Other Plant Sciences Commons^™

Limited Soil Water Recharge In Summer Affects Seasonal Isotopic Signatures Of Tree Xylem Water, Marius G. Floriancic, Gregory R. Goldsmith, Harsh Beria, Scott T. Allen, James W. Kirchner

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent studies have reported that xylem waters in forest trees during the summer growing season are often isotopically similar to winter, rather than summer, precipitation. Several hypotheses have been proposed to explain this observation, which can be viewed as a form of ecohydrological separation, but empirical tests spanning space and time remain limited. We hypothesise that variations in the seasonal origin of precipitation found in tree xylem waters can be explained by seasonal differences in soil water recharge. We test this hypothesis by evaluating to what extent climatic aridity can explain seasonal signals in extensive surveys of the isotope ratios …

Chinese Tallow Long-Term Impact On Stand Dynamics In A Bottomland Hardwood Forest Following Vegetation Management, Nicklaus R. Langlois

Electronic Theses and Dissertations

Chinese tallow (Triadica sebifera (L.) Small) is an invasive tree known to have negative impacts on bottomland hardwood forests. Chinese tallow is proficient in reproducing and surviving in bottomland hardwood forests because it is more flood and shade tolerant than most native trees. The long-term effectiveness of Chinese tallow control is an important topic to research as only a few long-term studies of Chinese tallow control have been conducted. A 10-year re-measurement of 22 paired plots installed in 2012 on the Pineywoods Mitigation Bank near Diboll, Texas following herbicide treatments examined Chinese tallow and native tree stand structure. Each …

Soil Reclamation Strategies In Construction Disturbed Soil, Alexis Koelling

All Graduate Reports and Creative Projects, Fall 2023 to Present

The rapid urbanization occurring in arid environments like the Intermountain West region of the U.S. significantly alters soil conditions. Construction of roads, buildings, and other infrastructure leads to the disturbance of soil structure, nutrient depletion, and reduced fertility. This research addresses the need for sustainable soil management practices that may restore soil health post-construction. In this study, the effectiveness of various soil amendments and application methods on specific soil parameters and turfgrass establishment in construction-disturbed soils was evaluated. The study highlights the critical role of soil amendments, particularly municipal solid waste (MSW) compost, in improving soil quality and plant growth. …

Emerging Sensing, Imaging, And Computational Technologies To Scale Nano-To Macroscale Rhizosphere Dynamics – Review And Research Perspectives, Amir H. Ahkami, Odeta Qafoku, Tiina Roose, Quanbing Mou, Yi Lu, Zoe G. Cardon, Yuxin Wu, Chunwei Chou, Joshua B. Fisher, Tamas Varga, Pubudu Handakumbura, Jayde A. Aufrecht, Arunima Bhattacharjee, James J. Moran

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The soil region influenced by plant roots, i.e., the rhizosphere, is one of the most complex biological habitats on Earth and significantly impacts global carbon flow and transformation. Understanding the structure and function of the rhizosphere is critically important for maintaining sustainable plant ecosystem services, designing engineered ecosystems for long-term soil carbon storage, and mitigating the effects of climate change. However, studying the biological and ecological processes and interactions in the rhizosphere requires advanced integrated technologies capable of decoding such a complex system at different scales. Here, we review how emerging approaches in sensing, imaging, and computational modeling …

Volcanic Diffuse Volatile Emissions Tracked By Plant Responses Detectable From Space, Robert R. Bogue, Peter M. J. Douglas, Joshua B. Fisher, John Stix

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Volcanic volatile emissions provide information about volcanic unrest but are difficult to detect with satellites. Volcanic degassing affects plants by elevating local CO2 and H2O concentrations, which may increase photosynthesis. Satellites can detect plant health, or a reaction to photosynthesis, through a Normalized Difference Vegetation Index (NDVI). This can act as a potential proxy for detecting changes in volcanic volatile emissions from space. We tested this method by analyzing 185 Landsat 5 and 8 images of the Tern Lake thermal area (TLTA) in northeast Yellowstone caldera from 1984 to 2022. We compared the NDVI values of the thermal area with …

