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Title: Environmental correlates of sensory sampling rate in the electrosensory system of Neotropical electric fishes.
Creator: Correa Roldan, Ericka, Crampton, William, Cook, Geoffrey, Correa, Sandra, University of Central Florida
Abstract / Description: The nocturnally-active freshwater Neotropical gymnotiform electric fish generate weak electric organ discharges (EODs) that are detected by electroreceptors to facilitate active electroreception (object detection and communication - including species recognition). The EOD rate of 'pulse-type' species varies among individuals as a function of activity rate and during sexual or agonistic interactions. The extent to which EOD rate varies between and within species in natural conditions, and the...
Show moreThe nocturnally-active freshwater Neotropical gymnotiform electric fish generate weak electric organ discharges (EODs) that are detected by electroreceptors to facilitate active electroreception (object detection and communication - including species recognition). The EOD rate of 'pulse-type' species varies among individuals as a function of activity rate and during sexual or agonistic interactions. The extent to which EOD rate varies between and within species in natural conditions, and the ecological and evolutionary factors that influence such variation are poorly known. EOD rate is presumed to represent a measure of sensory sampling rate, and therefore we hypothesized that water flow velocity may correlate positively to EOD rate variation (both between and within species). To test this hypothesis, we made nocturnal EOD-rate recordings of 862 non-breeding individuals of nine common species in rainforest streams of the upper Amazon. These recordings were accompanied by measurements of additional parameters hypothesized to influence intraspecific (but not interspecific) variation in pulse rate by influencing activity rate. These parameters included conductivity and turbidity (proxies for recent rainfall), temperature and dissolved oxygen (a possible metabolic constraint on signaling), body size (representing ontogeny), and moonlight intensity (a metric of predation risk). Using multiple regression in the form of linear mixed effect models, and model selection, we determined that none of these variables explain interspecific variation in EOD rate (-) suggesting that other factors such as species recognition or non-adaptive drift represent more important ultimate drivers of interspecific variation in pulse rate. However, at the intraspecific level, we reported a substantial reduction in mean pulse rate on nights with strong moonlight in two species, Brachyhypopomus sullivani and Gymnorhamphichthys rondoni. In two other species, Brachyhypopomus beebei and Brachyhypopomus verdii, we reported elevated pulse rate during periods of increased conductivity and/or turbidity that followed rainfall and consequent flooding of ephemeral swamps adjacent to terra-firme streams.
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Date Issued: 2019
Identifier: CFE0007618, ucf:52525
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007618

Title: Effect of predation risk and food availability on parental care and nest survival in suburban and wildland Florida Scrub-Jays.
Creator: Niederhauser, Joseph, Jenkins, David, Fedorka, Kenneth, Bowman, Reed, University of Central Florida
Abstract / Description: Individual organisms often use cues from their natural environments to determine many behavioral and life-history (")decisions.(") These (")decisions(") are usually adaptive, i.e. a response to selection, because the environmental cues on which they are based reliably correlate with increased fitness over time. When the selected behavioral response to a natural cue no longer provides a fitness benefit, then selection for a new response may occur but individuals maintaining the previously...
Show moreIndividual organisms often use cues from their natural environments to determine many behavioral and life-history (")decisions.(") These (")decisions(") are usually adaptive, i.e. a response to selection, because the environmental cues on which they are based reliably correlate with increased fitness over time. When the selected behavioral response to a natural cue no longer provides a fitness benefit, then selection for a new response may occur but individuals maintaining the previously selected response may suffer reduced survival and reproduction. Especially in human-modified landscapes individuals making a maladaptive behavioral or life-history choice based on those formerly reliable environmental cues may be faced with an (")evolutionary trap("). In urban, or suburban, environments many factors have been altered in ways that could lead to evolutionary traps. Inappropriate behavioral responses by many individuals could lead to reduced demographic performance of urban populations relative to their wildland counterparts and to the decline of entire urban populations. In birds, maladaptive patterns of nest provisioning or vigilance may occur (a) when human-provided adult foods are easier to feed young because they are more abundant and predictable than foods appropriate for nestlings, or (b) when birds' perception of predation risk, which can be influenced by human disturbance, is greater than the real risk. By provisioning or attending their nests more or less than what is appropriate given the environmental level of resources and risks, the behavior of suburban parents may be contributing to high levels of nest failure during the nesting stage. To determine whether maladaptive parental care influences nest survival during the nestling stage, I conducted an experiment using Florida Scrub-Jays (Aphelocoma coerluscens). Suburban scrub-jays have lower nest survival during the nestling stage but higher survival during the incubation stage relative to wildland jays. Both predators and food abundance vary greatly between suburban and wildland scrub. The suburbs have a greater abundance of predators that may prey on both adult scrub-jays and their nests and more foods appropriate for adults but less nestling-appropriate food. This variation in risks and resources should affect the parental care behavior of suburban scrub-jays, which in turn may affect patterns of nest survival. In pre-treatment observations, I found that suburban females spent more time brooding than wildland birds but suburban males did not provision any more than wildland males. Experimentally increasing the perception of adult predation risk reduced parental care in both suburban and wildland females. Increasing the availability of nestling food reduced parental care in suburban females but had no effect in wildland females. Increasing food availability, but not predation risk, decreased call rates but increased call frequency in nestling scrub-jays from both habitats. However, neither parental care nor food availability had much influence on nest survival during the nestling stage. Instead, side nest concealment and the presence of helpers were the most important variables in nest survival analyses prompting other explanations besides maladaptive parental behavior or lack of nestling food resources for the habitat-specific difference in nest survival during the nestling stage.
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Date Issued: 2012
Identifier: CFE0004219, ucf:49015
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004219

Title: Development During Middle School: An Ecological-Transactional, Cross-Section Examination of Early Adjustment.
Creator: White, Rachel, Renk, Kimberly, Bedwell, Jeffrey, Sims, Valerie, University of Central Florida
Abstract / Description: This study utilized an ecological framework to investigate the types of variables that influence adolescent adjustment during middle school and how influences change or stay the same depending on grade level. A cross-sectional approach was taken in which students entering the beginning of their Sixth Grade year and students nearing the end of their Eighth Grade year were administered a comprehensive questionnaire including items about psychological adjustment, parenting characteristics,...
Show moreThis study utilized an ecological framework to investigate the types of variables that influence adolescent adjustment during middle school and how influences change or stay the same depending on grade level. A cross-sectional approach was taken in which students entering the beginning of their Sixth Grade year and students nearing the end of their Eighth Grade year were administered a comprehensive questionnaire including items about psychological adjustment, parenting characteristics, community support characteristics, ethnic identity, acculturation status, and socio-economic status. Findings suggest that Sixth and Eighth Graders' experience of emotional and behavioral problems is influenced differently. This is particularly salient as it pertains to parenting support and acculturation variables. Findings support the notion that individualized, multi-systemic style interventions are valuable even within the developmental period of adolescence as important changes in risk and protective factors are taking place as one moves from early- to mid-adolescence.
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Date Issued: 2012
Identifier: CFE0004459, ucf:49347
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004459

