Interview with Lib Guerry

In her October 11, 2012 interview with Robert Ryals, Lib Guerry recalls her two-year experience at Winthrop. This interview was conducted for inclusion into the Louise Pettus Archives and Special Collections Oral History Program.https://digitalcommons.winthrop.edu/oralhistoryprogram/1112/thumbnail.jp

Catching the Right Wave: Evaluating Wave Energy Resources and Potential Compatibility with Existing Marine and Coastal Uses

Many hope that ocean waves will be a source for clean, safe, reliable and affordable energy, yet wave energy conversion facilities may affect marine ecosystems through a variety of mechanisms, including competition with other human uses. We developed a decision-support tool to assist siting wave energy facilities, which allows the user to balance the need for profitability of the facilities with the need to minimize conflicts with other ocean uses. Our wave energy model quantifies harvestable wave energy and evaluates the net present value (NPV) of a wave energy facility based on a capital investment analysis. The model has a flexible framework and can be easily applied to wave energy projects at local, regional, and global scales. We applied the model and compatibility analysis on the west coast of Vancouver Island, British Columbia, Canada to provide information for ongoing marine spatial planning, including potential wave energy projects. In particular, we conducted a spatial overlap analysis with a variety of existing uses and ecological characteristics, and a quantitative compatibility analysis with commercial fisheries data. We found that wave power and harvestable wave energy gradually increase offshore as wave conditions intensify. However, areas with high economic potential for wave energy facilities were closer to cable landing points because of the cost of bringing energy ashore and thus in nearshore areas that support a number of different human uses. We show that the maximum combined economic benefit from wave energy and other uses is likely to be realized if wave energy facilities are sited in areas that maximize wave energy NPV and minimize conflict with existing ocean uses. Our tools will help decision-makers explore alternative locations for wave energy facilities by mapping expected wave energy NPV and helping to identify sites that provide maximal returns yet avoid spatial competition with existing ocean uses

Dr. William Coffee Daniell

William Coffee Daniell was born in Greene County, Georgia in 1792 and died in Liberty County, Georgia in 1868. He was Mayor of Savannah from 1824 to 1826 and was a professional physician and planter as well as politician. He was the author of a text on medicine, an antebellum call for southern political and economic unity and numerous letters.https://digitalcommons.georgiasouthern.edu/sav-bios-lane/1048/thumbnail.jp

State Reunion Maintainability for Semi-Markov Models

In previous research the importance of both Markov and semi-Markov models in manpower planning is highlighted. Maintainability of population structures for different types of personnel strategies (i.e. under control by promotion and control by recruitment) were extensively investigated for various types of Markov models (homogeneous as well as non-homogeneous). Semi-Markov models are extensions of Markov models that account for duration of stay in the states. Less attention is paid to the study of maintainability for semi-Markov models. Although, some interesting maintainability results were obtained for non-homogeneous semi-Markov models. The current paper focuses on discrete-time homogeneous semi-Markov models, and explores the concept of maintainable population structures in this setting. In particular, a new concept of maintainability is introduced, the so-called State Reunion maintainability. It is shown that this concept of maintainability is closely related to maintainability for non-homogeneous Markov chains

Nutrient constraints on plant community production and organic matter accumulation of subtropical floating marshes

In the cycle of delta growth and decay, peat-forming wetlands span a time and space continuum. Later in the delta cycle, freshwater floating marshes become increasingly removed from external sediment subsidy and internal nutrient cycling controls plant productivity and organic matter accumulation. An interesting question is whether increased external nutrient loading can affect the basic processes that lead to peat formation—plant production and organic matter decomposition. I conducted several field studies to understand whether belowground organic matter accumulation and decomposition were affected with increased nutrient exposure; in addition, the plant community was monitored over three years. A laboratory soil respiration experiment was run to determine potential limiting nutrients to microbial activity. After two years, there was a reduction of total belowground organic matter accumulation with increased nutrients; this partially resulted from reduced belowground root deposition coupled with accelerated root decomposition. This reduction in belowground accumulation, however, may be related also to the disappearance of a common plant of the community following fertilization, and not necessarily from a phenotypic shift in the allocation pattern by the dominant plant species. Fertilization accounted for an approximate doubling in aboveground biomass, accompanied by decreased stem density, and decreased species richness. Compared to other species, the grass, maidencane (Panicum hemitomon) responded most positively to increased nutrient availability at both sites, while at one site goldenrod (Solidago sempervirens) eventually captured a significant proportion of biomass. Nutrient resorption efficiency of nitrogen (N) and phosphorus (P) were both decreased with increased fertility. The degree of N- or P-limitation observed across coastal populations of P. hemitomon reflect the composite influences of site geology, water source, fire frequency, and the more conservative cycling of P compared to N. Plant community nutrient limitation may not be a reliable predictor of the type of nutrient limitation to soil microbes. Floating marshes have developed and are sustained under nutrient restricted conditions compared to other coastal marshes. Although floating marshes may function as nutrient sinks, a change in community and plant allocation pattern can be predicted with increased nutrient enrichment of these wetland types