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- Title
- Using Land Cover Mapping and Landscape Metrics to Evaluate Effects of Urban Development on Ecological Integrity in Florida.
- Creator
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Gilbrook, Michael, Weishampel, John, Hinkle, Ross, Jenkins, David, Brody, Samuel, University of Central Florida
- Abstract / Description
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The widespread loss and degradation of habitat constitutes the largest threat to biodiversity in North America. While regulatory programs such as the Endangered Species Act of 1973 and wetland permitting under the Clean Water Act have addressed acute assaults on critical habitat, large areas of unprotected uplands have been lost. Urban development, particularly the advent of lower density suburban and rural sprawl, has greatly diminished the extent of contiguous patches of forest habitat and...
Show moreThe widespread loss and degradation of habitat constitutes the largest threat to biodiversity in North America. While regulatory programs such as the Endangered Species Act of 1973 and wetland permitting under the Clean Water Act have addressed acute assaults on critical habitat, large areas of unprotected uplands have been lost. Urban development, particularly the advent of lower density suburban and rural sprawl, has greatly diminished the extent of contiguous patches of forest habitat and introduced a host of other undesirable effects on ecosystem function. This study sought to evaluate the extent of urban sprawl and its effects on ecological integrity in Florida using Landsat-derived land cover data collected by the Florida Fish and Wildlife Conservation Commission (FWC) circa 1987 and 2003. Chapter 1 described a novel GIS technique for correcting the systematic errors in the FWC 1987 and 2003 land cover data and converting those data to a common classification system so that they could be used in any ad hoc land cover change analysis. Comparison to ground-truth observations demonstrated a significant improvement in the accuracy of the land cover data following the Land Cover Correction Process (LCCP). Change detection between 1987 and 2003 using the correct land cover revealed trends in land cover conversion that were very different from previously published results derived from the original FWC land cover data. Conversion to urban uses in the corrected data was 47,293 ha lower, and conversion to agricultural uses was reduced by 196,773 ha, resulting in 244,067 ha less anthropogenic land conversion than had been previously estimated. Although the corrected land cover data showed that overall land conversion of natural areas was lower compared to the earlier estimate, the corrected data showed proportionally greater habitat losses for four important habitat types: Pinelands (-10.08% in the corrected land cover as compared to -5.90% in the original FWC data); upland forest (-9.46% versus 6.37%); sandhill (-13.90% versus 11.18%); and scrub (-15.52% versus -9.83%). Given the relatively small areal extent of some of these habitats, the larger percent loss estimates over the study period revealed by the corrected land cover data are cause for even greater concern by conservation planners and policymakers. Now that its utility has been demonstrated, the LCCP technique can be applied to any pair of roughly similar land cover mapping datasets provided that their original classification systems can be composed by a cross-walk into a single scheme, and that one or more ancillary data sets are available to serve in the tie-breaker role performed here by the land use data from Florida's Water Management Districts. The Soil Survey Geographic (SSURGO) and State Soil Geographic (STATSGO) soils data of the National Resource Conservation Service, the National Land Cover Dataset (NLCD) or the statewide habitat mapping of the USGS GAP Analysis Program could be adapted to provide the ancillary tie-breaker data required by the LCCP to conduct change detection between disparate land cover data sources heretofore considered too incompatible for that purpose.In Chapter 2, measures of urban sprawl, habitat loss and fragmentation in Florida were estimated using the corrected land cover data for 1987 and 2003. The Northwest and North regions of the state exhibited significantly higher indices of urban sprawl, habitat loss and habitat fragmentation via application of the Moran's I statistic. Reducing urban sprawl and habitat fragmentation spatial metrics to simple ordination variables through the use of non-metric multidimensional scaling produced new measures of urban sprawl and habitat fragmentation that correlated strongly with the original FRAGSTATS metrics, but could be more easily mapped and interpreted. Urban and Habitat ordination metrics were each spatially autocorrelated (Local Moran's I and K-means grouping analyses) but not correlated to each other using the Procrustes analysis PROTEST statistic (m2 = 0.952, p = 0.061). In contrast, individual urban sprawl metrics (CA, NP, LPI, ED, SHAPE_AM and DCAD) correlated with habitat fragmentation. NP