Index Catalog // ScholarsArchive@OSU

A study on the effects of enhanced pCO2 on open ocean diazotrophic assemblages

Creator:: Gradoville, Mary Rose
Abstract:: Biological di-nitrogen (N₂) fixation is a key process in open-ocean ecosystems, where the new nitrogen (N) provided by marine diazotrophs can support a large fraction of primary productivity and carbon (C) drawdown. Recent laboratory studies have shown that elevated pCO₂ enhances the rate of N₂ fixation by select laboratory isolates...
Resource Type:: Masters Thesis
Full Text:: : _____________________________________________________________________ Ricardo M. Letelier Biological di-nitrogen (N2) fixation is a key process in open-ocean

Phosphorus control of nitrogen fixation

Creator:: Watkins-Brandt, Katie S.
Abstract:: Under conditions of fixed N-limitation, as with most oligotrophic systems, the process of biological N₂ fixation (diazotrophy) is favored, provided the necessary trace elements and vitamins are sufficient. Despite the well understood contributions of N₂ fixation in oligotrophic regions, the nutritional and ecological controls of marine diazotrophs have not been...
Resource Type:: Masters Thesis
Full Text:: : Angelicque E. White Ricardo M. Letelier Yvette H. Spitz Under conditions of fixed N

Functional groups, traits, and the performance of species in restoration

Creator:: Roberts, Rachael E. (Rachael Elaine)
Abstract:: In ecological restoration, species that are sown to increase the native plant diversity range in establishment ability. Some species readily establish, while others rarely do. This study set out to investigate some of the potential processes influencing species establishment, as well as the traits that are associated with the success...
Resource Type:: Masters Thesis
Full Text:: members of my committee, Eric Seabloom and Ricardo Letelier also provided great suggestions and helped

The Impact of Surface Ocean Mixing on Phytoplankton Communities and Associated Carbon Pools

Creator:: VerWey, Brian J.
Abstract:: Deep mixing events in the ocean’s surface layer act as physical drivers of carbon export by detraining dissolved and particulate organic matter, including surface phytoplankton communities, to depth. Once removed from the sunlit surface ocean environment, phytoplankton accumulation rates are dependent on the relative contributions of loss processes, such as...
Resource Type:: Masters Thesis
Full Text:: those that have provided pivotal insights along the way, including Dr. Ricardo Letelier, for your

Nitrogen isotopes in a global ocean biogeochemical model : constraints on the coupling between denitrification and nitrogen fixation

Creator:: Somes, Christopher J.
Abstract:: We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth System Climate Model designed for millennial timescale simulations. The model includes prognostic tracers for the stable nitrogen isotopes, ¹⁴N and ¹⁵N, in the nitrate (NO₃ˉ), phytoplankton, zooplankton, and detritus variables of the marine...
Resource Type:: Masters Thesis
Full Text:: invaluable to my growth as a scientist. I would like to thank my committee members Alan Mix and Ricardo

The Role of Iron: How Natural and Human-Induced Iron Fertilization Could Change Ocean Productivity

Creator:: Adroli, Nurmalia
Abstract:: Iron (Fe) is an important limiting nutrient that can affect the rate of ocean primary production because it is required by phytoplankton as an enzymatic cofactor in photosynthesis, nitrogen fixation, and other essential metabolic functions. Most Fe reaches the surface of the open ocean via atmospheric dust deposition, which is...
Resource Type:: Masters Thesis
Full Text:: advising committee, Prof. Michael Harte and Prof. Ricardo Letelier: thank you very much for your

Phytoplankton fluorescence and survival below the euphotic zone in the California current system

Creator:: Murphy, Alice M.
Resource Type:: Masters Thesis
Full Text:: , Tim Cowles. Thanks also to my committee members, Ricardo Letelier, Dan Shafer, and Jeriy Heidel

Fungal Secondary Metabolism of Basidiobolus meristosporus: a Novel Natural Product Reservoir

Creator:: Trautman, Ian A.
Abstract:: Secondary metabolites (SMs) play an integral role in the life history of most fungal species. Fungal metabolomic studies provide insights into how fungi perform certain ecological functions, how they compete and interact with other organisms, and the breadth of fungal chemodiversity. Fungal SMs have also been utilized for a variety...
Resource Type:: Masters Thesis
Full Text:: goes out to my committee members Drs. Jessie Uehling and Ricardo Letelier as well, for the time and