Title: Fine-scale geographic variation of stable isotope and fatty acid signatures of three fish species in the Indian River Lagoon, FL.
Creator: Odom, Jennifer, Worthy, Graham, Jenkins, David, Paperno, Richard, University of Central Florida
Abstract / Description: The Indian River Lagoon, Florida, is a unique closed (")bar built(") estuary system that has little interchange with the Atlantic Ocean and which is home to many resident species. Three fish species were investigated to see if their isotopic and fatty acid signatures differed based on geographic location. The goal was to assess the degree of resolution of spatial variation that is possible when using stable isotope and fatty acid signature analysis to interpret feeding habits and potential...
Show moreThe Indian River Lagoon, Florida, is a unique closed (")bar built(") estuary system that has little interchange with the Atlantic Ocean and which is home to many resident species. Three fish species were investigated to see if their isotopic and fatty acid signatures differed based on geographic location. The goal was to assess the degree of resolution of spatial variation that is possible when using stable isotope and fatty acid signature analysis to interpret feeding habits and potential linkages between feeding habits and health status. Spotted seatrout (n=40), pinfish (n=60) and white mullet (n=60) were collected over a 4 week period at sites 30 km apart in two distinct biogeographic regions of the IRL. Fish were analyzed for stable isotope (?13C and ?15N) and fatty acid composition. All three species were significantly different from each other in both isotopic and fatty acid signatures. In the North Indian River segment, spotted seatrout, white mullet and pinfish had mean values ((&)#177; SE) for ?13C of -18.00 (&)#177; 0.08, -14.59 (&)#177; 0.07 and -16.88 (&)#177; 0.04 respectively and for ?15N, mean values were 14.43 (&)#177; 0.05, 8.30 (&)#177; 0.04 and 10.43 (&)#177; 0.03 respectively. For the North-Central Indian River segment, spotted seatrout, white mullet and pinfish had mean values for ?13C of -18.98 (&)#177; 0.02, -16.25 (&)#177;0.06 and -16.94 (&)#177; 0.04 respectively and for ?15N, mean values were 14.21 (&)#177; 0.02, 8.07 (&)#177; 0.03 and 10.64 (&)#177;0.03 respectively. When species and location interactions were examined using ANCOVA, a post-hoc Tukey's HSD test showed that ?13C was significantly affected by sampling segment only for spotted seatrout and that there was no significant effect of location on ?15N values. Spotted seatrout was the only species that differed between segments for ?13C. Classification and Regression Tree (CART) analysis was then performed on the (")extended dietary fatty acids(") for each individual species and collection location. In this analysis, all three species were correctly identified to segment (white mullet - MR 2/53 p~ 0.03; spotted seatrout (MR 0/40), and pinfish (MR 0/56) indicating that individual species were exhibiting significant differences in their fatty acid signature over distances of 30 km. The ability to discern fine-scale differences in potential prey allows for the possibility of better resolution of dolphin feeding habits and hence a better understanding of both habitat utilization and health impacts. Due to limited exchange of clean salt water, contaminants can theoretically become a problem and there are indications that the health of the resident population of bottlenose dolphins (Tursiops truncatus) has been declining over recent years.
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Date Issued: 2012
Identifier: CFE0004329, ucf:49434
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004329

Title: PROSPECTS FOR CHANGE: CREATING A BLENDED LEARNING PROGRAM THROUGH A CULTURE OF SUPPORT.
Creator: Leach, Bill, Murphy, Patrick, University of Central Florida
Abstract / Description: Blended learning, a combination of traditional face to face (F2f) instruction and computer-mediated communication (CMC), is a popular trend in many universities and corporate settings today. Most universities provide faculty members course management systems, such as Blackboard, Angel, and others as a way to organize and transmit course materials to students. In order to assess the pedagogical value of blended learning in a university-level first year composition (FYC) environment, it is...
Show moreBlended learning, a combination of traditional face to face (F2f) instruction and computer-mediated communication (CMC), is a popular trend in many universities and corporate settings today. Most universities provide faculty members course management systems, such as Blackboard, Angel, and others as a way to organize and transmit course materials to students. In order to assess the pedagogical value of blended learning in a university-level first year composition (FYC) environment, it is necessary to view the environment through a critical lens and adequately train faculty in the need for and use of the features of the learning management software (LMS). The setting for this study is the Humanities and Communication Dept. of Florida Institute of Technology, a private university on FloridaÃ‚Â's east coast, consisting of around 6000 students. As I investigate the various pedagogical and theoretical issues of incorporating blended learning into the FYC environment, I critically examine the issues involved in implementing the program. I employ a blended research method to join the tracks of implementing a blended learning program and developing a culture of support together in the Humanities and Communication Department of Florida Tech. In examining program implementation, I use a combination of institutional critique, as advanced by Porter et al., together with an Ã‚Â"ecologicalÃ‚Â" methodology, as outlined by Nardi and OÃ‚Â'Day. In examining the feasibility of creating a culture of support through the design of a faculty workshop, I mainly use Richard SelfeÃ‚Â's methodology, although elements of the previous two methods operate as well. The results of my study provide a means by which faculty members can experience and realize the benefits, while avoiding the pitfalls, of implementing CMC into a f2f classroom and provide an action plan for other researchers to utilize in their own educational settings.
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Date Issued: 2010
Identifier: CFE0003057, ucf:48303
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003057

Title: UNDERSTANDING PLANT COMMUNITY COMPOSITION IN AGRICULTURAL WETLANDS: CONTEXT DEPENDENT EFFECTS AND PLANT INTERACTIONS.
Creator: Boughton, Elizabeth, Quintana-Ascencio, Pedro, University of Central Florida
Abstract / Description: Community composition results from an integrated combination of random processes, regional habitat spatial structure, local environmental conditions, and species interactions. For example, the outcome of plant interactions can change depending on local environmental conditions such as nutrient availability, land management, or herbivory intensity. In particular, plant interactions may vary between facilitation and competition depending on ecological context, with facilitation expected to be...
Show moreCommunity composition results from an integrated combination of random processes, regional habitat spatial structure, local environmental conditions, and species interactions. For example, the outcome of plant interactions can change depending on local environmental conditions such as nutrient availability, land management, or herbivory intensity. In particular, plant interactions may vary between facilitation and competition depending on ecological context, with facilitation expected to be prevalent under stressful conditions. I present the results of four studies that address different aspects of the community assemblage and dynamics emphasizing the synergistic effect of different processes. In the first, I investigated the importance of habitat isolation in determining species richness of wetlands with contrasting land use. The second describes an experiment to test the hypothesis that plant interactions with an unpalatable plant (Juncus effusus) would range from competition in ungrazed areas to facilitation in grazed areas and predicted that facilitative effects of Juncus would differ among functional groups of beneficiary species and be strongest when grazing was intense. In the third, I examine the community composition impacts of Juncus and predicted that Juncus would preserve functional diversity in grazed wetlands but that the effects of Juncus would vary along a grazing gradient. The fourth study investigated the relative importance of competition and nutrients in determining wetland invasion in two different land use types. Broadly, I demonstrate that the importance of different processes (habitat isolation, nutrient availability, competition/facilitation) to community composition is dependent on ecological conditions. This integrated view of community dynamics is interesting from a purely ecological perspective but also can be applied to understanding ecological problems such as exotic invasions and restoration of disturbed habitats.
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Date Issued: 2009
Identifier: CFE0002678, ucf:48234
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002678

