Physical and Environmental Geography Commons^™

Niobrara National Scenic River Condition Assessment, Sunil Narumalani, Gary D. Willson, Christine K. Lockert, Paul B. T. Merani

United States National Park Service: Publications

Executive Summary

Niobrara National Scenic River spans a 122-km (76-mile) long reach of the Niobrara River in rural, north-central Nebraska. The scenic river encompasses 9,338 ha (23,074 acres) of land and water, all of which is in private ownership, except for about 320 ha (790 acres). Because the scenic river does not own land, it achieves management goals by coordinating and collaborating with federal, state, and local jurisdictions and private landowners.

The central Niobrara River Valley is often referred to as a “biological crossroads” with plant and animal species representative of northern boreal forest, eastern deciduous forest, rocky mountain coniferous …

United States Land Cover Land Use Change, Albedo And Radiative Forcing: Past And Potential Climate Implications, Christopher A. Barnes

Electronic Theses and Dissertations

Land Cover Land Use (LCLU) change affects Earth surface properties including albedo that impose a radiative forcing on the climate. Recent spatially explicit satellite derived contemporary LCLU, albedo, and projected LCLU data are used to study the impact of LCLU change from 1973 to 2000, and from 2000 to 2050, on albedo and surface radiative forcing for the conterminous United States. Four research hypotheses concerned with past and potential future climate implications of LCLU change are addressed. The research described in this dissertation makes an important contribution to advancing understanding of the role of LCLU change on the climate system, …

Tracking Bare Sand Mobilization Arising From Landscape Manipulations In The Grasslands Destabilization Experiment (Gdex) In The Nebraska Sandhills Using Imaging Spectroscopy, Benjamin Helder

The Journal of Undergraduate Research

The Grassland Destabilization Experiment (GDEX) is a landscape scale manipulative experiment initiated in 2004 in the Nebraska Sandhills to evaluate changes in surface properties following the abrupt loss of stabilizing vegetation. The GDEX features five treatments allocated among ten plots of 120 m in diameter (1.13 ha). The Aggressive Bare Sand protocol included chemical defoliation and subsequent shallow disking and raking in 2004 to devegetate the plot with periodic physical disturbance to maintain bare sand. The Long Term Disturbance (Press) protocol includes an initial chemical defoliation in May 2005 and seasonal spring reapplications, but no physical disturbance. Short Term Disturbance …

Combining A Dispersal Model With Network Theory To Assess Habitat Connectivity, Todd R. Lookingbill, Robert H. Gardner, Joseph R. Ferrari, Cherry E. Keller

Geography and the Environment Faculty Publications

Assessing the potential for threatened species to persist and spread within fragmented landscapes requires the identification of core areas that can sustain resident populations and dispersal corridors that can link these core areas with isolated patches of remnant habitat. We developed a set of GIS tools, simulation methods, and network analysis procedures to assess potential landscape connectivity for the Delmarva fox squirrel (DFS; Sciurus niger cinereus), an endangered species inhabiting forested areas on the Delmarva Peninsula, USA. Information on the DFS’s life history and dispersal characteristics, together with data on the composition and configuration of land cover on the peninsula, …

Extractive Reserves, David S. Salisbury

Geography and the Environment Faculty Publications

Extractive reserves are territories dedicated to environmental protection and the sustainable use of nature resources by traditional populations. Reserves follow a traditional land tenure model based on individual family and communal property rights to common areas, such as forest trails used to extract or harvest nontimber forest products. Although the extractive reserve concept originates in the tropical forests of the Brazilian Amazon, reserves have also been created in aquatic, floodplain, and savanna landscapes throughout Brazil. There are now 50 extractive reserves covering more than 10 million hectares, an area larger than Portugal, and more continue to be created. Despite their …

Climatic And Spatial Variations Of Mount Rainier's Glaciers For The Last 12,000 Years, Michael Leslie Hekkers

Dissertations and Theses

Regional paleoclimatic proxies and current local climate variables and were analyzed to reconstruct paleoglaciers in an effort to assess glacier change On Mount Rainier. Despite the dry and generally warm conditions (sea surface temperatures (SST) -0.15°C to +1.8°C relative to current temperatures), the previously documented McNeeley II advance (10,900 - 9,950 cal yr B.P.) was likely produced by air temperature fluctuations. The average SST record and the terrestrial climate proxies show cooling temperatures with continued dryness between McNeeley II and the Burroughs Mountain advance (3,442 - 2,153 cal yr B.P.). The paleoclimate during the Burroughs Mountain advance was both cool …

