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Full-Text Articles in Physical Sciences and Mathematics

Chemical Investigation Of Dichloromethane Extract Of Aloe Vera Peels: An Agricultural Waste, Nazmul Huda Dec 2023

Chemical Investigation Of Dichloromethane Extract Of Aloe Vera Peels: An Agricultural Waste, Nazmul Huda

Theses and Dissertations

Aloe barbadensis Miller, commonly called Aloe Vera, is a widely popular succulent plant species cultivated across subtropical regions worldwide from India to the Tex-Mex border. Besides its historical uses, Aloe juice has garnered attention as a potential remedy for various ailments, particularly in treating various skin conditions and facilitating wound recovery, including obesity, diabetes, hepatitis, Crohn's disease, and ulcerative colitis. Regrettably, the agricultural practice following sap extraction involves discarding Aloe vera peels, constituting agricultural waste. As part of our continuous research on extraction, isolation, separation, and spectral characterization of value-added chemicals present in waste botanicals herein, …


Detection Of A Diverse Endophyte Assemblage Within Fungal Communities Associated With The Arundo Leaf Miner, Lasioptera Donacis (Diptera: Cecidomyiidae), Marie-Claude Bon, John A. Goolsby, Guy Mercadier, Fatiha Guermache, Javid Kashef, Massimo Cristofaro, Ann T. Vacek, Alan Kirk Apr 2023

Detection Of A Diverse Endophyte Assemblage Within Fungal Communities Associated With The Arundo Leaf Miner, Lasioptera Donacis (Diptera: Cecidomyiidae), Marie-Claude Bon, John A. Goolsby, Guy Mercadier, Fatiha Guermache, Javid Kashef, Massimo Cristofaro, Ann T. Vacek, Alan Kirk

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The larvae of Lasioptera donacis Coutin feed on fungal communities lining galleries within the mesophyll of leaf sheaths of Arundo donax in an aggregative manner. It has been stated that L. donacis could have established a fundamental symbiotic relationship with one fungus, although the fungal composition of these communities remains unsettled. Using a culture-dependent approach and ITS sequencing, the present work characterizes and compares the fungal communities associated with L. donacis in Eurasia with the endophytes of A. donax in Texas where L. donacis is absent. The 65 cultivable isolates obtained from L. donacis fungal communities were sorted into 15 …


South Texas Wildlife Activity Across A Fragmented Landscape And Road Mitigation Corridor, Caitlin K. Brett Dec 2022

South Texas Wildlife Activity Across A Fragmented Landscape And Road Mitigation Corridor, Caitlin K. Brett

Theses and Dissertations

Wildlife crossing structures (WCS) and roadside fencing are commonly installed to mitigate habitat fragmentation, wildlife road mortalities, and other negative effects that roads can have on the surrounding landscape. Eight such WCS were constructed below Farm-to-Market (FM)106 in Cameron County, Texas, across a 16 km corridor transecting the Laguna Atascosa National Wildlife Refuge. These WCS, paired with adjacent roadside fencing, were intended to prevent road mortalities of the endangered ocelot (Leopardus pardalis) and to mitigate the barrier effect of FM106 on this and other meso-mammal species. This study will analyze camera trap data from roadside and habitat reference …


Influence Of Pretreatments On Physiological Status And Post-Planting Survival Of Thornforest Seedlings In A Restoration Context, Douglas E. Mainhart Dec 2022

Influence Of Pretreatments On Physiological Status And Post-Planting Survival Of Thornforest Seedlings In A Restoration Context, Douglas E. Mainhart

Theses and Dissertations

Semi-arid ecosystems across the globe have faced land conversion posing a threat to the important ecosystem services they provide. Revegetation-centered restoration efforts in arid regions have low success due to limited water availability and higher temperatures. Typically, practitioners utilize methods that modify field conditions around seedlings to mitigate these stressors. I evaluated the efficacy of in-nursery treatments to improve plant water status. Three pretreatments were applied: elevated CO2, drought hardening, and an antitranspirant foliar spray. My goal was to understand how these pretreatments would impact survival and growth in the field and what physiological traits they altered. Elevated CO2 and …


