Digital Commons Network^™

The Tropical Grassland Society Of Australia Incorporated, David M. Orr, M. H. Shelton, C. A. Hall

IGC Proceedings (1977-2023)

The Tropical Grassland Society of Australia was formed in 1962 and became incorporated in 1987 and has the following aims:

• To publicise information of interest to primary producers and scientists
• To improve the relevance of research and adoption of technology through the flow of ideas between scientists and producers
• To publicise the findings of Australian pasture research and development to overseas workers, and to draw on their experience for application in Australia

Comments On The Present Activity Of Czech Specialists In Grassland Cultivation, B. Cagaš

IGC Proceedings (1977-2023)

Unlike some other countries, there is no officially established forage crop or grassland society in the Czech Republic. This, however, does not mean that activity in this field is lacking. Several institutions are involved in the development of grassland research. These are predominantly: Grassland Commission of the Section of Plant Production of the Czech Academy of Agricultural Science, Forage Crop Commission of the Bohemian-Moravian Union of Plant Breeders, Bohemian-Moravian Association of Plant Breeding and Seed Production and Association of Grass and Clover Seed Growers. Members of these institutions are researchers and breeders of grasses and legumes, university lecturers from departments …

American Forage And Grassland Council Technology Interaction And Policy Development, E. K. Twidwell, W. A. Tucker

IGC Proceedings (1977-2023)

The American Forage and Grassland Council (AFGC) is a national organisation which has been in existence since 1968. Membership of AFGC is about 2,500. The membership of AFGC is divided into three main sectors: private, public and industry. The private sector has the largest membership (60%), and private members are usually producers that are engaged in some type of agricultural enterprise involving the use of forages. The public sector members (30%) are educators and other government agency personnel that work with the general public. The industry sector (10%) involves various companies that deal with the forage industry. The AFGC Board …

The Ulster Grassland Society, J. Morrison

IGC Proceedings (1977-2023)

Northern Ireland is a grass-growing region. Grassland accounts for 92% of the area farmed (excluding hill land). So the great majority of farm businesses in the Province are, at least partly, dependent on grass as a source of ruminant feed and grassland farming makes a major impact on the environment and landscape of the Province.

The Ulster Grassland Society was formed in response to a realisation that grass should be treated as a crop in its own right with potential to produce high output in higher rainfall areas which include Northern Ireland. Although there had been informal meetings held since …

The Role Of Grassland Societies In The West Of Scotland, G. E. D. Tiley

IGC Proceedings (1977-2023)

Local grassland societies were first established in the United Kingdom in the 1950s, under the guiding hand of the national, British Grassland Society, itself founded in 1946. In the west of Scotland two local societies were formed: 1) the South West Scotland Grassland Society in 1962, covering the former counties of Ayrshire, Dumfries, Kirkcudbright and Wigtown; and 2) the Central Scotland Grassland Society for Lanark, Stirling, Renfrew, Dumbarton and Clackmannan. The declared aim of these two societies was to promote good grassland farming in all its aspects amongst members and to identify opportunities for improved grassland management, all to the …

The Leucaena Network: A Grazier Advocacy Organisation Ensuring The Future Of A Valuable Forage Resource For Northern Australia, K. Mclaughlin, B. F. Mullen, H. M. Shelton

IGC Proceedings (1977-2023)

Leucaena leucocephala is a productive and sustainable forage tree legume for beef cattle production in northern Australia. Following a protracted period of research and development to overcome agronomic and social constraints, substantial adoption by graziers is now occurring (Mullen, these proceedings). However, a recent challenge has threatened future development, viz. the perception by some environmentalists that leucaena is an environmental weed. In addition, production-oriented support from public research and development organisations has diminished significantly over the past 20 years. The Leucaena Network (TLN) was formed in July 2000, primarily to counter the anti-leucaena movement, but has since developed as an …

The Lotus Newsletter: An Electronic Lotus Research Community, Mónica Rebuffo

IGC Proceedings (1977-2023)

The Lotus Newsletter (LN) was created by Dr. W.F. Grant (former editor) in 1971, integrating scientists working on diverse aspects of research on Lotus spp. The LN received further impetus under the editorship of Dr. P.R. Beuselinck, who shaped the electronic version (http://www.psu.missouri.edu/lnl/). The newsletter aims to provide a vehicle for the exchange of information where opinions, in addition to established facts, can be presented. One of the strengths of the LN has been the lead article for each issue and the extensive bibliographic listing published every year, which facilitates access to recent literature. As a …

