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- Title
- SOIL MICROBIAL COMMUNITY DYNAMICS IN FLORIDA SCRUB ECOSYSTEM.
- Creator
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Albarracín, María, Weishampel, John F., University of Central Florida
- Abstract / Description
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Pyrogenic ecosystems are maintained by fires which vary in frequency, seasonality, and intensity. Florida oak-saw palmetto scrub ecosystem is characterized by fires occurring at intervals of 10-20 years. Diverse factors as private land acquisition and development has created a patchy distribution of scrub ecosystems and also interrupted the natural fire cycle. The effects of fire over plant regeneration and fauna habitat utilization of the scrub have been well characterized in previous...
Show morePyrogenic ecosystems are maintained by fires which vary in frequency, seasonality, and intensity. Florida oak-saw palmetto scrub ecosystem is characterized by fires occurring at intervals of 10-20 years. Diverse factors as private land acquisition and development has created a patchy distribution of scrub ecosystems and also interrupted the natural fire cycle. The effects of fire over plant regeneration and fauna habitat utilization of the scrub have been well characterized in previous research. In the present paper the objective is to characterize the short- and long-term fire effects on the soil microbial community. Fire effects were studied in a chronosequence, comprising a recently burned scrub during a winter-prescribed fire to scrub where fire did not occur for 40 years. The number of culturable cells was reduced by two orders of magnitude by indirect fire effects and environmental factors, principally hydric stress. However, the duration of fire effects was very short since the microbial community returned to pre-fire numbers and activity by day 47 after fire. Microbial community activity was distinctively related to inoculum density in the soil and litter samples. Soil and litter microbial communities showed differences in metabolic activity. There was no difference in substrate utilization pattern, but there was significant seasonal variation related to the decrease in water content during the month of May. Substrate utilization by litter microbial communities was higher during the month of January compared to soil microbial communities and this relationship was inversed during the month of May probably associated to the more stringent conditions, low water availability, on the litter layer. Seasonal effects outweighed fire effects in this study as this environmental constraint determined the microbial community structure and activity.
Show less - Date Issued
- 2005
- Identifier
- CFE0000472, ucf:46353
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000472
- Title
- TMDL BIOASSESSMENT SAMPLING OF BENTHIC MACROINVERTEBRATES FOR LAKE JESUP AND LAKE SEMINARY.
- Creator
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Eby, Gloria, Weishampel, John, University of Central Florida
- Abstract / Description
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The objective of this study was to obtain a bioassessment using benthic macroinvertebrates to meet TMDL (Total Maximum Daily Load) criteria for an oligotrophic (Lake Seminary) and an eutrophic (Lake Jesup) freshwater system in Seminole County, Florida. Monthly sampling of the benthic macroinverterbrate communities provided important biological data necessary to construct TMDL protocol and trophic state. Since macroinvertebrates are near the base of the food chain, they not only provide a...
Show moreThe objective of this study was to obtain a bioassessment using benthic macroinvertebrates to meet TMDL (Total Maximum Daily Load) criteria for an oligotrophic (Lake Seminary) and an eutrophic (Lake Jesup) freshwater system in Seminole County, Florida. Monthly sampling of the benthic macroinverterbrate communities provided important biological data necessary to construct TMDL protocol and trophic state. Since macroinvertebrates are near the base of the food chain, they not only provide a critical role in the natural flow of energy and cycling of nutrients through the food web, but also provide a good indication of water quality by their presence and abundance. This study suggests that TMDL protocol and reversal trends in eutrophication can be successfully monitored using benthic macroinvertebrate data. Comparative methodology between the LCI and conventional methods indicate that the LCI is a valid, cost-effective and rapid bioassessment method when compared to the conventional method and that the conventional method is an effective tool when more in depth benthic studies are needed as it shows distinct seasonal patterns and accounts for more of the sensitive, intolerant taxa. Furthermore, this type of biological monitoring and trend analysis aids in the implementation of anthropogenic controls that targets waters for TMDLs in suspect systems. When integrated within a watershed management plan, multi-metric indexing functions as an effective overall indicator of the biological condition within a waterbody responding to its watershed.
Show less - Date Issued
- 2008
- Identifier
- CFE0002126, ucf:47553
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002126
- Title
- SPATIOTEMPORAL VARIATION OF AVIAN POPULATIONS WITHIN GEOGRAPHICALLY ISOLATED FRESHWATER MARSHES.
- Creator
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Rodenbeck, Brian, Weishampel, John, University of Central Florida
- Abstract / Description
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Metacommunity connectivity, i.e., multi-species dispersal events, is vital to metapopulation persistence in patchy landscapes. Assessments of metacommunity connectivity are not trivial. However, a relationship between trophic rank and the species-area relationship has been found in previous studies, allowing for the use of the predator species-area relationship to act as a surrogate measure of actual metacommunity connectivity of prey species in some systems. For this study, avian species...
