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- Title
- EFFECTS OF ISOLATION ON METAPOPULATIONDYNAMICS IN SMALL-WORLD NETWORKS.
- Creator
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Bernard, Alaina, Jenkins, David, University of Central Florida
- Abstract / Description
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Simulation models are valuable for making predictions that may be tested in natural systems and for understanding observed patterns. The simulation model developed for this thesis evaluates the effects of spatial network architecture, including organism dispersal patterns and isolation of habitats, on metapopulations. Two fields were merged throughout this project: metapopulation biology and small-world network theory. Small-world networks are characterized in their extremes as scale-free or...
Show moreSimulation models are valuable for making predictions that may be tested in natural systems and for understanding observed patterns. The simulation model developed for this thesis evaluates the effects of spatial network architecture, including organism dispersal patterns and isolation of habitats, on metapopulations. Two fields were merged throughout this project: metapopulation biology and small-world network theory. Small-world networks are characterized in their extremes as scale-free or single-scale. These models potentially simulate the networks of habitats and corridors in which metapopulations operate. Small-world network theory has been used to describe systems as diverse as rivers, the world-wide-web, and protein interactions, but has not been used as an experimental treatment for metapopulation dynamics. I tested the effects of growth rate, dispersal pattern, network architecture (scale-free and single-scale), attack type (targeted or random), and attack severity (0, 5, 10, 20, or 40% attacked populations) on metapopulation size and inter-population variation in a simulated system designed to be relevant to conservation biology and ecology. Metapopulation size and inter-population variation changed due to combinations of dispersal pattern, growth rate, and attack severity. Specifically, metapopulations were most affected by a combination of unidirectional dispersal and low growth rate in both metapopulation number and inter-population variation. However, a significant difference between scale-free and single-scale metapopulations was not found due to a low connectivity in the modeled networks as well as limitations of experimental assumptions. However, future studies that alter the model's assumptions could improve understanding of the influence of landscape structure on at-risk metapopulations.
Show less - Date Issued
- 2007
- Identifier
- CFE0001877, ucf:47384
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001877
- Title
- TESTING THE PENINSULA EFFECT: DOES IT AFFECT FRESHWATER CRUSTACEANS INHABITING EPHEMERAL WETLANDS ON FLORIDA'S RIDGES?.
- Creator
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Rinne, Debra, Jenkins, David, University of Central Florida
- Abstract / Description
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The peninsula effect is a pattern of diversity wherein species richness decreases along a peninsula from base to tip and is attributed to three mechanisms: historical processes, habitat gradients, and immigration-extinction equilibrium. Numerous studies have reported conflicting results involving the existence, cause, and validity of the peninsula effect in part because they did not account for effects of history or habitat on species richness patterns and because most previous research...
Show moreThe peninsula effect is a pattern of diversity wherein species richness decreases along a peninsula from base to tip and is attributed to three mechanisms: historical processes, habitat gradients, and immigration-extinction equilibrium. Numerous studies have reported conflicting results involving the existence, cause, and validity of the peninsula effect in part because they did not account for effects of history or habitat on species richness patterns and because most previous research focused on organisms that actively disperse, which could confound results with behavioral habitat selection. Florida poses an excellent opportunity to study the peninsula effect because of its geological history and its unique ridges have similar histories (e.g. age, elevation, and sediment). Habitat changes down the peninsula, from a warm temperate climate in the north to a subtropical climate in the south. I studied freshwater crustaceans in isolated wetlands because crustaceans are diverse and disperse passively among these discrete habitats. My study design and statistical analyses controlled for two of the three mechanisms (habitat and history) that may generate a peninsula effect to better test for the third hypothesis (immigration-extinction equilibrium) on the Florida peninsula. Thirty-one wetlands were sampled for crustaceans monthly from November 2004 through April 2005, or until a site dried. Human disturbance was minimized by choosing isolated, ephemeral wetlands located within state reserves, parks, and forests located on four major ridges: Trail, Brooksville, Mount Dora and Lake Wales. I measured several environmental variables to assess habitat variation among sites. Limnological parameters included temperature, pH, dissolved oxygen, conductivity, chlorophyll á, pheophytin, total nitrogen, total phosphorus, and total hardness. Other habitat variables included surface area, distance to nearest water body, fish presence or absence, hydroperiod, total transmitted light and canopy openness. Crustacean species were identified to the lowest practical taxonomic level (typically species) and recorded as present or absent. A total of 53 different crustaceans were identified, including 41 cladocerans, 10 copepods, and 2 ostracods. In a multiple regression, environmental variables and sampling effort accounted for 57% of the variation in species richness. Regression of remaining variation (residuals) against latitude, which measures position along the peninsula, was not statistically significant. The same pattern was obtained when the sequence of regressions was reversed. Therefore, the peninsula effect does affect the species richness of freshwater crustaceans inhabiting ephemeral wetlands on Florida's ridges. Instead, variation in species richness was determined mainly by habitat differences, particularly the complex interaction of phosphorus levels, isolation, fish presence or absence, and hydroperiod. This study may serve as a model for more thorough analyses of mechanisms (history, habitat, and immigration-extinction) of a peninsula effect in other taxa.