and DCAD appeared to be particularly useful in predicting fragmentation, and county governments should take measures to reduce establishment of new urban patches to minimize NP and DCAD.Chapter 3 explored the relationship between environmental outcomes in habitat loss and fragmentation and the quality of county local government comprehensive plans. The use of NMS analysis provided a powerful technique for capturing the intrinsic variability of the Local Government Comprehensive Plan (LGCP) plan scoring systems of Brody (2003) and Pannozzo (2013) into a pair of variables each that could be used to explore associations with metrics of urban sprawl, habitat fragmentation and other county characteristics that influence urban growth and development. The geographic distribution of LGCP plan quality favored coastal counties with higher quality plans over inland counties, and there was some evidence that plans in Central and South regions of Peninsular Florida were superior to those in the North and Northwest Panhandle regions. Key factors in plan quality, specifically Coordination and Management, were strongly associated with urban sprawl or habitat fragmentation outcomes. The resources available to counties in the form of tax revenues, whether the county possessed a rural or urban economy, and the county's political makeup also appeared related to LGCP plan quality, urban sprawl or habitat fragmentation outcomes. More research will be needed to elucidate the specific causal mechanisms behind the implementation of local government planning that resulted in the observed environmental outcomes.
Show less - Date Issued
- 2014
- Identifier
- CFE0005497, ucf:50353
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005497
- 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
- Title
- The effects of urbanization on cypress (Taxodium distichum) in central Florida.
- Creator
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McCauley, Lisa, Jenkins, David, Quintana-Ascencio, Pedro, Hoffman, Eric, Ewel, Kathy, University of Central Florida
- Abstract / Description
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Urbanization is accelerating in the United States and is contributing to fragmentation of natural habitats, causing changes in species composition and declines in native species. Human population growth in Orlando is typical of growth in the southeastern United States and throughout the range of cypress (Taxodium distichum). Orlando has numerous isolated cypress wetlands, called cypress domes, and many remain among the current urbanized area. This makes Orlando ideal to study the effects of...
Show moreUrbanization is accelerating in the United States and is contributing to fragmentation of natural habitats, causing changes in species composition and declines in native species. Human population growth in Orlando is typical of growth in the southeastern United States and throughout the range of cypress (Taxodium distichum). Orlando has numerous isolated cypress wetlands, called cypress domes, and many remain among the current urbanized area. This makes Orlando ideal to study the effects of urbanization on cypress domes. Specifically, I tested how urbanization and its effects on fragmentation, hydrology, and fire regime) affected (a) the numbers and spatial pattern of cypress domes in central Florida and (b) the recruitment of cypress within cypress domes. Analysis of historical loss found over 3,000 cypress domes identified in images from1984, of which 26% were lost or degraded (i.e., no longer cypress-dominated) by 2004. Due to changed land use, many remaining cypress domes, formerly surrounded by natural lands, have become surrounded by urban lands causing spatial clustering and homogenization. Surprisingly, I found that both natural and urban cypress domes showed lower recruitment than agricultural cypress domes, where the natural fire regime has not been altered. The probability of cypress recruitment in cypress domes urbanized for more than 20 years is very low. Previous to that, cypress tends to recruit on the edge of cypress domes where there is less competition and hydrological conditions are more favorable. I estimate that only ~50% of the current cypress domes are recruiting and the existence of those wetlands are tied to the lifespan of the current adults. By 2104, I estimate that ~89% of the cypress domes currently recruiting will fail to recruit. I believe that reducing urban sprawl and restoring the natural fire regime to natural cypress domes will mitigate the current fate of cypress domes. Without this, cypress in isolated wetlands in central Florida, and providing Orlando urbanization is typical, throughout urbanized areas of the range, could be at risk. Cypress in urban areas will be then relegated to riparian zones and with unknown consequences for the species that utilize the former cypress dome habitat.
Show less - Date Issued
- 2011
- Identifier
- CFE0004136, ucf:49065
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004136
- Title
- Phylogenetic Community Structure of Aquatic Beetle Assemblages in a Multi-Wetland Experiment.
