Digital Commons Network^™

Biophysical, Grazing-Season Management, And Animal Traits Effects On Individual Animal Performance Of Cow-Calf Systems: Insights From A Long-Term Experiment In The Us Western Great Plains, G. Irisarri, P. A. Cipriotti, L. Castro Sardiña, M. Mortenson, J. D. Derner

IGC Proceedings (1997-2023)

Beef grazing systems require information on management, biophysical, and individual animal influences on performance metrics. However, long-term controlled experiments are lacking to comprehensively ascertain these individual and likely interacting influences. We used a legacy data set from the USDA Agricultural Research Service where individual weight gains were determined from on and off weights of Hereford cows and calves grazing native northern mixed-grass prairie, during the June through September season, from 1975-2001 near Cheyenne, Wyoming, USA. The herd size varied from a minimum of 10 to a maximum of 48 pairs across years. Management (on and off grazing dates and stocking …

Germination And Seedlings Heterotrophic Growth Of Cocksfoot (Dactylis Glomerata L.) In Response To Temperature, Abraham Escobar-Gutiérrez, L. Q. Ahmed

IGC Proceedings (1997-2023)

In the context of climate change, grasslands are considered, similar to forest, as an important sink for atmospheric CO₂. However, environmental change seems to go faster than species adaptation to survive on site. Germination and heterotrophic growth are key phases for plant, and consequently, communities’ establishment and structure. They are under genetic control and affected by temperature. The objective of this study was to analyze the intra-specific variability of six accessions of Dactylis glomerata in their responses to eight constant temperatures (5 to 40˚C) during germination and initial heterotrophic growth. The novelty of this work comes from the …

L-Grassf: A New Model For Simulating The Genetic Environment Interactions On The Reproductive Phenology Of Grasses, S. Rouet, Jean Louis Durand, D. Combes, A. Escobar Gutiérrez, D. Leclercq, R. Barillot

IGC Proceedings (1997-2023)

Predicting the reproductive phenology in perennial grasses is a major concern because it determines the quantity and quality of forage. It varies a lot depending on site, year and cultivar. Projections of future climates suggest significant changes in seasonal temperature pattern, with new combinations of temperature and photoperiod, whose consequences on the floral induction of perennial grasses are unknown. L-GrassF is a new Functional Structural Plant Model simulating genetic variability of the phenology of perennial ryegrass in order to better understand the perenniality of grasslands and better anticipate the effects of climate change. L-GrassF stems from a previous model (L-Grass) …

An Examination Of The Diurnal Variability In Nitrous Oxide Emissions, B. P. Hyde, A. F. Fanning, M. Ryan, O. T. Carton

IGC Proceedings (1997-2023)

It is generally assumed in field experiments, that the measurement of nitrous oxide (N₂O) using enclosed chambers for a period of 1 hour can be used to provide an estimate of daily emission rates. In the majority of studies, emission measurements are conducted between 0900 and 1300 h. However, clearly defined diurnal cycles in N₂O emission rates have been observed from both agricultural and forest soils in temperate regions as a consequence of diurnal fluctuations in temperature (Blackmer et al., 1982; Ball et al., 1999; Baggs et al., 2002). The objective of this …

Net Photosynthesis Rate And Chlorophyll Content Of Caucasian And White Clover Leaves Under Different Temperature Regimes, A. D. Black, R. J. Lucas, D. J. Moot

IGC Proceedings (1997-2023)

In spring and summer in intensive temperate pastures, Caucasian clover (Cc) (Trifolium ambiguum) has higher dry matter (DM) production rates than white clover (wc) (Trifolium repens) (Black et al., 2003). An examination of the physiological basis for these differences can provide a greater insight into the suitability of Cc for inclusion in temperate pastures. Specifically, leaf photosynthesis rate is a major driver of seasonal growth and is strongly regulated by temperature and chlorophyll content. This study aimed to compare the net photosynthesis rate (Pn) and chlorophyll content of Cc and wc leaves under different temperature …

