Agricultural Science Commons^™

Impact Of Solar Ultraviolet-B On The Proteome In Soybean Lines Differing In Flavonoid Contents, Chenping Xu, Joe H. Sullivan, Wesley M. Garrett, Thomas J. Caperna, Savithiry Natarajan

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) was used to systematically investigate the impact of solar ultraviolet- B (UV-B) radiation on the soybean leaf proteome. In order to investigate the protective role of flavonoids against UV-B, two isolines of the Clark cultivar (the standard line with moderate levels of flavonoids and the magenta line with reduced flavonoids) were grown in the field with or without natural levels of UV-B. The 12-day-old first trifoliates were harvested for proteomic analysis. More than 300 protein spots were reproducibly resolved and detected on each gel. Statistical analysis showed that 67 protein spots were significantly (P < 0.05) affected by solar UV-B. Many more spots were altered by UV-B in the magenta line than in the standard line. Another 12 protein spots were not altered by UV-B but showed significantly (P < 0.05) different accumulations between the two lines, and for most spots the line-specific differences were also observed under UV-B exclusion. Most of the differentially accumulated spots were identified by mass spectrometry. The proteins were quite diverse, and were involved in metabolism, energy, protein destination/storage, protein synthesis, disease/defense, transcription, and secondary metabolism. The results suggest that high levels of flavonoids lead to a reduction in UV-B sensitivity at the proteomic level.

Phylogenetic Relationships And Genetic Diversity Of The Usda Vigna Germplasm Collection Revealed By Gene-Derived Markers And Sequencing, Ming Li Wang, Noelle Barkley, Graves Gillaspie, Gary A. Pederson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Phylogenetic relationships in the USDA Vigna germplasm collection are somewhat unclear and their genetic diversity has not been measured empirically. To reveal interspecific phylogenetic relationships and assess their genetic diversity, 48 accessions representing 12 Vigna species were selected, and 30 gene-derived markers from legumes were employed. Some high-quality amplicons were sequenced. Indels (insertion/deletions) were discovered from the sequence alignments that were specific identifiers for some Vigna species. With regard to revealing polymorphisms, intron-spanning markers were more effective than exon-derived markers. These gene-derived markers were more successful in revealing interspecific polymorphisms than intraspecific polymorphisms at both the DNA fragment and sequence …

Pollen From The Exoskeletons Of Stable Flies, Stomoxys Calcitrans (Linnaeus 1758), In Gainesville, Florida, U.S.A., David M. Jarzen, Jerome Hogsette

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Stable flies are an important pest of humans and livestock. Despite being blood feeders, they also visit flowers to eat nectar. Stable flies with pollen adhering to their exoskeletons were collected at the University of Florida Horse Teaching Unit and taken to the Paleobotany and Palynology Laboratory at the Florida Museum of Natural History for processing and identification. The pollen on all the specimens was identified as Carolina willow, Salix caroliniana Michaux 1803. This small shrub or tree is found throughout Florida in wetland areas. This study demonstrates the utility of pollen analysis in interdisciplinary studies.

Biotinyl-Methyl 4-(Amidomethyl)Benzoate Is A Competitive Inhibitor Of Human Biotinidase, Keyna Kobza, Kittichai Chaiseeda, Gautam Sarath, James M. Takacs, Janos Zempleni

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Posttranslational modification of histones by biotinylation can be catalyzed by both biotinidase (BTD) and holocarboxylase synthetase. Biotinylation of histones is an important epigenetic mechanism to regulate gene expression, DNA repair, and chromatin remodeling. The role of BTD in histone biotinylation is somewhat ambiguous, given that BTD also catalyzes removal of the biotin tag from histones. Here, we sought to develop BTD inhibitors for future studies of the role of BTD in altering chromatin structure. We adopted an existing colorimetric BTD assay for use in a novel 96-well plate format to permit high-throughput screening of potential inhibitors. Biotin analogs were chemically …