Quantification of dry concentration factor for Cs-134 in marine diatom Thalassiosira Weissflogii

Creator:: Krzyaniak, Nathan Anthony
Abstract:: The Fukushima Daiichi nuclear disaster of 2011 made it apparent that releases of fission products to marine environments is a very real possibility. Additional data on the movement of material through marine environments can be used by radioecology personnel to assist with both ecosystem protection as well as environmental cleanup...
Resource Type:: Masters Thesis
Full Text:: , Ocean, and Atmospheric Sciences. These members include, but are not limited to, Dr. Ricardo Letelier

Photosynthetic Energy Allocation Strategies of Thalassiosira pseudonana During Light Limited Growth

Creator:: Fisher, Nerissa L.
Abstract:: Photosynthetic energy allocation strategies were investigated in the marine diatom, Thalassiosira pseudonana, grown under a wide range of light limitation. Steady-state, continuous cultures were established at three light-limited growth rates. Simultaneous measurements of photosynthetic activity were made that targeted different points in photosynthetic energy flow from gross to net photosynthesis....
Resource Type:: Masters Thesis
Full Text:: µmol photons m-2 s-1 that is a measure of light energy and intensity. A more complicated example

Production and partitioning of organic matter during simulated phytoplankton blooms

Creator:: Wetz, Michael S.
Abstract:: Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During...
Resource Type:: Masters Thesis
Full Text:: also thank my committee members, Ricardo Letelier, Evelyn Sherr, and Fred Prahl, for their willingness

Phytoplankton shading of marine benthic macrophytes: Implications for intertidal community structure

Creator:: Kavanaugh, Maria T.
Abstract:: Previous observations of light levels and phytoplankton abundances along the Oregon coast demonstrated that phytoplankton attenuated light sufficiently to potentially limit the growth of intertidal macrophytes and therefore structure local intertidal communities. Inspired by this observation, in spring 2004, I initiated a study to quantify the direct and indirect benthic...
Resource Type:: Masters Thesis
Full Text:: included Dr. Karina Nielsen, my minor professors- Dr. Ricardo Letelier (Oceanography) and Dr. Lisa Madsen

Magnesium sulfate ion association in seawater

Creator:: Gates, Richard Fredrick
Resource Type:: Masters Thesis
Full Text:: ) Title: MAGNESIUM SULFATE ION ASSOCIATION IN SEAWATER Abstract approved: Ricardo M. Py(kowicz The

Physiological impacts of groundwater and surface water application on desert graminoids of different geographic origin

Creator:: Abdallah, Mohamed (Mohamed Ahmed B.)
Abstract:: Desert plant communities are among the most sensitive to changes in soil water conditions. In areas with shallow aquifers, it is important to understand both the effects of groundwater alterations on vegetation and how changes in surface-soil water affect plant water uptake. Studies in arid environments have evaluated the effect...
Resource Type:: Masters Thesis
Full Text:: : Ricardo Mata-Gonzalez Desert plant communities are among the most sensitive to changes in soil water

The solubility of CaCO₃ in seawater and in electrolyte solutions

Creator:: Plath, David Carl
Resource Type:: Masters Thesis
Full Text:: . Johnson, and Ricardo M. Pytkov;icz School of Oceanography, Oregon State University, Corvallis, OP 97330

Measurement of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure

Creator:: Mehrbach, Carl
Abstract:: The apparent dissociation constants of carbonic acid were determined as functions of temperature and salinity in seawater at atmospheric pressure. There is fair agreement between my values of K'₁ and those of Buch et al. (1932), Lyman (1956), and Hansson (1971). My values, on the average, are 6.7% lower than...
Resource Type:: Masters Thesis
Full Text:: . Ricardo M. Pytkowicz for his suggestion of this research and his helpful advice. John Hawley's and Chas

Pressure dependence of the apparent dissociation constants of carbonic and boric acids in seawater

Creator:: Culberson, Charles Henry
Resource Type:: Masters Thesis
Full Text:: approved: Ricardo M. Pytkowicz The pressure coefficients of the first and second apparent dissociation

Determination of the apparent dissociation constants of phosphoric acid in seawater

Creator:: Kester, Dana R.
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Dana Ray Kester for the M.. S. in

