Soil Science Commons^™

Regional Trends In Early-Monsoon Rainfall Over Vietnam And Ccsm4 Attribution, Rong Li, S.-Y. Simon Wang, Robert R. Gillies, Brendan Buckley, Jin-Ho Yoon, Changrae Cho

Plants, Soils, and Climate Faculty Publications

The analysis of precipitation trends for Vietnam revealed that early-monsoon precipitation has increased over the past three decades but to varying degrees over the northern, central and southern portions of the country. Upon investigation, it was found that the change in early-monsoon precipitation is associated with changes in the low-level cyclonic airflow over the South China Sea and Indochina that is embedded in the large-scale atmospheric circulation associated with a “La Niña-like” anomalous sea surface temperature pattern with warming in the western Pacific and Indian Oceans and cooling in the eastern Pacific. The Community Climate System Model version 4 (CCSM4) …

Non-Methane Hydrocarbon Source Apportionment And Btex Risk Assessment Of Winter 2015 In Roosevelt, Utah, Jerimiah Lamb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Non-Methane Hydrocarbons (NMHC) monitored in Roosevelt Utah including Benzene, Toluene, Ethylbenzene and Xylene (collectively known as BTEX) are associated with deleterious effects including cancer. This study was designed to assess the origin and effect of the toxicants and addressed two points: 1) Source identification using the USEPA’s Positive Matrix Factorization (PMF) and NOAA’s Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and 2) A human health risk assessment based on ambient concentrations of BTEX collected at the Roosevelt site. Model fit indicated that the primary contributor to total NMHCs was local oil and gas operations and was supported by previous …

Sclerocactus Wetlandicus: Habitat Characterization, Seed Germination And Mycorrhizal Analysis, Kourtney T. Harding

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Uinta Basin hookless cactus (Sclerocactus wetlandicus) is a threatened species native to Eastern Utah. The cactus is found in a landscape highly disturbed by non-renewable energy production. To understand the environmental conditions that support natural growth of this cactus, we asked what types of plants were present in the same areas as the cactus, and if the types of plants were different in environments that were disturbed. From our assessment, we determined that the types of plants present in disturbed areas were drastically different from those present in undisturbed locations. Areas previously used for energy production are …

Effect Of Foliage And Root Carbon Quantity, Quality, And Fluxes On Soil Organic Carbon Stabilization In Montane Aspen And Conifer Stands In Utah, Antra Boča

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil organic carbon (SOC) positively affects many soil properties (e.g., fertility and water holding capacity), and the amount of carbon (C) in soil exceeds the amount in the atmosphere by about three times. Forest soils store as much C as is found in trees. Tree species differ in their effect on SOC pools. Quaking aspen forests in the Western US often store more stable SOC in the mineral soil than nearby conifers. During the last decades a decline in aspen cover, often followed by conifer encroachment, has been documented. A shift from aspen to conifer overstories may negatively affect the …

Accelerated Increase In The Arctic Tropospheric Warming Events Surpassing Stratospheric Warming Events During Winter, Shih-Yu (Simon) Wang, Yen-Heng Lin, Ming-Ying Lee, Jin-Ho Yoon, Jonathan D.D. Meyer, Philip J. Rasch

Plants, Soils, and Climate Faculty Publications

In January 2016, a robust reversal of the Arctic Oscillation (AO) took place associated with a rapid tropospheric warming in the Arctic region; this was followed by the occurrence of a classic sudden stratospheric warming in March-April. The succession of these two distinct Arctic warming events provides a stimulating opportunity to examine their characteristics in terms of similarities and differences. Historical cases of these two types of Arctic warming were identified and validated based upon tropical linkages with the Madden-Julian Oscillation and El Niño as well as those documented in previous studies. Our results indicate a recent and accelerated increase …

Rapid Surface-Water Volume Estimations In Beaver Ponds, Daniel J. Karran, Cherie J. Westbrook, Joseph Michael Wheaton, Carol A. Johnston, Angela Bedard-Haughn

Watershed Sciences Faculty Publications

Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range …

Assessing The Risk Of Carbon Dioxide Emissions From Blue Carbon Ecosystems, Catherine E. Lovelock, Trisha Brooke Atwood, Jeff Baldock, Carlos M. Duarte, Sharyn Hickey, Paul S. Lavery, Pere Masque, Peter I. Macreadie, Aurora M. Ricart, Oscar Serrano, Andy Steven