Production Of Distilled Spirits Using Grain Sorghum Through Liquid Fermentation, Thomas Weiss, Jikai Zhao, Ruijia Hu, Meicen Liu, Yonghui Li, Yi Zheng, Gordon Smith, Donghai Wang Sep 2022

Production Of Distilled Spirits Using Grain Sorghum Through Liquid Fermentation, Thomas Weiss, Jikai Zhao, Ruijia Hu, Meicen Liu, Yonghui Li, Yi Zheng, Gordon Smith, Donghai Wang

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The objectives of this research were to investigate the fermentation performance of US sorghum varieties for the production of distilled spirits as well as their associated coproducts and to study the formation of volatile compounds that are related to the flavor quality of the spirits. Three US sorghum varieties (red, white, and waxy sorghums) and four yeast strains (DADY, Ethanol Red, GR-2, and 71B) were used for distilled spirit production. Both sorghum variety and type of yeast strains had effects on alcohol concentration and alcohol yield. The alcohol concentration varied from 10.26 to 11.34% (v/v) while alcohol yield varied from …


Tree Ring Reconstructions Of Streamflow For The Lower Rio Grande Valley Of Texas, Adedolapo Mutiyat Adeyanju Aug 2022

Tree Ring Reconstructions Of Streamflow For The Lower Rio Grande Valley Of Texas, Adedolapo Mutiyat Adeyanju

Theses and Dissertations

The Rio Grande River is a major water source for people living within the USA-Mexico border. The Rio Grande River has its headwaters in the San Juan Mountains in Colorado and the Sierra Madre Occidental in Mexico before flowing into Texas through El-Paso. The water supply issues facing the Lower Rio Grande Basin (LRGB) are extremely complex from international restrictions to severe climate change. The river shares its flow between the U.S.A and Mexico based on the provisions of the 1944 treaty between the U.S.A and Mexico. The LRGB flow is regulated by releases from Falcon and Amistad Reservoirs managed …


Towards Conserving Crop Wild Relatives Along The Texas–Mexico Border: The Case Of Manihot Walkerae, Gisel Garza, Crystian Sadel Venegas Barrera, Jon Dale, José Guadalupe Martínez-Ávalos, Teresa Patricia Feria-Arroyo Apr 2022

Towards Conserving Crop Wild Relatives Along The Texas–Mexico Border: The Case Of Manihot Walkerae, Gisel Garza, Crystian Sadel Venegas Barrera, Jon Dale, José Guadalupe Martínez-Ávalos, Teresa Patricia Feria-Arroyo

Biology Faculty Publications and Presentations

Walker’s Manihot, Manihot walkerae, is an endangered species endemic to south Texas and northeastern Mexico and is a Crop Wild Relative (CWR) of the international and economically important crop cassava (M. esculenta). Manihot walkerae is globally endangered (IUCN’s Redlist, Texas list, USA); however, it is not recognized on the Mexican list of endangered species (NOM-059-SEMARNAT). We assessed the status of M. walkerae in Mexico and re-evaluated its global status. According to our analysis, M. walkerae should be considered an endangered species based on the IUCN’s assessment method and a threatened species in Mexico based on the Mexican criteria. Our findings …


Comparative Evaluation Of Physicochemical And Fermentative Responses Of Three Sorghum Varieties From Dryland And Irrigated Land And The Properties Of Proteins From Distillers’ Grains, Jikai Zhao, Thomas Weiss, Zhenjiao Du, Shan Hong, Scott R. Bean, Yonghui Li, Donghai Wang Mar 2022

Comparative Evaluation Of Physicochemical And Fermentative Responses Of Three Sorghum Varieties From Dryland And Irrigated Land And The Properties Of Proteins From Distillers’ Grains, Jikai Zhao, Thomas Weiss, Zhenjiao Du, Shan Hong, Scott R. Bean, Yonghui Li, Donghai Wang