Show less - Date Issued
- 2006
- Identifier
- CFE0001034, ucf:46809
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001034
- Title
- DISPERSAL BEHAVIOR OF MOSQUITOFISH (GAMBUSIA HOLBROOKI).
- Creator
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Alemadi, Shireen, Jenkins, David, University of Central Florida
- Abstract / Description
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Mosquitofish (Gambusia holbrooki) are native to the southeastern United States but invasive elsewhere, and are dominant predators in many ecosystems that they inhabit. Information on dispersal behavior will help better understand and predict mosquitofish metapopulation dynamics and invasions. I experimentally tested dispersal behavior of individual mosquitofish under a range of laboratory conditions relevant to field situations. Preliminary experiments showed that gender, lighting conditions,...
Show moreMosquitofish (Gambusia holbrooki) are native to the southeastern United States but invasive elsewhere, and are dominant predators in many ecosystems that they inhabit. Information on dispersal behavior will help better understand and predict mosquitofish metapopulation dynamics and invasions. I experimentally tested dispersal behavior of individual mosquitofish under a range of laboratory conditions relevant to field situations. Preliminary experiments showed that gender, lighting conditions, hunger and acclimation time did not significantly affect net dispersal rate. Power analysis based on this preliminary experiment determined that 6 replicate fish were sufficient for each subsequent experiment; I used 24 fish, and each fish was tested one time. Three factors that potentially could affect net swimming rate were tested: habitat of origin (permanent vs. temporary waters), water depth (3-24 mm), and the interaction between water depth and leaf litter type (upland and wetland). Fish from a temporary pond dispersed significantly faster than fish from a permanent pond, and fish dispersed significantly faster in deeper water than in shallower water. However, leaf litter significantly inhibited fish dispersal at all depths tested. Based on these experiments, G. holbrooki disperse more readily through relatively open and deeper (several centimeters) pathways between habitats such as roadside ditches, drainage canals and trails in flooded conditions. My results are useful for understanding mosquitofish dispersal behavior based on the abiotic and biotic factors examined in this experiment. I predict that mosquitofish can spread from a point of introduction at about 800 m per day, given and unobstructed path of only > 6 mm depth.
Show less - Date Issued
- 2006
- Identifier
- CFE0001001, ucf:46836
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001001
- Title
- GROWTH AND SURVIVAL OF BACTERIA IN SIMULATED MARTIAN CONDITIONS.
- Creator
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Berry, Bonnie, Jenkins, David, University of Central Florida
- Abstract / Description
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Escherichia coli and Serratia liquefaciens, two common microbial spacecraft contaminants known to replicate under low atmospheric pressures of 25 mb, were tested for growth and survival in simulated martian conditions. Stressors of high salinity, low temperature, and low pressure were screened alone and in combination to determine how they might affect microbial activity. Growth and survival of E. coli and S. liquefaciens under low temperatures (30, 20, 10, or 5 °C) with increasing...
Show moreEscherichia coli and Serratia liquefaciens, two common microbial spacecraft contaminants known to replicate under low atmospheric pressures of 25 mb, were tested for growth and survival in simulated martian conditions. Stressors of high salinity, low temperature, and low pressure were screened alone and in combination to determine how they might affect microbial activity. Growth and survival of E. coli and S. liquefaciens under low temperatures (30, 20, 10, or 5 °C) with increasing concentrations (0, 5, 10, or 20 %) of three salts believed to be present on the surface of Mars (MgCl2, MgSO4, NaCl) were monitored over 7 d. Results indicated higher growth rates for E. coli and S. liquefaciens at 30 and 20 °C and in solutions without salt or in 5 % concentrations. No increase in cell density occurred under the highest salt concentrations at any temperatures tested; however, survival rates were high, especially at 10 and 5 °C. Growth rates of E. coli and S. liquefaciens with and without salts at 1013, 100, or 25 mb of total atmospheric pressure were robust under all pressures. In a final experiment, E. coli was maintained in Mars-simulant soils in a Mars Simulation Chamber. Temperatures within the chamber were changed diurnally from -50 °C to 20 °C; UV light was present during daytime operation (8 hrs), and pressure was held at a constant 7.1 mb in a Mars atmosphere for 7 d. Results from the full-scale Mars simulation indicated that E. coli failed to increase its populations under simulated Mars conditions, but was not killed off by the low pressure, low temperature, or high salinity conditions. Escherichia coli, and potentially other bacteria from Earth, may be able to survive on Mars. Surviving bacteria may interfere with scientific studies or, if future conditions become more favorable for microbial growth, modify the martian atmosphere and biogeochemistry.