Watershed Sciences Faculty Publications

“Blue carbon” ecosystems, which include tidal marshes, mangrove forests, and seagrass meadows, have large stocks of organic carbon (C_org) in their soils. These carbon stocks are vulnerable to decomposition and – if degraded – can be released to the atmosphere in the form of CO₂. We present a framework to help assess the relative risk of CO₂ emissions from degraded soils, thereby supporting inclusion of soil C_org into blue carbon projects and establishing a means to prioritize management for their carbon values. Assessing the risk of CO₂ emissions after various kinds of disturbances …

The Optical Trapezoid Model: A Novel Approach To Remote Sensing Of Soil Moisture Applied To Sentinel-2 And Landsat-8 Observations, Morteza Sadeghi, Ebrahim Babaeian, Markus Tuller, Scott B. Jones

Plants, Soils, and Climate Faculty Publications

The “trapezoid” or “triangle” model constitutes the most popular approach to remote sensing (RS) of surface soil moisture based on coupled thermal (i.e., land surface temperature) and optical RS observations. The model, hereinafter referred to as Thermal-Optical TRAapezoid Model (TOTRAM), is based on interpretation of the pixel distribution within the land surface temperature - vegetation index (LST-VI) space. TOTRAM suffers from two inherent limitations. It is not applicable to satellites that do not provide thermal data (e.g., Sentinel-2) and it requires parameterization for each individual observation date. To overcome these restrictions we propose a novel OPtical TRApezoid Model (OPTRAM), which …

Simple Soil Quality Tests And Organic Management Practices For Orchards In The Intermountain West, Esther Oline Thomsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil health is often overlooked as a long-term management strategy as growers face an increasing number of short-term management challenges in the Intermountain West. The costs of inputs are rising and water resources are becoming more limited. Soil with poor health typically requires more amendments and fertlizers to meet crop needs. Soil health tests can help reveal management practices that reduce soil health, as well as those that improve soil health. Practices known to improve soil health are reduced to no tillage, cover crop use- especially legumes, and addition of mulch and other organic materials. Soil health testing is not …

Sensitivity Of Seven Diverse Species To Blue And Green Light: Interactions With Photon Flux, Michael Chase Snowden, Bruce Bugbee, Kevin R. Cope

Plants, Soils, and Climate Faculty Publications

Despite decades of research, the effects of spectral quality on plant growth, and development are not well understood. Much of our current understanding comes from studies with daily integrated light levels that are less than 10% of summer sunlight thus making it difficult to characterize interactions between light quality and quantity. Several studies have reported that growth is increased under fluorescent lamps compared to mixtures of wavelengths from LEDs. Conclusions regarding the effect of green light fraction range from detrimental to beneficial. Here we report the effects of eight blue and green light fractions at two photosynthetic photon fluxes (PPF; …

A Novel Qtl Associated With Dwarf Bunt Resistance In Idaho 444 Winter Wheat, Jianli Chen, Mary J. Guttieri, Junli Zhang, David Hole, Edward Souza, Blair Goates

Green Canyon Environmental Research Area, Logan Utah

Dwarf bunt [Tilletia controversa J.G. Kühn [as ‘contraversa’], in Rabenhorst, Hedwigia 13: 188 (1874)] is a destructive disease of wheat (Triticum aestivum L.) that reduces grain yield and quality. A number of distinct genes conferring resistance to dwarf bunt have been used by breeding programs for nearly 100 years. However, few markers were identified that can be used in selection of dwarf bunt resistance. A recombinant inbred line (RIL) population derived from the bunt-resistant germplasm, Idaho 444 (IDO444), and the susceptible cultivar, Rio Blanco, was evaluated for phenotypic reaction to dwarf bunt inoculation in four trials in …

Water Use Of Kentucky Bluegrass Varieties, Shawn Foster

Research on Capitol Hill

• With drought so prevalent in the West, water use on urban landscapes is being closely scrutinized with up to 60% of urban water use directed to landscape irrigation-primarily our lawns.
• Kentucky bluegrass (Poa pratensis L.) is widely used because of its soft texture, attractive color, and ability to recover from intensive use.
• More water-efficient varieties of Kentucky bluegrass may result in less irrigation yet maintain quality and function of the turf.

