Digital Commons Network^™

The Role Of Weed Control In Profitable Pastures, Scott Flynn, Pat Burch

Kentucky Grazing Conference

Pasture weeds compete for resources such as space, water, and nutrients. This competition reduces forage yield which in turn reduces the carrying capacity of a pasture. Although herbicide applications are needed to gain a quick upper hand on weed control most producers are deterred due to cost, the potential loss of pasture legumes, labor, or the belief that herbicide applications are required frequently to keep weed population under control. However, herbicide use in pastures should not be looked at in this manner but instead as an investment that can pay for itself very quickly and easily, and be long-term especially …

Role Of Legumes In Pastures, Garry D. Lacefield

Kentucky Grazing Conference

Successful livestock production is dependent on forage programs which supply large quantities of adequate quality, homegrown feed. A major percentage of the feed units for beef (83%) and dairy (61%) cattle come from forages. In addition, forages supply an estimated 91%, 72%, 15% and 99% of the nutrients consumed by sheep and goats, horses, swine and ruminant wildlife, respectively.

(How I Think About) Kentucky's Pastures: One Of Kentucky's Untapped Resources, Jimmy C. Henning

Kentucky Grazing Conference

One of the privileges of old(er) age is the prerogative to take liberties with assigned tasks. At the risk of confusing producers and offending more scientifically-current forage scientists, the topic of pasture as an untapped resource presented an opportunity to address task from an unexpected angle. Certainly, Kentucky’s pastures are a resource with untapped potential. But the idea that their value as a resource depends on how we think about them is one worth pursuing.

Foreword And Kfgc Award Winners [2013], Garry D. Lacefield, Christi L. Forsythe

Kentucky Grazing Conference

No abstract provided.

Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands, Chun-Mei Chiu

Open Access Dissertations

This study investigates wetland subsurface hydrology, as well as biogeochemistry - which is strongly influenced by water and temperature dynamics - as these interactions are expected to be highly significant, yet remain poorly represented in current ecosystem and climate models.

Northern wetlands have received widespread public attention due to steadily increasing summer mean global temperatures, extreme precipitation events and higher rates of natural greenhouse gas emissions, as well as the significant impacts on them due to human activities. The goal of my graduate research has been to improve quantification of the role of subsurface hydrology in northern wetlands by using …

Plant Community Composition And Structure Monitoring In Scotts Bluff National Monument, 2013 Annual Report, Isabel Ashton, Michael Prowatzke

United States National Park Service: Publications

Introduction

During the last century, much of the prairie within the Northern Great Plains has been plowed for cropland, planted with non-natives to maximize livestock production, or otherwise developed, making it one of the most threatened ecosystems in the United States. Within Nebraska, greater than 77% of the area of native mixed grass prairie has been lost since European settlement (Samson and Knopf 1994). The National Park Service (NPS) plays an important role in preserving and restoring some of the last pieces of intact prairies within its boundaries. The stewardship goal of the NPS is to “preserve ecological integrity and …

Pasture Condition Guide For The Kimberley, Kathryn Ryan, Elizabeth Tierney, Paul Novelly, Robert Mccartney

Bulletins 4000 -

This interactive guide has been produced as a tool for assessing pasture condition over a range of pasture types in the Kimberley. A pasture type is a distinctive mix of plant species, soil type and landscape position. For example, the Mitchell Grass Alluvial Plain Pasture type is a mixture of Mitchell grasses and other species occurring on black soil alluvial plains. Pasture condition is an important factor affecting the potential of the rangelands for animal production and is a useful indicator for the sustainability of production.