How Soil Properties Affect Egg Development And Larval Longevity Of A Grassland Insect Pest - An Empirically Based Model, S. N. Johnson, X. Zhang, J. W. Crawford, P. J. Gregory, S. C. Jarvis, P. J. Murray, I. M. Young

IGC Proceedings (1997-2023)

The clover root weevil (Sitona lepidus Gyllenhal.) is a destructive pest of white clover in temperate grasslands. Adults lay thousands of eggs that give rise to soil-dwelling larvae that initially feed on the root nodules housing symbiotic N2-fixing Rhizobium spp. bacteria. The period between egg hatch and consumption of root nodules by larvae is probably the most vulnerable part in the lifecycle, and if larvae do not locate roots relatively quickly they will die of starvation. In particular, the shells of eggs and the cuticles of emergent larvae are in constant physical contact with the external soil environment, so …

Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale

Coal Geology & Exploration

Permeability is an important parameter to characterize gas flow. In order to ensure the safe and efficient gas drainage, it is necessary to explore the evolution characteristics of coal reservoir gas seepage at different positions from the producing wellbores. However, the effective stress, the gas adsorption/desorption capacity of coal matrix and the temperature of coal reservoir are constantly changing with the gas drainage, and even the drainage damage may occur, which makes the gas migration behavior in coal seam extremely complicated. In order to explore the seepage characteristics of coal reservoir gas during gas drainage, the space-time evolution function of …

Are Soybean Models Ready For Climate Change Food Impact Assessments?, Kritika Kothari, Rafael Battisti, Kenneth J. Boote, Sotirios V. Archontoulis, Adriana Confalone, Julie Constantin, Santiago V. Cuadra, Philippe Debaeke, Babacar Faye, Brian Grant, Gerrit Hoogenboom, Qi Jing, Michael Van Der Laan, Fernando Antônio Macena Da Silva, Fabio R. Marin, Alireza Nehbandani, Claas Nendel, Larry C. Purcell, Budong Qian, Alex C. Ruane, Céline Schoving, Evandro H. F. M. Silva, Ward Smith, Afshin Soltani, Amit Srivastava, Nilson A. Vieira Jr., Stacey Slone, Montserrat Salmerón

Plant and Soil Sciences Faculty Publications

An accurate estimation of crop yield under climate change scenarios is essential to quantify our ability to feed a growing population and develop agronomic adaptations to meet future food demand. A coordinated evaluation of yield simulations from process-based eco-physiological models for climate change impact assessment is still missing for soybean, the most widely grown grain legume and the main source of protein in our food chain. In this first soybean multi-model study, we used ten prominent models capable of simulating soybean yield under varying temperature and atmospheric CO₂ concentration [CO₂] to quantify the uncertainty in soybean yield …

Seasonally And Diurnally Varying Cold Front Effects Along The Minnesotan North Shore Of Lake Superior, Matthew S. Van Den Broeke

Department of Earth and Atmospheric Sciences: Faculty Publications

Cold fronts are typically associated with cooling, drying and a strengthening wind that shifts to have a northerly component. Cold front effects at a particular point, however, are dependent upon pre-existing air mass characteristics. Here, we examine 634 passages of synoptic-scale cold fronts in northeastern Minnesota from 2010 to 2018. While these fronts are associated with the expected effects in some areas, they are often associated with warming and enhanced drying in the region directly influenced by an air mass from Lake Superior (coastal sites). Coastal sites experience warming during more than half of cold frontal passages, in contrast to …

Grasslands Classification In Yobe State Nigeria Using Integrated Orderly Classification System Of Grassland (Iocsg), S. Usman, M. G. Bala, Y. Shen

IGC Proceedings (1997-2023)

Integrated Orderly Classification System of Grassland (IOCSG) was initiated by Professor Ji-Zhou Ren in the 1960s and it has satisfactorily served to direct theory and practice of grassland classification for the last several decades in China. In this study IOCSG is adopted to classify the grasslands in Yobe state Nigeria, using 30 years (1984-2013) data on precipitation and temperature from 12 satellite stations across the state. Humidity (moisture index) was estimated as the ratio of precipitation per annum to annual temperature. The results revealed a trend of decline in precipitation and moisture index with latitude; from 772.63 mm and 0.72 …