Experimental Evidence For Drought Induced Alternative Stable States Of Soil Moisture, David A. Robinson, Scott B. Jones, Inma Lebron, Sabine Reinsch, Maria T. Dominguez, Andrew R. Smith, Davey L. Jones, Miles R. Marshall, Bridget A. Emmett

Plants, Soils, and Climate Faculty Publications

Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought, and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ∼10%. However, intense summer drought, …

Role Of The Strengthened El Nino Teleconnection In The May 2015 Floods Over The Southern Great Plains, S.-Y. Wang, W.-R. Huang, H.-H. Hsu, R. R. Gillies

Plants, Soils, and Climate Faculty Publications

The climate anomalies leading to the May 2015 floods in Texas and Oklahoma were analyzed in the context of El Niño teleconnection in a warmer climate. A developing El Niño tends to increase late-spring precipitation in the southern Great Plains, and this effect has intensified since 1980. Anthropogenic global warming contributed to the physical processes that caused the persistent precipitation in May 2015: Warming in the tropical Pacific acted to strengthen the teleconnection toward North America, modification of zonal wave 5 circulation that deepened the stationary trough west of Texas, and enhanced Great Plains low-level southerlies increasing moisture supply from …

Digital Soil Mapping Using Landscape Stratification For Arid Rangelands In The Eastern Great Basin, Central Utah, Brook B. Fonnesbeck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In some parts of the western US there is limited publicly available soil information that can be used to make land management decisions on both public and private land. A goal of the USDI Bureau of Land Management (BLM) in Utah was to map an area in central Utah where such soil maps and value-added information was not available for management and restoration decisions following a wildfire. In 2007, the Milford Flat Fire had burned more than 363,000 acres, removing vegetation that was holding erosion-sensitive soils in place. Following inconsistent results from stabilization and restoration efforts, this study was funded …

Machine Learning For Predicting Soil Classes In Three Semi-Arid Landscapes, Colby W. Brungard, Janis L. Boettinger, Michael C. Duniway, Skye A. Wills, Thomas C. Edwards Jr.

Plants, Soils, and Climate Faculty Publications

Mapping the spatial distribution of soil taxonomic classes is important for informing soil use and management decisions. Digital soil mapping (DSM) can quantitatively predict the spatial distribution of soil taxonomic classes. Key components of DSM are the method and the set of environmental covariates used to predict soil classes. Machine learning is a general term for a broad set of statistical modeling techniques. Many different machine learning models have been applied in the literature and there are different approaches for selecting covariates for DSM. However, there is little guidance as to which, if any, machine learning model and covariate set …

Response Of Stomatal Density And Bound Gas Exchange In Leaves Of Maize To Soil Water Deficit, Wensai Zhao, Yonglin Sun, Roger Kjelgren, Xiping Liu

Plants, Soils, and Climate Faculty Publications

Stomatal behavior in response to drought has been the focus of intensive research, but less attention has been paid to stomatal density. In this study, 5-week-old maize seedlings were exposed to different soil water contents. Stomatal density and size as well as leaf gas exchange were investigated after 2-, 4- and 6-weeks of treatment, which corresponded to the jointing, trumpeting, and filling stages of maize development. Results showed that new stomata were generated continually during leaf growth. Reduced soil water content significantly stimulated stomatal generation, resulting in a significant increase in stomatal density but a decrease in stomatal size and …

Registration Of ‘Newell’ Smooth Bromegrass, K P. Vogel, R B. Mitchell, B L. Waldron, M R. Haferkamp, J D. Berdahl, D D. Baltensperger, Galen Erickson, T J. Klopfenstein

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Warming, Competition, And Bromus Tectorum Population Growth Across An Elevation Gradient, Aldo Compagnoni, Peter B. Adler

Green Canyon Environmental Research Area, Logan Utah

Cheatgrass (Bromus tectorum) is one of the most problematic invasive plant species in North America and climate change threatens to exacerbate its impacts. We conducted a two‐year field experiment to test the effect of warming, competition, and seed source on cheatgrass performance across an elevation gradient in northern Utah. We hypothesized that warming would increase cheatgrass performance, but that warming effects would be limited by competing vegetation and by local adaptation of cheatgrass seed sources. The warming treatment relied on open top chambers, we removed vegetation to assess the effect of competition from neighboring vegetation, and we reciprocally …