Incorporating Satellite Derived Cloud Climatologies To Improve High Resolution Interpolation Of Daily Precipitation., Adam M. Wilson, Benoit Parmentier, Brian Mcgill, Rob Guralnick, Walter Jetz

Yale Day of Data

Conservation of biodiversity demands comprehension of evolutionary and ecological patterns and processes that occur over vast spatial and temporal scales. A central goal of ecology is to understand the factors that control the spatial distribution of species and this has become even more important in the face of climate change. However, at global scales there can be enormous uncertainty in environmental data used to model species distributions. Even ‘simple’ metrics such as mean annual precipitation are difficult to estimate in areas with few weather stations and available data sets do not quantify uncertainty in these surfaces. We are developing a …

Bioavailable Lead In Topsoil Collected From General Aviation Airports, Jerry H. Kavouras, Randal J. Demik, Allison C. Hopkins

Biology Department Faculty Articles

Representatives of the aviation community are interested in determining the environmental effects of leaded fuel emissions from general aviation flight operations. Soil is an environmental sink for lead to accumulate over time. This study measured bioavailable lead concentrations in topsoil at three general aviation airports and at one site with no general aviation operations in order to determine if general aviation aircraft operations are contributing to the contamination of airport topsoil at levels that require remediation by law. Bioavailable refers to substances that organisms can absorb, because they have access to them. Topsoil was collected from refueling areas, run-up areas, …

Comparison Of Arsenic Uptake And Oxidative Stress By Christmas Fern And Spider Brake Fern, Paul Lkanich, Pratheek Koneru, Robert Wei

Undergraduate Research Posters 2013

Plants are widely considered the most cost effective and environmentally friendly way to clean soils and waters contaminated with toxic metals, e.g. arsenic and mercury. We have focused our research on the uptake of arsenic and its biochemical effect on two species of fern, Spider brake fern and Christmas fern. Spider brake fern is known to be capable of accumulating significant amounts of arsenic. We wish to determine whether the levels of arsenic uptake in Christmas fern are comparable to Spider Brake fern (>1g kg-1 plant biomass) when both are grown under the same conditions. Another aim of the …

Transformations In Matter And Energy: Student Learning And Inquiry To Inform Teaching, Jenny Dauer

Discipline-Based Education Research Group Speaker Series

Learning progressions are descriptions of increasing levels of sophistication of student reasoning about a topic based on empirical evidence. Our learning progression framework about student explanations of carbon-transforming processes (e.g. photosynthesis, cellular respiration) describes how student’s interconnected and mutually supporting ideas and practices are deeply embedded in discourse at all levels of achievement. My research is in two areas: 1) applying the learning progression framework for student explanations of carbon-transforming processes to describe the most productive pathways for student learning, 2) extending the research to student reasoning during inquiry activities about carbon-transforming processes. One finding is that students who consistently …

Seed Burial Physical Environment Explains Departures From Regional Hydrothermal Model Of Giant Ragweed (Ambrosia Trifida) Seedling Emergence In U.S. Midwest, Adam S. Davis, Sharon Clay, John Cardina, Frank Forcella, John Lundquist, Christy Sprague

Agronomy, Horticulture and Plant Science Faculty Publications

Robust predictions of weed seedling emergence from the soil seedbank are needed to aid weed management. A common seed accession (Illinois) of giant ragweed was buried in replicate experimental gardens over 18 site years in Illinois, Michigan, Kansas, Nebraska, Ohio, and South Dakota to examine the importance of site and climate variability by year on seedling emergence. In a nonlinear mixed-effects modeling approach, we used a flexible sigmoidal function (Weibull) to model giant ragweed cumulative seedling emergence in relation to hydrothermal time accumulated in each site-year. An iterative search method across a range of base temperature (Tb ) and base …

Report Card On Sustainable Natural Resource Use In Agriculture, Robert Summers, David Weaver

All other publications

Condition and trend Nutrients, such as phosphorus (P), are essential for profitable agriculture in the south-west of WA; however, excess P – more than is required for optimal production – is stored in many agricultural soils. On average, pasture soils and arable soils contain 1.3 times and 1.6 times respectively, as much P as is required for optimal production. Production in P-enriched soils is more likely to be constrained by soil acidity (50–60% of pasture and arable soils), potassium (K) (50% of pasture soils and less than 10% of arable soils), and sulphur (S) (30% of pasture soils). Management implications …