Show less - Date Issued
- 2008
- Identifier
- CFE0002273, ucf:47856
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002273
- Title
- THE ROLE OF THE FERAL PIG (SUS SCROFA) AS A DISTURBANCE AGENT AND SEED DISPERSER IN CENTRAL FLORIDA'S NATURAL LANDS.
- Creator
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Brescacin, Camille, Jenkins, David, University of Central Florida
- Abstract / Description
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Feral pigs (Sus scrofa) are considered to be among the world's worst invasive species due to their successful invasion and ecological and economic impact to native and agricultural plants and animals around the world. Feral pigs are significant disturbance agents that destroy plant communities, change soil characteristics, alter nutrient cycling, and create open sites for colonization of both native and non-native plant species through their foraging behavior called rooting. In contrast to...
Show moreFeral pigs (Sus scrofa) are considered to be among the world's worst invasive species due to their successful invasion and ecological and economic impact to native and agricultural plants and animals around the world. Feral pigs are significant disturbance agents that destroy plant communities, change soil characteristics, alter nutrient cycling, and create open sites for colonization of both native and non-native plant species through their foraging behavior called rooting. In contrast to native animal disturbances, rooting is a striking feature in the landscape that varies in space, seasonal timing, frequency (number of times rooted), and intensity (depth of rooting). During this study, feral pigs rooted 7.7% of the search area, which increased to 12% when abandoned patches (baseline patches that were not rooted during this study) were included. Overall, feral pigs rooted and re-rooted habitats along roads and trails significantly more than wetlands. Rooting also varied temporally with the most rooting occurring during July-November, which also corresponds to the peak in rooting intensity. Implications to land managers include avoiding the installation of roads and trails near wet to mesic habitats or other habitats that contain species of concern in order to conserve habitat quality and recreational value. Despite less rooting activity, feral pigs still pose a significant threat to wetlands as evidenced by the large amount of abandoned patches documented. In order to conserve natural areas, effective management and development of efficient control methods is needed to keep feral pig populations in check. As a large opportunistic omnivore, feral pigs have the potential to be important vectors for endozoochorus seed dispersal of a variety of plant species. Feral pigs can travel long distances and have a gut retention time up to 49 hours, therefore seeds can be deposited throughout the landscape far from the parent plant. Over the course of this study, feral pigs dispersed 50 plant species from a wide range of ecological and morphological characteristics, though the majority were native, small seeded, wetland species. For most plant species, location of deposition matched their habitat preference and suggests a high probability of survival. Feral pigs disperse mainly wetland plant species, which has important implications for wetland conservation. However, feral pigs also deposited unwanted species into wetlands and predated the seeds of important wetland canopy tree species.
Show less - Date Issued
- 2010
- Identifier
- CFE0003468, ucf:48934
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003468
- Title
- IMPACT OF LANDSCAPE MANAGEMENT ON HOUSE MICE (MUS MUSCULUS) AND RED IMPORTED FIRE ANTS (SOLENOPSIS INVICTA).
- Creator
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Abelson, Jesse, Jenkins, David, University of Central Florida
- Abstract / Description
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Understanding of mechanisms that limit the abundance and distribution of species is central to ecology. The failure of mechanisms to regulate populations can result in population outbreaks. There have been two outbreaks of house mice in the past decade in central Florida. In my study, I examine the efficacy of landscape management in the form of mowing and plowed soil barriers to limit or prevent outbreaks of house mice in a former agricultural area. House mouse populations were highly...
Show moreUnderstanding of mechanisms that limit the abundance and distribution of species is central to ecology. The failure of mechanisms to regulate populations can result in population outbreaks. There have been two outbreaks of house mice in the past decade in central Florida. In my study, I examine the efficacy of landscape management in the form of mowing and plowed soil barriers to limit or prevent outbreaks of house mice in a former agricultural area. House mouse populations were highly variable, but were unaffected by mowing or plowed soil barriers. Red imported fire ants were ubiquitous in the study area regardless of land management treatments. Control of fire ants did not result in more house mice on treated plots.
Show less - Date Issued
- 2011
- Identifier
- CFE0003590, ucf:48899
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003590
- Title
- Variation in Prospecting Behavior and Drivers of Post-Fire Habitat Preference Among Juvenile Florida Scrub-Jays.