Title: Transforming the Aquatic Urban Landscape: Nutrient Status and Management of Stormwater Basins.
Creator: Skovira, Lindsay, Bohlen, Patrick, Fauth, John, Wang, Dingbao, University of Central Florida
Abstract / Description: Urbanization is a largely irreversible anthropogenic change that degrades environmental quality, including aquatic ecosystems. Stormwater ponds are a popular best management practice (BMP) to mitigate the effects of urban land use on downstream water bodies and contribute significantly to the total area of aquatic ecosystems in some urban watersheds. My research investigated the distribution of stormwater ponds and examined how different urban land uses influenced biophysicochemical...
Show moreUrbanization is a largely irreversible anthropogenic change that degrades environmental quality, including aquatic ecosystems. Stormwater ponds are a popular best management practice (BMP) to mitigate the effects of urban land use on downstream water bodies and contribute significantly to the total area of aquatic ecosystems in some urban watersheds. My research investigated the distribution of stormwater ponds and examined how different urban land uses influenced biophysicochemical conditions and management of those ponds in a rapidly developing suburban watershed in the Econlockhatchee River basin in Florida, USA. I evaluated limnological and ecological parameters in randomly-selected ponds distributed among three urban land-use classes: high-density residential, institutional, and roadways. Ecological measures included characterizing percentage cover and composition of littoral zone plant community and the extent of any algal mats. Limnological measures included physical parameters (pH, conductivity, dissolved oxygen, and clarity), and nutrient concentrations (nitrate, ammonium, total nitrogen, dissolved reactive phosphorus, total phosphorus, and chlorophyll a). I used a subjective management intensity index to compare pond management among land-use classes. Stormwater ponds represented 40.2% of the total area of non-forested freshwater systems in the watershed, and were dominated by residential land uses (43.7%), followed by roadways (14.7%), industrial (2.7%) and institutional (2.3%). Principal Component Analysis (PCA) revealed that ponds with higher total nitrogen (TN) and chlorophyll a (chla) concentrations had lower water clarity, and that both. TN and TP were positively correlated with chla. PCA scores for school ponds, which had the highest water clarity, differed significantly from those of expressway and residential ponds, along the first PCA axis. Repeated-measures analysis of variance showed that TN concentrations differed significantly between expressway and school ponds, with expressway ponds having TN concentrations 51.7% higher than schools. Both TP and TN varied differently through time in the different lands uses. Management intensity for removal of aquatic vegetation and algae was lower in school ponds than in expressway and residential ponds, and school ponds contained the highest abundance and diversity of vegetation. Different urban land uses had varying impacts on water quality, and more intense chemical use to control vegetation and algae was related to greater nutrient and chla concentrations and lower water clarity.
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Date Issued: 2016
Identifier: CFE0006845, ucf:51781
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006845

Title: The Diffusion and Performance of the Accountable Care Organization Model.
Creator: Lin, Yi-ling, Wan, Thomas, Malvey, Donna, Liu, Albert Xinliang, Steen, Julie, University of Central Florida
Abstract / Description: Background: Unity in pursuit of the Triple Aim: better health, better care, and lower per capita cost, can be achieved through a well-designed health care delivery system. The accountable care organizations (ACOs) model is considered a key component of health care delivery system improvement because the model fosters better coordination of care through clinical integration and financial accountability. Within the six Centers for Medicaid (&) Medicare Services (CMS) ACO programs, the Medicare...
Show moreBackground: Unity in pursuit of the Triple Aim: better health, better care, and lower per capita cost, can be achieved through a well-designed health care delivery system. The accountable care organizations (ACOs) model is considered a key component of health care delivery system improvement because the model fosters better coordination of care through clinical integration and financial accountability. Within the six Centers for Medicaid (&) Medicare Services (CMS) ACO programs, the Medicare Shared Savings Program (MSSP) ACO has the largest size with a total of 432 ACOs formed; the service subjects of the MSSP ACO are the fee-for-service beneficiaries. Recently, academicians and researchers have been attracted to exploring ACOs' formation and performance. However, most of the early ACO research types are either descriptive or case study. Also, early researchers had limited access to ACO data sets, so they could utilize only regional and demographic factors to identify the predictors of ACO formation.Purpose: An integrative theoretical framework, Rogers' diffusion of innovation theory and Duncan's POET model, was used to examine ACO formation and performance. The first purpose of this study was to determine the relative influences of contextual variables and ACO characteristic variables on how early an ACO model was adopted. The second purpose was to examine how executives' perceptions of ACO performance and the ACO first-year performance are influenced by the contextual variables, ACO characteristic variables, and timing of the adoption of an ACO model. Methods: A cross-sectional design was formulated to gather data from a survey supplemented by secondary data with the analysis unit at the organization level. Study participants in the ACO survey included 2012, 2013, 2014, and 2015 ACO cohorts. Logistic regression was performed to examine the effects of POET and Rogers' five core characteristics in the early adoption of an ACO model (dichotomous). Additionally, multiple linear regression analysis was used to examine the effects of POET and the timing of adoption of an ACO model in the perceptions of ACO performance. ACO first-year performance dataset consisted only of ACO cohorts from 2012 through 2014. Finally, confirmatory factor analysis and structural equation modeling were conducted to examine the measurement model of the ACO first-year performance and a full latent variable model, respectively. Major Findings: A survey of ACO executives/managers between October 2015 and February 2016 was conducted. The 447 MSSP ACOs in my mailing list yielded a response rate of 13.65 % (n=61). Of the 61 MSSP ACOs, 42 (52.5%) were late adopters whose contractual agreement with CMS started in 2014 or 2015, and 36 (59.0%) were with hospital-based composition. Among ACOs that participated in my survey, their current degree of IT adoption in functionalities (62.27 vs. 52.50 points), usage levels (65.19 vs. 49.49 points), and integration levels (62.24 vs. 53.37 points) were better than their initial years. The multiple logistic regression presented that MSSP ACOs were more likely to be early adopters of a CMS if their service areas had high unemployment rates (OR=2.23; 95% CI: 1.13 - 4.39). In the multiple linear regression analysis, the executives in the early ACOs perceived their organizations as more effective than the late adopters, with 12.65 points higher in an aggregate of eight ACO quality domains (p = .005). Three hundred and seventeen MSSP ACOs, with contractual agreements with CMS before 2015, had retained their year-one performance records (the actual ACO performance with eight quality domains). The variability in the actual ACO performance was explained by the predictor variables of the study with an R-square of 15%. The actual ACO performance was likely to be improved if ACOs had more Medicare assigned beneficiaries or had the hospital-based composition. On the other hand, if ACOs' service areas were located in areas of high poverty concentration, a high unemployment rate, or a lower competitive index, their ACO performance was relatively lower than their counterparts. Implications: The findings suggest that managers should consider strategies to increase economies of scale in size and to have hospital involvement in their ACOs in order to increase effective management. Inadequate capital for information technology improvements is the biggest barrier inhibiting healthcare providers' willingness to join an ACO. Regardless of rural or urban areas, financial support is still important for those potential ACO participants who are planning to invest in necessary infrastructure. ACOs that involved hospitals also showed better performance than those ACOs without hospital involvement. This information may help health policy makers to define core principles of the best ACO model in the future. Conclusions: This study makes a unique contribution using a theoretically integrative framework with Rogers' diffusion of innovation theory coupled with Duncan's POET model to examine ACO formation and ACO performance. In the early ACO adopters, three-fifths of the ACOs had hospital involvement; and the levels of their current IT degree in functionalities, usage levels, and integration levels are higher than the late ACO adopters. This study demonstrates that contextual variables, such as unemployment rates at ACO service areas, relatively influence how early an ACO model was adopted. Executives in the early ACOs had higher perceptions of overall organizational effectiveness as compared with the late adopters. The first-year performance of 2012, 2013, and 2014 ACO cohorts is positively influenced by the size of assigned Medicare beneficiaries and hospital-based ACO and is negatively influenced by the poverty rate, unemployment rate, and market competition scores (Herfindah-Hirschman Index).
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Date Issued: 2016
Identifier: CFE0006347, ucf:51576
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006347