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Three sorghum varieties [waxy sorghum (WS), high protein sorghum (HPS), and normal sorghum (NS)] grown under dryland and irrigated conditions were evaluated with respect to the physicochemical and fermentative properties. The proteins were extracted from wet distillers' grains with solubles (WDGS) and characterized in terms of purity and in vitro digestibility. Starch, crude protein, crude fat, and fiber contents of the sorghums ranged from 64.16 to 68.05 g/100 g, 11.49–13.54 g/100 g, 2.45–2.98 g/100 g, and 1.62–1.80 g/100 g, respectively. For the same variety, the sorghums grown under dryland conditions had higher protein (0.33–0.91 g/100 g) and lower …


Identifying Available Resources And Agricultural Practices Useful In Soil Fertility Management To Support Orange-Fleshed Sweet Potato Cultivation On Smallholder Farms In Mozambique, Rafaela Feola Conz, Engil Isadora Pujol Pereira, Abdul Naico, Maria Isabel Andrade, Johan Six Jan 2022

Identifying Available Resources And Agricultural Practices Useful In Soil Fertility Management To Support Orange-Fleshed Sweet Potato Cultivation On Smallholder Farms In Mozambique, Rafaela Feola Conz, Engil Isadora Pujol Pereira, Abdul Naico, Maria Isabel Andrade, Johan Six

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Orange-fleshed sweet potato is an important source of macro-and micronutrients for humans, particularly in resource-poor rural communities. However, sweet potato cultivation removes large amounts of nutrients from the soil. Hence, soil fertility replenishment is vital to secure long-term food production. The lack of access to fertilizers hinders the ability of farmers to supply and replenish soil nutrients, intensifying food insecurity. This study aimed at identifying locally available organic residues and agricultural practices with potential application in soil fertility management to prevent soil degradation in southern Mozambique. We conducted a survey to gather information on the farmers’ demographics and farming systems …


Native And Non-Native Plant Species Differentially Affect Arthropod Community Dynamics With Consequences For Crop Production In Lower Rio Grande Valley, Kaitlynn Lavallee, Pushpa G. Soti, Alexis Racelis, Rupesh R. Kariyat Jan 2022

Native And Non-Native Plant Species Differentially Affect Arthropod Community Dynamics With Consequences For Crop Production In Lower Rio Grande Valley, Kaitlynn Lavallee, Pushpa G. Soti, Alexis Racelis, Rupesh R. Kariyat

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

In agricultural ecosystems, arthropods play critical roles- including biocontrol, pollination services, and as herbivores. While herbivory negatively affects crop production, the recent decline in beneficial insect numbers have created a global concern, and consequently have led into multiple lines of conservation strategies. Agroecological practices that can provide sustenance, nesting, and refuge for beneficial organisms are considered as some of them, except we lack a better understanding of how seasonal and crop specific variation can affect their community dynamics. In this study, we examined this by investigating how native and non-native plants, when incorporated into a vegetable agroecosystem in Lower Rio …


Pre-Sowing Treatments Improve Germinability Of South Texas Native Plant Seeds, Kaitlynn Lavallee, Pushpa Soti, Hansapani Rodrigo, Rupesh R. Kariyat, Alexis Racelis Nov 2021

Pre-Sowing Treatments Improve Germinability Of South Texas Native Plant Seeds, Kaitlynn Lavallee, Pushpa Soti, Hansapani Rodrigo, Rupesh R. Kariyat, Alexis Racelis

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The incorporation of native plant species is central to restoration efforts, but this is often limited by both the availability of seeds and the relatively low viability and germination rates of commercially available seeds. Although pre-sowing treatments are commonly used to improve germination rates of seeds, the efficacy of these treatments is found to vary across species. In this study, we tested how four pre-sow treatments (physical scarification, acid scarification, cold stratification, and aerated hydropriming) affected the viability and seed germination rates of 12 commercially available plant species native to south Texas and commonly used in restoration efforts. Our results …