- Creator
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Sherer, David, Bohlen, Patrick, Bowman, Reed, Jenkins, David, University of Central Florida
- Abstract / Description
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Florida Scrub-Jays (Aphelocoma coerulescens, FLSJ; federally Threatened) are cooperatively breeding birds endemic to Florida and dependent on fire-maintained xeric oak scrub. FLSJs are year-round residents, highly territorial, and rarely disperse far from their natal territory. Lifetime reproductive success is highest among individuals breeding in early-successional habitat, usually less than 9 to 10 years post-fire. However, because scrub burns infrequently such early-successional, high...
Show moreFlorida Scrub-Jays (Aphelocoma coerulescens, FLSJ; federally Threatened) are cooperatively breeding birds endemic to Florida and dependent on fire-maintained xeric oak scrub. FLSJs are year-round residents, highly territorial, and rarely disperse far from their natal territory. Lifetime reproductive success is highest among individuals breeding in early-successional habitat, usually less than 9 to 10 years post-fire. However, because scrub burns infrequently such early-successional, high-quality habitat is extremely limited and competition for it as breeding space is likely intense. Because some birds live long enough to experience habitat succession, FLSJs also occupy later-successional overgrown scrub, even though both survival and fecundity decline. Although immigration rates into later-successional habitat decline, some birds settle there, perhaps to avoid competition. Prior to dispersal into new breeding territories, most non-breeders engage in pre-dispersal forays, which occur before and immediately after the breeding season. Because FLSJ territories occur across a gradient of post-fire succession, and young birds make frequent forays beyond their natal territories, and are highly visible while doing so, they are ideal models to test how individual and environmental factors drive habitat preference when exploring a post-fire mosaic. I investigated how individual behavioral phenotype, natal territory condition, and body condition relative to conspecifics influence extra-territorial foray behavior across a habitat mosaic that includes various time-since-fire (TSF) intervals. My study system was a population of individually marked FLSJs on 1,214-ha of managed scrub at Archbold Biological Station (Highlands County, Florida). I measured off-territory movements of 114 yearling birds in three annual cohorts and quantified habitat preference using fine-scale fire history records. These data, paired with behavioral assays and morphometric records for each individual FLSJ, allowed me to create and compare models of exploratory behavior underlying searching patterns during pre-breeding forays. My results indicate significant variation in habitat preference by individual FLSJs during forays, driven by an individual's behavioral phenotype and the TSF of its natal territory.
Show less - Date Issued
- 2019
- Identifier
- CFE0007864, ucf:52790
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007864
- Title
- An examination of beta diversity indices and their predictors in two large-scale systems.
- Creator
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Schroeder, Philip, Jenkins, David, King, Joshua, Fedorka, Kenneth, Myers, Jonathan, University of Central Florida
- Abstract / Description
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Biodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (?) can...
Show moreBiodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (?) can be broken down into within-site diversity (?) and between-site diversity (?). In particular, it has been noticed that the ? component of diversity is not as well studied or understood as the ? component. In this study I attempt to address this shortfall, by examining two questions: (1) how is ? is best measured and (2) what drives ?? To answer the first question, I look to find the measure of ? that is most robust to sampling error. While many ? indices have been proposed, few have considered how our methods of data gathering might affect those indices. Datasets collected from the real world will all likely have some sort of error within them as a result of the way they were sampled. Those errors will affect some indices more than others, and the indices that are least affected will be the most reliable for actual data. Once robust indices were identified, I used them to identify possible predictors of ? in two large, national datasets. The first dataset was the National Lakes Assessment created by the USEPA, in which diatoms were sampled from over 1000 lakes across the country. The second was the eBird dataset from the Cornell Lab of Ornithology, which used citizen science to generate a continuous dataset spanning both the last decade and the boundaries of the conterminous United States. ? calculated from these sources was regressed against relevant environmental variables to create a clearer understanding of the effects of the environment on the ? of two very different ecological systems.
Show less - Date Issued
- 2018
- Identifier
- CFE0007367, ucf:52088
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007367
- Title
- Do per-capita impact or abundance dominate the impact of an invader? Interactions among neighboring species in context-dependent competition.
- Creator
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Li, Haoyu, Quintana-Ascencio, Pedro, Jenkins, David, Boughton, Elizabeth, University of Central Florida
- Abstract / Description
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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.
Show less - Date Issued
- 2019
- Identifier
- CFE0007487, ucf:52685
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007487
- Title
- The ecology of central Florida's thief ants (Hymenoptera: Formicidae: Solenopsis).