Title: Habitat Use and Feeding Ecology of Delphinids Inferred from Stable Isotopes and Fatty Acid Signatures.
Creator: Browning, Nicole, Worthy, Graham, Jenkins, David, Hinkle, Charles, Cockcroft, Victor, University of Central Florida
Abstract / Description: Prey availability, directly or indirectly, affects all aspects of a predator's life history and is a primary factor influencing habitat selection and movements. This is especially true for delphinid species where it has been documented that the behaviors and movements of dolphins are strongly influenced by food availability. Unfortunately, the feeding ecology and habitat use patterns of many of these species are poorly understood. Many methodologies that have been employed to explore these...
Show morePrey availability, directly or indirectly, affects all aspects of a predator's life history and is a primary factor influencing habitat selection and movements. This is especially true for delphinid species where it has been documented that the behaviors and movements of dolphins are strongly influenced by food availability. Unfortunately, the feeding ecology and habitat use patterns of many of these species are poorly understood. Many methodologies that have been employed to explore these facets of dolphin ecology have limitations and constraints or are logistically infeasible. Stable isotope and fatty acid signature analyses have been used extensively on a wide variety of species and have been shown to be methodologies that overcome some of these limitations. These approaches can provide information on feeding habits and the geographic origin of the prey thereby giving tremendous insight into habitat usage patterns. The present study applied stable isotope and fatty acid signature methodologies to gain insight into the feeding ecology and habitat usage of various dolphin species to improve upon our understanding of these important facets of their life histories.The application of stable isotope analysis in ecological studies relies on both species and tissue specific measurements of parameters such as diet-tissue discrimination factors, the difference in stable isotope ratio between a consumer and its prey, and turnover rates, the change in tissue isotopic composition attributable to growth and tissue replacement. Initially, controlled studies were conducted and animals were switched from one isotopically distinct diet to another which allowed for the calculation of these values in bottlenose dolphin skin. Diet-tissue discrimination factors for dolphin skin averaged 2.20° for nitrogen and 0.82° for carbon. Average turnover rates (expressed in half-lives) in dolphin skin were 17 days for nitrogen and 16.5 days for carbon. The present study represents the first reported diet-tissue discrimination factors and turnover rates for carbon and nitrogen in the skin of any cetacean.Next, skin samples were collected from net-entangled and free-ranging dolphin species off the coast of South Africa and analyzed for stable carbon (?13C) and nitrogen (?15N) isotope ratios. The Indo-Pacific bottlenose dolphin (Tursiops aduncus), the common dolphin (Delphinus capensis), the striped dolphin (Stenella coeruleoalba), and the humpback dolphin (Sousa chinensis) all occur off the southeastern coast of South Africa with overlapping distributions. Isotopic signatures revealed resource partitioning among these four species of dolphins with differences in diets, as well as differences in the use of habitat. Mean values for ? 15N ranged from 11.92 (&)#177; 0.11° (n=3) for striped dolphins to 14.95 (&)#177; 0.19° (n=27) for humpback dolphins, indicating that these species are feeding at different trophic levels. Striped dolphin carbon isotope signatures were consistent with evidence that they typically forage further offshore (-17.94 (&)#177; 0.14°) and the carbon isotope values of the humpback dolphins reflected their use of inshore habitats by comparison (-15.16 (&)#177; 0.12°). Common and bottlenose dolphins for nitrogen (13.66 (&)#177; 0.08°, 14.35 (&)#177; 0.07° respectively) and carbon (-15.48 (&)#177; 0.07°, -15.76 (&)#177; 0.06° respectively) fell in between these two extremes. Analyses also revealed that males and females have differences in their diets. On average, males were enriched in ?15N by 0.74° compared to females suggesting some dietary differences in prey composition. Isotopic niche width has been compared to traditional measures of niches used by ecologists and was measured for these South African dolphins. Humpback and bottlenose dolphins had the largest standard elliptical area (SEA), striped dolphins had the smallest SEA, and the SEA for common dolphins was intermediate. Larger SEA values reflect a broader trophic diversity, while smaller SEA values reflect a narrower trophic diversity or a more specialized niche. Finally, a resident group of bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon (IRL) in east central Florida were sampled and explored for differences in isotopic signatures based on sex, age category, season, and location within the IRL. In addition to stable isotope analysis, fatty acid analysis was also used to compare and contrast the findings between the two techniques. Comparison of stable isotopic signatures revealed differences among age categories and among locations. Fatty acid analysis was able to discern further and found differences in the signatures between male and female dolphins. The combination of both techniques allowed for an extensive examination into the feeding ecology and habitat utilization of these resident dolphins. The Bayesian mixing model (Stable Isotope Analysis in R- SIAR) was validated using controlled study data and was found to be accurate when inputting isotopically distinct prey items (sources). The mixing model was then used to estimate the proportions of prey items that make up the diet of Indian River Lagoon bottlenose dolphins. Two models were run in which dolphins were grouped together (model 1) and dolphins were separated by year (model 2). Results of the model reaffirm stomach content analysis results previously obtained.Stable isotope techniques were applied to various dolphin species to gain better understanding of their feeding ecology and habitat utilization. Resource partitioning was suggested for four South African dolphin species which gives crucial insight into the ecology of both at-risk and data-deficient species. These discernments will provide much needed data to conservationists and managers and contributes to our general understanding of these species. This is the first study of its kind to undertake controlled diet studies with bottlenose dolphins which determined diet-tissue discrimination values and turnover rates for carbon and nitrogen isotopes in the skin of any cetacean. The current study is also the first of its kind to attempt to model bottlenose dolphin diet in the Indian River using stable isotopes. Food, being a primary driver for many species, can lend explanation of things like movement patterns, habitat usage, competition, reproductive success, survival, and the spread of diseases, which has been an issue in Indian River dolphins in recent years. Dietary information modeled in this study provided new data for the relative contribution of a suite of potential prey to an apex predator in the Indian River. Data produced through the current study contributes towards a large, unprecedented step forward in understanding dolphin ecology and the roll of cetacean stable isotope ecology.
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Date Issued: 2013
Identifier: CFE0004823, ucf:49733
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004823