Lignin, Sugar, And Furan Production Of Industrial Hemp Biomass Via An Integrated Process, Jikai Zhao, Jason Griffin, Kraig Roozeboom, Juhee Lee, Donghai Wang Nov 2021

Lignin, Sugar, And Furan Production Of Industrial Hemp Biomass Via An Integrated Process, Jikai Zhao, Jason Griffin, Kraig Roozeboom, Juhee Lee, Donghai Wang

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Traditional pretreatment of lignocellulosic biomass is often accompanied by washing and disposal of wastewater, which leads to overuse of water and loss of by-products. The objectives of this study were to validate the potential of an acid-base integrated process for simultaneous sugars, furans, and lignin production without washing and wastewater discarding. The difference in conversion performance among different biomass resources was also demonstrated. Parallel acetic acid (HOAc, pH = 2.25) and sodium hydroxide (NaOH, pH = 13.46) pretreatments followed by solid and liquid integration were applied to four genotypes of industrial hemp (Cannabis sativa L.) biomass that were harvested …


Uptake Analysis Of As(Iii) And As(V) By Cassia Fistula Seedlings, Valeria Velazquez Aug 2021

Uptake Analysis Of As(Iii) And As(V) By Cassia Fistula Seedlings, Valeria Velazquez

Theses and Dissertations

The natural and anthropogenic contamination of water by arsenic has become a major concern to the environment and public health. Phytoremediation is an attractive alternative to ecologically friendly remove contaminants at a potential high efficiency and low cost. Absorption of As(III) and As(V) was evaluated by the measuring the content of arsenic in the roots, leaves and stems Cassia fistula grown under controlled conditions in a hydroponics system. After seeds were germinated, the plants were grown in Hoagland nutrient solution individually supplemented with 1, 2, 5 ppm of As(III) and As(V). After two weeks of exposure, samples of leaves, roots, …


Chemical Investigation Of Camu Camu (Myrciaria Dubia) Leaves And Roots, Jorge L. Flores Aug 2021

Chemical Investigation Of Camu Camu (Myrciaria Dubia) Leaves And Roots, Jorge L. Flores

Theses and Dissertations

Flores, Jorge L., Chemical Investigation of Camu Camu (Myrciaria dubia) Leaves and Roots. Master of Science (MS), December, 2020, 45 pp., 8 Tables, 28 Figures, 21 references, 12 titles.Being the largest on the planet, the Amazon rainforest also has the greatest biodiversity of plant life on earth. In the lowland regions of the Amazon grows the Peruvian camu camu (Myrciaria dubia) plant. A short and shaggy shrub, camu camu produces a tasty but sour fruit. Camu camu’s berry-like fruit is widely consumed by the native people of the Amazon. Its distinguished richness in vitamin C, as …


Unravelling The Role Of Pgpr "Pseudomonas Fluorescens" In Semi- Arid Soils Of The Rio Grande Valley, Mandip Tamang May 2021

Unravelling The Role Of Pgpr "Pseudomonas Fluorescens" In Semi- Arid Soils Of The Rio Grande Valley, Mandip Tamang

Theses and Dissertations

Chapter 1: In this chapter, we have provided a review on the components of rhizosphere engineering and the potential use of PGPR and its challenges to serve as an efficient component for sustainable agriculture.

Chapter 2: In this chapter, we isolated 35 different strains of a PGPR, Pseudmonas fluorescens and characterized various plant growth promoting traits such as production of ammonia, protease, Indole acitic acid (IAA), 1-aminocyclopropane-1-carboxylate deaminase (ACC) deaminase, ammonia, hydrogen cyanide (HCN), and souliblization of zinc and phosphate.