- Creator
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Ohyama, Leo, King, Joshua, Jenkins, David, Fedorka, Kenneth, University of Central Florida
- Abstract / Description
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Thief ants of the genus Solenopsis are a diverse group of ants that are found in ant communities throughout the world. They have long been purported to practice lestobiosis, an interaction between small and larger-bodied ants, where small ants cryptically tunnel into larger-bodied ant nests within the subterranean environment and steal brood or eggs for consumption. Thief ants are extremely small, measuring 1-2 mm in length and many of the species within this group practice a subterranean...
Show moreThief ants of the genus Solenopsis are a diverse group of ants that are found in ant communities throughout the world. They have long been purported to practice lestobiosis, an interaction between small and larger-bodied ants, where small ants cryptically tunnel into larger-bodied ant nests within the subterranean environment and steal brood or eggs for consumption. Thief ants are extremely small, measuring 1-2 mm in length and many of the species within this group practice a subterranean life history, where they live the entirety of their lives exclusively belowground. Due to these key characteristics, the ecology and natural history of this group of ants has remained largely unknown despite their noted high abundance within the southeastern United States, especially in upland ecosystems. The purpose of this thesis is to improve our understanding of the ecology of this enigmatic group, providing a solid foundation for future work on their behavior, biology, and natural history. Therefore, this project first attempts to identify key abiotic environmental variables that potentially drive the diversity and distribution of this group in upland ecosystems. Next a field manipulation experiment was conducted in areas of high thief ant density to determine biotic effects between thief ants and the aboveground ant community. This was done by removing thief ants using belowground toxic baits and monitoring co-occurring ant worker abundances throughout a period of approximately 1 year. We found evidence that thief ants dominate belowground and diversity. Our field experiment also yielded evidence indicating that thief ants exert potential top-down regulation on entire ant communities.
Show less - Date Issued
- 2019
- Identifier
- CFE0007696, ucf:52408
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007696
- Title
- Unearthing the past and present of a semi-fossorial lizard: conservation genetics, phylogeography, and taxonomy of Plestiodon egregius.
- Creator
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Mercier, Kathryn, Savage, Anna, Parkinson, Christopher, Jenkins, David, University of Central Florida
- Abstract / Description
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Characterizing an organism's evolutionary history and population structure as well as understanding the forces shaping that divergence is crucial to conservation biology. A clear understanding of the patterns of diversity and divergence are imperative for the best management ofthe organism, while an awareness of what drives these patterns can lead to better predictions of how organisms will respond to future climate change. Historical climate changes and associated sea levelchange are among...
Show moreCharacterizing an organism's evolutionary history and population structure as well as understanding the forces shaping that divergence is crucial to conservation biology. A clear understanding of the patterns of diversity and divergence are imperative for the best management ofthe organism, while an awareness of what drives these patterns can lead to better predictions of how organisms will respond to future climate change. Historical climate changes and associated sea levelchange are among the main forces driving divergence in many species. To examine how effects of climate changes may have driven patterns of intraspecific divergence, I examined Mole Skinks,Plestiodon egregius, a semi-fossorial lizard of conservation concern. First, I characterized P. egregius evolutionary history and population structure using multiple data sources: morphological characters,mitochondrial sequences (mtDNA), and genome-wide single nucleotide polymorphisms (SNPs). I determined that SNP data distinguished population structure at a finer resolution than morphologyor mtDNA. From these data, I defined six conservation units within P. egregius, three of which are consistent with current subspecific taxonomy. Next, I used statistical phylogeography to examinehow the effects of historical climate change in the southeastern United States (US) may have driven patterns of intraspecific divergence in P. egregius. I devised a set of alternative hypotheses regardingthe historical distribution and dispersal of P. egregius to test using genome-wide SNP markers. I found support for a historical refugia within the southern scrub ridges in Florida followed byexpansion into the Florida peninsula and mainland US. Synthesizing the results from both studies, I evaluate the current subspecific taxonomy and discuss the conservation of P. egregius. Overall, Iconclude that P. egregius evolutionary history has been driven by historical sea level changes in the southeastern US, and that insular populations should be the focus of conservation efforts.
Show less - Date Issued
- 2018
- Identifier
- CFE0007225, ucf:52228
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007225
- Title
- Species and habitat interactions of the gopher tortoise: A keystone species?.
- Creator
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Catano, Christopher, Hinkle, Charles, Stout, I, Jenkins, David, University of Central Florida
- Abstract / Description
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Species-species and species-habitat interactions have been demonstrated to be important in influencing diversity across a variety of ecosystems. Despite generalities in the importance of these interactions, appropriate mechanisms to explain them are absent in many systems. In sandhill systems of the southeast U.S., gopher tortoises have been hypothesized to be a crucial species in the maintenance of diversity and function. However, the mechanisms and magnitude in which they influence their...
