesis (M.A.)--University of Wyoming, 2007. / An interdisciplinary thesis in American Studies and Environment and Natural Resources. Title from PDF title page (viewed on Oct. 31, 2008). Includes bibliographical references (p. 117-129).

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references.

Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references. Online version available on the World Wide Web.

No description available.

Bibliography: p. 191-200. Persistence mechanisms of Erodiophyllum elderi are investigated in terms of life history strategies and patchy population theory.

As the capital city of the Eastern Province of Saudi Arabia, Dammam has undergone rapid economic development in the last fifty years. Desert areas on the outskirts of the city have become outdoor recreational places and picnicking areas, despite not being designed for such use nor having basic facilities. In fact, local residents are finding these sites more attractive than the projects established specifically by the city authorities for recreational purposes. This research examines if socio-cultural factors in Saudi society are the only reasons for this pattern of outdoor recreation and also, the resulting impact on the desert environment itself. A mixed-methods approach is used, based on questionnaires, go-along interviews and participant observation, in order to understand how people are using the desert and what it means to them. The physical and ecological condition of the popular sites was also compared with the condition of an unused and also, a protected area in the same region. In addition, a Global Positioning System was used to establish the mutually acceptable distances maintained between desert picnickers to satisfy privacy and territorial needs. The research shows that Dammam residents use desert areas as outdoor recreation spaces to escape from their urban environment, allowing women, particularly, to be close to nature and retain their privacy, besides experiencing a feeling of freedom and undertaking numerous activities with the full confidence that no stranger will intrude. It also shows that for many users, the silence of the desert and its remoteness enhances spirituality, and contemplation of God’s natural creation. In general, it builds a picture of family members and also groups of single males gathering in the desert for specific recreational reasons, highlighting the importance of such recreation in local people’s lives across different ages and genders. This increasing number of desert users, however, is found to be damaging the desert environment and its long-term sustainability is threatened by vehicle use, litter, fires and erosion. This is an urgent issue for residents and the professional and governmental bodies responsible for its management. Thus, this research also establishes basic guidelines for new developments that can better manage and protect the desert environment.

xxviii, 463 p. : ill., maps. A print copy of this title is available through the UO Libraries under the call number: KNIGHT F868.M65 J45 1991 / The environmental context and chronology of the transition from Early Holocene Lake Mojave to Middle Holocene Pinto cultural complexes of the southern California deserts has long been debated. This dissertation re-examines that debate, based on excavations at two major sites, and a rethinking of our most basic assumptions concerning culture change, cultural ecology, site formation processes, and dating techniques. Archaeological data recovered from two Lake Mojave/Pinto sites at Fort Irwin, in the Central Mojave Desert, were analyzed in order to track chronologically sensitive shifts in Lake Mojave-Pinto artifact assemblages through time. The archaeological assemblages recovered from Rogers Ridge and the Henwood sites were carefully analyzed into 36 depositional/analytical components for this task. Defining and chronologically ordering these assemblages required systematic consideration of artifact distributions and the development and application of 3 obsidian hydration rates based on associations with twelve 14C dates. The analysis shows that the Pinto Complex occurred in three phases. Phase I, ca. 8,200 to 7,500 BP, is marked by the addition of Pinto points to the Lake Mojave assemblage and a continuation of the basic Lake Mojave settlementsubsistence patterns. Phase II, 7,500 to 5,000 BP, is marked by the gradual disappearance of Lake Mojave points from the archaeological assemblages. Dramatic decreases in assemblage size and increases in assemblage diversity mark changing logistical strategies to infrequent and specialized site use. Phase III, 5,000 to 4,000 BP, is marked by a strong predominance of Pinto points and slightly larger assemblages. Patterns of variation among assemblages suggest that logistical strategies continued to emphasize infrequent and specialized site useage. The link between environmental change and shifting settlement-subsistence strategies was apparently relatively direct during the Pinto period, Environmental changes during the Early Holocene (11,000 to 8,000 BP) Mojave Desert led to subsistence stress among populations of the Pinto Complex. Cultural adjustments resulted in smaller human populations moving through larger home territories. It is suggested that critical thresholds in communication and mating networks were crossed which resulted in the collapse of social systems in the Mojave Desert about 7,000 BP. / Committee in charge: C. Melvin Aikens, Ann Simonds, Don E. Dumond, and William Loy

abstract: Biological diversity is threatened by increasing anthropogenic modification of natural environments and increasing demands on natural resources. Sonoran desert tortoises (Gopherus morafkai) currently have Candidate status under the Endangered Species Act (ESA) based on health and habitat threats. To ensure this animal persists in the midst of multiple threats requires an understanding of the life history and ecology of each population. I looked at one physiological and one behavioral aspect of a population of tortoises at the Sugarloaf Mountain (SL) study site in central Arizona, USA. I used 21 years of capture-recapture records to estimate growth parameters of the entire population. I investigated habitat selection of juvenile tortoises by selecting 117 locations of 11 tortoises that had been tracked by radio-telemetry one to three times weekly for two years, selecting locations from both summer active season and during winter hibernation. I compared 22 microhabitat variables of tortoise locations to random SL locations to determine habitat use and availability. Male tortoises at SL reach a greater asymptotic length than females, and males and females appear to grow at the same rate. Juvenile tortoises at the SL site use steep rocky hillsides with high proportions of sand and annual vegetation, few succulents, and enclosed shelters in summer. They use enclosed shelters on steep slopes for winter hibernation. An understanding of these features can allow managers to quantify Sonoran desert tortoise habitat needs and life history characteristics and to understand the impact of land use policies. / Dissertation/Thesis / M.S. Applied Biological Sciences 2012

Knowledge of the thermal ecology of a species can improve model predictions for temperature-induced population collapse, which in light of climate change is increasingly important for species with limited distributions. Here, we use a multi-faceted approach to quantify and integrate the thermal ecology, properties of the thermal habitat, and past and present distribution of the diurnal, xeric-adapted, and active-foraging Namibian lizard Pedioplanis husabensis (Sauria: Lacertidae) to model its local extinction risk under future climate change scenarios. We asked whether climatic conditions in various regions of its range are already so extreme that local extirpations of P. husabensis have already occurred, or whether this micro-endemic species is adapted to these extreme conditions and uses behavior to mitigate the environmental challenges. To address this, we collected thermoregulation and climate data at a micro-scale level and combined it with micro-and macroclimate data across the species' range to model extinction risk. We found that P. husabensis inhabits a thermally harsh environment, but also has high thermal preference. In cooler parts of its range, individuals are capable of leaving thermally favorable conditions-based on the species' thermal preference-unused during the day, probably to maintain low metabolic rates. Furthermore, during the summer, we observed that individuals regulate at body temperatures below the species' high thermal preference to avoid body temperatures approaching the critical thermal maximum. We find that populations of this species are currently persisting even at the hottest localities within the species' geographic distribution. We found no evidence of range shifts since the 1960s despite a documented increase in air temperatures. Nevertheless, P. husabensis only has a small safety margin between the upper limit of its thermal preference and the critical thermal maximum and might undergo range reductions in the near future under even the most moderate climate change scenarios.

Doctorat en philosophie et lettres / info:eu-repo/semantics/nonPublished