Characterization Of Boreal-Arctic Vegetation Growth Phases And Active Soil Layer Dynamics In The High-Latitudes Of North America: A Study Combining Multi-Year In Situ And Satellite-Based Observations, Michael G. Brown

Dissertations, Theses, and Capstone Projects

This dissertation examined the seasonal freeze/thaw activity in boreal-Arctic soils and vegetation physiology in Alaska, USA and Alberta, Canada, using in situ environmental measurements and passive microwave satellite observations. The boreal-Arctic high-latitudes have been experiencing ecosystem changes more rapidly in comparison to the rest of Earth due to the presently warming climatic conditions having a magnified effect over Polar Regions. Currently, the boreal-Arctic is a carbon sink; however, recent studies indicate a shift over the next century to become a carbon source. High-latitude vegetation and cold soil dynamics are influenced by climatic shifts and are largely responsible for the regions …

Middle Savannah River: An A/R/Tographic Ecopedagogical Ethnography Experimenting With Rhizomatic Perspectives, Lisa Augustine-Chizmar

College of Graduate Studies: Theses & Dissertations

This research is an experiment in perspective. Using the four commonplaces (Schwab, 1978), I practiced letting the Savannah River teach me what there is to know about the water, the land, the people, and the other entities that depend on ki through artistic, ethnographic, and ecopedagogical lenses. The ethnographic findings describe the social actors that depend on ki and give a voice to the River. The a/r/tographic findings display the River on a canvas map through two hundred years using paint, clay, photography, video, abstract acrylics, and fabric. Together, these methods contribute to a unique ecopedagogical journey. This word cloud …

Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson

Scripps Senior Theses

We are experiencing a climate crisis that must be confronted with strategic mitigation. Pomona College contributes to the climate crisis through its emissions for which there is a baseline record. However there is no baseline record of the climate mitigation currently performed by the trees on Pomona’s campus through carbon storage. This study seeks to determine a current baseline quantity of carbon stored and sequestrated by Pomona’s trees as well as possible courses of climate mitigation for Pomona College to take. Initial information gathering was conducted through interviews with several stakeholders. This study was conducted using data collected prior to …

Technical Note: On Uncertainties In Plant Water Isotopic Composition Following Extraction By Cryogenic Vacuum Distillation, Haoyu Diao, Philipp Schuler, Gregory R. Goldsmith, Rolf T. W. Siegwolf, Matthias Saurer, Marco M. Lehmann

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent studies have challenged the interpretation of plant water isotopes obtained through cryogenic vacuum distillation (CVD) based on observations of a large 2H fractionation. These studies have hypothesized the existence of an H-atom exchange between water and organic tissue during CVD extraction with the magnitude of H exchange related to relative water content of the sample; however, clear evidence is lacking. Here, we systematically tested the uncertainties in the isotopic composition of CVD-extracted water by conducting a series of incubation and rehydration experiments using isotopically depleted water, water at natural isotope abundance, woody materials with exchangeable H, and organic materials …

Kikuyu (Cenchrus Clandestinus) For Dryland Salinity Management, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Kikuyu (Cenchrus clandestinus) is a subtropical, perennial C4 grass that is widely used as a pasture and turf.

It has some salinity tolerance, and moderate waterlogging tolerance. Kikuyu is commonly established from seed and can also be grown from vegetative plantings, unlike marine couch, saltwater couch and Distichlis (vegetative only).

We recommend that any dryland salinity management is part of a whole farm, and preferably a whole catchment, water management plan.

Samphires (Tecticornia Species) For Dryland Salinity Management In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Samphire is the common name for native plants from the genus Tecticornia (synonym Halosarcia). Although slower growing than saltbush and bluebush species, samphires have higher tolerance to saline conditions and waterlogging, and are common in waterlogged saline areas of south-west Western Australia.

Samphire is not a desirable grazing species.