Show moreSpecies-species and species-habitat interactions have been demonstrated to be important in influencing diversity across a variety of ecosystems. Despite generalities in the importance of these interactions, appropriate mechanisms to explain them are absent in many systems. In sandhill systems of the southeast U.S., gopher tortoises have been hypothesized to be a crucial species in the maintenance of diversity and function. However, the mechanisms and magnitude in which they influence their communities and habitats have rarely been empirically quantified. I examined how habitat structure influences tortoise abandonment of burrows and how tortoise densities influence non-volant vertebrate community diversity. Tortoise burrow abandonment is directly influenced by canopy closure, with each percent increase in canopy cover relating to a ~2% increase in the probability of burrow abandonment. In addition, tortoise burrow density was positively correlated with diversity and evenness, but not species richness. This influence was directly proportional to burrow density, supporting a dominance role for this species and rejecting the commonly asserted keystone species mechanism. I also quantified the influence of tortoises in influencing diversity relative to other environmental and habitat variables. Through this research, I have demonstrated that disturbance and habitat structure are important, but diversity responds most to density of burrows in the habitat. These findings demonstrate the intricate relationships interacting to maintaining diversity in sandhill systems. In particular, habitat change leading to declines of gopher tortoises may have drastic negative impacts on vertebrate species diversity.
Show less - Date Issued
- 2012
- Identifier
- CFE0004526, ucf:49246
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004526
- Title
- Effect of predation risk and food availability on parental care and nest survival in suburban and wildland Florida Scrub-Jays.
- Creator
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Niederhauser, Joseph, Jenkins, David, Fedorka, Kenneth, Bowman, Reed, University of Central Florida
- Abstract / Description
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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.
Show less - Date Issued
- 2012
- Identifier
- CFE0004219, ucf:49015
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004219
- Title
- Fine-scale geographic variation of stable isotope and fatty acid signatures of three fish species in the Indian River Lagoon, FL.
- Creator
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Odom, Jennifer, Worthy, Graham, Jenkins, David, Paperno, Richard, University of Central Florida
- Abstract / Description
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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.
Show less - Date Issued
- 2012
- Identifier
- CFE0004329, ucf:49434
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004329
- Title
- Climate Change and the Evolution of Insect Immune Function.
- Creator
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Perry, Danae, Fedorka, Kenneth, Jenkins, David, Hoffman, Eric, University of Central Florida
- Abstract / Description
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Insects are ectothermic organisms that have physiological, behavioral and life-history traits directly influenced by their environment. Investigations have shown that many insects use melanin to permanently darken their cuticles in cooler or drier climates to improve thermoregulation and desiccation resistance. Melanin is a major component of pathogen defense in insects. This suggests that environmentally driven adaptive changes in cuticular melanin may non-adaptively shape insect immune...
Show moreInsects are ectothermic organisms that have physiological, behavioral and life-history traits directly influenced by their environment. Investigations have shown that many insects use melanin to permanently darken their cuticles in cooler or drier climates to improve thermoregulation and desiccation resistance. Melanin is a major component of pathogen defense in insects. This suggests that environmentally driven adaptive changes in cuticular melanin may non-adaptively shape insect immune function. This hypothesis has been referred to as climate-related Cuticle Dependent Immune Investment (climate-related CDII). Climate-related CDII also suggests that a warming climate could lead to the evolution of a weakened melanin-based immune response due to direct selection for lighter cuticles. Climate-related CDII has not been investigated with regard to climate change. Using Drosophila melanogaster, the first part of this study investigated if the documented pattern of lowered immune function in warmer temperatures offsets the expected gain in metabolic rate. The second part of this project investigated how a warming thermal environment will affect the evolution of insect immune function by quantifying changes in melanization and immune function over multiple generations in a changing thermal environment. In the first investigation there was evidence for weakened immune function in males, while females saw an offset by gaining a metabolic boost. The second investigation showed evidence that warming treatments evolved lowered overall immune function. This project gives evidence that insect immune function has the potential to be weakened by increasing temperatures. Insect immune function is a major contributing factor to insect abundances. A decrease in beneficial insects or an increase in harmful insects or pathogens they vector could have detrimental environment and human health consequences.?
Show less - Date Issued
- 2017
- Identifier
- CFE0006638, ucf:51256
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006638
- Title
- Does the journey matter more than the destination? The contribution of geospatial characteristics and local variables to invasive Pomacea maculata distribution across ranchland wetlands.