- Creator
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Kelly, Sandor, Jenkins, David, Parkinson, Christopher, Crampton, William, Song, Hojun, University of Central Florida
- Abstract / Description
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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.
Show less - Date Issued
- 2012
- Identifier
- CFE0004394, ucf:49388
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004394
- Title
- Cross-Continental Insights into Jaguar (Panthera onca) Ecology and Conservation.
- Creator
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Figel, Joseph, Noss, Reed, Quintana-Ascencio, Pedro, Jenkins, David, Quigley, Howard, University of Central Florida
- Abstract / Description
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The jaguar (Panthera onca) is a widely distributed large carnivore and the focal species of a range-wide connectivity initiative known as the jaguar conservation network (JCN). Comprised of ~83 Jaguar Conservation Units (JCUs) and ~75 corridors from northern Mexico to Argentina, the JCN functions as a conduit for jaguar movement and gene flow. Key linkages in the network are imperiled by human population growth, large-scale agriculture, highway expansion, and other infrastructural development...
Show moreThe jaguar (Panthera onca) is a widely distributed large carnivore and the focal species of a range-wide connectivity initiative known as the jaguar conservation network (JCN). Comprised of ~83 Jaguar Conservation Units (JCUs) and ~75 corridors from northern Mexico to Argentina, the JCN functions as a conduit for jaguar movement and gene flow. Key linkages in the network are imperiled by human population growth, large-scale agriculture, highway expansion, and other infrastructural development. Labeled (")corridors of concern,(") these vulnerable linkages are imperative to the maintenance of connectivity and genetic diversity throughout jaguar distribution. I take a multi-faceted approach to analyze conservation issues and identify potential solutions in three of the most vulnerable connections of the JCN. I estimate densities and assess local residents' perceptions of jaguars in a fragmented JCU in western Mexico, analyze 3 years of data from 275 camera-trap sites to evaluate jaguar habitat use in a corridor of concern in Colombia, and quantify the umbrella value of jaguars for endemic herpetofauna in Nuclear Central America, a ~ 370,000 km(&)#178; sub-region of the Mesoamerican biodiversity hotspot. My research produces the first jaguar density estimate in a JCU containing human population densities (>)50 people/km2 and provides the strongest support for jaguar association with wetlands collected to date. In Nuclear Central America, one of the most important yet vulnerable areas of the JCN, I demonstrate the umbrella value of this wide-ranging felid. I conclude with a discussion on the need to reevaluate extirpation thresholds of jaguars in human-use landscapes, to direct more research on wetlands as keystone habitats for jaguars, and to further assess the utility of umbrella analyses using jaguars as focal species to support holistic conservation planning.
Show less - Date Issued
- 2017
- Identifier
- CFE0006591, ucf:51258
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006591
- Title
- Wetland diversity in a disturbance-maintained landscape: Effects of fire and a fire surrogate on aquatic amphibian survival and species depauperateness.
- Creator
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Klaus, Joyce, Noss, Reed, Quintana-Ascencio, Pedro, Jenkins, David, Dr. L. Katherine Kirkman, University of Central Florida
- Abstract / Description
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Disturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open...