Identifying Potential Carbon Flux Responses To Shifting Hydroecological And Climactic Regimes In The Peace-Athabasca Delta, Caleb W. Light

Theses and Dissertations (Comprehensive)

The CO2 flux response of organic carbon stored in lake sediments and littoral peat contained in sensitive, northern wetlands may contribute to accelerating atmospheric CO2 concentrations. Temperature and moisture conditions are important variables that affect the rate and quantity of CO2 released to the atmosphere from organic matter stored in lake sediments and peat. Antecedent hydroecological conditions also influence the direction and magnitude of CO2 fluxes to the atmosphere in a changing environment. To better understand and characterize the role of antecedent conditions on CO2 fluxes, this study combines paleolimnological reconstructions with laboratory incubations of littoral peat and lake sediment …

Spatial And Spatial-Temporal Analysis Of Grizzly Bear Movement Patterns As Related To Underlying Landscapes Across Multiple Scales, Barbara Lynn Carra

Theses and Dissertations (Comprehensive)

Studying the movements of grizzly bears (Ursus arctos) in Alberta is imperative for scientifically informed management practices. To properly balance industry requirements with conservation imperatives, it is necessary to understand the spatial and spatial-temporal movement patterns of grizzly bears as they relate to underlying landscape properties. As part of the Foothills Research Institute Grizzly Bear Research Program, this dissertation explored both fine and largescale movement patterns generated from global positioning system (GPS) radiotelemetry data.

Between 1999 and 2005, grizzly bears were captured and radio-collared across western Alberta. The temporal resolution of GPS data collection had a large impact …

Controls On Terrestrial Evapotranspiration From A Forest-Wetland Complex In The Western Boreal Plain, Alberta, Canada, Scott M. Brown

Theses and Dissertations (Comprehensive)

The Western Boreal Plain (WBP) of North Central Alberta consists of a mosaic wetlands and aspen (Populus tremuloides) dominated uplands. This region operates within a moisture deficit regime where precipitation (P) and evapotranspiration (ET) are the dominant hydrologic fluxes. As such these systems are extremely susceptible to the slightest to the slightest climatic variability that may upset the balance between P and ET. Vegetation composition is the dominant control on wetland ET, and itself is extremely dynamic within these wetland environments, which can be attributed to varying moisture regimes along with micrometeorological variations. To address this variability in …

A Late-Quaternary Record Of Environmental Variability From Lake Sediment Cores, Wind River Range, Wyoming, Tyler Johnson

Dissertations and Theses @ UNI

Sediment cores from two alpine lakes in Wyoming's Wind River Range were collected and analyzed to establish a record of depositional and mineralogical variability. Due to the hydrologic setting and isolation of Fiddlers and Louis lakes, these cores yielded the longest continuous limnological record in the region that extends back nearly 20,000 years to full-glacial conditions, a rarity for alpine lakes in the western United States.

To develop a paleolimnological record for Fiddlers and Louis lakes, the sediment cores were analyzed using four laboratory techniques. These techniques included particle size analysis, x-ray diffraction, heavy mineral analysis, and loss-on-ignition. Radiocarbon ages …

The Transnational Networks Of Cultural Commodities: Peruvian Food In San Francisco, Kelsey Ann Brain

Dissertations and Theses

In a setting of increased movement, communication, and flows across space, commodity chain networks bring valued cultural commodities to transnational communities. This research examines the networks bringing foreign cuisine ingredients to Peruvian transnational communities in San Francisco, California. It seeks to answer three inter-related questions: 1) What are the origins and transportation networks bringing Peruvian food items to San Francisco; 2) Who controls and benefits from the movement of this food and resulting capital; and 3) How do networks vary for different classes of end consumers?

Chefs of ten Peruvian restaurants and ten Peruvian migrants in the San Francisco area …

Influence Of Wetland Landscape Structure On Duck Nest Success At Malheur National Wildlife Refuge, Oregon, Daniel Robert Craver

Geography Masters Research Papers

The decline of waterfowl populations and their requisite wetland habitats remains a concern. Because migratory bird refuges are often artificial landscapes of actively managed wetlands, and wildlife populations experience their greatest change during the breeding season, refuges should be designed to maximize breeding habitat. While past nest success studies have focused on at-nest variables, new approaches are needed to evaluate the effect of composition and configuration of plant communities at the landscape scale. This study aims to quantify landscape patterns within individual refuge management units to determine influence upon historical nesting success averages of ducks at Malheur National Wildlife Refuge …