Other Ecology and Evolutionary Biology Commons^™

Effect Of Dung Beetles On Dung Decomposition And Nuntrient Cycling In A Nebraska Rangeland, Kenneth Shay Evans

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

Management practice can have impacts on the abundance and frequency of dung beetle populations and nutrient cycling in grazing systems. Also, agriculture and livestock production land use is a considerable source of anthropogenic greenhouse gas (GHG) emissions, which are known to be one of the causes of global climate change. In this study, we evaluated the effect of dung beetle presence on the fluxes of greenhouse gasses (GHG’s) from dung pats in the semi-arid Sandhills region of Nebraska, by using closed chambers to measure the fluxes of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N …

Tallgrass Prairie Vegetation Response To Spring Fires And Bison Grazing, Stephen L. Winter, Brady W. Allred, Karen R. Hickman, Samuel D. Fuhlendorf

School of Natural Resources: Faculty Publications

Spring fires in tallgrass prairie can create environmental conditions conducive to plant growth in the subsequent growing season. Following fires, burned areas can also be attractive to grazing animals such as bison (Bison bison). Sustained grazing activity within recently burned areas can alter vegetation structure relative to nearby landscape patches that haven’t burned recently. In 2007, we collected data on bison grazing activity, vegetation structure, and the growth and reproduction of a perennial forb, Arnoglossum plantagineum, in Oklahoma tallgrass prairie. We compared these variables in landscape patches that had burned in the spring of 2007 to measurements …

Patch Burning: Integrating Fire And Grazing To Promote Heterogeneity, John R. Weir, Samuel D. Fuhlendorf, David M. Engle, Terrence G. Bidwell, D. Chad Cummings, R. Dwayne Elmore, Ryan F. Limb, Brady W. Allred, J. Derek Scasta, Stephen L. Winter

United States Fish and Wildlife: Staff Publications

Heterogeneity refers to the differences in habitats across the landscape, and it is required for diverse plant and wildlife communities. Some heterogeneity is inherent, caused by differences in soils, while most heterogeneity is disturbance driven. Climate, fire, and grazing are the main three disturbance factors that have historically shaped the landscape. All three are still very important to the continued diversity and health of the plants and animals associated with our prairies, shrublands, and forestlands across the Great Plains. While we cannot control the climate, we can manage grazing by stocking rate, season of use, and kind and type of …

Carbon Dynamics In A Phragmites Australis Invaded Riparian Wetland, Steven Walters

School of Natural Resources: Dissertations, Theses, and Student Research

Invasive plant species are widely recognized as a major threat to biodiversity and ecosystem stability. Wetland ecosystems tend to be much more susceptible to invasions because of their location on the landscape where water, nutrients, and the impacts of disturbances accumulate. Invasive plants have the ability to alter ecosystem processes and community/population dynamics. The ability of invasive plants to alter these processes can have profound economic consequences. In the United States, control of invasive wetland species alone costs approximately 155 million dollars annually. The state of Nebraska spends 2 million dollars annually controlling invasive plant species in the Platte River …

Reproductive Ecology Of Two Common Woody Species, Juniperus Sabina And Artemisia Santolinifolia, In Mountain Steppes Of Southern Mongolia, Katrin Ronnenberg

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

The present study describes the reproductive ecology of the prostrate shrub Juniperus sabina and the dwarf shrub Artemisia santolinifolia in dry mountain steppes of southern Mongolia. Whereas stands of the juniper are located at the drought limit of the genus’ distributional range, the genus Artemisia is typical of central Asian drylands. Both species produce large numbers of reproductive organs. For Juniperus sabina, however, only 2.5% of the morphologically intact seeds were found to be viable. Correspondingly, neither seedlings nor saplings were found in the field, and recruitment by reseeding happens at most rarely under the present climatic conditions.

