Now showing items 4270-4289 of 6384

• Paleoecology and ecomorphology of the giant short-faced bear in Eastern Beringia

The short-faced bear (Arctodus simus) was a widespread Tremarctine bear indigenous to North America until its extinction around 11,500 BP. Arctodus inhabited Pleistocene ice-free refugia in Eastern Beringia (the northwestern limit of its range) until at least 20,000 BP. Because of its gracile, long-legged build and extremely large size, most paleontologists believe this bear was a high-speed pursuit predator which had preyed on the largest herbivores of Pleistocene North America. Alternatively, energetic arguments have been used to suggest that Arctodus was too large to be carnivorous and evolved its large size within an herbivorous or omnivorous niche. To test these competing hypotheses, I reconstructed aspects of Arctodus' trophic position and paleodiet by analyzing stable isotope ratios ($\delta\ \sp{13}$C and $\delta\ \sp{15}$N) in bone collagen extracted from east Beringian fossils. Other bears and carnivores from Beringia were analyzed to help interpret the results. Isotopes reveal that Arctodus was highly carnivorous, it fed on herbivores which consumed C3 vegetation, and it did not eat salmon. The herbivore/omnivore hypothesis is thus rejected. Predatory hypotheses predict that we should find certain morphological features in a predatory bear which would enhance one or more of the following skills: top running speed, acceleration, or maneuverability at high speeds. I re-analyzed the postcranial morphology of Arctodus and used data on running speed and bone strength in other large mammals to show that a bear the size of Arctodus with long, gracile limbs would not have been able to endure the extreme dynamic forces incurred during predatory activities. Instead, Arctodus' morphology and body size indicate it had evolved to maximize locomotor efficiency using a pacing gait. I suggest that Arctodus evolved as a specialized scavenger adapted to cover an extremely large home range in order to seek out, procure, and defend large-mammal carcasses from other carnivores. By modeling herbivore populations and their mortality, I show that enough carcass biomass was being produced in Pleistocene Beringia to make this scavenging niche energetically feasible. The model helps show that Arctodus' extinction probably is best tied to a reduction of year-round carcasses on the landscape, a condition which arose in the Holocene when the herbivore fauna became less diverse and began to experience more seasonal mortality.
• Paleoecology of Twin Cays: interpretation of palynological, isotopic, and stomatal proxies in a peat core from Belize

Reconstructions of Holocene climate from numerous mid- and high-latitude sites have identified millennial-scale cool and arid intervals at 8,200 and 4,200 yrs. B.P. The global nature of these events can only be established by examination of Holocene climate records from low latitude sites. The Central American island of West Twin Cays was chosen as the study location due to its thick peat deposits, which allow for the reconstruction of Holocene vegetation, sea level, and climate for the Belize coastal region. Rhizophora mangle (red mangrove) dominated the island's vegetation since its formation 8,200 cal. yrs. B.P. Alternating periods dominated by dwarf or tall R. mangle reflect changes in phosphorus and nitrogen availability. Heightened Myrsine-type pollen concentrations between 6,300 and 4,200 cal. yrs. B.P. suggests lower sea levels and drier climates. Regional warming accompanied by increased precipitation in the middle to late Holocene is recorded by an increase in exotic Pinus concentrations. These vegetation shifts correlate with regional Central American climate changes and westem Atlantic sea level shifts at 8,200 and 4,200 cal. yrs. B.P. More importantly, these data link Central American changes to worldwide climate events.
• Paleoenvironmental changes at treeline: a 6,500 year long pollen and stable isotope record

Combined pollen, macrofossil and stable-isotope records from two lakes in the sub-alpine zone of the north-central Alaska Range indicate significant changes in vegetation and lake productivity during the past 6̃750 ¹⁴C yrs BP. These changes are associated with neoglacial cooling and climate variations during the Little Ice-Age (LIA). Highest spruce densities occurred during a period from 5,000 ¹⁴C yrs BP and 2,500 ¹⁴C yrs BP and coincided with the onset of cooler and moister climate. The shifts in climate, which resulted in increased effective moisture levels in Central Alaska, possibly shifted the competitive balance towards spruce and against tundra taxa. Lake productivity declined as climate cooled. A brief episode of climate amelioration between 1,500 ¹⁴C yrs BP and 800 ¹⁴C yrs was followed by cooking events of the LIA which resulted in decreased spruce densities in the sub-alpine forest-tundra zone and a possible lowering in treeline at higher elevation.