Tall Wheatgrass (Thinopyrum Ponticum) For Dryland Salinity Management, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Tall wheatgrass (Thinopyrum ponticum) has been widely planted in Western Australia on saline land in the southern agricultural areas, on land that shows signs of salt and is not permanently waterlogged.

The information provided here assumes that tall wheatgrass is being grazed effectively by livestock.

Soil Response Of Helicopter Liming In The Monongahela National Forest, Jarrett Douglas Fowler

Graduate Theses, Dissertations, and Problem Reports (ETD)

Soils in the Monongahela National Forest (MNF) are acidic due to sandstone parent material, acid deposition, uptake of base cations by vegetation, and release of organic acids by organic matter (OM) decomposition. Increases in soil acidity have caused declines in forest health and changed species composition and nutrient status. Liming can neutralize soil acidity, but no large-scale liming projects have been done on acid forest soils in the USA. In anticipation of acquiring funding for a proposed liming project in the MNF, in 2007 and 2009 10 sites were selected to sample and analyze soils before lime was applied. In …

Plant And Soil Responses To Sediment Deposition And Nutrient Enrichment In Healthy, Deteriorating, And Newly Created Coastal Marshes In Barataria Basin, Louisiana: Implications For Mississippi River Sediment Diversions, Gina N. Groseclose

LSU Master's Theses

To offset wetland loss in the Mississippi River Delta, sediment diversions that will re-introduce river water and sediment into wetlands are being planned for the lower Mississippi River. River diversions will also deliver high nutrient loads, which may reduce belowground plant productivity, reducing inputs of organic matter important for marsh accretion to keep pace with sea-level rise. However, belowground productivity responses to the combinatory effects of sediment and nutrients are unknown. To test the hypotheses that nutrient enrichment and sediment deposition interact to influence vegetation structure, belowground plant productivity and decomposition, and surface accretion, a field experiment was implemented in …

Long-Term Ndvi And Recent Vegetation Cover Profiles Of Major Offshore Island Nesting Sites Of Sea Turtles In Saudi Waters Of The Northern Arabian Gulf, Rommel H. Maneja, Jeffrey D. Miller, Wenzhao Li, Hesham El-Askary, Ace Vincent B. Flandez, Joshua J. Dagoy, Joselito Francis A. Alcaria, Abdullajid U. Basali, Khaled A. Al-Abdulkader, Ronald A. Loughland, Mohamed A. Qurban

Mathematics, Physics, and Computer Science Faculty Articles and Research

Vegetation is an important ecological component of offshore islands in the Arabian Gulf (AG), which maintains long-term resilience of these islands. This is achieved by influencing sediment retention and moisture acquisition via condensation during periods of high humidity and by providing a variety of microhabitats for island fauna. The resilience of offshore islands’ ecosystems in the Saudi waters is important because they host the largest number of nesting hawksbill and green turtles in the AG. This study defines the characteristics and the long-term trends in vegetation cover of the offshore islands used by sea turtles as nesting grounds in the …

Estimating Live Fuel Moisture Using Smap L-Band Radiometer Soil Moisture For Southern California, Usa, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Live fuel moisture (LFM) is a field-measured indicator of vegetation water content and a crucial observation of vegetation flammability. This study presents a new multi-variant regression model to estimate LFM in the Mediterranean ecosystem of Southern California, USA, using the Soil Moisture Active Passive (SMAP) L-band radiometer soil moisture (SMAP SM) from April 2015 to December 2018 over 12 chamise (Adenostoma fasciculatum) LFM sites. The two-month lag between SMAP SM and LFM was utilized either as steps to synchronize the SMAP SM to the LFM series or as the leading time window to calculate the accumulative SMAP SM. …

Cogongrass (Imperata Cylindrica (L.) Beauv.) In Louisiana: Cause And Consequence, Lorissa A. Radunzel-Davis