Grassland Technology Interaction And Policy Evolution In Canada, Duane H. Mccartney, P. Jefferson

IGC Proceedings (1977-2023)

Canada is the world's second largest country covering approximately 10 million km² (McCartney & Horton, 1997). About 90% of Canada is uninhabited with 90 percent of Canadians living within 500 km of the American border. The forage resources used by livestock grazing and the production of forage crops covers over 36 million ha of Canada's land base (3.6%) and is divided into 72% native range (26 million ha), 11% cultivated pastures (4 million ha) and 17% forage crops (6 million ha) There are 25 million ha in grain and oilseed crops (McCartney & Horton, 1997).

The Great Mission Of The Chinese Grassland Society: Grassland Strategic Research, F. Hong

IGC Proceedings (1977-2023)

The Chinese Grassland Society (CGS) was founded in 1979 in Beijing. Since 1991, it has become a national science society authorised by the State Ministry of Civil Affairs. The basic task of CGS is to unite the national grassland scientists and technicians for academic exchanges at home and abroad, to popularise grassland science, to train qualified personnel for the further development of grassland science and to accelerate the development of grassland science. The Society is affiliated with ten professional committees and sponsors the academic journals: Acta Agrestia Sinica, Acta Prataculturae Sinica and China Grassland.

Change In Grassland Science: Implications For Training, Research And Grassland Societies, G. Lemaire, R. J. Wilkins, J. Hodgson

IGC Proceedings (1977-2023)

In most of the world the priority for production-oriented research has been succeeded by the need for grassland research to focus on systems which satisfy requirements relating to the stability and protection of land, water and atmospheric resources and to biodiversity, in addition to production efficiency. This dictates not only a new approach to research, but also new approaches for the organisation of research, the training and development of research scientists and the activities of Grassland Societies and associated organisations.

Citizen Scientists: Efforts By The Tri-Societies To Inject Science Into Us Policymaking, E. Bergfeld, K. Glasener

IGC Proceedings (1977-2023)

The Tri-Societies (American Society of Agronomy, Crop Science Society of America and Soil Science Society of America), the largest life science professional societies in the United States (US) dedicated to the agronomic, crop and soil sciences, encompass approximately 18,000 members globally and include approximately 14,000 certified professionals who are a direct conduit to the farming communities across the US. The Tri-Societies' US-based federal science policy programmes have been active for decades. There is a Washington, DC-based Director of Science Policy, Congressional Science Fellows (CSF) and Science Policy Interns.

Pronghorn Survival And Resource Selection In Western Nebraska's Agriculturally Dominated Landscape, Katie Piecora

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

Nebraska’s pronghorn population has been stable over the last decade, yet their presence on the landscape remains a contentious subject amongst private landowners. Conversion of grassland for crop production and increased anthropogenic activity has drastically altered pronghorn behavior throughout their current range, however basic ecology and resource use by pronghorn in Nebraska remains poorly understood. Establishing baseline population metrics and seasonal patterns of resource use for this population at the eastern periphery of the species range is critical to guide management actions. We deployed GPS collars on 110 adult pronghorn to quantify survival, mortality risk, and seasonal resource selection in …

Visualizing Oceanographic Data To Depict Long-Term Changes In Phytoplankton, Patricia S. Thibodeau, Jongsun Kim

School of Earth, Environmental, & Marine Sciences Faculty Publications

Oceanographic time series provide an important perspective on environmental processes in ecosystems. The Narragansett Bay Long-Term Plankton Time Series (NBPTS) in Narragansett Bay, Rhode Island, USA, represents one of the longest plankton time series (1959-present) of its kind in the world and presents a unique opportunity to visualize long-term change within an aquatic ecosystem. Phytoplankton represent the base of the food web in most marine systems, including Narragansett Bay. Therefore, communicating their importance to the 2.4 billion people who live within the coastal ocean is critical. We developed a protocol with the goal of visualizing the diversity and magnitude of …

The Emergence Of Convergence, Shana M. Sundstrom, David G. Angeler, Jessica G. Ernakovich, Jorge H. Garcia, Joseph A. Hamm, Orville Huntington, Craig R. Allen

