8 resultados para Q34 - Natural Resources and Domestic and International Conflicts

em DigitalCommons@University of Nebraska - Lincoln


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It's a great pleasure to welcome you to this very first recognition ceremony for the Omtvedt Innovation Awards. We are present here to honor innovation strengths of the Institute of Agriculture and Natural Resources, and certainly the four faculty members receiving today's awards are greatly deserving of this recognition. Just hearing about their work is gratifying!

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Grassland ecosystems have been severely reduced and grassland bird populations have experienced consistent declines. National Park Service (NPS) properties on the Great Plains provide breeding habitat for grassland songbirds, though little is known about the quality of this habitat. A short-term study on songbirds at three NPS properties complemented current monitoring, providing an among park comparison addressing grassland bird productivity and fidelity relative to NPS property size. During 2008-2009, I assessed avian species richness, and estimated bird density and grassland songbird nest success. Bird species richness was greatest at small and medium sites, while number of nesting obligate species was greatest at the large site. Species-specific densities varied among sites, with few grassland obligates occurring at all three sites. Nest success estimates for grassland obligates were highest at the small site and lower at the large site. Another method to quantify habitat quality is assessment of breeding site fidelity. Current extrinsic markers used in monitoring site fidelity are inadequate for small birds; stable isotope analyses provide an alternative. I compared two techniques for assigning stable isotope tissue origin and measured grassland songbird site fidelity. My method of assigning origin provided site-specific variances of expected stable isotope values, an improvement over the most commonly used method. Fidelity tended to be higher at the large site, which may indicate a more robust breeding community of grassland birds. The small size of two of my sites precluded large sample sizes and made strong inferences difficult. To quantify how scientists cope with weak inference, I conducted a literature review. Strong inference was rarely observed, and most authors of weak-inference papers provided specific management recommendations. I suggest that adaptive management is an ideal method to resolve uncertainty from weak inference. Managers should consider my results within the context of regional and global management and the extent to which their unit might aide songbird conservation.

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During the last decade, leaf tatters has been reported in white oak and hackberry across several Midwestern states. Herbicide spray drift studies have shown that chloroacetamides can induce leaf tatters. The objectives of this research were to: 1) identify vulnerable bud developmental stages in hackberry and 2) determine if different commercial chloroacetamides affect severity of leaf tatters. In 2008, a preliminary spray drift experiment was conducted on mature trees from a former hackberry provenance test stand. Acetochlor (Harness), S-metolachlor (Dual II Magnum), and dimethenamid (Outlook) were applied at concentrations approximating 27%, 54%, 81%, or 108% of the recommended field rate. Three developmental stages before bud burst were present on the selected trees. Leaf tatters did not develop on the selected hackberry trees. However, symptoms were observed on neighboring, non-target hackberry trees, which had been in the leaf unfolding and expanding stages at the time of spraying. In 2009, three year old hackberry seedlings were treated with 1%, 10%, and 100% of the recommended field rate of acetochlor (Harness), S-metolachlor (Dual II Magnum), and dimethenamid (Outlook). Folded buds and two unfolding leaf developmental stages were present on seedlings. Another spray study was conducted on 32 mature hackberry trees from the provenance stand. A solution of 5608 mg a.i./L dimethenamid (Outlook) was applied to trees in the unfolding and/or expanding leaf stage. Treated trees represented four provenances. Image analysis was used to calculate seedling and mature tree leaf areas and estimate the seedling percentage of leaf tissue loss. Foliar damage was not significantly different between seedlings treated with water, 1%, or 10% of the field rate. Foliar damage was significantly different between seedlings treated with 1% or 100% of the field rate, and between seedlings treated with 10% or 100% of the field rate. Foliar damage in seedlings was not significantly different between the developmental stages. Additionally, symptoms of leaf tatters were observed on the treated mature hackberry. Future studies should focus on chloroacetamide concentrations above 10% of the recommended field rate.

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ABSTRACT Riparian buffer zones are important sites of biodiversity, sediment trapping, pollutant removal, and hydrologic regulation that have significant implications for both people and wildlife. Urbanization’s influence on and need for adequate water quality increases the need for careful planning in regards to riparian areas. Wildlife are key components in the ecosystem functions of riparian zones and require consideration in peri-urban planning as well. This study reviews relevant literature to determine the recommended minimum riparian buffer width for maintaining water quality and habitat along Stevens Creek in Lincoln, Nebraska. Only sources that listed a specific purpose related to water quality and habitat for their buffer width recommendations were considered. The study found that the baseline buffer width recommended for Stevens Creek that would be adequate for both water quality maintenance and basic habitat is 50 ft (15 m) per side. This number may be modified based on other factors such as slope, soil particle size, adjacent land use, the presence of certain wildlife communities, stream size, and stream order.