Comparison Of Corn And Switchgrass On Marginal Soils For Bioenergy, Gary E. Varvel, Kenneth P. Vogel, Robert B. Mitchell, R. F. Follett, J. M. Kimble

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Crop residues such as corn (Zea mays L.) stover are viewed as an abundant and inexpensive source of biomass that can be removed from fields to produce bioenergy. Assumptions revised form include that with minimum or no-tillage farming methods, there will be no deleterious production or environmental effects. A long-term field study was established in eastern Nebraska, USA, to compare the switchgrass managed as a biomass energy crop versus no-till corn on a non-irrigated site, marginal for row-crop production, in the western Corn Belt. Our objective in this paper is to report on corn stover removal effects on corn …

Chapter 19. Remediation Of Drinking Water For Rural Populations, W. J. Hunter

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Nitrate is the most common nitrogen contaminant in raw water supplies. In rural areas agricultural activities that involve the use of fertilizers and animal manures are major sources of nitrate contamination. Several processes are currently available that can effectively remove nitrate from raw water. Systems that are suitable for small rural communities include reverse osmosis, ion exchange, and electrodialysis. However, all of these systems move nitrate from raw water and concentrate it in a reject water or brine. Disposal of the reject water can be a major expense as well as an environmental issue. Several emerging systems are under development …

Auditing And Assessing Air Quality In Concentrated Feeding Operations, N. A. Cole, R. Todd, B. Auvermann, D. B. Parker

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The potential adverse effects of concentrated animal feeding operations (CAFO) on the environment are a growing concern. The air quality issues of most concern to CAFO vary but generally include ammonia, hydrogen sulfide, particulate matter, volatile organic compounds, greenhouse gases, and odors. Air pollutants may be regulated by federal and state laws or by nuisance complaints. The United States Environmental Protection Agency, and poultry, swine, and dairy industries recently agreed to the National Air Emissions Monitoring System to fund research on atmospheric emissions from production farms in the United States. Air quality regulations may be based on actual emissions, atmospheric …

Evaluation Of Beef Cattle Operations Utilizing Different Seasons Of Calving, Weaning Strategies, Postweaning Management, And Retained Ownership, R. E. Kruse, M. W. Tess, E. E. Grings, R. E. Short, R. K. Heitschmidt, W. A. Phillips, H. S. Mayeux

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Data from a 3-yr study in Montana were utilized to evaluate impacts of season of calving, weaning strategy, and retained ownership of steer calves on enterprise profitability. Calving seasons were late winter (LW), early spring (ES), or late spring (LS). Each season had 2 weaning times: 190 (LW190, ES190) or 240 (LW240, ES240) d for LW and ES, and 140 (LS140) or 190 (LS190) d for LS. Backgrounding options included shipping steers to Oklahoma (OK1), or backgrounding in Montana to a constant age (MT2) or weight (MT3). Steers from OK1 and MT2 were finished in Oklahoma in confinement or via …

Nebraska Promotes Sorghum And Pearl Millet Food Processing In East Africa, Intsormil

INTSORMIL Impacts and Bulletins

Sorghum and millet are ideal crops for many parts of Africa. However, sorghum and millet’s use as food sources for large urban populations in West Africa is hampered by 1) lack of infrastructure for conveying and demonstrating the food value of sorghum and millet to small business investors, 2) limitations on the supply of high quality grains to processors, 3) lack of small processors, 4) lack of educational resources related to small business development, 5) lack of product development expertise, and 6) lack of knowledge of evidence supporting nutritional claims associated with sorghum and millet consumption.

The Department of Food …

A Physiological Basis For Controlling Leafy Spurge On Nebraska Rangeland, Rob B. Mitchell, Corey Moffet, Ron Sosebee

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Applying herbicides at the appropriate physiological stage is an important consideration to effectively control leafy spurge.

