Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 11 of 11

Full-Text Articles in Entire DC Network

Quantification And Characterization Of Net Precipitation Bacterial Flux From A Subtropical Epiphyte-Laden Oak Forest, Preston Pound Jan 2017

Quantification And Characterization Of Net Precipitation Bacterial Flux From A Subtropical Epiphyte-Laden Oak Forest, Preston Pound

Electronic Theses and Dissertations

Transport pathways of microbes between ecosystem spheres (atmosphere, phyllosphere, and pedosphere) represent major fluxes in nutrient cycles and have the potential to significantly affect microbially-mediated biogeochemical processes. We quantified a previously unexamined microbial flux from the phyllosphere to the pedosphere during rainfall via throughfall (rainfall dripping from the canopy and through gaps) and stemflow (rainwater funneled down the stem). Bacterial concentrations were quantified using flow cytometry and validated with quantitative Polymerase Chain Reaction (qPCR) assays for samples from a Quercus virginiana (oak)- forest with heavy epiphyte cover (Tillandsia usneoides, Spanish moss) in coastal Georgia (Southeastern USA). Bacteria concentrations …


Comparative Floristic Studies Of Georgian Sandhill Ecosystems Reveals A Dynamic Composition Of Endemics And Generalists, James M. Long, John Schenk Jan 2017

Comparative Floristic Studies Of Georgian Sandhill Ecosystems Reveals A Dynamic Composition Of Endemics And Generalists, James M. Long, John Schenk

Honors College Theses

Sandhill habitats are characterized by sandy, xeric soils that contain a unique assemblage of plants and animals. Similar to the broader long-leaf pine (Pinus palustris) and wire grass (Aristida stricta) ecosystem that sandhills are a subset of, agriculture, development, and habitat modifications have caused sandhill ecosystems to become degraded, putting many species at risk of extinction. Previous studies have focused on diversity within individual sandhills, leaving us with an incomplete understanding of how these communities form, what species are endemic, whether endemics are widespread across sandhills, and how species have adapted to these communities. To gain a more comprehensive understanding …


Inbreeding Depression In The Introduced Spider Latrodectus Geometricus, Margaret A. Howard Jan 2017

Inbreeding Depression In The Introduced Spider Latrodectus Geometricus, Margaret A. Howard

Honors College Theses

The brown widow spider (Latrodectus geometricus) is thought to be native to South America or Southern Africa, but its distribution has expanded to most continents by human introduction. In the continental USA, L. geometricus was first documented in south Florida in the 1930’s. In the early 2000’s a population expansion occurred, and this species is now found in Florida, Georgia, South Carolina, Alabama, Mississippi, Louisiana, Texas, and southern California. Introduced species may face many obstacles when establishing a new population. One common obstacle might be severe inbreeding following founder events or genetic bottlenecks. The purpose of this study was …


Determining The Reproductive Patterns Of The Titan Acorn Barnacle (Megabalanus Coccopoma) In Its Introduced Range, Isabel L. Moran Ms. Jan 2017

Determining The Reproductive Patterns Of The Titan Acorn Barnacle (Megabalanus Coccopoma) In Its Introduced Range, Isabel L. Moran Ms.

Honors College Theses

Invasive species are a significant conservation concern given their contribution to native species decline. The barnacle, Megabalanus coccopoma, is a common invasive species in tropical and subtropical regions of both the Pacific and Atlantic oceans. Little is known about the life history and ecology of M. coccopoma, and data on reproductive biology could provide valuable insight into its propensity to establish introduced populations. Most species of barnacle (including M. coccopoma) are hermaphroditic, but self-fertilization is rare in species studied to date. A recent genetic study of introduced M. coccopoma populations in the southeastern US showed high levels of …


The Role Of Habitat Management In Shaping Predation, Animal Color, And Gene Flow In A Metapopulation Of Florida Scrub Lizards (Sceloporus Woodi), Richard William Orton Jan 2017

The Role Of Habitat Management In Shaping Predation, Animal Color, And Gene Flow In A Metapopulation Of Florida Scrub Lizards (Sceloporus Woodi), Richard William Orton

Electronic Theses and Dissertations

Anthropogenic disturbance is known to affect biological diversity at the community, species, and genetic levels. Habitat fragmentation, in particular, has been shown to impact predator abundance and distribution, impede dispersal, and augment genetic drift. In small populations, which often result from habitat fragmentation, the effects of human disturbance may be disproportionately expressed. Small populations are more susceptible to selection pressures and random drift because genetic and phenotypic frequencies can become rapidly fixed, in comparison to larger populations. In turn, fixation of maladaptive alleles or morphs can accelerate extinction. For example, cryptic color polymorphism can be maintained by apostatic selection, where …


Evolutionary Linkage Of Mimetic And Non-Mimetic Color Traits In A Coral Snake Mimicry Complex, John D. Curlis Jr Jan 2017

Evolutionary Linkage Of Mimetic And Non-Mimetic Color Traits In A Coral Snake Mimicry Complex, John D. Curlis Jr