Title: The Effect of Landscape Variables on Adult Mosquito (Diptera:Culicidae)Diversity and Behavior.
Creator: Debevec, Caitlyn, Jenkins, David, King, Joshua, Rothermel, Betsie, Boughton, Raoul, University of Central Florida
Abstract / Description: Diseases vectored by mosquitoes cause millions of deaths each year. In modern times Florida's disease risk has been reduced due to efforts to lessen the prevalence of mosquitoes through habitat modification of non-adults. With emerging diseases (i.e. Dengue and Chikunguya) encroaching into Florida from the Caribbean, this traditional approach may not be enough. Alternatively, we can better understand the ecology of how disease works in an ecosystem. One possible way is through the Dilution...
Show moreDiseases vectored by mosquitoes cause millions of deaths each year. In modern times Florida's disease risk has been reduced due to efforts to lessen the prevalence of mosquitoes through habitat modification of non-adults. With emerging diseases (i.e. Dengue and Chikunguya) encroaching into Florida from the Caribbean, this traditional approach may not be enough. Alternatively, we can better understand the ecology of how disease works in an ecosystem. One possible way is through the Dilution Effect, which states that the more species that are in a system the lower the chance for zoonosis. This project models mosquito diversity across regions, land use, and vegetation height in South-Central Florida, for the purpose of identifying predictors that indicate a higher disease risk using information theory (AICc). The plains and coastal regions as well as the developed areas have a relatively higher risk of disease. Florida is a fire maintained habitat, but has been fire suppressed for the last century. Archbold Biological Station (ABS) has used prescribed fires since the early 1980s to try and restore a more natural system. This has created a mosaic of different fire histories. Fire affects the structures that mosquitoes rest under during the day (they are vulnerable to desiccation during the day and hide in darker/shady places), therefore there is a high likelihood that fire will have some effect on mosquito assemblages. This project used model selection to determine the most plausible set of predictors that describe the effect of fire on mosquito assemblages at ABS, using information theory (AICc). In general, time of season accounted for the largest proportion of the variation in the data and TSF had negligible effect on adult mosquito assemblages measured as abundance, speices richness, and Jost D.
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Date Issued: 2015
Identifier: CFE0005780, ucf:50063
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005780

Title: Landscaping Perceptions and Behaviors: Socio-ecological Drivers of Nitrogen in the Residential Landscape.
Creator: Souto, Leesa, Hinkle, Charles, Canan, Penelope, Noss, Reed, Weishampel, John, Pals, Heili, University of Central Florida
Abstract / Description: Driven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen...
Show moreDriven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen inputs to aquatic systems requires a better understanding of the links between residential landscape management and the potential for fertilizer loss. This dissertation examines the linkages between the human behaviors contributing nitrogen to the suburban landscape and the resulting environmental impacts. Framed in socio-psychological theory and social marketing research, the outcomes of this dissertation contribute much needed information to the growing realm of interdisciplinary science that expands integrative theory, develops mixed methods, utilizes spatial and temporal analyses, and conducts actionable research.
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Date Issued: 2012
Identifier: CFE0004604, ucf:49931
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004604

Title: AFFORDANCES IN THE DESIGN OF VIRTUAL ENVIRONMENTS.
Creator: Gross, David Charles, 4., Stannry, Kay M., University of Central Florida
Abstract / Description: Human-computer interaction design principles largely focus on static representations and have yet to fully incorporate theories of perception appropriate for the dynamic multimodal interactions inherent to virtual environment (VE) interaction. Theories of direct perception, in particular affordance theory, may prove particularly relevant to enhancing VE interaction design. The present research constructs a conceptual model of how affordances are realized in the natural world and how lack of...
Show moreHuman-computer interaction design principles largely focus on static representations and have yet to fully incorporate theories of perception appropriate for the dynamic multimodal interactions inherent to virtual environment (VE) interaction. Theories of direct perception, in particular affordance theory, may prove particularly relevant to enhancing VE interaction design. The present research constructs a conceptual model of how affordances are realized in the natural world and how lack of sensory stimuli may lead to realization failures in virtual environments. Implications of the model were empirically investigated by examining three affordances: passability, catchability, and flyability. The experimental design involved four factors for each of the three affordances and was implemented as a fractional factorial design. The results demonstrated that providing affording cues led to behavior closely in-line with real-world behavior. More specifically, when given affording cues participants tended to rotate their virtual bodies when entering narrow passageways, accurately judge balls as catchable, and fly when conditions warranted it. The results support the conceptual model and demonstrate 1) that substituting designed cues via sensory stimuli in available sensory modalities for absent or impoverished modalities may enable the perception of affordances in VEs; 2) that sensory stimuli substitutions provide potential approaches for enabling the perception of affordances in a VE which in the real world are cross-modal; and 3) that affordances relating to specific action capabilities may be enabled by designed sensory stimuli. This research lays an empirical foundation for a science of VE design based on choosing and implementing design properties so as to evoke targeted user behavior
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Date Issued: 2004
Identifier: CFE0000061, ucf:46108
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000061