Enhanced Uv Inactivation Of Adenoviruses Under Polychromatic Uv Lamps, Karl G. Linden, Jeanette Thurston, Raymond Schaefer, James P. Malley Jr.

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Adenovirus is recognized as the most UV-resistant waterborne pathogen of concern to public health microbiologists. The U.S. EPA has stipulated that a UV fluence (dose) of 186 mJ cm^-2 is required for 4-log inactivation credit in water treatment. However, all adenovirus inactivation data to date published in the peer-reviewed literature have been based on UV disinfection experiments using UV irradiation at 253.7 nm produced from a conventional low-pressure UV source. The work reported here presents inactivation data for adenovirus based on polychromatic UV sources and details the significant enhancement in inactivation achieved using these polychromatic sources. When full-spectrum, medium-pressure …

Livestock Production System Management Responses To Thermal Challenges, J. A. Nienabar, G. L. Hahn

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The adaptive capabilities of animals and livestock production systems have been emphasized in this report. Biometeorology has a key role in rational management to meet the challenges of thermal environments. While the focus is primarily on cattle in warm or hot climates, the importance of dynamic animal responses to environmental challenges applies to all species and climates. Methods used to mitigate environmental challenges focus on heat loss/heat production balance. Under cold stress, reduction of heat loss is the key. Under heat stress, reduction of heat load or increasing heat loss are the primary management tools, although heat-tolerant animals are also …

Characterization Of Polymeric Proteins From Vitreous And Floury Sorghum Endosperm, B. Ioerger, S. R. Bean, M. R. Tuinstra, Jeffrey F. Pedersen, J. Erpelding, K. M. Lee, T. J. Herrman

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Differences in protein content and composition between vitreous and floury endosperm were investigated using a number of different techniques. Differences in protein cross-linking between vitreous and floury endosperm were investigated using differential solubility, size exclusion chromatography (SEC), and analysis of sulfhydryl content and composition. Vitreous endosperm was found to have higher levels of total protein and kafirins, but floury endosperm had a higher proportion of γ-kafirins than the vitreous. Floury endosperm was found to have higher levels of SDS-soluble proteins than SDS-insoluble proteins extracted using sonication than vitreous endosperm. Conversely, vitreous endosperm had a greater proportion of the insoluble proteins. …

The Mycotoxin Threat To Food Safety, Ervin Balazs, James S. Schepers

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This workshop entitled “Mycotoxins from the Field to the Table” held in Omaha, Nebraska, USA from 29 November to 1 December, 2006 evolved from the OECD (Organization for Economic Co-operation and Development) Co-operative Research Program on “Biological Resource Management” that was initiated in 1979. It currently focuses on three specific areas, namely the natural resources challenge, sustainability in practice, and the food chain. This workshop was organized under the sustainability and food chain themes.

The Cooperative Research Program's two major activities are promotion of expert exchanges by supporting postdoctoral fellowship awards up to 26 weeks in an OECD host laboratory …

Source Tracking Of Microbial Intrusion In Water Systems Using Artificial Neural Networks, Minyoung Kim, Christopher Y. Choi, Charles P. Garba

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A ‘‘what-if’’ scenario where biological agents are accidentally or deliberately introduced into a water system was generated, and artificial neural network (ANN) models were applied to identify the pathogenic release location to isolate the contaminated area and minimize its hazards. The spatiotemporal distribution of Escherichia coli 15597 along the water system was employed to locate pollutants by inversely interpreting transport patterns of Escherichia coli using ANNs. Results showed that dispersion patterns of Escherichia coli were positively correlated to pH, turbidity, and conductivity (R² = 0.90–0.96), and the ANN models successfully identified the source location of Escherichia coli introduced into …

Biofuel Feedstocks: The Risk Of Future Invasions, Joseph M. Ditomaso, Jacob N. Barney, Alison M. Fox