Geographic variation in distribution and cover of principle native and non-native plant species along gradients of topography, climate, and disturbance in protected-area sagebrush steppe communities of the Columbia Plateau

Creator:: Esposito, Daniel M.
Abstract:: The sagebrush steppe ecosystem of the Columbia Plateau has become degraded by a long history of alternative land use and associated perturbations. Protection of remnant stands of intact sagebrush steppe currently relies upon their preservation within the nation's network of parks and protected-areas. The John Day Fossil Beds National Monument,...
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Daniel M. Esposito

Long-term Fire Effects on Plant Succession and Exotic Weeds in Protected Area Sagebrush Steppe, John Day Fossil Beds National Monument, Oregon

Creator:: Reed-Dustin, Claire Marie
Abstract:: The historical function of fire in sagebrush steppe has been altered by 19th century overgrazing, active fire suppression, annual grass invasion and encroachment of woody species. The significance of fire to these systems is known, but research on long-term fire effects are limited. The Sheep Rock management unit of the...
Resource Type:: Masters Thesis
Full Text:: , Oregon Abstract approved: ________________________________________________________ Ricardo Mata

An optimization model to allocate forestry incentives funds in teak plantations of the southern-coastal region of Guatemala

Creator:: Pavez, Ricardo
Abstract:: Guatemala is internationally recognized as a country suitable to invest in the forestry industry. The first Guatemalan Forest Incentive Program – PINFOR- was implemented in 1996 to foster local forestry through cost-sharing. However, it lacks both formal land use planning processes and mechanisms to assess economic potential of projects, so...
Resource Type:: Masters Thesis
Full Text:: Ricardo Pavez for the degree of Master of Science in Sustainable Forest Management presented on June 12th

Biomass production and water use of common plant species in Owens Valley, California, USA

Creator:: Evans, Tracie L.
Abstract:: This study evaluated biomass production, water-use efficiency (WUE), biomass allocation, and water use characteristics of common plant species in Owens Valley, California, USA. The species studied were the grasses Distichlis spicata, Leymus triticoides, and Sporobolus airoides, the forbs Glycyrrhiza lepidota, Juncus arcticus, and Salsola tragus (annual), the desert shrubs Artemisia...
Resource Type:: Masters Thesis
Full Text:: approved: _________________________________________________________________ Ricardo Mata-González

Vegetation as Impacted by Soil Characteristics and Moisture in a Conservation Wetland, Willamette Valley, OR

Creator:: Aslan, Fevziye
Abstract:: Wetland degradation has negative influences on wetland functions and services. The understanding of wetland functions requires the intersection of two science disciplines, ecohydrology and plant physiology for a correct approach on wetland restoration and management. Although studies assessing ecohydrological relationships to protect wetlands are relatively common, studies evaluating both ecohydrological...
Resource Type:: Masters Thesis
Full Text:: Ricardo Mata-Gonzalez Wetland degradation has negative influences on wetland functions and

Mycological Maintenance of Rangelands and the Impacts of a Thatch Forming Invasive Annual Grass (Taeniatherum caput-medusae)

Creator:: Hovland, Matthew
Abstract:: Arbuscular mycorrhizal fungi (AMF) may exert profound influences on ecosystem resilience and invasion resistance in western North American sagebrush steppe and other arid rangeland plant communities. Maintenance of plant community structure through ecological feedbacks such as facilitation of nutrient cycling and uptake by host plants, physical and chemical contributions to...
Resource Type:: Masters Thesis
Full Text:: : ______________________________________________________ Ricardo Mata-Gonzalez Arbuscular mycorrhizal fungi (AMF) may exert profound

Aspen Drought Stress Response, Snow Cover and Soil Moisture Dynamics on an Oregon Bunchgrass Prairie

Creator:: Neary, Andrew
Abstract:: Quaking aspen, Populus tremuloides, has experienced severe declines in recent years in part due to the effects of changing climate and extreme drought. As the dominant deciduous tree in Western North American forests, aspen plays a critical role in forest biodiversity and ecosystem function. Therefore, the persistence of this species...
Resource Type:: Masters Thesis
Full Text:: : _____________________________________________________________________ Ricardo Mata-Gonzalez Quaking aspen, Populus tremuloides, has experienced severe declines