Faculty Publications

Science is increasingly a collaborative pursuit. Although the modern scientific enterprise owes much to individuals working at the core of their field, humanity is increasingly confronted by highly complex problems that require the integration of a variety of disciplinary and methodological expertise. In 2016, the U.S. National Science Foundation launched an initiative prioritizing support for convergence research as a means of “solving vexing research problems, in particular, complex problems focusing on societal needs.” We discuss our understanding of the objectives of convergence research and describe in detail the conditions and processes likely to generate successful convergence research. We use our …

Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid

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

Paleoecology relies on understanding relationships between modern animals and their environment. Animals are adapted to niches in their environments, and those physical adaptations, or functional traits, are utilized as proxies to interpret aspects of paleo-ecosystems. Much is known about individual functional traits in extant mammals and their relationship to the environment. Less is known about how multiple functional traits across a community can be utilized for paleoecological interpretations. I develop models utilizing traits in mammalian communities at the biome level. For Chapter 1, I build a model for North American regional biomes using mammalian trait frequencies. I quantify changes in …

Cambrian Explosion Condensed: High-Precision Geochronology Of The Lower Wood Canyon Formation, Nevada, Lyle L. Nelson, James L. Crowley, Emily F. Smith, Darin M. Schwartz, Eben B. Hodgin, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

The geologically rapid appearance of fossils of modern animal phyla within Cambrian strata is a defining characteristic of the history of life on Earth. However, temporal calibration of the base of the Cambrian Period remains uncertain within millions of years, which has resulted in mounting challenges to the concept of a discrete Cambrian explosion. We present precise zircon U–Pb dates for the lower Wood Canyon Formation, Nevada. These data demonstrate the base of the Cambrian Period, as defined by both ichnofossil biostratigraphy and carbon isotope chemostratigraphy, was younger than 533 Mya, at least 6 My later than currently recognized. This …

Disentangling Groundwater Dynamics At Oregon's Mckenzie River Headwaters, Taylor Nicole Salazar

Dissertations and Theses

Widespread mountain snowpack declines have been occurring across the western United States over the last century, and are increasing in duration and severity, with several record-breaking low-snowpack years in the last decade. In the Pacific Northwest, summer streamflow is largely a result of melting snow and groundwater discharge, as summers are typically dry and warm in this Mediterranean bioclimate, thus making spring-fed rivers critical for regional water resources. However, current trends and predictions in hydroclimate modeling indicate spring-fed rivers will experience reduced summer discharge driven by the increasingly larger impact of anthropogenic climate change (warming) on (decreased) mountain snowpack. A …

Sustainability Of Permanent Grassland On A Low Moor Soil With Different N And K Nutrient Management, K. Orlovius, J. Pickert

IGC Proceedings (1977-2023)

After the reunification of Germany fertilisation with P and K was strongly reduced in the eastern states of Germany due to the poor financial situation of the farms. Particularly on sites with a low nutrient delivery capacity, such a nutrient management strategy implies the risk of decreasing soil fertility. On a low moor soil with permanent grassland a 4 - year trial with different N and K fertilisation was set up to study the development of dry matter production and K concentrations in the grass.

Assessing Ecological Relationships Among Late Triassic Vertebrates In Petrified Forest National Park, Alexandra Davis Apgar

Earth and Planetary Sciences ETDs

The complex vertebrate ecosystem of the Late Triassic has not yet been fully understood, largely due to oversimplification of hypothesized trophic hierarchies and limited preservation of direct evidence of faunal interaction. Paleocommunity reconstruction attempts can also fall victim to taphonomic biases, time-averaging inaccuracies, and non-analogue paleoecologies. Utilizing a combination of PAIRS analysis and NMDS ordination, we highlight vertebrate faunal relationships within the Adamanian and Revueltian faunachrons of Petrified Forest National Park, assess the likelihood that these patterns have ecological rather than preservational drivers, and examine how these potential interactions may have been impacted by the Adamanian-Revueltian turnover event. We are …

Visualization Of Productivity Zones Based On Nitrogen Mass Balance Model In Narragansett Bay, Rhode Island, Jongsun Kim, Myung Hwangbo, Patricia S. Thibodeau, Georgia Rhodes, Emma Hogarth, Stewart Copeland