Vegetation and plant resources can impact forager mobility and subsistence strategies. However, misconceptions about the preservation of organics in subarctic archaeological contexts and underestimations of the importance of plant resources to foraging societies limit paleoethnobotanical research in high-latitude environments. This research draws upon concepts from human behavioral ecology to address questions relating to site seasonality, plant resource use, land use, and deposition and taphonomy. The model developed in this thesis outlines expectations of seasonal archaeobotanical assemblages for Late Pleistocene and Holocene sites in interior Alaska. I consider these expectations in light of plant macroremains found in anthropogenic features from Components 1 and 3 (approximately 13,300 and 11,500 cal yr BP, respectively) at the Upward Sun River site, located in central Alaska. Site-specific methods include bulk sampling of feature matrix in the field and wet-sieving matrix in the laboratory to collect organic remains. Analytical measures of density, diversity, and ubiquity tie together the model expectations and the results from Upward Sun River. The dominance of common bearberry in the Component 1 archaeobotanical assemblage meets the expectations of a late summer or fall occupation. This suggests that site occupants may have focused on mitigating the risk of starvation in winter months by foraging for seasonally predictable and storable resources. The variability in results from the Component 3 features could relate to longer-term occupations that extended from mid-summer to early fall, in which site occupants foraged for locally available and predictable plant resources such as blueberry or low-bush cranberry species. In this thesis, I argue that large mammal resources were a key component in Late Pleistocene and Holocene subsistence strategies. However, foragers were flexible in their behavior and also targeted small mammals, fish, waterfowl, and plant resources in response to environmental conditions and cultural preferences. The results illustrate the long-standing use of culturally and economically important plant resources in interior Alaska and draw attention to aspects of human behavior that are under-conceptualized in northern archaeology, such as the gender division of labor, domestic behavior, and potential impacts of plant resource exploitation on mobility and land use.
• Paleohydrology of a catastrophic flood release from Okmok caldera and post-flood eruption history at Okmok Volcano, Umnak Island, Alaska

Okmok caldera, located on the northeastern end of Umnak Island, Alaska, contained a 5.8 x 10⁹m³ lake that catastrophically drained as a result of failure of the 2050 yr. B.P. caldera rim between 1560 and 1010 yr. B.P. Flow competence equations, dam-break models, and the Simplified Dam-Break computer model were used to estimate the paleohydrology of the flood. Models indicate that the peak discharge at the breach in the caldera rim was at least 5.8 x 10⁴ m³/s, and the maximum possible discharge was 1.9 x 10⁶ m³/s. A second smaller flood release occurred 190 yr B.P., coinciding with the 1817 A.D. eruption, and destroyed a small Aleut village at Cape Tanak. Stratigraphic analysis reveals that Okmok Volcano has maintained a high level of volcanic activity following the large flood release. Major eruptive events producing air-fall tephra deposits average 1 every 80 years since 1010 yr. B.P.
• Paleomagnetism Of The Wrangellia And Alexander Terranes And The Tectonic History Of Southern Alaska

Wrangellia was the first Alaskan tectonostratigraphic terrane to be widely accepted as allochthonous with respect to North America. There is, however, considerable disagreement as to the age of emplacement of this terrane as well as the hemisphere in which it originated. Some 800 paleomagnetic samples were collected from 24 localities in southern Alaska to elucidate the paleolatitude translation history of Wrangellia and other associated terranes. Data of known polarity from the Skolai Group (Pennsylvanian/Permian) strongly suggest that Wrangellia originated at 10-15 degrees North latitude. The Permian Pybus Dolomite yields a 9 degree S paleolatitude and suggests that the Alexander terrane moved southward in late Paleozoic and Triassic time. Evaluation of geologic data indicates that the Wrangellia and Alexander terranes amalgamated in an oceanic setting in mid to Late Jurassic time. Paleomagnetism of the Brothers Volcanics (Alexander terrane) and MacColl Ridge Formation (Wrangellia) documents a low latitude for both terranes during the Cretaceous, thereby precluding a pre-Tertiary age of emplacement for the amalgamated superterrane. Speculative apparent polar wander paths for Wrangellia and the Alexander terranes, in addition to geologic and biogeographic constraints, allow development of the following hypothetical tectonic model. Both the Alexander and Wrangellia terranes originated in the northern hemisphere adjacent to western North America in mid-paleozoic and late Paleozoic times, respectively. The Alexander terrane moved into the southern hemisphere during the Paleozoic and Wrangellia began moving southward in the Late Triassic or Early Jurassic. These two terranes amalgamated in mid to low southern paleolatitudes in later Jurassic time and formed part of a composite terrane, here termed the Southern Alaska superterrane. This superterrane began northward translation in Late Jurassic time, accreting to North America in Tertiary time.
• Paleopedology, palynology, and geochronological interpretation of alluvial paleosols, Cenomanian Dunvegan formation, Alberta, Canada