Show moreDisturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open-structured, fire-maintained vegetation but shrubs and trees encroach into fire-dependent ecosystems where fire has been excluded. Prescribed burning and mechanical removal are commonly used as restoration tools to control encroachment. To better assess and compare the restoration potential of these tools, a more thorough understanding of how they change vegetation structure and habitat suitability for animals is necessary.The southeastern U.S. is a diversity hot-spot for amphibians, many of which require ephemeral wetlands embedded in longleaf pine uplands for the aquatic phase of their life cycle. Amphibian diversity has been declining in recent decades and habitat loss/degradation has been cited as one of the leading causes. Although often overlooked in studies of fire ecology, the ephemeral wetlands required by many amphibians are also fire-dependent habitats that have been negatively impacted by lack of fire. To understand how disturbance interacts with wetland vegetation and aquatic-phase amphibians, three disturbance treatments meant to mimic the effects of natural disturbance on vegetation structure were applied randomly to 28 dry ephemeral wetlands in the Lower Coastal Plain of South Carolina, U.S. The treatments consisted of early growing-season prescribed fire, mechanical vegetation removal (a proposed fire surrogate), and a combination of mechanical removal plus fire; some sites were left untreated for reference. Vegetation structure was quantified and amphibian assemblages were monitored before and after treatments. In addition, one species of amphibian was used in a tadpole survival experiment to examine differences in performance among treatments. Other factors that could be affected by treatments and in turn influence amphibians were measured, including water chemistry, wetland depth, quantity and quality of epilithon, and leaf litter composition.Amphibian survival was lowest, and species depauperateness highest in untreated wetlands. Depauperateness of species whose range was restricted to the range of longleaf pine was lowest in sites that had mechanical treatment plus fire. The mechanical plus fire treatment created the most open vegetation structure with lowest leaf litter accumulation, especially of hardwood litter, conditions correlated with high amphibian survival and diversity. When data from this study was combined with data from a previous study of similar nearby wetlands, a pattern emerged in which one suite of species was absent from recently burned sites, while an entirely different suite of species was absent from long-unburned sites. This evidence suggests that disturbance is related to a shift in amphibian assemblage possibly due to changes in vegetation structure and perhaps wetland ecology in general, from an algal-based system maintained by frequent fire to a detrital-based system that develops in the absence of fire.
Show less - Date Issued
- 2013
- Identifier
- CFE0005015, ucf:49994
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005015
- Title
- Dispersal, Gene Flow, and Adaptive Evolution During Invasion: Testing Range-Limit Theory with the Asian Tiger Mosquito.
- Creator
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Medley, Kimberly, Jenkins, David, Quintana-Ascencio, Pedro, Hoffman, Eric, Lounibos, Phil, University of Central Florida
- Abstract / Description
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Understanding the factors that make non-native species successful invaders is an important step towards mitigating spread. At the same time, species invasions can serve as natural experiments to test range-limit theory. Range-limit theory postulates declines in local abundance (abundant center model) and genetic diversity (central-peripheral hypothesis) towards range edges because of underlying environmental gradients. Such declines constrain adaptation to marginal habitats via gene swamping....
Show moreUnderstanding the factors that make non-native species successful invaders is an important step towards mitigating spread. At the same time, species invasions can serve as natural experiments to test range-limit theory. Range-limit theory postulates declines in local abundance (abundant center model) and genetic diversity (central-peripheral hypothesis) towards range edges because of underlying environmental gradients. Such declines constrain adaptation to marginal habitats via gene swamping. However, broader evolutionary theory predicts intermediate rates of immigration into range-edge populations can relieve genetic drift and improve adaptive potential. I tested hypotheses generated from theory while illuminating aspects affecting of the invasion of the Asian tiger mosquito (Aedes albopictus Skuse) into the US. Using reciprocal distribution modeling, I found US populations occupied significantly different climate and habitat than in their native range (SE Asia). Most inconsistencies were found in the northern US range, where Ae. albopictus has recently crept northward, providing an opportunity to test range-limit theory as the range reaches its limit. Because of its limited natural dispersal ability, rapid spread after the 1985 US introduction pointed to human-aided dispersal. I tested the current role of human-aided versus natural dispersal using a landscape genetics framework, and found that natural dispersal dominated current patterns. Some distant localities were highly genetically similar, indicating potential human-aided transport in limited cases. Asymmetric gene flow from core to edge localities supported the abundant center model, but uniformly high genetic diversity contrasted with the central-marginal hypothesis. I detected a significant signature of local adaptation by overwintering diapause-induced eggs in multiple field sites using reciprocal transplants. Surprisingly, most genotypes from throughout the range produced large offspring when overwintered at the range edge. Relative offspring mass between home and away winters peaked at an intermediate immigration rate. These results show that rapid adaptation has occurred in US populations of Ae. albopictus and highlight the potential for further spread. Genetic admixture from multiple introductions may explain high genetic diversity throughout the US range and contribute to high offspring size for all genotypes overwintered at the range edge. Finally, my work highlights the need for a better understanding of contemporary ecological and evolutionary processes leading to range-limits (or expansion) to more accurately reflect processes occurring in a human-dominated world.
Show less - Date Issued
- 2012
- Identifier
- CFE0004635, ucf:49891
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004635