Has Winter Weather In Southwest Ohio Been Affected By The El Niño Southern Oscillation, The North Atlantic Oscillation, The Pacific Decadal Oscillation, And The Atlantic Multidecadal Oscillation?, John A. Blue

Browse all Theses and Dissertations

Winter temperature and precipitation in Southwest Ohio over the last century were examined for anomalies attributable to teleconnections with large-scale atmospheric perturbations caused by the El Niño Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO). The record of temperature gives evidence of a teleconnection with the NAO, ENSO, and PDO, with the strongest link being for phases of the NAO. Most winters during positive NAO phases had mean monthly temperature warmer than the century long mean, and the majority of negative NAO phase winters had colder temperatures. The difference …

Effects Of Dry Matter Content And Microbial Additive On Tifton 85 (Cynodon Dactylon Ssp.) Wilted Silage Fermentation Parameters, Luiz Gustavo Nussio, F. G. Castro, J. M. Simas, C. M. Haddad, P. Toledo, A. L. Merchan

IGC Proceedings (1997-2023)

The objective of this study was to evaluate the wilting and the addition of a bacterial-enzymatic additive effects on the fermentation parameters of Tifton 85 (Cynodon dactylon spp.) silage. Forage was stored as 326 kg bales wrapped with a plastic film. Treatments consisted of 5 forage dry matter levels (20-30%, 30-40%, 40-50%, 50 -60% e 60 a 70%) without additive and 3 dry matter levels (20-30%, 40-50%, e 60-70%) with additive. Buffered propionic acid solution was sprayed onto 60-70% dry matter bales, prior to wrapping, determining an additional treatment. Core samples were taken at 0, 6, 12 hours …

Forage Quality And The Environment, C. E. Lascano, A. Schmidt, R. Barahona

IGC Proceedings (1997-2023)

The influence of environmental factors on forage quality of temperate and tropical grasses has been reviewed by several authors, who summarized how light, temperature, drought and soil nutrients influence chemical composition, and digestibility of forages grown in contrasting areas of the world. The effects of season of the year on forage growth, grazing behavior and animal performance have also been the subject of numerous papers and reviews. However, there are few recent reviews that summarize how changes in climatic and edaphic factors influence forage quality of legumes with variable levels of condensed tannins (CT), which are important secondary compounds in …

Assessing The Water Quality Of Three Bar-Built Estuaries In The Central Coast Of California, Micaelina Sarmiento Martinez

Master of Science in Environmental Sciences and Management Projects

Estuaries are coastal confluences with innumerable ecosystem services. With the continuous change in land use including the increasing number of people moving to live in coastal areas and on-going agricultural operations, these coastal systems are being adversely impacted. Climate change is also negatively affecting estuaries. Subsequently, this research study assessed the water quality, monthly, at three different locations of three bar-built estuaries in the Central Coast of California. Water quality was evaluated by the change in chlorophyll-a, nitrogen, phosphorus, pH, temperature, dissolved oxygen, and specific conductivity over the course of 19 months. The eutrophication potential and the role of open …

Effects Of Photoperiod, Low Temperature And N Nutrition On Vsp Accumulation In Taproot Of Alfalfa, J. C. Avice, C. Noquet, A. Ourry, J. J. Volenec

IGC Proceedings (1997-2023)

In Medicago sativa L., vegetative storage protein (VSP), specifically accumulated in taproot, are strongly involved in nitrogen storage. How the accumulation of such VSPs is regulated remains largely unknown. Experiments were designed with non-nodulated alfalfa to determine if length of the photoperiod, a decrease of temperature, or high availability of mineral nitrogen may induce the accumulation of VSPs. ¹⁵N labelling was used to quantify nitrogen uptake and its further relative translocation within the plant while VSPs accumulation was analysed by ELISA quantification. Results showed that environmental factors such as shortening daylength or low temperature changed biomass allocation within the …