Electronic Theses and Dissertations

Color polymorphism in aposematic mimicry systems is a perplexing phenomenon for evolutionary biologists, as theoretically the benefits of converging on a model phenotype should constrain the evolution of phenotypic diversity in these systems (i.e., color polymorphism should not occur). Nevertheless, color polymorphism in mimicry systems is prevalent throughout many taxa. In some of these systems, the evolution of color polymorphism results in the existence of non-mimetic morphs, such as those that are cryptic. The case of ground snakes (Sonora semiannulata) is unique in that color polymorphism encompasses both mimetic and cryptic morphs, as well as individual mimetic and …


Factors Affecting Growth Rates And Preferred Body Temperatures In Hatchling Gopher Tortoises, Gopherus Polyphemus: Clutch And Sex, Matthew Carey Jan 2017

Factors Affecting Growth Rates And Preferred Body Temperatures In Hatchling Gopher Tortoises, Gopherus Polyphemus: Clutch And Sex, Matthew Carey

Electronic Theses and Dissertations

Post hatching growth rates in tortoises can affect size at sexual maturity This study looks at what affect clutch and sex has on hatchling tortoises from these two sites as this data is lacking/insufficient from two populations in Southeast Georgia. Eggs were allowed to incubate in natural nests and then were collected between August 19-21, 2015 and hatched in an incubator in the lab. When they hatched, the tortoises were kept in a single room with a rearing temperature that averaged 26.9° C. Sex was determined using laparoscopy at the end of the study to ensure gonad development and to …


Connecting The Dots: A Food Web Of The Lower Ogeechee River, Allison K. Lutz Jan 2017

Connecting The Dots: A Food Web Of The Lower Ogeechee River, Allison K. Lutz

Electronic Theses and Dissertations

The Ogeechee is a fifth order river that originates in the Georgia Piedmont region and flows through the Coastal Plain region in the Southeastern portion of the state. The Ogeechee is one of the last unregulated rivers in Georgia; allowing for studies to occur under a natural flow regime. To my knowledge, studies that incorporate fish into ecological networks (e.g., food webs) are yet to be developed for the Ogeechee River, thus, one of the main objectives of this research was to address this knowledge gap. Five fish species were collected from June 2016 to October 2016 in order to …


Silver Nanoparticle Fate And Accumulation In The Aquatic Food Web Of Stream Microcosms, Stefan J. Petersen Jan 2017

Silver Nanoparticle Fate And Accumulation In The Aquatic Food Web Of Stream Microcosms, Stefan J. Petersen

Electronic Theses and Dissertations

Silver nanoparticles (AgNPs) are used in 25% of all nano-enabled products and applied for anti-microbial properties. Silver nanoparticles are discharged into aquatic environments through wastewater discharge, runoff, and chemical spills. Once in aquatic environments silver nanoparticles have the potential to harm aquatic organisms. While the fate of silver nanoparticles in lentic systems has been investigated, limited information is available for the fate of silver nanoparticles in flowing environments. The purpose of this study was to compare the fate of AgNPs following a one-time pulsed application simulating a chemical spill, or small repetitive applications simulating effluent discharge, in artificial stream communities …


Assessing The Genetic Status And Factors Leading To The Decline Of The Roanoke Bass (Ambloplites Cavifrons), Jackman C. Eschenroeder Jan 2017

Assessing The Genetic Status And Factors Leading To The Decline Of The Roanoke Bass (Ambloplites Cavifrons), Jackman C. Eschenroeder

Electronic Theses and Dissertations

Although numerous factors have led to the staggering declines in freshwater biodiversity throughout the United States and the world, habitat alteration and introduced species pose some of the greatest challenges to conservation efforts. Learning more about how these two factors lead to the decline of an endemic organism could help prevent the future loss of unique species and the premature conclusion of evolutionary trajectories. Roanoke bass (Ambloplites cavifrons) is a sport fish endemic to portions of the Roanoke, Chowan, Tar, and Neuse river basins of North Carolina and Virginia. This species has been in decline for many years, …


A Population Genetic Investigation Of The Reticulated Flatwoods Salamander (Ambystoma Bishopi) On Eglin Air Force Base, Alexander S. Wendt Jan 2017

A Population Genetic Investigation Of The Reticulated Flatwoods Salamander (Ambystoma Bishopi) On Eglin Air Force Base, Alexander S. Wendt

Electronic Theses and Dissertations

The reticulated flatwoods salamander (RFS) is an endangered salamander with a unique life history. One of the largest known, best studied refuges for RFS is found on Eglin Air Force Base, and these RFS have been sampled and managed extensively since 2010. My thesis seeks to better understand RFS by using genetic techniques to address several unknowns, including: 1) determining the population structuring of RFS and the manageable units for species conservation, 2) estimating the size and status of populations, 3) understanding dispersal of RFS and factors that influence this, 4) exploring the breeding biology and recruitment patterns of RFS …