Chapter 3: In this chapter, we tested the influence of plant beneficial soil microbe, P. fluorescens, on the growth and …


Compost And Biochar To Promote Soil Biological Activities Under Sweet Potatoes Cultivation In A Subtropical Semiarid Region, Josabeth Navarro, Jahdiel Salazar, James Jihoon Kang, Jason Parsons, Chu-Lin Cheng, Alexandria Castillo, Engil Isadora Pujol Pereira Nov 2020

Compost And Biochar To Promote Soil Biological Activities Under Sweet Potatoes Cultivation In A Subtropical Semiarid Region, Josabeth Navarro, Jahdiel Salazar, James Jihoon Kang, Jason Parsons, Chu-Lin Cheng, Alexandria Castillo, Engil Isadora Pujol Pereira

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

South Texas is located in a subtropical semiarid climate, and due to high temperature and irregular precipitation, farmers opt to leave their fields fallow during the summer months jeopardizing overall soil health. We evaluated whether sweet potato (Ipomoea batatas) cultivation coupled with drip irrigation could restore soil biological activities compared with bare fallow. Additionally, because sweet potatoes have high demand of soil nutrients, especially potassium (K), we evaluated the nutrient supply of locally sourced soil amendments. Sweet potato was cultivated during summer 2018 in McAllen, Texas, under control (no fertilizer), NPK (synthetic fertilizer), RC (yard-waste compost), and AC (compost produced …


Overexpression Of Strigolactone-Associated Genes Exerts Fine-Tuning Selection On Soybean Rhizosphere Bacterial And Fungal Microbiome, Fang Liu, John Hollis Rice, Valeria Lopes, Parwinder Grewal, Sarah L. Lebeis, Tarek Hewezi, Margaret E. Staton Jul 2020

Overexpression Of Strigolactone-Associated Genes Exerts Fine-Tuning Selection On Soybean Rhizosphere Bacterial And Fungal Microbiome, Fang Liu, John Hollis Rice, Valeria Lopes, Parwinder Grewal, Sarah L. Lebeis, Tarek Hewezi, Margaret E. Staton

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Strigolactones are a recently discovered class of carotenoid-derived plant hormones with a wide variety of functions, including acting as signaling molecules in the rhizosphere to promote arbuscular mycorrhizal fungi colonization and parasitic seed germination. To determine whether strigolactones influence the recruitment of microbes to the rhizosphere, we characterized both bacterial and fungal communities in response to the overexpression of genes involved in strigolactone biosynthesis (MAX1d) and signaling perception (D14 and MAX2a) in soybean (Glycine max). The amplicon sequencing-based results suggest that strigolactone overexpression lines had altered soybean rhizosphere bacteria composition at both the community …


Bacterial Community Dissimilarity In Soils Is Driven By Long-Termland-Use Practices, Aditi Sengupta, Janani Hariharan, Parwinder Grewal, Warren A. Dick Jan 2020

Bacterial Community Dissimilarity In Soils Is Driven By Long-Termland-Use Practices, Aditi Sengupta, Janani Hariharan, Parwinder Grewal, Warren A. Dick

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Land‐use practices impact soil microbial functionality and biodiversity, with reports suggesting that anthropogenic activities potentially result in reduced microbial functions and loss of species. The objective of this study was to assess the effect of long‐term (>50 yr) land use (natural forest and grassland, and agricultural land) on soil bacterial community structure. A high‐throughput sequencing‐by‐synthesis approach of the 16S rRNA gene was used to study bacterial community and predicted functional profiles of Alfisols, as affected by variables including land‐use (forest, grass, agricultural) and soil/crop management (rotation and tillage) in long‐term experimental plots in Hoytville, OH. The distribution of the …


Screening Potential Citrus Rootstocks For Phytophthora Nicotianae Tolerance, Madhurababu Kunta, Sandy Chavez, Zenaida Viloria, Hilda S. Del Rio, Madhavi Devanaboina, George Yanev, Jong-Won Park, Eliezer S. Louzada Jan 2020