Sedimentology And Shallow Groundwater Responses Of A Coastal Marsh Along A Salinity Gradient: A Case Study In Grand Bay National Estuarine Research Reserve, Mississippi, James Thompson

Master's Theses

Climate change and relative sea level rise is resulting in saltwater intrusion and inundation of coastal marshes. This study investigates factors affecting marsh hydrology, including sediment composition, seasonal variability, and coastal storms in Grand Bay National Estuarine Research Reserve (NERR) near Pascagoula, Mississippi. Analysis of sediment includes color, organic matter, carbonate, magnetic susceptibility, and particle size. Shallow groundwater hydrologic trends between Summer 2015 and Fall 2016 are established along a salinity gradient at four sites using water levels, temperature, and conductivity monitored at the surface and in piezometers at depths of 0.75m, 1.5m, and 2.25m.

Sediment analysis indicates reducing conditions …

Influence Of Salinity And Temperature On The Germination And Seedling Growth Of Chloris Virgata Swartz, Hongxiang Zhang, Daowei Zhou, Yu Tian

IGC Proceedings (1997-2023)

No abstract provided.

Germination Characteristics Of Haloxylon Bunge Seeds, L. R. Tong, J. G. Han

IGC Proceedings (1997-2023)

No abstract provided.

Influence Of Seasonal Changes And Variety On The Water‐Soluble Carbohydrate (Wsc) Content Of Varieties Of Lolium Perenne In Sweden, Magnus A. Halling

IGC Proceedings (1997-2023)

No abstract provided.

The Impact Of Temperature On Seed Germination In Diverse Accessions Of 4 Wild Vigna Species, Yanrong Wang, J. Hanson

IGC Proceedings (1997-2023)

No abstract provided.

Effect Of Temperature Changes On Germination Of Three Range Grass Species And Implication For Their Conservation, E. C. Kirwa, W. N. Mnene, E. N. Muthiani, P. Mweki

IGC Proceedings (1997-2023)

No abstract provided.

A Numerical Approach To Verify The Reservoir Temperature Of The Afyon Geothermal Fields, Turkey, Özgür Karaoğlu

Turkish Journal of Earth Sciences

Geothermal energy constitutes an important renewable resource in Turkey that has been extensively utilized for heating buildings, power generation, greenhouse farming and various other industries. One of the most remarkable geothermal locations in Turkey is the low-enthalpy area of Afyon, where five main low-temperature (30-110 °C) geothermal fields are exploited. However, further exploration drilling sites have proven inconclusive, casting doubts on the effective presence of high-temperature geothermal systems in the region. Part of the challenge is that the geometry, size and depth of the heat source of the geothermal system is poorly constrained. It is documented that the Afyon region …

Finite Volume Modeling Of Bathymetry And Fault-Controlled Fluid Circulation In The Sea Of Marmara, Eli̇f Şen, Doğa Doğan

Turkish Journal of Earth Sciences

Fluid vents in the Sea of Marmara were discovered and investigated by several studies. In this paper, a numerical model is created for the first time to determine the possible transport mechanism behind those fluid emissions at the seafloor. The finite volume method is used for numerical simulations by implementing a commercial finite volume code, ANSYS-Fluent. The thermal and physical rock properties used in our models are taken from previous studies. Bathymetry, fault-controlled fluid flow velocities, and temperature distribution patterns for the Central Basin and Western High in the Sea of Marmara are simulated and presented. Effects of faults, thickness …

Long Term Nutrient And Chlorophyll A Dynamics Across Long Island Sound And Impacts On Dissolved Oxygen Conditions Within The Western Sound (1991-2019), Sherry Perreira

Dissertations and Theses

Nitrogen overload, eutrophication, and hypoxia have been challenging and persistent water quality problems in Long Island Sound (LIS) over the past decades with major impacts on commercial industries, ecology, and recreational activities in the region. Recognizing these problems, the EPA enforced three phases of the Clean Water Act (CWA) to reduce nitrogen loads in an effort to improve this important estuary. This study examines how nitrogen (NH₃, NO_x & TDN), chlorophyll a (CHLA), and dissolved oxygen (DO) concentrations changed in LIS over the past 30 years, in response to water quality regulations as well as changes in …