Title: POLITICAL ECOLOGY OF MEDICINAL PLANT USE IN RURAL NEPAL: GLOBALIZATION, ENVIRONMENTAL DEGRADATION, AND CULTURAL TRANSFORMATION.
Creator: Dovydaitis, Emily, Vajravelu, Rani, University of Central Florida
Abstract / Description: Prior to the advent of biomedicine, rural communities in Nepal relied on phytochemically active compounds in medicinal plants as their primary source of medicine; however, ethnobotanical practices have shifted over time due to economic, environmental, and sociocultural stimuli. Findings from 2016 fieldwork conducted in Dumrikharka, Nepal and Tutung, Nepal are compared to existing literature to describe the political ecology of medicinal plants in rural Nepal. Anthropogenic climate change...
Show morePrior to the advent of biomedicine, rural communities in Nepal relied on phytochemically active compounds in medicinal plants as their primary source of medicine; however, ethnobotanical practices have shifted over time due to economic, environmental, and sociocultural stimuli. Findings from 2016 fieldwork conducted in Dumrikharka, Nepal and Tutung, Nepal are compared to existing literature to describe the political ecology of medicinal plants in rural Nepal. Anthropogenic climate change threatens individual plant species and ecosystem biodiversity. Globalized markets unabated by weak conservation programs place increasing demands on medicinal plants. As indigenous plants become overharvested and more difficult to access, Nepalis incorporate non-indigenous plants into the local pharmacopeia. Novel use of non-indigenous plants illustrates both the dynamic, resilient nature of traditional medicine systems and a loss of biodiversity. Social changes, including outmigration to other countries, notions of modernity, and preference for pharmaceutical drugs, reduce potential candidates to learn and preserve ethnobotanical knowledge. Waterborne pathogens caused by inadequate sanitation infrastructure continue to endanger Nepali populations. The dearth of clinical facilities throughout rural areas, when coupled with the decline ethnobotanical knowledge and traditional healers, poses a gap in healthcare jeopardizing vulnerable, marginalized populations. These factors reinforce the unequal distribution of resources in one of the world's poorest countries, buttressing power inequalities and economic inequities.
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Date Issued: 2017
Identifier: CFH2000240, ucf:46008
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000240

Title: JUVENILE GREEN TURTLE (CHELONIA MYDAS) FORAGING ECOLOGY:FEEDING SELECTIVITY AND FORAGE NUTRIENT ANALYSIS.
Creator: Gilbert, Eliza, Ehrhart, Llewellyn, University of Central Florida
Abstract / Description: For the endangered green turtle, Chelonia mydas, a fundamental component of recovery and conservation is an understanding of its foraging ecology. Foraging optimality models suggest animals will select resources of high quality over those of low quality. For green turtles, this behavior is important, as sufficient quantities of nutritionally adequate forage items are necessary for growth and reproduction. One intrinsic element in the understanding of green turtle foraging ecology is to...
Show moreFor the endangered green turtle, Chelonia mydas, a fundamental component of recovery and conservation is an understanding of its foraging ecology. Foraging optimality models suggest animals will select resources of high quality over those of low quality. For green turtles, this behavior is important, as sufficient quantities of nutritionally adequate forage items are necessary for growth and reproduction. One intrinsic element in the understanding of green turtle foraging ecology is to identify and document the availability and quality of forage resources preferred by green turtles. The objectives of this study were: 1) determine whether juvenile green turtles showed a feeding preference by comparing prey items in the diet to the availability of those items in the habitat, 2) identify species for which there was selection or avoidance, 3) identify nutritional factors determining selection or avoidance of prey items, and 4) evaluate the nutritional content of the diet. This research was conducted by comparing lavage samples from juvenile green turtles to samples from benthic surveys within the habitat. To determine feeding preference, Ivlev's Electivity Index was used to compare ingested species of algae with those available in the habitat. Nutritional analysis of forage was conducted to identify possible nutrients relating to feeding preference. Juvenile green turtles selectively foraged on Chlorophyta and Rhodophyta. Results indicate that diet selection was based on nutritional content. Both the composite diet and the main diet item, Hypnea spp, had a higher gross energy value, were higher in protein, and lower in fiber than prey items that were avoided. Conservation of green turtles requires effective habitat management, which must be informed by an understanding and evaluation of the habitat. For juvenile green turtles, this study indicates that habitats dominated by Chlorophyta and Rhodophyta may be more important for the health of green turtle populations than habitats dominated by Phaeophyta.
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Date Issued: 2005
Identifier: CFE0000487, ucf:46355
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000487

Title: STABLE ISOTOPE TURNOVER RATES AND DIET-TISSUE DISCRIMINATION IN THE SKIN OF WEST INDIAN MANATEES: IMPLICATIONS FOR EVALUATING THEIR FEEDING ECOLOGY AND HABITAT USE.
Creator: Alves, Christy, Worthy, Graham, University of Central Florida
Abstract / Description: The West Indian manatee (Trichechus manatus) is an herbivorous marine mammal that occupies freshwater, estuarine, and marine habitats. Despite being considered endangered, relatively little is known about the feeding ecology of either of the two recognized subspecies, the Florida manatee (T.m. latirostris) and Caribbean or Antillean manatee (T.m. manatus). A better understanding of their respective feeding preferences and habitat use is essential to establish criteria on which conservation...
Show moreThe West Indian manatee (Trichechus manatus) is an herbivorous marine mammal that occupies freshwater, estuarine, and marine habitats. Despite being considered endangered, relatively little is known about the feeding ecology of either of the two recognized subspecies, the Florida manatee (T.m. latirostris) and Caribbean or Antillean manatee (T.m. manatus). A better understanding of their respective feeding preferences and habitat use is essential to establish criteria on which conservation plans can be based. The present study expands on previous work on manatee feeding ecology by both assessing the application of stable isotope analysis to manatee tissue and providing critical baseline parameters for accurate isotopic data interpretation. The present study was the first to calculate stable isotope turnover rate in the skin of any marine mammal. Stable carbon and nitrogen isotope ratios were examined over a period of more than one year in the epidermis of rescued Florida manatees that were transitioning from a diet of aquatic forage to terrestrial forage (lettuce) in captivity. Mean half-life for 13C turnover in manatee epidermis was 55 days and mean half-life for 15N turnover was 42 days. Due to these slow turnover rates, carbon and nitrogen stable isotope analysis in manatee epidermis is useful in summarizing average dietary intake over a long period of time rather than assessing recent diet. In addition to turnover rate, a diet-tissue discrimination value of 2.8‰ for 13C was calculated for long-term captive manatees on a lettuce diet. Turnover and diet-tissue discrimination results were subsequently used to interpret carbon and nitrogen stable isotope data in epidermis samples collected from free-ranging manatees in Florida, Belize, and Puerto Rico. This study was the first application of stable isotope analysis to Antillean manatees. Regional differences in stable isotope ratios in manatee skin were consistent with ratios in plant samples collected in those regions. Signatures in the skin of manatees sampled in Belize and Puerto Rico indicated a diet composed mainly of seagrasses, whereas those of Florida manatees exhibited greater variation. Mixing model results indicated manatees sampled from Crystal River and Homosassa Springs had an overall average intake of primarily freshwater vegetation whereas manatees sampled from Big Bend Power Plant, Ten Thousand Islands, and Warm Mineral Springs fed primarily on seagrasses. Possible diet-tissue discrimination values for 15N ranged from 1.0 to 1.5‰. Stable isotope analysis can be successfully applied to interpret manatee feeding behavior over a long period of time, specifically the use of freshwater vegetation vs. seagrasses, and can aid in improving conservation efforts.
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Date Issued: 2007
Identifier: CFE0001599, ucf:47161
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001599

