Modeling Sediment Accumulation in North American Playa Wetlands in Response to Climate Change, 1940–2100

Playa wetlands on the west-central Great Plains of North America are vulnerable to sediment infilling from upland agriculture, putting at risk several important ecosystem services as well as essential habitats and food resources of diverse wetland-dependent biota. Climate predictions for this semi-arid area indicate reduced precipitation which may alter rates of erosion, runoff, and sedimentation of playas. We forecasted erosion rates, sediment depths, and resultant playa wetland depths across the west-central Great Plains and examined the relative roles of land use context and projected changes in precipitation in the sedimentation process. We estimated erosion with the Revised Universal Soil Loss Equation (RUSLE) using historic values and downscaled precipitation predictions from three general circulation models and three emissions scenarios. We calibrated RUSLE results using field sediment measurements. RUSLE is appealing for regional scale modeling because it uses climate forecasts with monthly resolution and other widely available values including soil texture, slope and land use. Sediment accumulation rates will continue near historic levels through 2070 and will be sufficient to cause most playas (if not already filled) to fill with sediment within the next 100 years in the absence of mitigation. Land use surrounding the playa, whether grassland or tilled cropland, is more influential in sediment accumulation than climate-driven precipitation change

Recital Program

Recital program for students of Lexie Hansen, Haley Bradshaw, Eliza Nelson, Kylee Paul, Mark Gubler, Lauren Malouf, Holly Ganoe, and Janessa LeMmon.https://digitalcommons.usu.edu/music_programs/1106/thumbnail.jp

Characteristics of wildfire-igniting lightning in the western United States

Includes bibliographical references.2015 Fall.Annually, over half the wildfires on federal lands in the conterminous western United States are caused by lightning. However, broad-scale characteristics of wildfire-igniting lightning flashes are poorly understood, and limit our ability to predict what role climate change might have on lightning patterns and in turn on future patterns of wildfire. I investigated lightning-wildfire relationships by comparing the characteristics of lightning flashes that start fires to those that do not across 29 ecoregions in the western US from 2003-2007. After accounting for ecoregional variation, I found little meaningful difference in characteristics of igniting flashes including the proportion of positive flashes, proportion of negative flashes with long continuing current, number of strokes per flash (multiplier), or flash peak current (all attributes thought to be related to ignition potential). In contrast, I found that wildfires are associated with significantly higher lightning flash densities near fire locations compared to further away. However, the role of flash density varied significantly between ecoregions. Given the non-uniqueness of igniting flashes, simple proxies such as storm frequency or intensity may be sufficient to estimate likelihood of lightning ignitions under changing climatic conditions. However, these estimates must be mediated based on ecosystem response to potential ignitions

Avian Conservation in the Prairie Pothole Region, Northern Great Plains: Understanding the Links between Climate, Ecosystem Processes, Wetland Management, and Bird Communities

Historically, the Prairie Pothole Region (PPR) of North America was characterized by myriad semi-permanent, seasonal, and temporary wetlands interspersed among rivers in a context of prairie uplands. These wetlands have supported millions of en route and breeding wetland-dependent birds. Today, expanses of the PPR landscape are dominated by intensive agriculture, and many of the remaining habitats have been impacted by altered water regimes, increasing sedimentation, and changes in plant communities. Climate change is likely to cause further alterations by shifting the seasonal availability and distribution of water and vegetation communities. Climate change will also affect the phenology (annual recurrence of phenomena) of vegetation green-up, seed production, and insect emergence. In concert, these changes could alter the capacity of PPR habitats to support waterbirds. Consequently, natural-resource managers and conservation planners in the PPR have an immediate need for effective tools that can evaluate the effects these changes would have on wetland-dependent bird communities. To that end, a team of U.S. Geological Survey (USGS) scientists and cooperators with expertise in the sciences of climate, hydrology, and ecology has convened to address the potential impacts of climate change on wetland-dependent bird species in the PPR. This team is developing a set of products, including: (1) a synthesis of current knowledge on the interrelationships of climate, wetlands condition, and bird communities; and (2) data on historical and future projections of climate (these projections will be formatted for use in standard mapping software). We will develop models to: (1) forecast effects and biological outcomes of climate change on water quality and quantity in wetlands and riverine ecosystems of the PPR; (2) elucidate relationships between climate, streamflow, water management, and wetland plants; and (3) understand and forecast bird responses to changing habitat conditions and to the timing of resource availability. The outcomes of this research will inform and assist managers and conservation professionals tasked with conserving populations of wetland-dependent birds

Senior Thesis Collections

PLEASE NOTE: Where applicable, the audio has been removed from this file due to copyrighted material. The garments shown here were created in response to the Senior Thesis design challenge: create a complete collection that reflects your philosophy or the essence of your personal vision

Street Policing, Injecting Drug Use and Harm Reduction in a Russian City: A Qualitative Study of Police Perspectives

We undertook a qualitative exploration of police perspectives on injecting drug use and needle and syringe access among injecting drug users (IDUs) in a Russian city which has witnessed explosive spread of HIV associated with drug injecting. Twenty-seven in-depth qualitative interviews were conducted in May 2002 with police officers of varying rank who reported having regular contact with IDUs. All interviews were tape-recorded, transcribed, translated and coded thematically. Accounts upheld an approach to policing which emphasised high street-based visibility and close surveillance of IDUs. IDUs were depicted as ‘potential criminals’ warranting a ‘pre-emptive’ approach to the prevention of drug-related crime. Street policing was described as a means of maintaining close surveillance leading to the official registration of persons suspected or proven to be users of illicit drugs. Such registration enabled further ongoing surveillance, including through stop and search procedures. While aware of drug users' reluctance to carry injecting equipment linked to their fears of detention or arrest, accounts suggested that the confiscation of previously used injecting equipment can constitute evidence in relation to drugs possession charges and that discovery of clean injecting equipment may be sufficient to raise suspicion and/or further investigation, including through stop and search or questioning. Our findings suggest an uneasy relationship between street policing and needle and syringe access, whereby policing strategies can undermine an HIV prevention ethos promoting needle and syringe accessibility among IDUs. We conclude that facilitating partnerships between policing agencies and HIV prevention initiatives are a critical feature of creating environments conducive for risk reduction