Migration Of The Frozen/Melted Basal Boundary Linked To ~100 Kilometers Of Ice Margin Retreat, Western Greenland Ice Sheet, Aidan Ripley Stansberry

Graduate Student Theses, Dissertations, & Professional Papers

The geometry and thermal structure of western Greenland ice sheet have evolved over the last 11 kyr in response to Holocene climate. Evolution of the frozen and melted fractions of the bed associated with the ice sheet retreat over this time frame remains unclear. We address this question using a thermo-mechanically coupled flowline model to simulate a 11 kyr period of ice sheet retreat in west central Greenland. Our transient flow-line modeling includes high order stresses, thermally active bedrock, a well-informed climate that is constrained by an established record of ice margin retreat. We partition the transient heat balance into …

Investigation Of Affecting Some Climatic Factors On Distribution Of Plant Societies In Eastern Alborz (Ir‐Iran), Mohammadreza Tatian, Muhammad Ali Bahmanyar, Reza Tamartash, Hamid Jalilvand

IGC Proceedings (1997-2023)

No abstract provided.

Spatial Fingerprint Of Younger Dryas Cooling And Warming In Eastern North America, David Fastovich, James M. Russell, Stephen T. Jackson, Teresa R. Krause, Shaun A. Marcott, John W. Williams

Faculty Authored Articles

The Younger Dryas (YD, 12.9–11.7 ka) is the most recent, near‐global interval of abrupt climate change with rates similar to modern global warming. Understanding the causes and biodiversity effects of YD climate changes requires determining the spatial fingerprints of past temperature changes. Here we build pollen‐based and branched glycerol dialkyl glycerol tetraether‐based temperature reconstructions in eastern North America (ENA) to better understand deglacial temperature evolution. YD cooling was pronounced in the northeastern United States and muted in the north central United States. Florida sites warmed during the YD, while other southeastern sites maintained a relatively stable climate. This fingerprint is …

Infrared Heater Arrays For Warming Grazingland Field Plots, Bruce A. Kimball, Matthew M. Conley, Shiping Wang, Xingwu Lin, Caiyun Luo, Jack Morgan, David Smith

IGC Proceedings (1997-2023)

No abstract provided.

Patagonian Aridification At The Onset Of The Mid‐Miocene Climatic Optimum, Robin B. Trayler, Matthew J. Kohn, M. Susana Bargo, José I. Cuitiño, Richard F. Kay, Caroline A. E. Strömberg, Sergio F. Vizcaíno

Geosciences Faculty Publications and Presentations

Fossil‐rich sediments of the Santa Cruz Formation, Patagonia, Argentina, span the initiation of the Miocene Climatic Optimum (MCO), the most recent period of warm and wet conditions in the Cenozoic. These conditions drove the expansion of tropical and subtropical ecosystems to much higher latitudes, with the fossiliferous Santa Cruz Formation recording one of the southernmost examples. We collected new carbon and oxygen isotope compositions of herbivore tooth enamel from fossils ~17.4 to 16.4 Ma in age to investigate ecological and climatic changes across the initiation of the MCO. Enamel δ¹³C values are consistent with a C₃‐dominated …

Applications Of Continuous Snowpack Temperature Monitoring, Peter J. Youngblood

Boise State University Theses and Dissertations

Predicting metamorphism within seasonal snowpacks is critical for avalanche forecasting and runoff timing as it relates to water supply management. Snowpack temperature gradients play a key role in snow metamorphism, and their magnitude controls how snow strength changes; therefore, they are of interest to avalanche forecasters. Before major melt, the snowpack must warm to isothermal conditions at 0°C. Measuring this transition from warming to the ripening phase could help improve our current models for runoff timing. Measuring snowpack temperature gradients is currently a non-automated process that requires disturbance of the snow profile, and only gives a snapshot in time of …