Title: SPATIOTEMPORAL VARIATION OF AVIAN POPULATIONS WITHIN GEOGRAPHICALLY ISOLATED FRESHWATER MARSHES.
Creator: Rodenbeck, Brian, Weishampel, John, University of Central Florida
Abstract / Description: Metacommunity connectivity, i.e., multi-species dispersal events, is vital to metapopulation persistence in patchy landscapes. Assessments of metacommunity connectivity are not trivial. However, a relationship between trophic rank and the species-area relationship has been found in previous studies, allowing for the use of the predator species-area relationship to act as a surrogate measure of actual metacommunity connectivity of prey species in some systems. For this study, avian species...
Show moreMetacommunity connectivity, i.e., multi-species dispersal events, is vital to metapopulation persistence in patchy landscapes. Assessments of metacommunity connectivity are not trivial. However, a relationship between trophic rank and the species-area relationship has been found in previous studies, allowing for the use of the predator species-area relationship to act as a surrogate measure of actual metacommunity connectivity of prey species in some systems. For this study, avian species were selected as they are generalist top predators within the study system. Predator species richness within geographically isolated freshwater marshes is influenced by a number of factors. I explore the relative roles of patch area, seasonality, hydroperiod, isolation, and vegetation structure on habitat use in the isolated freshwater marshes embedded within the dry prairie ecosystem of Central Florida. Predator species richness was surveyed in 50 sites for three seasons: fall 2005, winter 2005/06, and spring 2006 and the observed avian assemblage measures were subdivided into foraging guilds for analysis. Wading guild (e.g., egrets, herons, bitterns) species richness was correlated with hydroperiod and vegetation structural variables while perching guild (e.g., blackbirds, sparrows, meadowlarks) species richness was correlated with isolation, hydroperiod, and area annually. Overall predator and all guild species richness measures were also correlated with patch area for all seasons. These results suggest that while a complex mixture of patch area, hydroperiod and isolation influence habitat utilization that varies by season and at the community, guild and individual species level, the underlying predictors that define habitat use in wetlands annually includes hydroperiod, and is not exclusively patch area. Additionally, seasonal differences in predator species richness were found to be significant in some cases indicating that future avian population studies may benefit by sampling outside of the normally studied spring breeding season. Results of this study support the use of predator species richness as a suitable assay of metacommunity connectivity of prey species. Applications and implications of this approach toward future conservation efforts are discussed.
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Date Issued: 2007
Identifier: CFE0001766, ucf:47253
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001766

Title: WHOSE SUSTAINABILITY? AN ANALYSIS OF A COMMUNITY FARMING PROGRAM'S FOOD JUSTICE AND ENVIRONMENTAL SUSTAINABILITY AGENDA.
Creator: Davenport, Sarah, Mishtal, Joanna, University of Central Florida
Abstract / Description: As the 1960s Environmental movement has grown, sustainability and justice discourses have come to the fore of the movement. While environmental justice discourse considers the unequal effects of environmental burdens, the language that frames "sustainability" is often socially and politically neutral. This thesis critically examines sustainability initiatives and practices of an urban farming organization in Florida. Based on ethnographic fieldwork in 2017, I explore the extent to which these...
Show moreAs the 1960s Environmental movement has grown, sustainability and justice discourses have come to the fore of the movement. While environmental justice discourse considers the unequal effects of environmental burdens, the language that frames "sustainability" is often socially and politically neutral. This thesis critically examines sustainability initiatives and practices of an urban farming organization in Florida. Based on ethnographic fieldwork in 2017, I explore the extent to which these initiatives incorporate race, ethnicity, and socioeconomic class when working to provide sustainably grown food in diverse communities. I argue that the organization's focus on justice for the environment, rather than for communities, and education as a barrier in low-income, food desert neighborhoods neglects to integrate experiences of those living on the margins into their initiatives. This research raises awareness of the need for a critical examination of sustainability in practice and a politically aware incorporation of environmental justice themes into sustainability agendas.
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Date Issued: 2018
Identifier: CFH2000402, ucf:45805
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000402

Title: Do per-capita impact or abundance dominate the impact of an invader? Interactions among neighboring species in context-dependent competition.
Creator: Li, Haoyu, Quintana-Ascencio, Pedro, Jenkins, David, Boughton, Elizabeth, University of Central Florida
Abstract / Description: Evaluating relative species competitive strength is a central question in community ecology, with strong implications for invasion ecology. Models assessing invader success consider three components: distribution, abundance and per-capita impact. However, relative strength and interactions among these factors remain unclear when applying to specific invasion scenarios. We hypothesized that performance of native and non-native species will vary as a function of direct and indirect effects at...
Show moreEvaluating relative species competitive strength is a central question in community ecology, with strong implications for invasion ecology. Models assessing invader success consider three components: distribution, abundance and per-capita impact. However, relative strength and interactions among these factors remain unclear when applying to specific invasion scenarios. We hypothesized that performance of native and non-native species will vary as a function of direct and indirect effects at different abundances and scales. We conducted a replacement experiment between two dominant grasses in subtropical grasslands (the native Axonopus fissifolius and the non-native Paspalum notatum) in central Florida, USA. Thirty fenced plots (1 m x 3 m each) representing a gradient (15 levels) of increasing non-native groundcover and decreasing native groundcover were set up in November 2017. We transplanted individuals of these two species in subplots (12 subplots and 36 transplants per plot; 1080 plants in total) in a 2*2 factorial design (mixed /single focal species * 2/4 transplants per subplot). Leaf length/number and plant biomass were evaluated at the beginning and end of the experiment along with plot species composition and soil nutrients. Over 92% of transplants of each grass species survived until harvest (11 months). There were significant differences in leaf length, leaf number and plant biomass between conspecific/allospecific subplots. Both P. notatum and A. fissifolius performed better when transplanted in non-native P. notatum subplots. There were also interactions between conspecific/allospecific subplot treatment (direct effects) and the gradient of increasing Paspalum notatum /decreasing Axonopus fissifolius groundcover (indirect effects) treatments. Increasing P. notatum in the whole plot made environments more favorable for both grass species. Effects were consistent for leaf length/number and biomass of the two focal species. More comprehensive evaluation on indirect effects need to be considered when examining competition between non-native species and native species.
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Date Issued: 2019
Identifier: CFE0007487, ucf:52685
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007487