Innovative Gis Approach For Assessing Juniper Expansion, Daniel L. Zvirzdin, Dr. Steven Petersen

Journal of Undergraduate Research

Since European settlement piñon (Pinus) and juniper (Juniperus) (PJ) woodlands have expanded their range to more than 40 million hectares; this expansion constitutes one of the greatest afforestations of our time and is due to many factors including high intensity grazing, fire suppression, increased atmospheric CO2 concentrations, and climate change (Romme et al. 2009). As these woodlands expand into other ecosystems negative impacts to ecosystem services often occur as natural fire regimes, plant community structure, water and nutrient cycles, and biodiversity are altered. While the extent of these negative impacts are site dependent, PJ cover and density can be important …

Fractionation And Isolation Of The Anti-Tumoral Activity Of An Indigenous Tongan Medicinal Extract, Steven D. Christenson, Dr. Gary M. Booth, Dr. Steven G. Wood

Journal of Undergraduate Research

Vai Haka is the Tongan name given to a medicinal extract prepared and prescribed by indigenous healers on the island kingdom of Tonga. Used as a treatment for morning sickness (hyper-emesis), the mixture is prepared by boiling the barks of four different rainforest tree species. These species are Tarrena sambucina, Syzigium malaccense, Alphitonia zizyphoides, and Macaranga harveyana. Studies by Cox (et al) demonstrated biological activity in each of these species from a Guinea Pig Ileum assay.1 Further work by Cox documented that each species is used individually by Samoan healers to treat internal distress.2 Thus bioactivity is well documented through …

Phosphorus Agronomic Efficiency In Maize-Based Cropping Systems: A Focus On Western Kenya, J. Kihara, S. Njoroge

All Peer-Reviewed Publications

Phosphorus (P) is facing a quantity and quality supply issue and increasing its use efficiency is important for its continued use and profitability in crop production. The objective of this study was to determine how agronomic efficiency of P (PAE) in different environments and management systems in western Kenya is affected by N application, inherent soil fertility and organic resources. We used data constituting over 2700 data points from 126 farm fields of 25 different studies conducted from 1996 to 2009. Potassium (K) deficiency is negligible in western Kenya while ommission of P and N result in a 50% and …

Timing Of Favorable Conditions, Competition And Fertility Interact To Govern Recruitment Of Invasive Chinese Tallow Tree In Stressful Environments, Christopher A. Gabler, Evan Siemann

School of Earth, Environmental, & Marine Sciences Faculty Publications

The rate of new exotic recruitment following removal of adult invaders (reinvasion pressure) influences restoration outcomes and costs but is highly variable and poorly understood. We hypothesize that broad variation in average reinvasion pressure of Triadica sebifera (Chinese tallow tree, a major invader) arises from differences among habitats in spatiotemporal availability of realized recruitment windows. These windows are periods of variable duration long enough to permit establishment given local environmental conditions. We tested this hypothesis via a greenhouse mesocosm experiment that quantified how the duration of favorable moisture conditions prior to flood or drought stress (window duration), competition and nutrient …

Identifying Molecular Markers Associated With Salt And Boron Tolerance In Poplar Trees, Darshanpreet Gill, Nathan Follen, Davis W. Cheng, Kyan Salehi, Gary Banuelos, James P. Prince

STAR Program Research Presentations

Standard irrigation practices promote salt and boron accumulation in soils on the Westside of Central California. The build-up of these inorganic salts leads to the degradation of arable land and reduction of crop production. Different clones of poplar trees have been shown to grow in salt- and boron-contaminated soils, and in doing so, gradually remove significant amounts of these inorganic salts from the soil. In an effort to identify molecular markers linked with salt and boron tolerance in poplars, 31 PCR primer pairs have been designed based on candidate genes identified from the literature, and an additional 31 PCR primer …

Vegetation Response After Invasive Tamarix Spp. Removal In The Riparian Zone And Semi-Arid Rangeland Ecosystems, Hisham Nagi El Waer

