Physical Sciences and Mathematics Commons^™

Assessment Of Bridge Pier Response To Fire, Vehicle Impact, And Air Blast, Chen Fang, Qusai Alomari, Daniel G. Linzell

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Highway bridges exposed to intentional or unintentional fire followed by combined vehicle impact and air blast are at risk of significant damage and, possibly, collapse. Limited studies examining the complex effects of these extreme demands on bridge support elements and parametrizing their response and damage are found in the open literature. Research that is presented is part of an ongoing numerical investigation examining round, multi-column, reinforced concrete (RC), bridge pier behavior subject to multi-hazard scenarios involving fire, vehicle impact, and air blast. Detailed nonlinear finite element analysis models of single columns and multi-column piers supported by a pile foundation system …

Using Airborne And Desis Imaging Spectroscopy To Map Plant Diversity Across The Largest Contiguous Tract Of Tallgrass Prairie On Earth, Hamed Gholizadeh, Adam P. Dixon, Kimberly H. Plan, Nicholas A. Mcmillan, Rober G. Hamilton, Samuel D. Fuhlendorf, Jeannine Cavender-Bares, John A. Gamon

School of Natural Resources: Faculty Publications

Grassland ecosystems are under threat globally, primarily due to land-use and land-cover changes that have adversely affected their biodiversity. Given the negative ecological impacts of biodiversity loss in grasslands, there is an urgent need for developing an operational biodiversity monitoring system that functions in these ecosystems. In this paper, we assessed the capability of airborne and spaceborne imaging spectroscopy (also known as hyperspectral imaging) to capture plant α-diversity in a large naturally-assembled grassland while considering the impact of common management practices, specifically prescribed fire. We collected a robust insitu plant diversity data set, including species composition and percent cover from …

Increased Abundance Of The Common Raven Within The Ranges Of Greater And Gunnison Sage-Grouse: Influence Of Anthropogenic Subsidies And Fire, Jonathan B. Dinkins, Lindsey R. Perry, Jeffrey L. Beck, Jimmy D. Taylor

USDA Wildlife Services: Staff Publications

The common raven (Corvus corax; raven) is native to North America and has increased in abundance, especially throughout western North America, during the last century. Human subsidies have facilitated raven dispersal into less suitable habitats and enabled these populations to maintain higher annual survival and reproduction. Concomitantly, overabundant raven populations are impacting other native at-risk species such as the greater sage-grouse (Centrocercus urophasianus) and potentially the Gunnison sage-grouse (C. minimus). Using Breeding Bird Survey data from 1995–2014, we evaluated raven count data to quantitatively describe changes in abundance and expansion into sagebrush ( …

Plant Community Response To Disturbances In Nebraska Sandhills Upland Prairie, Josiah D. Dallmann

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Historically, disturbances shaped prairie ecosystems both directly through events like fire and soil moving by animals, as well as indirectly through dynamic rainfall patterns and periodic flux in seed availabilities. We hypothesized that the implementation of several distinct disturbance events in Nebraska Sandhills upland prairie would have measurable effects on plant community composition. We implemented mid-spring fire, soil disturbance in the form of disking, seed addition of native forbs on disked plots, as well as early summer supplemental watering (to mimic minor rainfall events during abnormally dry periods) during 2016 and 2017. Plant community response during the first and second …

Complex Vegetation Dynamics At The Fire-Grazing-Drought Nexus, Christine H. Bielski

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The discipline of ecology long ago moved away from viewing systems as static entities where disturbance processes, environmental stochasticity, and spatiotemporal variability play minor roles in determining ecosystem structure and function. Ecological theory continue to develop frameworks and statistical techniques capable of describing the inherent complexity in natural systems. However, in dealing with the complexity in nature, many applied disciplines have yet to adopt such frameworks or statistical techniques. The objective of this study was bridge the gap between ecological theory and application by using complex systems theory to describe grassland vegetation dynamics at the fire-grazing-drought nexus. Chapters 2 and …

Spatial Continuous Biomass Burning Emission Inventory: Application To Wrf-Chem Model Over The Northern Sub-Saharan African Region, Yun Yue

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Fire, as a significant global source of trace gases and aerosol particles, plays an important role in perturbations of the chemical and physical properties of the atmosphere. Fire products from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on polar-orbiting satellites Terra and Aqua are largely used in several emission inventories. However, the MODIS fire products have inherent limitations due to the following reasons: (a) they cannot detect fires underneath clouds; (b) the fire detection sensitivity decreases at the edge of MODIS scan where viewing angles and MODIS pixel sizes are bigger than at nadir; and (c) there are gaps between MODIS …

Flying By Fire: Making Controlled Burns Safer For Humans And Uavs, Rebecca Horzewski, Carrick Detweiler

UCARE Research Products

A temperature sensing circuit board was developed that will allow Nimbus Lab's controlled burn starting UAV to react to the temperatures around it.