Restoration of Annual Grass-invaded Landscapes in the Sagebrush Steppe using Perennial Grass Seed Technologies and Wyoming Big Sagebrush Transplanting

Creator:: Holfus, Corinna M.
Abstract:: Within the sagebrush steppe ecosystem, invasive annual grasses are of growing management concern as they outcompete native vegetation, change the fundamental nutrient cycling processes, decrease biodiversity, and increase frequency of wildfires. The most widely used and effective management tool to decrease invasive annual grass abundance, is the use of pre-emergent...
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Corinna M. Holfus

Optimal communications system design for array-based electric generation

Creator:: Orozco, Ricardo
Abstract:: The world's demand for energy is an ongoing challenge, which has yet to be overcome. The efforts to find clean energy alternatives to fossil fuels have been hampered by the lack of investment in technology and research. Among these clean energy alternatives are ocean waves and wind. Wind power is...
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Ricardo Orozco for the degree of Master of Science in Electrical and

A complex distribution of water masses and related circulation off northern California in July 1981

Creator:: Olivera, Ricardo Martin
Resource Type:: Masters Thesis
Full Text:: Ricardo Martin Olivera A THESIS submitted to Oregon State Universtiy in partial fulfillment of the

Aspects of manganese nutrition in filbert trees

Creator:: Silberman, Ricardo S.
Abstract:: Lime was applied at different rates to filbert trees grown in containers in an acid soil. As lime application rate increased, the leaf Mn and extractable soil Mn were significantly reduced. In control trees leaf Mn was over 1300 ppm, but no growth reduction or Mn toxicity symptoms were found....
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Ricardo S. Silberman for the

Long-term Fuel Succession in the Sagebrush-steppe

Creator:: Reis, Schyler Ainsworth
Abstract:: Historically fire has been the primary disturbance factor in the sagebrush-steppe. The settlement of the West by Euro-Americans, grazing by domestic livestock, and the concomitant spread of invasive species have altered the historical fire regime. Understanding the long-term vegetation structure and fuel succession of the various sagebrush-dominated communities of this...
Resource Type:: Masters Thesis
Full Text:: advisors J. Boone Kauffman and Lisa M. Ellsworth. Their combined interest in my success has been

Carbonate chemistry of the North Pacific Ocean

Creator:: Wei, Ching-ling
Abstract:: This thesis covers a wide area of the North Pacific Ocean, latitudinally from 10° to 55°N and longitudinally from Japan to the U.S. coast. With two longitudinal cruises as the main data sources and selected literature data sets as supplementary data source, the distribution of physical and chemical properties in...
Resource Type:: Masters Thesis

Optimization and computer control of batch retort process operations : conduction-heated foods

Creator:: Simpson-Rivera, Ricardo Jose
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Ricardo Jos6 Simpson-Rivera for

Grazing Effects on Fuels and Plant Community Characteristics across Three Community Types in Wyoming Big Sagebrush Steppe

Creator:: Thomas, Tyler W.
Abstract:: Livestock grazing is the prominent land use in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) steppe and has been present since the late 1800’s. There have been calls to remove livestock grazing from rangelands as historic grazing practices resulted in the degradation of some...
Resource Type:: Masters Thesis
Full Text:: : ______________________________________________________ Kirk W. Davies Ricardo Mata-Gonzalez Livestock grazing is the prominent land use in

Survival Rates and Cause-Specific Mortality of Mule Deer in South-Central Oregon

Creator:: Mulligan, Elizabeth M.
Abstract:: It is critical for wildlife managers to understand the population dynamics of a harvested species, particularly for ungulates, which are a valuable wildlife resource. Due to concerns that mule deer (Odocoileus hemionus) populations in Oregon were declining, more comprehensive data on population vital rates and the factors potentially affecting them...
Resource Type:: Masters Thesis
Full Text:: in South-Central Oregon AN ABSTRACT OF THE THESIS OF Elizabeth M. Mulligan for the

Assessment of mule deer fawn survival and birth site habitat attributes in south-central Oregon

Creator:: Speten, David
Abstract:: Mule deer (Odocoileus hemionus) populations in south-central Oregon are near their lowest levels since census efforts began in 1961. I investigated fawn survival, cause-specific mortality, and factors contributing to mortality from 2010 – 2012 to identify potential causes for the decline. I also explored pre-parturition and parturition site characteristics. I...
Resource Type:: Masters Thesis
Full Text:: M. Sanchez Mule deer (Odocoileus hemionus) populations in south-central Oregon are near their