LSU Master's Theses

Cogongrass (Imperata cylindrica (L.) Beauv.), an invasive species from East Asia, is found worldwide and is problematic in several countries. In the United States, it grows primarily in the Southeast, reducing biodiversity by growing in dense patches and potentially causing mortality and reducing value of native and planted pinelands due to a high burning temperature. Using Lee Memorial Forest, a Louisiana State University AgCenter property in Washington Parish as a study site, this thesis explores cogongrass in Louisiana with emphasis on soil microbes and soil legacy effects on native plant species. Cogongrass populations at Lee Memorial Forest were more …

Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Rain recharges soil water storages and either percolates downward into aquifers and streams or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored. We characterize the seasonal origins of waters in soils and trees by comparing their midsummer isotopic signatures (δ2H) to seasonal isotopic cycles in precipitation, using a new seasonal origin index. Across 182 Swiss forest sites, xylem water isotopic signatures show that summer rain was not the predominant water source …

Holocene Fire History Reconstruction Of A Mid-Evaluation Mixed-Conifer Forest In The Eastern Cascades, Washington, Zoe Rushton

All Master's Theses

Fire histories of mid-elevation mixed-conifer forests (MEMC) are uncommon, particularly in the eastern Cascades of Washington. As a result, fire regimes and the effects of 20th century fire suppression in these forests are not well understood. In the summer of 2014 a 7.80 meter-long sediment core was extracted from Long Lake, located approximately 45 km west of Yakima, WA, which exists in a grand fir-dominated mixed-conifer forest. Fire activity for the Long Lake watershed was reconstructed using macroscopic charcoal analysis and pollen analysis was used to reconstruct vegetation change through time. Charcoal results show low fire activity in the early …

Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté

Science and Technology Department Faculty Journal Articles

Past changes in the atmospheric concentration of carbon dioxide (PCO2) have had a major impact on earth system dynamics; yet, reconstructing secular trends of past PCO2 remains a prevalent challenge in paleoclimate studies. The current long-term PCO2reconstructions rely largely on the compilation of many different proxies, often with discrepancies among proxies, particularly for periods older than 100 million years (Ma). Here, we reconstructed Phanerozoic PCO2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛp) that increases as PCO2 increases. This concept has been widely applied to alkenones, but here, we …

The Evaluation Of Two Different Harvesting 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) Leaves From Plants Grown In A Wiregrass Tunnel House, Edward Sparks, Raymon Shange, Jacquelyn Jackson, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore

Professional Agricultural Workers Journal

A study was conducted to determine if a 100% or 50% harvest intensity of ‘Topbunch’ collards leaves could be a recommended practice for Tunnel House producers. The experiment was conducted as a split-plot design with harvest dates as main plots, and harvesting intensity of 100% or 50% of leaves as sub-plots. All treatments were replicated three times, drip irrigated, and fertilized according to soil test recommendations. The results showed significant interactions between harvest methods and dates for number and weight of leaves harvested. There were also significant differences for the weight of leaves harvested and numbers. The leaf recovery rates …

Estimating Live Fuel Moisture In Southern California Using Remote Sensing Vegetation Water Content Proxies, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Wonhee Cho, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Wildfires are a major ecological disturbance in Southern California and often lead to great destruction along the Wildland-Urban Interface. Live fuel moisture has been used as an important indicator of wildfire risk in measurements of vegetation water content. However, the limited field measurements of live fuel moisture in both time and space have affected the accuracy of wildfire risk estimations. Traditional estimation of live fuel moisture using remote sensing data was based on vegetation indices, indirect proxies of vegetation water content and subject to influence from weather conditions. In this study, we investigated the feasibility of estimating live fuel moisture …

Assessing Responses Of Betula Papyrifera (Paper Birch) To Climate Variability In A Remnant Population Along The Niobrara River In Nebraska Through Dendroecological And Remote Sensing Techniques, Evan Bumann

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

Remnant populations of the boreal species Betula papyrifera, found along north-facing canyons and river banks of the Niobrara River Valley in north-central Nebraska, represent one of the southernmost distributions of the species in North America. Although, the species has persisted in the Great Plains after the Wisconsin Glaciation due to the local topography and microclimatic conditions, canopy dieback has been reported in recent years, which is believed to be attributed to temperature change. Therefore, the goals of this research are to: 1) use dendroecological techniques, or the study of tree rings to assess the responses B. papyrifera to intra- and …

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; …

Evaluating Pedestrial Compaction Variation & Soil Organic C Content, Gunner B. Decker

Scholars Week

Over time, playing fields are monitored by overall appearance. However, pedestrian compaction is not evenly distributed throughout the entire surface.