Foraging Decisions Underlying Restricted Space Use: Effects Of Fire And Forage Maturation On Large Herbivore Nutrient Uptake, Edward J. Raynor, Anthony Joern, Jesse B. Nippert, John M. Briggs

School of Natural Resources: Faculty Publications

Recent models suggest that herbivores optimize nutrient intake by selecting patches of low to intermediate vegetation biomass. We assessed the application of this hypothesis to plains bison (Bison bison) in an experimental grassland managed with fire by estimating daily rates of nutrient intake in relation to grass biomass and by measuring patch selection in experimental watersheds in which grass biomass was manipulated by prescribed burning. Digestible crude protein content of grass declined linearly with increasing biomass, and the mean digestible protein content relative to grass biomass was greater in burned watersheds than watersheds not burned that spring (intercept; F_{1,251 …}

Biomass Burning, Land-Cover Change, And The Hydrological Cycle In Northern Sub-Saharan Africa, Charles Ichoku, Luke T. Ellison, K. Elena Willmot, Toshihisa Matsui, Amin K. Dezfuli, Charles K. Gatebe, Jun Wang, Eric M. Wilcox, Jejung Lee, Jimmy Adegoke, Churchill Okonkwo, John Bolten, Frederick S. Policelli, Shahid Habib

Department of Earth and Atmospheric Sciences: Faculty Publications

The Northern Sub-Saharan African (NSSA) region, which accounts for 20%–25%of the global carbon emissions from biomass burning, also suffers from frequent drought episodes and other disruptions to the hydrological cycle whose adverse societal impacts have been widely reported during the last several decades. This paper presents a conceptual framework of the NSSA regional climate system components that may be linked to biomass burning, as well as detailed analyses of a variety of satellite data for 2001–2014 in conjunction with relevant model-assimilated variables. Satellite fire detections in NSSA show that the vast majority (>75%) occurs in the savanna and woody …

Soil Chemical Responses To Fire Seasonality And Frequency In A Texas Grassland, Domingo M. Jariel Jr., R. James Ansley, Betty A. Kramp, David L. Jones

The Prairie Naturalist

On a clay-loam mixed grassland dominated by honey mesquite (Prosopis glandulosa Torr.) in northern Texas, we quantified soil pH, soil organic carbon (OC), electrical conductivity (EC), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) in response to various effects of summer and winter fire treatments from 1991–1996. We conducted summer fire between August and September, and winter fire between January and March. Treatments that included summer fires increased soil pH, EC, Na, and Cu and temporarily decreased soil OC and Mn (P ≤ 0.05). The winter fire treatment …

Soil Health After Intense Ponderosa Pine Forest Fire In North Central Nebraska, Amanda Hefner

Department of Environmental Studies: Undergraduate Student Theses

In late July 2012, the Region 24 Complex fire consumed over 76, 000 acres of north central Nebraska. This area consists of ponderosa pine forest with high densities of eastern redcedar, deciduous hardwood forest, and Sandhills prairie. This incredible event provided an occasion to examine the effect of the fire on soil nitrification and soil erosion at The Nature Conservancy’s Niobrara Valley Preserve. Eighteen 900m² plots were established in regions chosen for their topographic location (footslope, midslope, and ridgetop), forest density, and directional slope (north vs. south facing slope). Each plot was split into nine subplots with 25 erosion …

State Of The Art Satellite And Airborne Marine Oil Spill Remote Sensing: Application To The Bp Deepwater Horizon Oil Spill, Ira Leifer, William J. Lehr, Debra Simecek-Beatty, Eliza Bradley, Roger Clark, Philip Dennison, Yongxiang Hu, Scott Matheson, Cathleen E. Jones, Benjamin Holt, Molly Reif, Dar A. Roberts, Jan Svejkovsky, Gregg Swayze, Jennifer Wozencraft

United States Department of Commerce: Staff Publications

The vast and persistent Deepwater Horizon (DWH) spill challenged response capabilities, which required accurate, quantitative oil assessment at synoptic and operational scales. Although experienced observers are a spill response's mainstay, few trained observers and confounding factors including weather, oil emulsification, and scene illumination geometry present challenges. DWH spill and impact monitoring was aided by extensive airborne and spaceborne passive and active remote sensing.

Oil slick thickness and oil-to-water emulsion ratios are key spill response parameters for containment/cleanup and were derived quantitatively for thick (>0.1 mm) slicks from AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) data using a spectral library approach based …

Recruitment Of Larix Sibirica Ledeb. In Closed Forest Stands, On Clear-Felling Sites And At Fire-Sites In The Forests Of Mongolia, Vasiliy T. Yarmishko, Nikolay N. Slemnev

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The paper deals with recruitment patterns in larch forests of Mongolia following anthropogenic impacts (felling, fires), and describes successional trends in highland forest communities. It is established that mass seed recruitment of Larix sibirica Ledeb. took place during anomalous combinations of hydrothermal conditions supposedly occurring at periods of about 100 years. During the last decades, frequent fires of various intensities put serious constraints on reforestation of the larch, and induced successional trends in disturbed forests.