Screening Potential Citrus Rootstocks For Phytophthora Nicotianae Tolerance, Madhurababu Kunta, Sandy Chavez, Zenaida Viloria, Hilda S. Del Rio, Madhavi Devanaboina, George Yanev, Jong-Won Park, Eliezer S. Louzada

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Seeds from four citrus rootstocks including sour orange, Bitters-C22 citrandarin, Sarawak pummelo 3 Rio Red grapefruit, and Sarawak pummelo 3Bower mandarin were exposed to high inoculum levels of Phytophthora nicotianae to screen for tolerance. Inoculation of pregerminated seeds (PGIS) and non-PGIS was carried out. The average P. nicotianae propagule counts from the soil samples where these seedlings were raised ranged from 424 to 1361 colony forming units/cm3. The proportion of live to dead plants was recorded at 11months postinoculation, which showed that Sarawak3Bower performed significantly better than other rootstocks. Evaluation of the rootstocks 18 months postinoculation resulted in only one …


Biochar Enhances Nitrous Oxide Reduction In Acidic But Not In Near-Neutral Ph Soil, Engil Isadora Pujol Pereira, Jerome Lechot, Rafaela Feola Conz, Abmael Da Silva Cardoso, Johan Six Oct 2019

Biochar Enhances Nitrous Oxide Reduction In Acidic But Not In Near-Neutral Ph Soil, Engil Isadora Pujol Pereira, Jerome Lechot, Rafaela Feola Conz, Abmael Da Silva Cardoso, Johan Six

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

We quantified nitrous oxide (N2O) fluxes and total denitrification (N2O + N2) in an acidic (Ferralsol) and a near-neutral pH soil (Cambisol) to determine whether biochar’s alkalinization effect could be the mechanism inducing potential reductions in N2O fluxes. In Ferralsol, decreases in N2O emissions and in the N2O to N2O + N2 ratio were observed in both biochar and lime treatments. In Cambisol, neither biochar nor lime decreased N2O emissions, despite significantly increasing soil pH. The abundance and community structure of nosZ gene-bearing microorganisms indicated that gene abundances did not explain biochar effects, but a higher diversity of nosZ gene-bearing …


Agricultural Intensification And Urbanization Negatively Impact Soil Nematode Richness And Abundance: A Meta-Analysis, Satyendra K. Pothula, Parwinder Grewal, Robert M. Auge, Arnold M. Saxton, Ernest C. Bernard Apr 2019

Agricultural Intensification And Urbanization Negatively Impact Soil Nematode Richness And Abundance: A Meta-Analysis, Satyendra K. Pothula, Parwinder Grewal, Robert M. Auge, Arnold M. Saxton, Ernest C. Bernard

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Human activity has extensively transformed the land surface by agricultural intensification and urbanization. In soil, nematodes are the most abundant invertebrates. The effect of human interventions was assessed on overall richness, overall abundance, richness and abundance of nematodes of each trophic group and colonizer-persister (c-p) guild by comparing urban, agriculture and disturbed grassland (DGL) with natural grassland (NGL) and forest ecosystems. Meta-analyses were conducted to generate quantitative summaries from 111 published articles that met the inclusion criteria, 91 expressed data in grams and 20 expressed data in cm3. Results from data expressed per 100 g of soil indicated that overall …


Phytochemical Investigation Of Magnolia Grandiflora Green Seed Cones: Analytical And Phytoceutical Studies, Bo Garza, Alondra Echeverria, Felipe Gonzalez, Orlando Castillo, Thomas Eubanks, Debasish Bandyopadhyay Apr 2019

Phytochemical Investigation Of Magnolia Grandiflora Green Seed Cones: Analytical And Phytoceutical Studies, Bo Garza, Alondra Echeverria, Felipe Gonzalez, Orlando Castillo, Thomas Eubanks, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