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

In an effort to decrease greenhouse gas emissions, expand domestic energy production, and maintain economic growth, public and private investments are being used to pursue dedicated feedstock crops for biofuel production. Unlike food crops grown for grain-based ethanol (e.g., corn), which require high inputs of fertilizers and pesticides and typically are grown on prime agricultural land, proposed lignocellulose-based energy crops (e.g., switchgrass) typically have a neutral or negative carbon budget, require relatively few economic or environmental inputs, and can be cultivated on marginal, lower-productivity land. Thus, a rapidly growing industry related to crop selection, cultivar improvement, and conversion technologies is …

Convergence Of Agriculture And Energy: Ii. Producing Cellulosic Biomass For Biofuels, Steven L. Fales, J. Richard Hess, Wallace Wilhelm, Don Erbach, William D. Provine, Kenneth P. Vogel, Todd A. Peterson, Edward C. A. Runge

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Global energy demand is increasing as known global petroleum supplies are decreas¬ing. Calls to supplement or replace the current fossil-based energy system with new, envi¬ronmentally and economically sustainable strategies continue to increase, especially in light of more expensive traditional energy sources. Various governmental agencies and working groups have set aggressive targets and timelines for decreasing fossil fuel consumption by substituting bio-based energy (Bush 2007; Foust et al. 2007; Perlack et al. 2005; Smith et al. 2004). The alignment and continuity of these goals is illustrated in Figure 1.
Current biofuel production in the United States relies primarily on corn grain …

K12-Biotinylated Histone H4 Marks Heterochromatin In Human Lymphoblastoma Cells, Gabriela Camporeale, Anna M. Oommen, Jacob B. Griffin, Gautam Sarath, Janos Zempleni

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Covalent modifications of histones play crucial roles in chromatin structure and genomic stability. Recently, we reported a novel modification of histones: biotinylation of lysine residues. Here we provide evidence that K12-biotinylated histone H4 (K12Bio H4) maps specifically to both heterochromatin (alpha satellite repeats in pericentromeric regions) and transcriptionally repressed chromatin (γ-G globin and interleukin-2) in human lymphoblastoma cells. The abundance of K12Bio H4 in these regions was similar to that of K9-dimethylated histone H3, a known marker for heterochromatin. Likewise, K8-biotinylated histone H4 (K8Bio H4) mapped to heterochromatin, but the relative enrichment was smaller compared with K12Bio H4. Stimulation of …

Engineering, Nutrient Removal, And Feedstock Conversion Evaluations Of Four Corn Stover Harvest Scenarios, Reed L. Hoskinson, Douglas L. Karlen, Stuart J. Birrell, Corey W. Radtke, Wally Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Crop residue has been identified as a near-term source of biomass for renewable fuel, heat, power, chemicals and other bio-materials. A prototype one-pass harvest system was used to collect residue samples from a corn (Zea mays L.) field near Ames, IA. Four harvest scenarios (low cut, high-cut top, high-cut bottom, and normal cut) were evaluated and are expressed as collected stover harvest indices (CSHI). High-cut top and high-cut bottom samples were obtained from the same plot in separate operations. Chemical composition, dilute acid pretreatment response, ethanol conversion yield and efficiency, and thermochemical conversion for each scenario were determined. Mean …

Source Tracking Of Microbial Intrusion In Water Systems Using Artificial Neural Networks, Minyoung Kim, Christopher Y. Choi, Charles P. Gerba

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A ‘‘what-if’’ scenario where biological agents are accidentally or deliberately introduced into a water system was generated, and artificial neural network (ANN) models were applied to identify the pathogenic release location to isolate the contaminated area and minimize its hazards. The spatiotemporal distribution of Escherichia coli 15597 along the water system was employed to locate pollutants by inversely interpreting transport patterns of E. coli using ANNs. Results showed that dispersion patterns of E. coli were positively correlated to pH, turbidity, and conductivity (R² = 0.90–0.96), and the ANN models successfully identified the source location of E. coli introduced into …

