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Full-Text Articles in Life Sciences

Investigating The Effect Of A Facultative Symbiont, Hamiltonella Defensa, On Pea Aphid, Acyrthosiphon Pisum, Fecundity And Behavior In Elevated Co₂ Atmospheres, Tyler J. Follman Jan 2022

Investigating The Effect Of A Facultative Symbiont, Hamiltonella Defensa, On Pea Aphid, Acyrthosiphon Pisum, Fecundity And Behavior In Elevated Co₂ Atmospheres, Tyler J. Follman

Electronic Theses and Dissertations

As atmospheric carbon dioxide (CO2) levels continue to rise, it is important to study how economically important organisms, like the pea aphid, Acyrthosiphon pisum, will react to these conditions. The pea aphid feeds on the phloem of crop plants like alfalfa, peas, and fava beans, where it not only directly harms the plant but also can spread plant viruses. A wide variety of factors can influence pea aphid fecundity and behavior. Some of these factors are abiotic, like atmospheric conditions, and some are biotic, like microorganisms with which the pea aphid has a mutualistic relationship. In this thesis, …


The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson Jan 2021

The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson

Electronic Theses and Dissertations

Ocean acidification (OA) caused by CO2 emissions is projected to decrease seawater pH to 7.6 by 2100. Scleractinian corals are at risk because excess H+ in seawater binds to carbonate (CO32-), reducing its availability for CaCO3 skeletons. The energy demand for skeletal growth increases as pH decreases because corals must actively purge excess H+ from their seawater sourced calcifying fluid to maintain high calcification rates. In scleractinian corals it is hypothesized that photosynthesis by symbiotic algae is critical to meet this increased energy demand. To test this hypothesis, I conducted laboratory and field …


Assessing Short-Term Microalgal Community Responses Over Altering Hydrological Conditions In Experimental Wetlands Of Costal Georgia, Maggie M. Kuhn Jan 2021

Assessing Short-Term Microalgal Community Responses Over Altering Hydrological Conditions In Experimental Wetlands Of Costal Georgia, Maggie M. Kuhn

Electronic Theses and Dissertations

Wetlands provide valuable ecosystem services such as nutrient cycling and carbon storage. Microalgae (i.e., diatoms) provide the foundation of primary production and determine rates of energy transfer throughout the system. Climate change models predict an increase in frequency of intense storms and severe drought conditions that pose a threat to known hydrological regimes and wetland ecosystem stability. The purpose of my study was to assess the effects of water permanence (i.e., duration of flooding) on diatom community structure in experimental wetlands. I predicted that wetlands with prolonged periods of flooding (i.e., permanent) would harbor a consistent diatom community throughout flooding …


Macroinvertebrate Responses To Hydrological Variation In Experimental Wetlands., Sergio A. Sabat-Bonilla Jan 2021

Macroinvertebrate Responses To Hydrological Variation In Experimental Wetlands., Sergio A. Sabat-Bonilla

Electronic Theses and Dissertations

Predicted increases in the frequency of intense storms and periods of severe drought due to climate change represent a threat to wetland macroinvertebrate communities through alterations to the hydrological regime. I used experimental ponds to assess the effects of water permanence (i.e., duration of flooding) on the communities of aquatic macroinvertebrates. I predicted that permanent ponds would harbor higher diversity of longer-lived taxa whereas temporary ones will favor colonization by quick turnover, short-lived taxa and support lower consumer diversity. Results show differences in macroinvertebrate communities between permanent and temporary ponds can be mostly explained by hydrology and the amount of …


Sexual Dimorphism Of Thermal Preference In Florida Scrub Lizards (Sceloporus Woodi) And Predicting Response To Climate Change In Two Rare Habitats, Sidney E. Anderson Jan 2021

Sexual Dimorphism Of Thermal Preference In Florida Scrub Lizards (Sceloporus Woodi) And Predicting Response To Climate Change In Two Rare Habitats, Sidney E. Anderson

Electronic Theses and Dissertations

The Florida Scrub Lizard (Sceloporus woodi) is endemic to Florida, where it inhabits fragments of xeric sandhill uplands including endangered long-leaf pine and sand pine scrub habitats. Lizards depend on a predictable range of temperatures to maximize their growth and productivity, and to do so, they shuttle among various thermal micro-environments. Thus, the spatial distribution of temperatures in the habitat is important. Habitats dominated by either high or low extremes of an organism’s preference are energetically costly and dangerous (less optimal), especially to gravid females. This study examines thermal preference of a near-threatened species that also inhabits increasingly rare habitats. …


Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer Jan 2019

Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer

Electronic Theses and Dissertations

Wetlands are one of the world's largest known carbon sinks while comprising only a small amount of the Earth's surface. However, the amount of carbon sequestered by wetlands is shrinking as droughts and human disturbance increases. Carbon in wetlands is stored through the contrast of decomposition and sedimentation of organic matter and absorption of CO2 from the atmosphere by soil microbes. Understanding how changing hydrological regimes and increased wildfires will affect wetland soil and microbial processes is important in the face of predicted climate change for future wetland conservation practices. Specifically, I seek to understand the response of southeastern …


Thermal And Low Oxygen Tolerance Of A Southern Population Of Striped Bass (Morone Saxatilis), Daniel A. Lleras Jan 2019

Thermal And Low Oxygen Tolerance Of A Southern Population Of Striped Bass (Morone Saxatilis), Daniel A. Lleras

Electronic Theses and Dissertations

Climate change projections estimate a 2-3°C increase in water temperatures by the end of the century. The amount of habitat with suitable temperature and oxygen concentration for aquatic organisms will also be reduced. Striped bass (Morone saxatilis) inhabiting the rivers in Southeastern Georgia make an interesting study system as they do not participate in summer coastal migrations typical of their northern conspecifics. Instead, fish in this southern population remain in freshwater environments that experience warming and decreases in dissolved oxygen. The present study aims to determine the thermal and low oxygen tolerance of juvenile striped bass collected from …