Electronic Theses and Dissertations

Removal of Tamarix spp. (a.k.a. tamarisk, saltcedar, Athel) invasion is often involved in restoration of Western, riparian habitat; however monitoring of vegetation after removal is often neglected and thus opportunity for adaptive management lost. To address this need, I have conducted three and half years of monitoring vegetation response after invasive Tamarix removal in twenty-five sites on the East and Western Colorado, starting fall 2009. I am also comparing six different methodologies: Point intercept, line transect, nearest neighbor, meter-square quadrats, nested Whittaker plots, and densitometer with the objective of developing monitoring protocols that can be used by …

The Characterization Of Algae Grown On Nutrient Removal Systems And Evaluation Of Potential Uses For The Resulting Biomass, Kristin Hampel

Dissertations

Eutrophication resulting from excess nutrient loads is a major environmental issue that affects surface water quality and causes surplus primary production, thereby reducing dissolved oxygen concentrations. A method for managing nutrients in surface waters involves absorption of excess nutrients by deliberately cultivating benthic algal turf biomass, then harvesting it for a variety of uses, including biofuels, soil amendments, or feed supplements, thus coupling nutrient removal to additional economic drivers.

The goals of this work are to (1) evaluate the composition of algal biomass grown to remove surface water nutrients, (2) compare biomass grown at different geographic locations and in dissimilar …

Establishment Guide For Sub-Tropical Grasses : Key Steps To Success, Geoff Allan Moore, Ronald J. Yates, Phil Barrett-Lennard, Phil Nichols, Brad Wintle, John Titterington, Chris Loo

Bulletins 4000 -

Sub-tropical perennial grasses are now widely sown in the Northern Agricultural region (NAR) and on the south coast of Western Australia (WA). Since 2000, more than 50 000 ha have been sown to perennial grasses in the NAR and about 150 000 ha on the south coast, mainly kikuyu.

Systematics, Climate, And Ecology Of Fossil And Extant Nyssa (Nyssaceae, Cornales) And Implications Of Nyssa Grayensis Sp. Nov. From The Gray Fossil Site, Northeast Tennessee, Nathan R. Noll

Electronic Theses and Dissertations

The Late Hemphillian (latest Miocene or earliest Pliocene, 7-4.5 Ma) Gray Fossil Site in northeastern Tennessee is interpreted to represent a lacustrine paleokarst fed by a river or stream. This research focuses on the morphological and systematic relations of Nyssa endocarps (fruit pits) from the fossil site to extinct and extant Nyssa species. A combination of metric and nonmetric traits allows recognition of a new species: Nyssa grayensis sp. nov. This fossil species shares the most similarities with the extant Nyssa ogeche Bartram ex Marshall from southeast North America and the Eocene fossil Nyssa eolignitica Berry from western Tennessee. Affinities …

Remote Sensing Of Green Leaf Area Index In Maize And Soybean: From Close-Range To Satellite, Anthony L. Nguy-Robertson

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

This dissertation seeks to explore alternative methodologies for estimating green leaf area index (LAI) and crop developmental stages. Specifically this research [1] developed an approach for creating a Moderate Resolution Imaging Spectroradiometer (MODIS) high spatial resolution product for estimating green LAI on the base of data collected using two different close-range sensors. It was determined that the vegetation indices (VIs) Wide Dynamic Range Vegetation Index (WDRVI) and Enhanced Vegetation Index 2 (EVI2) were capable of accurate estimation of green LAI from MODIS 250 m data using models developed from hyperspectral (RMSE < 0.69 m² m^-2; CV < 33%) or multispectral sensors (RMSE < 0.69 m² m^-2; …

Seasonal Fires, Bison Grazing, And The Tallgrass Prairie Forb Arnoglossum Plantagineum Raf., Stephen L. Winter, Karen R. Hickman, Carla L. Goad, Samuel D. Fuhlendorf, Mark S. Gregory