- Creator
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Pierre, Steffan, Quintana-Ascencio, Pedro, Jenkins, David, Boughton, Elizabeth, University of Central Florida
- Abstract / Description
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Geospatial characteristics such as isolation and avenues of connectivity influence an invader's pattern of dispersal and distribution. However many examinations of invasion success ignore the contribution of dispersal to patterns of invasion and focus only on the local environmental/habitat factors. This study examines the interaction of geospatial characteristics, that may influence dispersal, and local environmental factors, that may govern successful occupation, on the likelihood of...
Show moreGeospatial characteristics such as isolation and avenues of connectivity influence an invader's pattern of dispersal and distribution. However many examinations of invasion success ignore the contribution of dispersal to patterns of invasion and focus only on the local environmental/habitat factors. This study examines the interaction of geospatial characteristics, that may influence dispersal, and local environmental factors, that may govern successful occupation, on the likelihood of invasion (invasability) of wetlands within an agriculturally modified landscape. I examined the current invasion of seasonal wetlands in south-central Florida ranchland by non-native apple snails (Pomacea maculata (Ampullariidae)) as a model system for understanding this interaction. I surveyed spatial occurrence of P. maculata in 171 wetlands in 2014 and found they occurred in 43% of wetlands surveyed. I evaluated how occurrence was related to geospatial variables (proximity to propagule sources, shoreline complexity, interwetland distance, elevation, area and ditch presence) and wetland characteristics (pH, water hardness, conductivity and soil type) for 95 wetlands. Presence of ditch connections and more neutral water pH were associated with P. maculata occurrence. I did not find evidence that Euclidean distance and minimum ditch distance were associated with P. maculata occurrence. I also performed a 5 month field experiment where I translocated snails to previously occupied and non-occupied wetlands and measured snail survival and growth (20 wetlands from November to March). This experiment evaluated if non-occurrence during survey was more likely to be associated with unfavorable habitat conditions or dispersal limitation. Wetland pH and water hardness explained variation in P. maculata survival, and wetland pH best explained growth. I did not find evidence that prior occupancy affected the snail survival and growth, which suggests previously unoccupied wetlands are due to dispersal limitation. These results emphasize that man-made conduits can increase permeability of the landscape, facilitating the dispersal and introduction of nonnative species and the need for the inclusion of dispersal metrics in understanding invasive species distribution.
Show less - Date Issued
- 2015
- Identifier
- CFE0006374, ucf:51527
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006374
- Title
- From pet to pest? The potential global range and food web effects of a generalist carnivore.
- Creator
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Bevan, Hannah, Jenkins, David, Noss, Reed, Campbell, Todd, University of Central Florida
- Abstract / Description
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The Nile monitor lizard [Varanus niloticus (Linnaeus, 1766)] is a generalist carnivore, native to Sub-Saharan Africa and the Nile River but now established in North America as a result of the pet trade. Once introduced, they are a potential invasive threat to native wildlife. Here, I create ensemble species distribution models (SDMs) to predict the global distribution of this generalist carnivore given current and future climate conditions. I then quantify the monitor's potential effects on...
Show moreThe Nile monitor lizard [Varanus niloticus (Linnaeus, 1766)] is a generalist carnivore, native to Sub-Saharan Africa and the Nile River but now established in North America as a result of the pet trade. Once introduced, they are a potential invasive threat to native wildlife. Here, I create ensemble species distribution models (SDMs) to predict the global distribution of this generalist carnivore given current and future climate conditions. I then quantify the monitor's potential effects on 85 food webs representing (>)900 different species within the projected regions based on stomach content data. Climate, vegetation, and elevation data are used for 507 georeferenced observation points from the Nile monitor's native range to produce current and future (2070) ensemble SDMs. Explanatory variables are evaluated as ten alternative models organized in three subsets according to model assumptions. The true skill statistic (TSS), sensitivity, and specificity were used to assess model performance, and the best subset was averaged to represent an ensemble model. Food web impacts after the generalist predator's addition are determined by changes in nine metrics of food web structure. The most predictive (TSS scores ?0.87) ensemble SDM was based on the MARS and FDA algorithms using elevation and climate for current and future conditions. This model shows that, if introduced, Nile monitors will likely spread into many regions in the Americas, the Caribbean, Madagascar, Southeast Asia, and Australia. Assuming unabated carbon emissions by 2070, climate change will enhance that potential range. Adding Nile monitors to food webs generally increases overall trophic links, connectance, link density, and fraction of intermediate taxa, with decreases in the fraction of top and basal taxa. These results are consistent with a generalist predator that affects many species and is likely to affect food web stability. The potential Nile monitor range is vast and encompasses multiple biodiversity hotspots. Given many strong food web interactions by this generalist predator, vulnerable regions should actively prohibit/regulate Nile monitors as pets, enforce those restrictions, and promote exotic pet amnesty programs. Southern US states should especially act soon to prevent spread of the Nile monitor to the Neotropics from its current introduced population in Florida and as released pets.