Spatial Complexity In Fragmenting Amazonian Rainforests: Do Feedbacks From Edge Effects Push Forests Towards An Ecological Threshold?, Graeme S. Cumming, Jane Southworth, Xanic J. Rondon, Matthew Marsik

United States Department of Commerce: Staff Publications

Deforestation and resulting landscape fragmentation are important concerns in many tropical areas. Deforestation is a complex process with many potential feedback loops, many of which are ignored in models that attempt to interpolate forest loss based on past deforestation rates. In addition, most ecological studies of the impacts of deforestation have focused on landscapes that are already fragmented. These studies ignore the fact that edge effects, such as anthropogenic fire, reach their maximum well before habitat connectivity is lost and may create positive feedbacks that result in further fragmentation. We developed a simple model to explore the potential influence of …

Effect Of Fires On Soil Organic Carbon Pool And Mineralization In A Northeastern China Wetland, Hongmei Zhao, Daniel Q. Tong, Qianxin Lin, Xianguo Lu, Guoping Wang

United States Department of Commerce: Staff Publications

Fire occurs frequently over wetland, but little is known of its impact on soil carbon variations and carbon mineralization, process that are potentially important in global carbon cycle. To investigate this issue, we have designed and implemented a two-year field campaign to quality the effects of fire seasonality and frequency on soil carbon abundance and carbon mineralization in a wetland of the Sanjiang Plain in Northeastern China. A total of 4 burning experiments were conducted over 12 wetland plots from autumn 2007 to spring 2009. Our results show that after burning soil organic carbon (OC) increased in the burned soils …

Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn

United States Geological Survey: Staff Publications

Effects of wildfire on amphibians are complex, and some species may benefit from the severe disturbance of stand-replacing fire. Boreal Toads (Bufo boreas boreas) in Glacier National Park, Montana, USA increased in occurrence after fires in 2001 and 2003. We used radio telemetry to track adult B. boreas in a mosaic of terrestrial habitats with different burn severities to better understand factors related to the post-fire pulse in breeding activity. Toads used severely burned habitats more than expected and partially burned habitats less than expected. No toads were relocated in unburned habitat, but little of the study area …

Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn

United States Geological Survey: Staff Publications

Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree·days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads colonized burned wetlands because they were warmer than unburned wetlands and selected specific …

Responses Of Pond-Breeding Amphibians To Wildfire: Short-Term Patterns In Occupancy And Colonization, Blake R. Hossack, Paul Stephen Corn

United States Geological Survey: Staff Publications

Wildland fires are expected to become more frequent and severe in many ecosystems, potentially posing a threat to many sensitive species. We evaluated the effects of a large, stand-replacement wildfire on three species of pond-breeding amphibians by estimating changes in occupancy of breeding sites during the three years before and after the fire burned 42 of 83 previously surveyed wetlands. Annual occupancy and colonization for each species was estimated using recently developed models that incorporate detection probabilities to provide unbiased parameter estimates. We did not find negative effects of the fire on the occupancy or colonization rates of the long-toed …

Gastrointestinal Morphology Of Female White-Tailed And Mule Deer: Effects Of Fire, Reproduction, And Feeding Type, Teresa J. Zimmerman, Jonathan A. Jenks, David M. Leslie Jr.

United States Geological Survey: Staff Publications

We assessed variation in length, width, density, and surface enlargement factor of papillae; rumen and intestinal digesta weight; intestinal length; and intestinal tissue weight of reproductive and nonreproductive female white-tailed (Odocoileus virginianus) and mule deer (O. hemionus) using similar burned and unburned habitat. Deer were collected from study areas in Custer and Pennington counties, South Dakota, in and adjacent to a wildfire burn. Length of papillae and enlargement factor of papillae surface of white-tailed deer and mule deer were greater in burned than unburned habitat, and dry weight of rumen digesta of white-tailed deer was greater …

Fire Does Not Alter Vegetation In Infertile Prairie, Johannes M.H. Knops

School of Biological Sciences: Faculty Publications

The paradigm in prairie ecology is that fire is one of the key factors deter-mining vegetation composition. fire can impact grassland ecosystems in various ways, including changing plant species composition and inducing nitro-gen loss. I found that 17 years of different burning frequencies in infertile grassland had only a minor impact on the vegetation composition and diversity. The only major impact from increasing the frequency of fires was a decrease of Poa pratensis abundance. However, other plant species did not r-spond to the change in Poa abundance. This result contrasts with previous studies in savannas and more productive grasslands, where …

A Vegetation And Fire History Of Lake Titicaca Since The Last Glacial Maximum, Gina M. Paduano, Mark B. Bush, Paul A. Baker, Sherilyn C. Fritz, Geoffrey O. Seltzer

Department of Earth and Atmospheric Sciences: Faculty Publications

Fine-resolution fossil pollen and charcoal analyses reconstruct a vegetation and fire history in the area surrounding Lake Titicaca (3810 m, Peru/Bolivia) since ca. 27,500 cal yr BP (hereafter BP). Time control was based on 26 accelerator mass spectrometer (AMS) radiocarbon dates. Seventeen AMS dates and 155 pollen and charcoal samples between ca. 17,500 BP and ca. 3,100 BP allow a centennial-scale reconstruction of deglacial and early- to mid-Holocene events. Local and regional fire signals were based on the separation of two charcoal size fractions, ≥180 μm and 179–65 μm. Charcoal abundance correlated closely with the proportion of woody taxa present …