Comparison Of Laboratory Methods And An In Situ Method For Estimating Nitrogen Mineralization In An Irrigated Silt-Loam Soil, Brian J. Wienhold

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Nitrogen (N) mineralization makes a considerable contribution to crop-available N and is difficult to estimate. Reliable methods for measuring N mineralization are needed to produce data sets for developing N-mineralization models, as a component in fertilizer recommendation algorithms, and to assess the effect of management practices on N mineralization. Numerous methods are available for estimating N mineralization. Laboratory methods are relatively easy but may not reflect conditions in the field, and field methods are usually labor-intensive. A study was conducted to compare N-mineralization estimates using anaerobic and aerobic laboratory methods and an in situ field method for the 0- to …

The Effect Of Residue C:N Ratio On The Turnover Of N And C In Various Soil Organic Matter Fractions, Ana B. Wingeyer

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

Identifying soil organic matter (SOM) fractions that contribute to soil indigenous nitrogen (N) supply and understanding their turnover under different management constitute necessary tools toward an efficient N use. The objectives of this study were: i) trace the endpoint of carbon (C) flux from residue inputs into SOM; and ii) asses the role of the light fraction (LF), mobile humic acid (MHA) fraction and calcium humate (CaHA) fraction as N sources for heterotrophic decomposition of fresh plant residues with contrasting C:N ratio. A long-term aerobic soil incubation was carried out on ¹⁵N-labeled soil samples from Lincoln and Mead, NE. …

Usda-Ars Lincoln Location Contact Information

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Grain, Forage, & Bioenergy Research Unit
Mid-West Livestock Research Unit
Soil & Water Conservation Research Unit
Employee Listing

The mission of the USDA / ARS programs at Lincoln, Nebraska is to improve the productivity, stability of production, sustainability and profitability of crop and livestock production systems in the Great Plains

The Lincoln Location is a part of the Northern Plains Area (NPA) of the Agricultural Research Service (ARS), a Research, Education and Economics (REE) agency, and the main in-house research arm of the United States Department of Agriculture (USDA)

Internode Structure And Cell Wall Composition In Maturing Tillers Of Switchgrass (Panicum Virgatum. L), Gautam Sarath, Lisa M. Baird, Kenneth P. Vogel, Robert B. Mitchell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This work examined cell composition gradients in maturing tillers of switchgrass (Panicum virgatuln L. ) with the aim of developing baseline information on this important forage and biomass crop. Flowering tillers were collected from plants raised from seeds in a greenhouse and field, harvested at soil level and separated into internodes beginning with the node subtending the peduncle. Internodes were analyzed using microscopy, by fiber digestion, high-performance liquid chromatography and by gas chromatography-mass spectrometry to obtain anatomical and compositional data. Microscopy demonstrated the development and maturation of cortical fibers which eventually became confluent with the fiber sheath surrounding vascular …

Cloning And Expression Of An Atrazine Inducible Cytochrome P450, Cyp4g33, From Chironomus Tentans (Diptera: Chironomidae), Diana K. Londono, Herbert A.A. Siqueira, Haichuan Wang, Gautam Sarath, Michael J. Lydy, Blair D. Siegfried

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Previous studies performed in our laboratory have measured the effect of atrazine exposure on cytochrome P450-dependent monooxygenase activity and have found increased activity in midge larvae (Chironomus tentans) as a result of atrazine exposure (1– 10 ppm). Here we report the cloning and expression of a specific C. tentans CYP4 gene that is responsive to atrazine induction with an open reading frame of 1678 bp which encodes a putative protein of 559 amino acid residues. Alignments of deduced amino acid sequences with other insect P450 genes and phylogenetic analysis indicated a high degree of similarity to other insect …