Soil Water Flux Estimates From Streaming Potential And Penta-Needle Heat Pulse Probe Measurements, Pawel J. Szafruga

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Growing populations, coupled with climate change and resource depletion, have heightened concern about water management. The growing need to better manage agricultural systems, including irrigation and fertilizer application, as well the lasting consequences of excess application of nitrogen and other nutrients, could be remedied with an improved method to monitor soil water movement. Despite huge technological advances, a tool to measure soil water flow at the low rates found in the field has not been developed. Current methods lack the precision to provide the needed accuracy to fully understand soil-water dynamics, as well as the ability to provide instantaneous information. …

Linking Montane Soil Moisture Measurements To Evapotranspiration Using Inverse Numerical Modeling, Ling Lv

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Evapotranspiration (ET) and soil moisture play important roles in annual water delivered from snowpack to reservoirs, lakes and streams. Indeed, ET and soil moisture are key factors dictating the performance of the regional climate models in the intermountain west (IMW) of the USA. Water resources management and climate modeling require accurate prediction of ET and areal soil moisture for reliable estimates of ongoing and future water needs. This research has examined ways to estimate ET from four common vegetation types in the IMW (aspen, conifer, grass and sage) using local soil moisture measurements from an advanced instrumentation network located in …

Warming, Soil Moisture, And Loss Of Snow Increase Bromus Tectorum’S Population Growth Rate, Aldo Compagnoni, Peter B. Adler

Green Canyon Environmental Research Area, Logan Utah

Climate change threatens to exacerbate the impacts of invasive species. In temperate ecosystems, direct effects of warming may be compounded by dramatic reductions in winter snow cover. Cheatgrass (Bromus tectorum) is arguably the most destructive biological invader in basins of the North American Intermountain West, and warming could increase its performance through direct effects on demographic rates or through indirect effects mediated by loss of snow. We conducted a two-year experimental manipulation of temperature and snow pack to test whether 1) warming increases cheatgrass population growth rate and 2) reduced snow cover contributes to cheatgrass’ positive response to …

Methylmercury Fate In The Hypersaline Environment Of The Great Salt Lake: A Critical Review Of Current Knowledge, Danielle Barandiaran

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Methylmercury (MeHg) is a highly potent neurotoxic form of the environmental pollutant Mercury (Hg). The processes that are responsible for the conversion of Hg to MeHg are known to be both biotic and abiotic in freshwater systems. Although MeHg contamination is well documented in Great Salt Lake (GSL), the conversion of Hg into MeHg is not well-understood in saline environments much less in hypersaline waters such as GSL. The GSL is a broad, shallow high altitude (1280 m above sea level) lake that is exposed to large amounts of ultraviolet radiation and evaporation, which lead to great volatilization losses of …

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

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Two New Species Of Trigonotylus (Hemiptera: Heteroptera: Miridae: Stenodemini) From Western Canada And Northwestern United States, G G.E. Scudder, Michael D. Schwartz

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

The Role Of Fine-Scale Habitat Associations In Structuring Spider Assemblages: Determinants Of Spatial Patterns In Community Compostion, Stephanie M. Cobbold

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Livestock Foraging Behavior In Response To Sequence And Interactions Among Alkaloids, Tannins, And Saponins, Tiffany L. Jensen

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Process-Based Management Of Downy Brome In Salt Desert Shrublands: Assessing Pre- And Post- Rehabilitation Soil And Vegetation Attributes, Merilynn Carol Hirsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As an ecosystem driver, downy brome (Bromus tectorum L.) presents obstacles to land rehabilitation efforts, including restoring desirable species cover. Because damaged ecosystems may have crossed both abiotic and biotic thresholds, ecologically-based control strategies may assist with altering successional trajectories and restoring desirable plant species. My thesis research had three objectives: 1) assess soil and vegetation relationships in degraded salt desert ecosystems prior to implementing downy brome control treatments, 2) determine the effects of control treatments on soil properties and resident plant species, and 3) evaluate the relative importance of shrubland soil type, herbicide type, and herbicide rate on seedling …

Temperature Increase Effects On Sagebrush Ecosystem Forbs: Exprimental Evidence And Range Manager Perspectives, Hilary Louise Whitcomb

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used …