Developing The Framework For A Risk Map For Mite Vectored Viruses In Wheat Resulting From Pre-Harvest Hail Damage, Anthony L. Nguy-Robertson, Arthur Zygielbaum, Anthony J. Mcmechan, Gary L. Hein, Stephen N. Wegulo, Abby R. Stilwell, Travis M. Smith

Department of Plant Pathology: Faculty Publications

There is a strong economic incentive to reduce mite-vectored virus outbreaks. Most outbreaks in the central High Plains of the United States occur in the presence of volunteer wheat that emerges before harvest as a result of hail storms. This study provides a conceptual framework for developing a risk map for wheat diseases caused by mite-vectored viruses based on pre-harvest hail events. Traditional methods that use NDVI were found to be unsuitable due to low chlorophyll content in wheat at harvest. Site-level hyperspectral reflectance from mechanically hailed wheat showed increased canopy albedo. Therefore, any increase in NIR combined with large …

Screening Of Olive Cultivars For Tolerance To Fusicladium Oleagineum In South Africa, Zakhele Cyril Msimango

Professional Agricultural Workers Journal

Abstract

This study evaluated commercial olive cultivars for resistance to olive leaf spot (OLS). A growth chamber trial was undertaken with one temperature treatment (16°C) applied during inoculation while a relative humidity (RH) of above 80% was maintained. Plants were kept for 48 hours at 99% RH after inoculation and then moved to shade netted area for disease development at a temperature of 25±5°C. The results were used for categorizing the eight olive cultivars evaluated in this study according to their OLS susceptibility. ‘Frantoio’ was categorized as most tolerant; ‘Nandi’ and ‘Leccino’ were found to be moderately tolerant, and ‘Nocellara …

Rapid Fluctuations In Mid-Latitude Siliceous Plankton Production During The Middle Eocene Climatic Optimum (Odp Site 1051, Western North Atlantic), Jakub Witkowski, Steven M. Bohaty, Kirsty M. Edgar, David M. Harwood

ANDRILL Research and Publications

The Middle Eocene Climatic Optimum (MECO; ~ 40 million years ago [Ma]) is one of the most prominent transient global warming events in the Paleogene. Although the event is well documented in geochemical and isotopic proxy records at many locations, the marine biotic response to the MECO remains poorly constrained. We present new high-resolution, quantitative records of siliceous microplankton assemblages from the MECO interval of Ocean Drilling Program (ODP) Site 1051 in the subtropical western North Atlantic Ocean, which are interpreted in the context of published foraminiferal and bulk carbonate stable isotope (δ¹⁸O and δ¹³C) records. …

Boron Nutrition Of Burley And Dark Tobacco, Laura Ann Frakes Mitchell

Theses and Dissertations--Plant and Soil Sciences

The incidences of suspected Boron (B) deficiency have increased recently in Kentucky tobacco fields, potentially due to recent changes in management practices. The symptoms observed in the field include; hollow stalk, stunted growth, deformed or no bud formation, small slits on the lower leaf midrib and uncontrollable breaking of the midrib approximately two inches from the stalk. B is a micronutrient tobacco needs in minute amounts, however excessive additions of B could cause toxicity. The objectives of this work were to 1) establish critical points for B sufficiency, 2) describe and define B deficiency and toxicity symptoms and 3) develop …

The Imperative Of Conserving California's Foothill Oak Woodlands, Lauren Phillips

Social Sciences

No abstract provided.