Resource Selection and Space Use of Western Long-eared Myotis (Myotis evotis) in a Western Juniper (Juniperus occidentalis) Woodland of Central Oregon

Creator:: Anthony, Christopher R.
Abstract:: Identifying habitat and spatial requirements of wildlife species across multiple spatial scales is a challenging, yet crucial component of wildlife management. Habitat use of bats is particularly difficult to study, and managing habitat to conserve bats is especially challenging because bats are highly vagile organisms that exploit several different types...
Resource Type:: Masters Thesis
Full Text:: : _____________________________________________________________________ Dana M. Sanchez Identifying habitat and spatial requirements of wildlife species across

Vegetation and Small Mammal Responses to Western Juniper (Juniperus occidentalis) Control in Eastern Oregon

Creator:: Morozumi, Corinne N.
Abstract:: Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions of people. They are some of the most vulnerable ecosystems in the United States and have been altered by human activities such as livestock...
Resource Type:: Masters Thesis
Full Text:: M. Sanchez Shrub-steppe ecosystems of western North America provide habitat for many wildlife

Non-native and native plant species distributions and variability along an elevation gradient in the Wallowa Mountains, Oregon

Creator:: Averett, Joshua P.
Abstract:: Invasion by non-native plants into natural areas is an important component of global change that threatens biodiversity and ecosystem structure and function. Mountains are currently among the least invaded ecosystems, however, these biodiversity hotspots are increasingly under threat of exotic plant invasion. Evaluation of plant species distribution patterns in mountain...
Resource Type:: Masters Thesis
Full Text:: : ______________________________________________________ Timothy DelCurto, Michael M. Borman Invasion by non-native plants into natural areas is an

Simulation of transients following a turbine trip in boiling water reactors by analog techniques

Creator:: Lopez Montes de Oca, Ricardo G.
Resource Type:: Masters Thesis
Full Text:: boiling water reactors by analog techniques AN ABSTRACT OF THE THESIS OF Ricardo G.Lopez Montes de Oca

A Ross-Macdonald Model with Vector Demography

Creator:: Reyes Grimaldo, Ricardo Noe Gerardo
Abstract:: Malaria is a vector-borne disease that has affected humans and other animals for a long time and which has shown high prevalence among different populations. During the beginning of the 20th century, Sir Ronald Ross and George Macdonald developed a model that represents the spread of malaria through the interaction...
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Ricardo Noe Gerardo Reyes

Ecohydrologic Connections in Semiarid Rangeland Ecosystems in Oregon

Creator:: Durfee, Nicole M.
Abstract:: An improved understanding of the ecohydrologic relationships in semiarid rangelands is imperative for the development of effective rehabilitation and land management practices. This thesis addresses the ecohydrologic relationships of two significant issues concerning semiarid rangeland ecosystems: western juniper encroachment and increasing stream temperatures. This thesis is divided into two chapters;...
Resource Type:: Masters Thesis
Full Text:: to extend my thanks to my committee: Dr. Ochoa, Dr. Todd Jarvis, Dr. Serkan Ates, and Dr. Ricardo

Evaluating tools used to estimate and manage browse available to wintering moose on the Copper River Delta, Alaska

Creator:: Smythe, Sharon E.
Abstract:: Ungulates comprise some of the most well researched and intensely managed wildlife populations on earth. As such, they are recognized as ideal study subjects for developing and modifying management tools or theories (Danell et al. 1994, Shipley 2010). An introduced moose (Alces alces gigas) population on the Copper River Delta...
Resource Type:: Masters Thesis
Full Text:: : ______________________________________________________________________________ Dana M. Sanchez Ungulates comprise some of the most well researched and intensely managed

The Ecological Recovery of Saguaro National Park after Removal of Cattle Grazing and Associated Succession

Creator:: Summers, Ryan J.
Abstract:: In the area that is now Saguaro National Park East, grazing began in the 1880's. Because of the impact to the iconic saguaro cactus as well as all palatable plant species in the area, ecological damage in the park were determined to be so great that anti-grazing conservationists challenged the...
Resource Type:: Masters Thesis
Full Text:: Ricardo Mata-Gonzalez Abstract In the area that is now Saguaro National Park East, grazing began in