Title: Relating ancient Maya land use legacies to the contemporary forest of Caracol, Belize.
Creator: Hightower, Jessica, Weishampel, John, Quintana-Ascencio, Pedro, VonHolle, Mary, Chase, Arlen, University of Central Florida
Abstract / Description: Human land use legacies have significant and long lasting impacts across landscapes. However, investigating the impacts of ancient land use legacies ((>)400 years) remains problematic due to the difficulty in detecting ancient land uses, especially those beneath dense canopies. The city of Caracol, one of the most important Maya archaeological sites in Belize, was abandoned after the collapse of the Maya civilization (ca. A.D. 900), leaving behind numerous structures, causeways, and...
Show moreHuman land use legacies have significant and long lasting impacts across landscapes. However, investigating the impacts of ancient land use legacies ((>)400 years) remains problematic due to the difficulty in detecting ancient land uses, especially those beneath dense canopies. The city of Caracol, one of the most important Maya archaeological sites in Belize, was abandoned after the collapse of the Maya civilization (ca. A.D. 900), leaving behind numerous structures, causeways, and agricultural terraces that persist beneath the dense tropical forest of western Belize. LiDAR (Light Detection and Ranging) technology enables detection of below canopy Maya archaeological features, providing an ideal opportunity to study the effects of ancient land use legacies on contemporary tropical forest composition. LiDAR also provided us with a detailed record of the 3-dimensional forest structure over the 200 km2 study area. This allowed the investigation how ancient land uses continue to impact both forest composition, in terms of tree species, and forest structure. I recorded tree species over four land use categories: 1) structures, 2) causeways, 3) terraced, and 4) non-terraced land. Using non-metric multidimensional scaling (NMS) and multi-response permutation procedures (MRPP) to test for differences between the classes, I found significantly distinct tree communities associated with the presence of terraces and the underlying topography. Terraced slopes appear to function as micro-valleys on the side of a hill, creating an environmental "bridge" between slope and valley tree communities. Tree species composition over causeways and structures was also found to be significantly different from terraced and non-terraced plots. Forest structure was assessed by extracting LiDAR points for terraced (n=150) and non-terraced (n=150) 0.25 ha plots. I calculated average canopy height, canopy closure, and vertical diversity from the height bins of the LiDAR points, using slope, elevation, and aspect as covariates. Using PerMANOVA I determined that forest structure over terraces was significantly different from non-terraced land. Terraces appear to mediate the effect of slope, resulting in less structural variation between slope and non-sloped land. These results led to the conclusion that human land uses abandoned (>)1000 years ago continue to impact the contemporary forests.
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Date Issued: 2012
Identifier: CFE0004250, ucf:49497
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004250

Title: Phylogenetic Community Structure of Aquatic Beetle Assemblages in a Multi-Wetland Experiment.
Creator: Kelly, Sandor, Jenkins, David, Parkinson, Christopher, Crampton, William, Song, Hojun, University of Central Florida
Abstract / Description: Phylogenetic Community Structure (PCS) metrics are becoming more common in community ecology. PCS metrics estimate the phylogenetic relatedness among members of an ecological community or assemblage. If ecological traits are conserved, then phylogenetic clustering (i.e., taxa are more closely related than expected by chance) indicates habitat filtering as the key process in community assembly. On the other hand, a pattern of phylogenetic overdispersion (i.e., taxa are more distantly related...
Show morePhylogenetic Community Structure (PCS) metrics are becoming more common in community ecology. PCS metrics estimate the phylogenetic relatedness among members of an ecological community or assemblage. If ecological traits are conserved, then phylogenetic clustering (i.e., taxa are more closely related than expected by chance) indicates habitat filtering as the key process in community assembly. On the other hand, a pattern of phylogenetic overdispersion (i.e., taxa are more distantly related than expected by chance) suggests competition is dominant. Most studies to date have used PCS of unmanipulated ecosystems, but the value of PCS metrics will be best revealed in experiments. This project used PCS for aquatic beetle (Coleoptera) assemblages in experimentally manipulated seasonal wetlands on a cattle ranch in south-central Florida, and compared PCS metrics to standard ecological metrics. Wetlands were experimentally treated with all combinations of pasture management, fencing to exclude cattle, and controlled burning during 2006-2009. Beetle assemblages in fenced wetlands were significantly more overdispersed compared to non-fenced wetlands, suggesting that this treatment decreases habitat filtering, causing competition to become the dominant process in community formation. There was also a significant pasture x fence x burn interaction effect, with assemblages in wetlands differing in PCS depending on what combination of the three treatments were applied. Phylogenetic Diversity (PD (-) a measure of branch length of a community or assemblage on a phylogenetic tree) was highly correlated with genera richness (number of genera), and these metrics along with the expected number of genera (D (-) an ecological diversity index) found significant differences among burn treatments and a pasture x burn interaction. The results of this study indicate that PCS metrics complement classical ecological methods and should be widely applied.
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Date Issued: 2012
Identifier: CFE0004394, ucf:49388
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004394

ecology (8)	+ -
Florida (5)	+ -
feeding ecology (4)	+ -
biology (3)	+ -
Ecology (2)	+ -

LiDAR (2)	+ -
birds (2)	+ -
community ecology (2)	+ -
competition (2)	+ -
landscape ecology (2)	+ -
management (2)	+ -
remote sensing (2)	+ -
stable isotope (2)	+ -
stable isotopes (2)	+ -
urban ecology (2)	+ -
Accountable Care Organizations (1)	+ -
Adolescence (1)	+ -
Allele (1)	+ -
Ancient Agriculture (1)	+ -
Aphelocoma coerulescens (1)	+ -
Balancing Selection (1)	+ -
Behavioral ecology (1)	+ -
Biodiversity (1)	+ -
Biology (1)	+ -
Built-In Photovoltaics (1)	+ -
C-type lectins (1)	+ -
Capture Recapture (1)	+ -
Chelonia mydas (1)	+ -
Climate change (1)	+ -
Diffusion Modeling (1)	+ -

ETD Collection (45)	+ -
Honors Collection (4)	+ -

University of Central Florida (47)	+ -
Jenkins, David (9)	+ -
Weishampel, John (8)	+ -
Noss, Reed (6)	+ -
King, Joshua (5)	+ -

Quintana-Ascencio, Pedro (5)	+ -
Worthy, Graham (5)	+ -
Fedorka, Kenneth (4)	+ -
Hinkle, Charles (3)	+ -
Hinkle, Ross (3)	+ -
Hoffman, Eric (3)	+ -
Bohlen, Patrick (2)	+ -
Boughton, Elizabeth (2)	+ -
Bowman, Reed (2)	+ -
Crampton, William (2)	+ -
Moore, Sean (2)	+ -
Murphy, Patrick (2)	+ -
Parkinson, Christopher (2)	+ -
Savage, Anna (2)	+ -
Song, Hojun (2)	+ -
VonHolle, Mary (2)	+ -
Wan, Thomas (2)	+ -
, (1)	+ -
Alves, Christy (1)	+ -
Barber, Sarah (1)	+ -
Baudelet, Matthieu (1)	+ -
Bedwell, Jeffrey (1)	+ -
Beever, Jonathan (1)	+ -
Boughton, Raoul (1)	+ -
Browning, Nicole (1)	+ -

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