School of Earth, Environmental, & Marine Sciences Faculty Publications

Primary productivity in the coastal regions, linked to eutrophication and hypoxia, provides a critical understanding of ecosystem function. Although primary productivity largely depends on riverine nutrient inputs, estimation of the extent of riverine nutrient influences in the coastal regions is challenging. A nitrogen mass balance model is a practical tool to evaluate coastal ocean productivity to understand biological mechanisms beyond data observations. This study visualizes the biological production zones in Narragansett Bay, Rhode Island, USA, where hypoxia frequently occurs, by applying a nitrogen mass balance model. The Bay is divided into three zones - brown, green, and blue zones - …

Holocene Rice Rats (Genus Oryzomys) From The Upper Mississippi River Drainage Basin, Hugh H. Genoways

Zea E-Books Collection

The expansion and collapse of the geographic range of the Texas rice rat (Oryzomys texensis) in the upper Mississippi River drainage basin at the end of the Holocene was a unique event in North American mammals. In a period of about 4000 years with a point of origin near the American Bottom in Illinois, these small rodents extended their geographic range in a straight-line distance of over 950 km to the west into Nebraska and the same distance to the east into Pennsylvania. Then in less than 400 years this range expansion collapsed back to a point where …

Adsorptive–Photocatalytic Performance For Antibiotic And Personal Care Product Using Cu0.5Mn0.5Fe2O4, Chanat Chokejaroenrat, Chainarong Sakulthaew, Athaphon Angkaew, Apiladda Pattanateeradetch, Wuttinun Raksajit, Kanokwan Teingtham, Piyaporn Phansak, Pawee Klongvessa, Daniel D. Snow, Clifford E. Harris, Steven Comfort

Nebraska Water Center: Faculty Publications

The amount of antibiotics and personal care products entering local sewage systems and ultimately natural waters is increasing and raising concerns about long-term human health effects. We developed an adsorptive photocatalyst, Cu_0.5Mn_0.5Fe₂O₄ nanoparticles, utilizing co-precipitation and calcination with melamine, and quantified its efficacy in removing paraben and oxytetracycline (OTC). During melamine calcination, Cu_0.5Mn_0.5Fe₂O₄ recrystallized, improving material crystallinity and purity for the adsorptive–photocatalytic reaction. Kinetic experiments showed that all four parabens and OTC were removed within 120 and 45 min. We found that contaminant adsorption and reaction …

Short-Term Responses Of Soil Carbon, Nitrogen, And Microbial Biomass To Cover Crop Mixtures And Monocultures, Igor Alexandre De Souza, Amanda B. Daly, Jorg Schnecker, Nicholas D. Warren, Adalfredo Rocha Lobo Jr., Richard G. Smith, Andre Fonseca Brito, A. Stuart Grandy

Faculty Publications

Increasingly, cover crops are being adopted for the purpose of improving soil health, yet the timescale and magnitude by which living annual cover crops might modify soil chemical and biological aspects of soil health is not well understood. At the same time, there is growing interest among farmers in cover crop mixtures due to perceptions that species-rich cover crop communities will enhance soil health relative to monocultures. In a field experiment in southeast New Hampshire, we investigated how groups of cover crops grown as monocultures and mixtures for specific seasonal niches (winter/spring, summer, and fall) influenced levels of soil nitrogen …

Droughtscape, Summer 2023, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Summer 2023

Mentoring Experiences Of Undergraduate Students And Faculty Members In Science, Technology, Engineering, And Mathematics, Pamela Martínez Oquendo

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

I present a comprehensive view of mentoring experiences of undergraduate students and faculty members in science, technology, engineering, and mathematics (STEM). In Chapter 1, I describe a brief outline of this dissertation. In Chapter 2, I present an interpretative phenomenological analysis of the lived experiences of former STEM undergraduate mentors of the Nebraska STEM For You (NE STEM 4U) afterschool mentoring program. In Chapter 3, I describe how the ramifications of faculty mentorship influence the science pipeline using a qualitative synthesis. In Chapter 4, I describe how the STEM faculty-student mentoring engagement involves a strong psychological support component using a …

Effects Of Landslides On Terrestrial Carbon Stocks With A Coupled Geomorphic-Biologic Model: Southeast Alaska, United States, Adam M. Booth, Brian Buma, S. Nagorski