School of Natural Resources: Faculty Publications

Fire and grazing can interact to affect the structure and composition of vegetation communities in a manner that may differ from the effects of fire or grazing that occurs in isolation of the other. In order to better understand the effects of a fire-grazing interaction at the level of an individual plant species, we studied the response of a perennial tallgrass prairie forb, Arnoglossum plantagineum Raf., to the interaction of spring and summer fires with grazing by bison (Bison bison L.). During one field season (2006), we collected data in areas that had been treated with summer fires while …

Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Interspecific Variation In Leaf-Level Biogenic Emissions Of The Bambuseae, Andrea Natalie Melnychenko

Dissertations and Theses

Plants emit a diverse range of biogenic volatile organic compounds (BVOCs) into the atmosphere, of which isoprene is the most abundantly emitted. Isoprene significantly affects biological and atmospheric processes, but the range of isoprene and BVOCs present in bamboos has not been well characterized. In this thesis I explore the range of isoprene emission found in bamboos and relate it to plant morphological and physiological characteristics. In addition, I measure and relate the entire suite of BVOCs present in the bamboos to their fundamental isoprene emission rate.

Interspecific variation in isoprene emission documented in a comprehensive survey of bamboos. Two …

Comparative Feedstock Analysis In Setaria Viridis L. As A Model For C4 Bioenergy Grasses And Panicoid Crop Species, Carloalberto Petti, Andrew Shearer, Mizuki Tateno, Mathew J. Ruwaya, Sue E. Nokes, Tom Brutnell, Seth Debolt

Horticulture Faculty Publications

Second generation feedstocks for bioethanol will likely include a sizable proportion of perennial C4 grasses, principally in the Panicoideae clade. The Panicoideae contain agronomically important annual grasses including Zea mays L. (maize), Sorghum bicolor (L.) Moench (sorghum), and Saccharum officinarum L. (sugar cane) as well as promising second generation perennial feedstocks including Miscanthus × giganteus and Panicum virgatum L. (switchgrass). The underlying complexity of these polyploid grass genomes is a major limitation for their direct manipulation and thus driving a need for rapidly cycling comparative model. Setaria viridis (green millet) is a rapid cycling C4 panicoid grass with a relatively …

Estudios Científicos En El Estado De Hidalgo Y Zonas Aledañas, Volumen Ii, Griselda Pulido-Flores, Scott Monks

Zea E-Books Collection

Los 16 capítulos que conforman este libro son una contribución al conocimiento de la biodiversidad y conservación de los recursos naturales en el estado de Hidalgo, México.

Se aborda el derecho de propiedad intelectual en la biodiversidad, citando algunos ejemplos de México. Así mismo, se presenta un estudio de la biodiversidad y distribución de la herpetofauna en cuatro tipos de vegetación. Desde el punto de vista de la helmintología se presentan dos estudios de los helmintos parásitos de vertebrados silvestres; con nuevos registros de hospederos y localidades de algunas especies de helmintos para Hidalgo. También, se aborda el uso de …

Lower San Luis Obispo Creek Stewardship Plan, Raven Lukehart, Daniel Bohlman

Natural Resources Management and Environmental Sciences

No abstract provided.

Contributions Of Stocked And Naturally Reproduced Rainbow Trout In The Deerfield Reservoir System, Jacob L. Davis, Jerry W. Wilhite, Greg Simpson, Michael E. Barnes, Kaite N. Bertrand, David W. Willis

The Prairie Naturalist

Deerfield Reservoir in the Black Hills of South Dakota and its tributary system are managed as hatchery supplemented rainbow trout (Oncorhynchus mykiss) fisheries. Three genetically unique strains of rainbow trout (Shasta, Erwin and McConaughy) are stocked into the system. Recently, juvenile rainbow trout of unknown origin were collected in the tributary system above Deerfield Reservoir, indicating potential natural reproduction. Understanding the genetic origins and ability of these rainbow trout to contribute to the fishery is essential in determining the proper management strategy for these waters. Our objectives were to 1) evaluate the genetic origins of potentially naturally reproduced rainbow trout …