Source, evolution, and eruptive history of the Cold Spring Creek volcanics, Beaverhead County, Montana

Creator:: Ivy, Susan Denise
Resource Type:: Masters Thesis
Full Text:: Taylor and Ricardo Pytkowicz. Robert Pearson of the Survey in Denver took time to introduce me to the

Tackifier Type and Concentration have Varying Impacts on Growth of Dryland Mosses

Creator:: Blankenship, Wyatt D.
Abstract:: There is growing interest in using biocrusts (assemblages of cyanobacteria, lichens, mosses, and other taxa in various proportions covering the upper few millimeters of the soil surface) to assist in restoring ecosystem function and native plant communities in dryland ecosystems. Biocrusts can be transplanted and established using jute or thatch,...
Resource Type:: Masters Thesis
Full Text:: lab group, and being among the best and most passionate teachers I have ever had. To Ricardo Mata

Glyphosate Resistance and Tolerance in Italian Ryegrass (Lolium perenne spp multiflorum) : Termination Treatments, Cultivar, and Resistance Evaluation

Creator:: MacPherran, Robert Chase
Abstract:: Annual ryegrass, or Italian ryegrass (Lolium perenne spp. multiflorum), has been the most stable, in terms of acres, grass produced for the past 25 years in Oregon. Increased interest in Italian ryegrass as a cover crop has increased demand for quality seed. Ideal Italian ryegrass cover crop cultivars are named...
Resource Type:: Masters Thesis
Full Text:: cover crop (Hively and Cox 2001). Italian ryegrass densities of 0.7 to 93 plants m-2 reduced wheat

Long-term Ecohydrologic Response to Western Juniper (Juniperus occidentalis) Control in Semiarid Watersheds of Central Oregon : A Paired Watershed Study

Creator:: Ray, Grace L.
Abstract:: Rangelands span over 50% of the globe and approximately 70% of the United States. Although livestock production is an important use of rangelands, the benefits of rangelands are highly diverse. Humans find intrinsic value in protecting these unique and variable landscapes for wildlife, vegetation, and recreation enthusiasts. Woodland plant encroachment...
Resource Type:: Masters Thesis
Full Text:: , Dr. Ricardo Mata-Gonzalez, Dr. Steve Wondzell and Dr. Christopher Stills. I am grateful for your

Development of baseline data on Oregon's high desert vernal pools

Creator:: Wyland, Sara Alice
Abstract:: Vernal pools are ephemeral surface water wetlands with unique hydrology, ecology and species composition. Rare and endemic species rely on vernal pool habitat due to specialization traits the species possess because they are adapted to the extreme conditions. Many vernal pool basins have been topographically and hydrologically altered and are...
Resource Type:: Masters Thesis
Full Text:: members, Dr. Paul Adamus and Dr. Ricardo Mata-Gonzalez, for honoring me with their time, expertise and

Response of Striga-susceptible and Striga-resistant sorghum genotypes to soil phosphorus and colonization by an arbuscular mycorrhizal fungus

Creator:: Leytem, Alicia B.
Abstract:: Striga, a genus of obligate parasitic weeds in the family Orobanchaceae, has been identified as the most important biological factor limiting agricultural productivity in sub-Saharan Africa. Germination of Striga seeds is triggered by strigolactone root exudates from host plants. Strigolactones also induce hyphal branching in arbuscular mycorrhizal (AM) fungi, which...
Resource Type:: Masters Thesis
Full Text:: Ricardo Mata-Gonzalez for their support, encouragement, and expertise through this process. In

Using Stable Isotopes to Estimate the Mean Recharge Elevation of Water Sources in the Central America Region

Creator:: Arellano, Lisabeth N.
Abstract:: Knowledge of the mean recharge elevation (MRE) of water resources is important for informing conservation and protection practices where water security is threatened by population growth, urban expansion, and land and climate changes. In this study a Bayesian approach was developed and applied to determine the MRE of 682 surface...
Resource Type:: Masters Thesis
Full Text:: and MREC = 0.9493 (MCE) – 28.24 (r2 = 0.93, MAE = 150 m (Pacific) and r2 = 0.76, MAE = 216 m

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