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Full-Text Articles in Physical Sciences and Mathematics

Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti Sep 2022

Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti

Biology Faculty Publications and Presentations

The goal of this study was to predict the range expansion potential of an invasive forage grass, Guinea grass (Megathyrsus maximus). We collected rhizosphere soil samples of M. maximus and coexisting species from 150 different locations and analysed them for soil properties. We estimated the probability of M. maximus presence as a function of soil moisture, organic matter, pH, salinity, total N, and CN ratio using logistic regression. Presence of M. maximus was associated with higher soil moisture, higher organic matter, pH, and nitrogen, but lower salinity and CN ratio. Soil nitrogen and moisture …


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 …


Cover Crops May Exacerbate Moisture Limitations On South Texas Dryland Farms, Stephanie Kasper, Faeqa Mohsin, Lindsey Richards, Alexis Racelis Apr 2022

Cover Crops May Exacerbate Moisture Limitations On South Texas Dryland Farms, Stephanie Kasper, Faeqa Mohsin, Lindsey Richards, Alexis Racelis

Biology Faculty Publications and Presentations

Cover crops are a sustainable management tool for mediating weed pressure, reducing soil erosion, and enhancing soil organic carbon (C) and nitrogen (N) levels. Yet, adoption rates across water-limited farms in Texas remain low, especially among producers without irrigation access, due to concerns that cover crop use of soil moisture will negatively impact subsequent cash crop yields. This three-year cover crop trial in a rain-fed sorghum (Sorghum bicolor L.) farm in Lyford, Texas, trialed different cover crop mixes and seeding rates and confirmed that cover cropping leads to significant soil moisture deficits and cash crop failure when rainfall is low …


Cetacean Strandings In The Us Pacific Northwest 2000–2019 Reveal Potential Linkages To Oceanographic Variability, Amanda J. Warlick, Jessica L. Huggins, Dyanna M. Lambourn, Deborah A. Duffield, Dalin Nichole D'Alessandro, James M. Rice, John Calambokidis, M. Bradley Hanson, Joseph K. Gaydos, Multiple Additional Authors Mar 2022

Cetacean Strandings In The Us Pacific Northwest 2000–2019 Reveal Potential Linkages To Oceanographic Variability, Amanda J. Warlick, Jessica L. Huggins, Dyanna M. Lambourn, Deborah A. Duffield, Dalin Nichole D'Alessandro, James M. Rice, John Calambokidis, M. Bradley Hanson, Joseph K. Gaydos, Multiple Additional Authors

Biology Faculty Publications and Presentations

Studying patterns in marine mammal stranding cases can provide insight into changes in population health, abundance, and distribution. Cetaceans along the United States West coast strand for a wide variety of reasons, including disease, injury, and poor nutritional status, all of which may be caused by both natural and anthropogenic factors. Examining the potential drivers of these stranding cases can reveal how populations respond to changes in their habitat, notably oceanographic variability and anthropogenic activities. In this study, we aim to synthesize recent patterns in 1,819 cetacean strandings across 26 species in the Pacific Northwest from 2000 to 2019 to …


New Opportunities And Untapped Scientific Potential In The Abyssal Ocean, Jeffrey J. Marlowe, Rika E. Anderson, Anna-Louise Reysenbach, Jeffrey S. Seewald, Timothy M. Shank, Andreas P. Teske, V. Dorsey Wanless, S. Adam Soule Feb 2022

New Opportunities And Untapped Scientific Potential In The Abyssal Ocean, Jeffrey J. Marlowe, Rika E. Anderson, Anna-Louise Reysenbach, Jeffrey S. Seewald, Timothy M. Shank, Andreas P. Teske, V. Dorsey Wanless, S. Adam Soule

Biology Faculty Publications and Presentations

The abyssal ocean covers more than half of the Earth’s surface, yet remains understudied and underappreciated. In this Perspectives article, we mark the occasion of the Deep Submergence Vehicle Alvin’s increased depth range (from 4500 to 6500 m) to highlight the scientific potential of the abyssal seafloor. From a geologic perspective, ultra-slow spreading mid-ocean ridges, Petit Spot volcanism, transform faults, and subduction zones put the full life cycle of oceanic crust on display in the abyss, revealing constructive and destructive forces over wide ranges in time and space. Geochemically, the abyssal pressure regime influences the solubility of constituents such as …