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(1 - 8 of 8)
- 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
- 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
- Fear and Loathing in the Super Organism: Foraging Strategy Doesn't Change Forager Response in a Landscape of Fear.
- Creator
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Schadegg, Philip, King, Joshua, De Bekker, Charissa, Fedorka, Kenneth, University of Central Florida
- Abstract / Description
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Understanding how predators impact keystone species, like ants, is very important for our understanding of ecology because of ants' importance in shaping community dynamics and ecosystem functions. In this thesis I present research investigating the role of the ant-specialized spider Anasaitis canosa in influencing the foraging behavior of four ant species (Formica pallidefulva, Odontomachus ruginodis, Pheidole obscurithorax (&) Solenopsis invicta). Collectively, these four species use...
Show moreUnderstanding how predators impact keystone species, like ants, is very important for our understanding of ecology because of ants' importance in shaping community dynamics and ecosystem functions. In this thesis I present research investigating the role of the ant-specialized spider Anasaitis canosa in influencing the foraging behavior of four ant species (Formica pallidefulva, Odontomachus ruginodis, Pheidole obscurithorax (&) Solenopsis invicta). Collectively, these four species use foraging strategies exhibited by most ants. I conducted two experiments to quantify the impacts of spider predation on ant prey. The first used forty colonies of four ant species to investigate how A. canosa changed foraging behavior at both the individual and colony level. The second used 27 lab-reared S. invicta colonies to see if there was any evidence for innate predatory avoidance in foragers and if predatory avoidance was influenced by learning. A field study observed the density and prey choices of A. canosa in 3 sites within the UCF arboretum. In sum, no consistent change in foraging occurred in the presence of A. canosa, over time scales sufficient to detect colony-level impacts and thus colonies as a whole appear to be risk insensitive. Na(&)#239;ve colonies had more ants beginning foraging before a single ant would return in their first trial compared to the second trial. This suggests forager learning occurs as foragers respond to the perception of a predator, and that S. invicta can reduce individual risk through increasing forager numbers. A. canosa predation rates and density were calculated and based on these estimates an approximate impact upon a colony was made. Most importantly, 13 foragers/m2 inside each foraging cohort can be expected to have prior experience with the spider.
Show less - Date Issued
- 2019
- Identifier
- CFE0007859, ucf:52792
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007859
- Title
- Flying under the LiDAR: relating forest structure to bat community diversity.
- Creator
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Butterfield, Anna, Weishampel, John, Noss, Reed, King, Joshua, University of Central Florida
- Abstract / Description
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Bats are important to many ecological processes such as pollination, insect (and by proxy, disease) control, and seed dispersal and can be used to monitor ecosystem health. However, they are facing unprecedented extinction risks from habitat degradation as well as pressures from pathogens (e.g., white-nose syndrome) and wind turbines. LiDAR allows ecologists to measure structural variables of forested landscapes with increased precision and accuracy at broader spatial scales than previously...
Show moreBats are important to many ecological processes such as pollination, insect (and by proxy, disease) control, and seed dispersal and can be used to monitor ecosystem health. However, they are facing unprecedented extinction risks from habitat degradation as well as pressures from pathogens (e.g., white-nose syndrome) and wind turbines. LiDAR allows ecologists to measure structural variables of forested landscapes with increased precision and accuracy at broader spatial scales than previously possible. This study used airborne LiDAR to classify forest habitat/canopy structure at the Ordway-Swisher Biological Station (OSBS) in north central Florida. LiDAR data were acquired by the National Ecological Observatory Network (NEON) airborne observation platform in summer 2014. OSBS consists of open-canopy pine savannas, closed-canopy hardwood hammocks, and seasonally inundated basin marshes. Multiple forest structural parameters (e.g., mean, maximum, and standard deviation of canopy height) were derived from LiDAR point clouds using the USDA software program FUSION. K-means clustering was used to segregate each 5x5 m raster across the ~3765 ha OSBS area into six different clusters based on the derived canopy metrics. Cluster averages for maximum, mean, and standard deviation of return heights ranged from 0 to 19.4 m, 0 to 15.3 m, and 0 to 3.0 m, respectively. To determine the relationships among these landscape-canopy features and bat species diversity and abundances, AnaBat II bat detectors were deployed from May to September in 2015 stratified by these distinct clusters. A statistical regression model selection approach was performed in order to evaluate how forest structural attributes such as understory clutter, vertical canopy structure, open and closed canopy, etc. and landscape metrics influence bat communities. The most informative models showed that a combination of site-specific (e.g., midstory clutter and entropy) and landscape level attributes (e.g., area of water and service road length) contributed to bat community patterns. This knowledge provides a deeper understanding of habitat-species interactions to better manage survival of these species and provides insight into new tools for landscape management as they apply to specific species.
Show less - Date Issued
- 2016
- Identifier
- CFE0006177, ucf:51151
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006177
- Title
- Habitat distribution and abundance of crayfishes in two Florida spring-fed rivers.
- Creator
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Manteuffel, Tiffani, Hinkle, Ross, King, Joshua, Stout, I, Stolen, Eric, University of Central Florida
- Abstract / Description
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Crayfish are an economically and ecologically important invertebrate, however, research on crayfish in native habitats is patchy at best, including in Florida, even though the Southeastern U.S. is one of the most speciose areas globally. This study investigated patterns of abundance and habitat distribution of two crayfishes (Procambarus paeninsulanus and P. fallax) in two Florida spring-fed rivers (Wakulla River and Silver River, respectively). Study sites were surveyed once each season from...
Show moreCrayfish are an economically and ecologically important invertebrate, however, research on crayfish in native habitats is patchy at best, including in Florida, even though the Southeastern U.S. is one of the most speciose areas globally. This study investigated patterns of abundance and habitat distribution of two crayfishes (Procambarus paeninsulanus and P. fallax) in two Florida spring-fed rivers (Wakulla River and Silver River, respectively). Study sites were surveyed once each season from April 2015 to March 2016 with baited minnow traps checked every other day, four times each survey. Habitat and environmental parameters evaluated included dominant vegetation or bottom type, percent cover, organic matter content, water depth, moon illumination and dissolved oxygen. Abundance was estimated with N-mixture models. Model selection judged the relative evidence between hypotheses relating habitat and environmental covariates to crayfish abundance. P. paeninsulanus distribution and abundance in Wakulla River was explained by time of year, dissolved oxygen and dominant bottom and vegetation type. P. fallax distribution and abundance in Silver River was explained by time of year and percent coverage of vegetation. Detection of P. paeninsulanus was higher than P. fallax and abundance of P. paeninsulanus was more heterogenous than P. fallax (6-18 versus 12-14 per site in summer survey). Distribution of P. paeninsulanus as described by vegetation and bottom type also seems to follow heterogeneity in management areas in Wakulla River. Results will assist managers in understanding potential impact of herbicidal control of Hydrilla verticillata on crayfish. This study also fills knowledge gaps on Florida crayfish natural history and ecology.
Show less - Date Issued
- 2016
- Identifier
- CFE0006474, ucf:51442
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006474
- 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
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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
- 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
- Title
- The Effect of Landscape Variables on Adult Mosquito (Diptera:Culicidae)Diversity and Behavior.
- Creator
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Debevec, Caitlyn, Jenkins, David, King, Joshua, Rothermel, Betsie, Boughton, Raoul, University of Central Florida
- Abstract / Description
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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.
Show less - Date Issued
- 2015
- Identifier
- CFE0005780, ucf:50063
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005780