Show less - Date Issued
- 2016
- Identifier
- CFE0006441, ucf:51446
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006441
- Title
- Pasture Management, the Red Imported Fire Ant (Solenopsis invicta) and Dung Beetle Mediated Ecosystem Services.
- Creator
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Steele, Christen, King, Joshua, Jenkins, David, Boughton, Elizabeth, University of Central Florida
- Abstract / Description
-
Grazing animals in Florida deposit over 20 million metric tons of dung per year, making dung a significant non-point source of pollution (extrapolated from Fincher, 1981). Degradation of this dung occurs naturally, primarily due to a diverse group of beetles (Order Coleoptera) primarily in the families Scarabaeidae and Geotrupidae(hereafter dung beetles). Dung that is not degraded becomes a non-point source of pollutants and may be leached into water bodies. Additionally, dung provides an...
Show moreGrazing animals in Florida deposit over 20 million metric tons of dung per year, making dung a significant non-point source of pollution (extrapolated from Fincher, 1981). Degradation of this dung occurs naturally, primarily due to a diverse group of beetles (Order Coleoptera) primarily in the families Scarabaeidae and Geotrupidae(hereafter dung beetles). Dung that is not degraded becomes a non-point source of pollutants and may be leached into water bodies. Additionally, dung provides an incubation site for the pests and parasites of both humans and livestock. Thus, as dung beetles consume and degrade dung, they provide a multitude of ecosystem services by increasing the rate of dung decomposition in pasture ecosystems. The non- native fire ant Solenopsis invicta has been observed to frequently utilize dung as a site to forage for the larvae of other insects. Based on the known food preferences of S. invicta, dung beetle adults and larvae fit the profile of a potential food source. Whether the ecosystem services provided by dung beetles are being reduced, un-impacted, or potentially increased through complementarity is unclear. Thus, this project sought to first map the distribution of S. invicta within pasture habitats along a disturbance gradient. Next, a field experiment was employed to test whether the interaction between S. invicta and native dung beetle communities impacts the provisioning of two ecosystem services: rate of dung degradation and parasite suppression.
Show less - Date Issued
- 2016
- Identifier
- CFE0006400, ucf:51461
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006400
- Title
- Habitat Use and Feeding Ecology of Delphinids Inferred from Stable Isotopes and Fatty Acid Signatures.
- Creator
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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.
Show less - Date Issued
- 2013
- Identifier
- CFE0004823, ucf:49733
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004823
- Title
- Effects of mechanical habitat disturbance on the diversity and network structure of plant-bee interaction networks in Central Florida.
- Creator
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Carman, Karlie, Hinkle, Ross, Jenkins, David, King, Joshua, University of Central Florida
- Abstract / Description
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Ecological interactions within a community shape the structure of ecosystems and influence ecosystem function. Plant-pollinator interactions exist as mutualistic exchange networks that may collapse as habitat loss occurs, thereby threatening the overall health of an ecosystem. Understanding the impacts of human-mediated habitat disturbance on ecological interactions is therefore crucial for conservation efforts. Archbold Biological Station (ABS) in Venus, Florida contains over 2000 hectares...
Show moreEcological interactions within a community shape the structure of ecosystems and influence ecosystem function. Plant-pollinator interactions exist as mutualistic exchange networks that may collapse as habitat loss occurs, thereby threatening the overall health of an ecosystem. Understanding the impacts of human-mediated habitat disturbance on ecological interactions is therefore crucial for conservation efforts. Archbold Biological Station (ABS) in Venus, Florida contains over 2000 hectares of protected Florida scrub habitat nested within a human-dominated environment that is threatened by anthropogenic habitat disturbance. In past studies, over 113 bee species and 157 associated host plants, many endemic to the Lake Wales Ridge, have been found on ABS property, providing an understanding of this system's plant-bee network. Using those data as a baseline, this study investigated the effects of varying levels of mechanical habitat disturbance intensity on the diversity and network structure of plant-bee interaction networks. Flowering plant abundance, richness, diversity, and composition as well as bee abundance and composition were significantly different across mechanical habitat disturbance levels. Interactions between bees and flowering plants also differed with varying disturbance intensity. From these results, it is clear that plants, bees and interactions between them are impacted by mechanical habitat disturbance in this system. This project informs management efforts not only for natural systems with the threat of alteration, but also for agricultural systems, many of which heavily rely on flower visitation by bee pollinators. This research also contributes to the growing field of interaction ecology by increasing understanding of habitat alteration effects on a valuable ecological interaction and ultimately ecosystem function.
Show less - Date Issued
- 2014
- Identifier
- CFE0005311, ucf:50505
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005311