Comparative Genomics Reveals Functional Transcriptional Control Sequences In The Prop1 Gene, Robert D. Ward, Minchul Cho, S. A. Camper, Shannon W. Davis, Lori T. Raetzman, Timothy P.L. Smith, Constance Esposito, Robert H. Lyons, Jan-Fang Cheng, Edward M. Rubin, Simon J. Rhodes

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Mutations in PROP1 are a common genetic cause of multiple pituitary hormone deficiency (MPHD). We used a comparative genomics approach to predict the transcriptional regulatory domains of Prop1 and tested them in cell culture and mice. A BAC transgene containing Prop1 completely rescues the Prop1 mutant phenotype, demonstrating that the regulatory elements necessary for proper Prop1 transcription are contained within the BAC. We generated DNA sequences from the PROP1 genes in lemur, pig, and five different primate species. Comparison of these with available human and mouse PROP1 sequences identified three putative regulatory sequences that are highly conserved. These are located …

What We Do Know About Rice (Oryza Sativa) Hemoglobins, Veronica Lira-Ruan, Emily H. Ross, Mark S. Hargrove, Gautam Sarath, Raul Arredondo-Peter, Robert V. Klucas

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Nonsymbiotic hemoglobins (nsHb) are proteins widely distributed in land plants, however their function in plant organs is still not known. Rice nsHbs have been characterized in detail and represent a model to study plant nsHbs. Rice recombinant Hb1 (rHb1) has a very high affinity for O₂ (1,800 μM^-1 s^-1), because the dissociation constant is extremely low (k_off = 0.038 s^-1). X-ray analysis and site-directed mutagenesis showed that the low dissociation constant of rHb1 is partially due to the stabilization of bound O₂ by distal His. This characteristic suggests that the function of …

Tillage And Rotation Effect On Corn–Soybean Energy Balances In Eastern Nebraska, G.-W. Rathke, Brian Wienhold, Wallace Wilhelm, W. Diepenbrock

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Data from a field experiment conducted in eastern Nebraska over 16 years (1986–2001) were used to determine the energy balance of corn (Zea mays L.) and soybean (Glycine max L.) as affected by tillage treatments and rotation. Tillage treatments included chisel plow, tandem disk, moldboard plow, ridge-tillage, no-till and subsoil tillage. Crop sequences were continuous corn, continuous soybean, corn in a corn–soybean rotation and soybean in a soybean–corn rotation. The energy balance was assessed by comparing the parameters: energy gain (net energy output), energy intensity (energy input per unit grain equivalent, GE) and output/input ratio. Changes in plant …

An Avidin-Based Assay For Histone Debiotinylase Activity In Human Cell Nuclei, Yap Ching Chew, Gautam Sarath, Janos Zempleni

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The covalent binding of biotin to histones participates in heterochromatin formation, cell cycle progression and cellular response to DNA breaks. Biotinylation of histones appears to be a reversible process, but the identity of enzymes that remove biotin marks is largely unknown. Our long-term goal is to identify histone debiotinylases in human cells. Here we developed an avidin-based plate assay to quantify histone debiotinylase activities in nuclear extracts. This assay is an essential first step in purifying and identifying histone debiotinylases from human cells. Using this assay, we demonstrated that debiotinylation of histones depends on temperature and pH, consistent with enzyme …

Modeling Beaver Dam Effects On Ecohydraulics And Sedimentation In An Agricultural Watershed, Mary Carla Mccullough, Dean E. Eisenhauer, Michael G. Dosskey, David M. Admiraal

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Populations of North American beaver (Castor canadensis) have increased in recent decades throughout the agricultural Midwestern U.S., leading to an increase in the frequency of beaver dams in small streams. The impact of beaver dams on channel structure in this region is not known. Our field observations indicate that beaver dams are too dynamic and their affects on channel structure occur over longer time frames than is practical to study with field measurements. Modeling is therefore needed to determine if beaver dams will help stabilize and aggrade incised streams. The objective of this paper is to determine how …