Phytochemicals are inevitable part of human civilization. It is impossible to say exactly when menfolk started to take plant portions to cure various diseases. Phytochemical investigation of diethyl ether and ethanol extracts of Magnolia grandiflora green seed cones has been carried out. Extraction, isolation, and identification of the phytochemicals were carried out. Structures were determined by various analytical methods including extensive nuclear magnetic resonance, gas chromatography‐ mass spectroscopy, and X‐ray crystallographic analyses. Structures of the three compounds viz. 5,5′‐diallyl‐[1,1′‐biphenyl]‐2,2′‐diol (I), 3′,5‐diallyl‐[1,1′‐biphenyl]‐2,4′‐ diol (II), and (3S,3aS,8S,9aS,10aR,10bS,E)‐8‐hydroxy‐3,6,9a‐trimethyl‐3a,4,5,8,9,9a, 10a,10b‐octahydrooxireno[2′,3′:9,10]cyclodeca[1,2‐b]furan‐2(3H)‐one (III) were confirmed by X‐ray crystallographic analysis. GS‐MS studies of the isolated oil, eluted …


A Heuristic Classification Of Woody Plants Based On Contrasting Shade And Drought Strategies, Liang Wei, Chonggang Xu, Steven Jansen, Hang Zhou, Bradley O. Christoffersen, William T. Pockman, Richard S. Middleton, John D. Marshall, Nate G. Mcdowell Jan 2019

A Heuristic Classification Of Woody Plants Based On Contrasting Shade And Drought Strategies, Liang Wei, Chonggang Xu, Steven Jansen, Hang Zhou, Bradley O. Christoffersen, William T. Pockman, Richard S. Middleton, John D. Marshall, Nate G. Mcdowell

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Woody plants vary in their adaptations to drought and shade. For a better prediction of vegetation responses to drought and shade within dynamic global vegetation models, it is critical to group species into functional types with similar adaptations. One of the key challenges is that the adaptations are generally determined by a large number of plant traits that may not be available for a large number of species. In this study, we present two heuristic woody plant groups that were separated using cluster analysis in a three-dimensional trait–environment space based on three key metrics for each species: mean xylem embolism …


Functional Predictions Of Microbial Communities In Soil As Affected By Long‐Term Tillage Practices, Janani Hariharan, Aditi Sengupta, Parwinder Grewal, Warren A. Dick Dec 2017

Functional Predictions Of Microbial Communities In Soil As Affected By Long‐Term Tillage Practices, Janani Hariharan, Aditi Sengupta, Parwinder Grewal, Warren A. Dick

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Core Ideas

  • Microbial function is important but difficult to assess in soil.
  • An omics‐driven tool, PICRUSt, was used to characterize functions of soil microbial communities.
  • No‐tillage compared with plow tillage was functionally enriched for most nutrient cycles.
  • Many other functions integral to soil health can be explored by the PICRUSt omics approach.

Soil microbial communities affect the soil's biological, chemical, and physical properties, but there is still a knowledge gap regarding the long‐term impact of tillage practices on soil microbial dynamics. Additionally, the accurate identification of belowground microbial functions is a topic of active interest. In this study, microbial community …


N2o Emissions From California Farmlands: A Review, Elizabeth Verhoeven, Engil Isadora Pujol Pereira, Charlotte Decock, Gina Garland, Taryn Kennedy, Emma Suddick, William Horwath, Johan Six Sep 2017

N2o Emissions From California Farmlands: A Review, Elizabeth Verhoeven, Engil Isadora Pujol Pereira, Charlotte Decock, Gina Garland, Taryn Kennedy, Emma Suddick, William Horwath, Johan Six

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Of the greenhouse gases emitted from cropland, nitrous oxide (N2O) has the highest global warming potential. The state of California acknowledges that agriculture both contributes to and is affected by climate change, and in 2016 it adopted legislation to help growers reduce emissions of greenhouse gases, explicitly including N2O. Nitrous oxide emissions can vary widely due to environmental and agronomic factors with most emission estimates coming from temperate grain systems. There is, however, a dearth of emission estimates from perennial and vegetable cropping systems commonly found in California's Mediterranean climate. Therefore, emission factors (EFs) specific to California conditions are needed …