The Dunvegan Formation is a mid-Cretaceous deltaic deposit exposed in the Rocky Mountain foothills of Alberta and British Columbia along the Peace River Valley. Intrinsic features of Dunvegan Formation paleosols understood through micromorphology, geochemical, and mineralogical analysis provide a paleoclimatic interpretation of warm to cool temperate. Micromorphological and geochemical analysis lead to reconstruction of the depositional and pedogenic histories of the five primary paleosols of this study. Preserved palynomorphs of the paleosols are primarily composed of fern spores with much less abundant conifer and cycad species. The paleoclimate based on the palynomorphs is humid and ranges from cool temperate to subtropical. The overall paleoenvironmental interpretation based on both paleosols and palynology is humid cool to warm temperate. Geochronology using the ⁴⁰Ar/³⁹Ar dating method was implemented in an effort to date pedogenesis. This technique needs further refinement in order to be successful in dating paleosols. The multi-proxy approach of this study lead to a more complete interpretation of the climatic, pedogenic and depositional history and should be used in the future.
• Palmer Center for Sustainable Living

Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska Fairbanks, 2009
• Palmer Research Center

Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska Fairbanks, 1993-11
The Agricultural and Forestry Experiment Station, University of Alaska Fairbanks, operates the Palmer Research Center. Included are offices and laboratory facilities in Palmer and the Matanuska Experiment Farm outside of Palmer. Researchers at these locations solve problems related to agriculture, forestry and the environment. State and federal agencies, private industry and the university sponsor and fund the research.
• Paluwiigum beksdid Sugt'stun aggaggtatuguut Port Graham's Sugt'stun workers plan

This Sustainability Plan was written for the Native Village of Port Graham for their language program, Tamamta Litnaurluta. The Native Village of Port Graham, a federally recognized tribe that serves the Sugpiaq people of Port Graham, Alaska, received a three-year language immersion grant from the Administration for Native Americans (ANA) to provide language instruction for students ranging from Head Start through the 12th grade. The ANA grant will expire at the end of the 2015-2016 school year. This Sustainability Plan provides programmatic recommendations for the Native Village of Port Graham to consider for continuing Tamamta Litnaurluta beyond the life of the grant. The Sustainability Plan includes a funding plan, which contains grants the Tribe can pursue, and a sustainable income plan that address possible scenarios for the operating costs of the language program.
• Pandalid shrimps in a tidewater-glacier fjord, Aialik Bay Alaska

Vertical migration and food habits of pandalid shrimps in Aialik Bay, a tidewater-glacier fjord, were related to suspended sediment load and available food resources. Suspended sediments from subglacial streams resulted in Secchi depths of 0.4-1.0 m near the glacier, increasing with distance from the glacier to 1.0-5.0 m near the sill. A large proportion of the Pandalus borealis and P. goniurus populations responded to reduced light in the upper bay by remaining in midwater throughout the day and night. Shrimp food resources, represented by zooplankton and benthos, were reduced in abundance and diversity near the glacier as compared to the region near the sill. Shrimps fed more intensively near or at the bottom than in midwater. The most common items in stomachs of P. borealis were unidentifiable organic matter (84.5%), sediment (83.1%), crustacean fragments (60.9%), identified crustaceans (16.9%), mollusks (16.3%), foraminiferans (15.1%), and plant material (10.0%).
• Pandering to glory: Sheldon Jackson's path to Alaska

Presbyterian missionary Sheldon Jackson is a celebrated figure in Alaska history. He is known predominantly for his efforts facilitating the establishment of public schools for Alaska Native people during the late nineteenth century. Jackson's methods have been historically overlooked as being reform-minded initiatives characteristic of Indian assimilation. As a result, historians have concluded that Jackson was a humanitarian with benevolent intentions. Unfortunately, such assessments ignore Jackson's educational platform, which was built upon fictitious slander against indigenous people and the manipulation of Christian women. In addition to speaking tours, Jackson published many editorials, articles, and books alleging that Alaska Native people were barbarous monsters. The propaganda Jackson employed in Alaska was no different from the propaganda he used against Mormons and Native Americans. However, Jackson was maligned for his strategy in the continental United States, whereas in Alaska he was celebrated as a reformer and an authority figure due to ignorance about the northern territory. Alaska captured the public imagination, and Jackson lied about Alaska Native culture for the remainder of his career in order to maintain his Christian enterprise.