Geology Faculty Publications and Presentations

Landslides influence the global carbon (C) cycle by facilitating transfer of terrestrial C in biomass and soils to offshore depocenters and redistributing C within the landscape, affecting the terrestrial C reservoir itself. How landslides affect terrestrial C stocks is rarely quantified, so we derive a model that couples stochastic landslides with terrestrial C dynamics, calibrated to temperate rainforests in southeast Alaska, United States. Modeled landslides episodically transfer C from scars to deposits and destroy living biomass. After a landslide, total C stocks on the scar recover, while those on the deposit either increase (in the case of living biomass) or …

Decreased Moderate To Vigorous Physical Activity Levels In Children With Asthma Are Associated With Increased Traffic-Related Air Pollutants, Juan Aguilera, Soyoung Jeon, Amit U. Raysoni, Wen-Whai Li, Leah D. Whigham

School of Earth, Environmental, & Marine Sciences Faculty Publications

People with asthma, particularly young children, are more adversely aected by trac emissions-and regular exercise reduces asthma symptoms and improves lung function. We studied the relationship between air pollution and objectively measured physical activity in children with asthma who were attending a school near a freeway. We continuously monitored air pollutants-PM2.5, PM10, nitrogen dioxide (NO2), and ozone (O3)-at the school for 10 weeks and measured physical activity levels via accelerometry in children (n = 12, ages 6-12 years). Concentrations of PM2.5, PM10, and NO2 were negatively associated with moderate to vigorous physical activity (PM2.5 and PM10: p < .001; NO2: p = …

Applications Of Environmental Dna (Edna) To Detect Subterranean And Aquatic Invasive Species: A Critical Review On The Challenges And Limitations Of Edna Metabarcoding, Sakib Tahmid Rishan, Richard Kline, Md Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

The world is struggling to solve a devastating biodiversity loss that not only affects the extinction of treasured species and irreplaceable genetic variation, but also jeopardizes the food production, health, and safety of people. All initiatives aimed to conserve biodiversity rely heavily on the monitoring of both species and populations to get accurate spatial patterns and overall population assessments. Conventional monitoring techniques, such as visual surveys and counting individuals, are problematic due to challenges in identifying cryptic species or immature life stages. Environmental DNA (eDNA) is a relatively new technology that has the potential to be a faster, non-invasive, and …

Nitrous Oxide Cycling In The Eastern Tropical North Pacific Oxygen Deficient Zone From Concentrations, Stable Isotopes And Isotopomers, Margaret Ann Gaspar

Theses and Dissertations

Nitrous oxide (N₂O) is a potent greenhouse gas and ozone depleting substance. It is estimated that the ocean accounts for about one third of total atmospheric emissions, which mostly occur in Oxygen Deficient Zones (ODZs) connected to coastal upwelling regions. Modeling efforts and high-resolution datasets are starting to provide a clearer picture of global marine N₂O fluxes, spatiotemporal variability, and the impacts of submesoscale processes on N₂O distributions. We measured nitrous oxide concentrations, stable isotope ratios and isotopomers at 7 open ocean stations along a transect crossing the Eastern Tropical North Pacific ODZ as …

Oxygen And Hydrogen Isotopic Evidence That KamaʻEhuakanaloa (LōʻIhi) Seamount Hydrothermal Systems Are Recharged By Deep Pacific Seawater, Eric W. Chan, Brianna A. Alanis, Christopher R. German, Darlene S. S. Lim, John A. Breier

School of Earth, Environmental, & Marine Sciences Faculty Publications

We observed negative and positive δ18O and δ2H deviations from fluids collected at Kamaʻehuakanaloa (previously known as Lōʻihi) seamount relative to Pacific seawater from the same depth. Hydrothermal vents on the crater floor of Pele's Pit at Kamaʻehuakanaloa, at a depth of 1320 m, had δ18O and δ2H values as low as −0.19‰ and −0.3‰, respectively. Seawater collected within the caldera, within a zone 45 m above the crater floor, had δ18O and δ2H values as high as 1.15‰ and 6.5‰, respectively. In comparison, Pacific seawater at 1200 m and 1400 m at nearby station ALOHA exhibit intermediate δ18O and …