Alternative Restoration Treatments To Maximize Growth And Survival Of Tamaulipan Thornscrub Species During Seeding Establishment, Jennifer Lynn Vela Jul 2015

Alternative Restoration Treatments To Maximize Growth And Survival Of Tamaulipan Thornscrub Species During Seeding Establishment, Jennifer Lynn Vela

Theses and Dissertations - UTB/UTPA

Anthropogenic activities that destroy, degrade, or fragment terrestrial ecosystems have long-lasting detrimental impacts on ecosystem function, services, and biodiversity. The Tamaulipan thornscrub ecoregion of south Texas and northeastern Mexico has sustained considerable loss, degradation, and fragmentation due land conversion for agriculture, urbanization, and introduction of invasive flora and fauna. In an attempt to restore habitat for endangered and migratory animals, United States Fish and Wildlife Service has undertaken a large-scale thornscrub revegetation effort in south Texas. The goal of this study was to develop effective restoration techniques to promote growth and survival of Tamaulipan thornscrub species during seedling establishment. Beginning …


Evaluation Of Control Strategies For The Spread Of Citrus Greening, Vicente Valle Martinez Jul 2015

Evaluation Of Control Strategies For The Spread Of Citrus Greening, Vicente Valle Martinez

Theses and Dissertations - UTB/UTPA

Huanglongbing, also known as citrus greening, is a vector-based disease in citrus (with no cure known to date) that has drastically affected the citrus production in Florida in less than a decade and has been recently detected in Texas and California. In this paper, an epidemic model of the spatial spread of the disease is implemented among commercial and residential groves by taking into consideration the diffusion patterns of the psyllid vectors. A system of differential equations resembling one for malaria infection in humans is derived to evaluate different control methods such as quarantine, treatment, removal, foliar treatment, and pest …


An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy Jan 2015

An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy

Chemistry Faculty Publications and Presentations

The phenomenon of seed dormancy is widespread in plants and serves to prevent all or most of a given population from germinating at the “wrong” time, e.g., during an unusually mild fall in an area subject to typically harsh winters. Seed dormancy is an effective survival strategy in many plant populations, but may greatly complicate efforts to establish large cohorts of seedlings (groups of similar age or developmental stage) needed for re-search and other purposes. In an effort to break seed dormancy in common sunflower, Helianthus annuus L. (Asteraceae), we conducted experiments designed to compare germination times and overall germination …


Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt Jan 2015

Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt

Physics and Astronomy Faculty Publications and Presentations

Supervised image classifications developed from 23 x 23 cm aerial color-infrared aerial photographs (1:5,000 scale) were used to evaluate temporal changes in vegetative cover occurring within three 150 x 300-m research sites on South Padre Island, Texas. Use of high-resolution digitized imagery (ground pixel resolution of ca. 0.1 m) and survey-grade GPS for positional measurements of ground control points (20-25 1.0m2 targets within each research site) resulted in consistently high levels of geometric accuracy, with root mean square errors (RMSEs) ranging between 0.397 – 2.867. Similarly, use of relatively simple information categories (dry and wet sand, live and dead vegetative …


Monitoring Citrus Nutrition In The Rio Grande Valley For Fertilizer Recommendations, Iram Lopez May 2014

Monitoring Citrus Nutrition In The Rio Grande Valley For Fertilizer Recommendations, Iram Lopez

Theses and Dissertations - UTB/UTPA

Soil fertility and plant nutrition is crucial for a better yield and consistent harvest in the Rio Grande Valley for local farmers growing citrus trees. A field of oranges and a field of grapefruits were monitored and nutrition deficiencies were noticed that played an important role during fruit set. Soil samples that were taken throughout the year were analyzed via a carbon dioxide extraction method that mimics the way plants naturally take up nutrients or extract nutrients from every soil type. Macronutrients such as the N, P, K, Na, Ca, Mg and some of the micronutrients (Zn, Fe, Mn, and …