Instead, …

Compensation For Herbivory In Wild Sunflower: Response To Simulated Damage By The Head-Clipping Weevil, Diana Pilson, Karin L. Decker

Diana Pilson Publications

Herbivore damage is generally detrimental to plant fitness, and the evolutionary response of plant populations to damage can involve either increased resistance or increased tolerance. While characters that contribute to resistance, such as secondary chemicals and trichomes, are relatively well understood, characters that contribute to a plant’s ability to tolerate damage have received much less attention. Using Helianthus annuus (wild sunflower) and simulated damage of Haplorhynchites aeneus (head-clipping weevil) as a model system, we examined morphological characters and developmental processes that contribute to compensatory ability. We performed a factorial experiment that included three levels of damage (none, the first two, …

Influence Of Prairie Dogs On Vegetation In Kansas Shortgrass Prairie, Stephen L. Winter, Jack F. Cully Jr., Jeffrey S. Pontius

United States Fish and Wildlife: Staff Publications

We quantified plant species richness, frequency, percent cover and percent bare ground on black-tailed prairie dog colonies and non-colonized areas in southwest Kansas in 1996 and 1997. In 1996 field sampling occurred after 12 months of below-average precipitation, while field sampling in 1997 occurred after 10 months of above-average precipitation. In 1996 prairie dog colonies were characterized by lower percentages of grass cover and higher percentages of forb cover than non-colonized sites, but there was no difference in percent bare ground. In 1997 percent grass cover, forb cover and bare ground was similar for prairie dog colonies and non-colonized areas. …

Plant Hybrid Zones And Insect Host Range Expansion, Diana Pilson

Diana Pilson Publications

The hybrid bridge hypothesis suggests that plant hybrids ‘‘bridge’’ the genetic gap between actual and potential host species, and that, for this reason, herbivorous insects are more likely to evolve an expanded host range in the presence of hybrids. While intuitively appealing, the hypothesis has two implicit assumptions: that phenotypic gaps between potential hosts limit host range, and that characters controlling host use are additively inherited in plant hybrids. Evaluation of these assumptions suggests that operation of the hybrid bridge hypothesis is relatively uncommon. In addition, the hypothesis has not been well integrated into existing theoretical and empirical work on …

Pflanzengesellchaften Der Mongolei, Werner Hilbig

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

First paragraphs of the introduction:

In Fortführung der Forschungsreisen der russischen Floristen und Pflanzengeouraphen im vorigen und Anfang dieses Jahrhunderts wurden erste Expeditionen zur systematischen Erforschung der Naturressourcen der Mongolei in den 20er und 30er Jahren durchgeführt. Sie wurden von der Akademie der Wissenschaften der UdSSR und der Akademie der Wissenschaften der MVR (vorher Wissenschaftliches Komitee der MVR) organisiert. Auch die von der Geographischen GeselIschaft und der Akademie der Wissenschaften der UdSSR durchgeführten Expeditionen zur Erforschung der natürlichen Bedingungen und der Landwirtschaft in der Mongolei schufen Möglichkeiten zur Entwicklung der geobotanischen Forschungsrichtung (vgl. GUBANOV u. HILBIG 1989).

Als erste eigenständi"e …

Arapaho Prairie, Arthur County, Nebraska: Approximate Ap Grid For Gis, Kathleen H. Keeler, A. T. Harrison, L. S. Vescio

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Grid map of field sites at Arapaho Prairie in Arthur County, Nebraska. Scale 1 5/16" = 1/4 mile. Shows permanently marked vegetation quadrats, blowouts and ravine washouts, roads, and 100' contour intervals. Part of the map was destroyed by mice. What remains of the map as of 2013 is shown.

Effect Of Time Of Cutting On Yield And Botanical Composition Of Prairie Hay In Southeastern Nebraska, Elverne C. Conard, Vincent H. Arthaud

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Approximately three and one-third million acres of native prairie are harvested annually in Nebraska for hay. In the four-year period 1948-1951, the State ranked first in wild hay production with an average yield of more than two and one-quarter million tons per year. This crop is an important natural resource in Nebraska's livestock industry. Studies were initiated in 1945 to determine the effects of time of cutting on the yield and feeding value of prairie hay in southeastern Nebraska. The studies were continued through the summer of 1952 to determine the effects of different cutting treatments on the vigor and …