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ABSTRACT Nebraska has a veritable wealth of groundwater. The High Plains Aquifer underlies most of the state, and within its sand and gravel deposits, many interconnected aquifers provide fresh water for a variety of uses. One of the most spectacular examples of this resource is the artesian well. Beaver Crossing, Nebraska was once home to one of the most prolific artesian systems in the state before its demise. Founded in the 1880’s, Beaver Crossing soon became known for its many artesian wells, that provided leisure activities and supported profitable business ventures such as small farming, ice production and aquiculture. Eventually these wells would dry up and the town of Beaver Crossing would never see the level of commerce and activity that it saw during its early years. I decided to research this subject because I lived in Beaver Crossing for twelve years. While I lived there I heard stories about the artesian wells, the nationally recognized lily pond, and the large public pool fed by underground water that was plentiful around town. I was interested in knowing what happened to the water, the wells, the pool and businesses. . . And, in the wake of their disappearance, what happened to the town. To research this topic I looked at accounts of the history of Seward County and Beaver Crossing. I also studied the basic geology underlying the Great Plains, as well as local geology and issues pertaining to groundwater levels, such as rainfall amounts, drought and irrigation. As irrigation became a factor in rural Nebraska and through several documented droughts, groundwater levels all over the state declined. At the same time the artesian system in Beaver Crossing all but disappeared.

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Urban systems are manifestations of human adaptation to the natural environment. City size distributions are the expression of hierarchical processes acting upon urban systems. In this paper, we test the entire city size distributions for the southeastern and southwestern United States (1990), as well as the size classes in these regions for power law behavior. We interpret the differences in the size of the regional city size distributions as the manifestation of variable growth dynamics dependent upon city size. Size classics in the city size distributions are snapshots of stable states within urban systems in flux.

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Two new records of Tadarida brasiliensis mexicana are reported from Nebraska. The literature records of this taxon from the central United States are summarized. In this region of North America, these bats occupy a “natal range” where the species carries on regular reproductive activities and the populations are relatively stable, including California, Arizona, New Mexico, Texas, and Oklahoma. To the north of the natal range of T. b. mexicana is a “pioneering zone” where, under favorable conditions, the species is capable of reproducing and conducting its normal activities. The pioneering zone of the Mexican free-tailed bat includes Barber and Comanche counties in Kansas and as far north as Mesa and Saguache counties in southwestern Colorado. Finally, to the north of the pioneering zone, there is a much larger area that is proposed as the “exploring zone” in which only a few individuals of the species are found. Reproductive activities do not occur on any regular basis in the exploring zone, which encompasses the remainder of Colorado and Kansas as well as the states of Wyoming, Nebraska, Iowa, Illinois, Missouri, and southeastern South Dakota.

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“Music at the Fair!” gives the daily musical programs for The Trans-Mississippi and International Exposition, held in Omaha, Nebraska, June 1 through October 31, 1898. The Trans-Mississippi and International Exposition brought an unprecedented array of local, national, and international musical acts to Omaha, NE in 1898. This served to designate Omaha, "the gateway to the west" as a musical hub, as well as to incite musical excitement in the region. Some of the more popular acts featured were the Theodore Thomas Orchestra, the U.S. Marine Band, and the Apollo Club of Chicago. Many more groups and their musical programs can be found within the pages of this site. The “Music at the Fair!” website was created by Grace Carey, and last revised on May 19, 2006.It is the result of a two- year research grant funded by an Undergraduate Creative Activities and Research Experiences (UCARE) grant through the University of Nebraska at Lincoln. It is an extension of an ongoing project on music at the TME by Music Professor Peter Lefferts. The primary sources of information for the site are the following newspapers from June – November 1898: The Omaha Daily Bee, the Omaha Evening Bee, and the Omaha World Herald, and the the official programs of the fair located in the archives at the Omaha Public Library. I would like to thank the helpful staff at the Nebraska State Historical Society and the downtown branch of the Omaha Public Library. Site Creator: Grace Carey Project Advisor: Peter Lefferts, Professor of Music History at the University of Nebraska, Lincoln The linked “Document” is a flat PDF version of the interactive website. To download the fully interactive html version, click on the “Related file” to download the zipped folder. When unzipped, click on the file named “index” to enter the website.