Show moreMetacommunity connectivity, i.e., multi-species dispersal events, is vital to metapopulation persistence in patchy landscapes. Assessments of metacommunity connectivity are not trivial. However, a relationship between trophic rank and the species-area relationship has been found in previous studies, allowing for the use of the predator species-area relationship to act as a surrogate measure of actual metacommunity connectivity of prey species in some systems. For this study, avian species were selected as they are generalist top predators within the study system. Predator species richness within geographically isolated freshwater marshes is influenced by a number of factors. I explore the relative roles of patch area, seasonality, hydroperiod, isolation, and vegetation structure on habitat use in the isolated freshwater marshes embedded within the dry prairie ecosystem of Central Florida. Predator species richness was surveyed in 50 sites for three seasons: fall 2005, winter 2005/06, and spring 2006 and the observed avian assemblage measures were subdivided into foraging guilds for analysis. Wading guild (e.g., egrets, herons, bitterns) species richness was correlated with hydroperiod and vegetation structural variables while perching guild (e.g., blackbirds, sparrows, meadowlarks) species richness was correlated with isolation, hydroperiod, and area annually. Overall predator and all guild species richness measures were also correlated with patch area for all seasons. These results suggest that while a complex mixture of patch area, hydroperiod and isolation influence habitat utilization that varies by season and at the community, guild and individual species level, the underlying predictors that define habitat use in wetlands annually includes hydroperiod, and is not exclusively patch area. Additionally, seasonal differences in predator species richness were found to be significant in some cases indicating that future avian population studies may benefit by sampling outside of the normally studied spring breeding season. Results of this study support the use of predator species richness as a suitable assay of metacommunity connectivity of prey species. Applications and implications of this approach toward future conservation efforts are discussed.
Show less - Date Issued
- 2007
- Identifier
- CFE0001766, ucf:47253
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001766
- Title
- SEASONAL AND DIEL PATTERNS OF MANATEE HABITAT USE.
- Creator
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Ross, Monica, Weishampel, John, University of Central Florida
- Abstract / Description
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State and Federal agencies have created sanctuaries and speed zones to help reduce manatee mortality while incorporating the recreational and commercial resource needs of these same habitats for humans. Specific habitat resources are considered necessary to increase manatee survivorship. We have only recently begun to address how manatees use some of these resources based on physiological or reproductive strategies. In this study, I quantified patterns of habitat use during seasonal and diel...
Show moreState and Federal agencies have created sanctuaries and speed zones to help reduce manatee mortality while incorporating the recreational and commercial resource needs of these same habitats for humans. Specific habitat resources are considered necessary to increase manatee survivorship. We have only recently begun to address how manatees use some of these resources based on physiological or reproductive strategies. In this study, I quantified patterns of habitat use during seasonal and diel periods for different sex and reproductive manatee classes using data from a radio-telemetry study conducted by the Florida Fish and Wildlife Conservation Commission during 1991-1996. I used five environmental geographic data layers: bathymetry, distance to seagrass, distance to shoreline, distance to warm water refuge sites, and distance to fresh water sources, to discriminate seasonal and diel habitat use patterns for different manatee classes: males (M), females with calves (FWC), and females without calves (FNC). Mean occupancy values were calculated for environmental variable locations and seasonal, diel, and manatee class differences were tested using a Multi-Response Permutation Procedure (MRPP). Nonmetric Multidimensional Scaling (NMS) was used to visualize the ordination patterns of the manatee classes and to assess importance of correlated environmental variables. Significant differences in habitat use were noted between summer and winter based on distances to warm water, seagrass, and fresh water sources but similar habitat use patterns were exhibited within summer diel periods among manatee classes. All manatee classes appeared to have used a higher proportion of locations closer in proximity to seagrass at night than day in winter indicating a disproportionate difference in feeding bouts between diel periods. These differences may be attributed to adjusting feeding strategies to reduce thermoregulatory costs or to decrease human interactions. Differences in patterns were exhibited for the winter diel periods specifically for the FWC manatee classes during winter days. FWC had a higher proportion of locations within the warm water refuges during the day indicating a possible trade off situation between food consumption and thermal exposure. This study demonstrates coarse and fine scale patterns of variation in habitat use for manatees both seasonally and daily within winter. It also suggests that during winter months, manatees were not just utilizing their habitat but they appeared to have preferences and selection for certain habitat types. Recovery of a species is greatly enhanced when patterns of habitat use within the species' environment has been clearly defined. Understanding more specifically what types of habitats manatees choose might allow management to adjust strategies for protection of key habitats while encouraging further recovery of this species.
Show less - Date Issued
- 2007
- Identifier
- CFE0001896, ucf:47408
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001896
- Title
- LAND USE EFFECTS ON LAKE WATER QUALITY IN CENTRAL FLORIDA.
- Creator
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Seiler, Jonathan, Weishampel, John F., University of Central Florida
- Abstract / Description
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ABSTRACT Land use affects the water quality of lakes. Different land use types yield different effects due to varying amounts and constituents of runoff. In this study, the effects of surrounding land use on the water quality of 50 lakes in Seminole County, Florida was assessed. Using GIS, I placed buffers of 100 and 500 m around each lake. The percentages of land use type were calculated within these buffers for 1990 and 1995. An ordination of lakes was done using Canonical Correspondence...
Show moreABSTRACT Land use affects the water quality of lakes. Different land use types yield different effects due to varying amounts and constituents of runoff. In this study, the effects of surrounding land use on the water quality of 50 lakes in Seminole County, Florida was assessed. Using GIS, I placed buffers of 100 and 500 m around each lake. The percentages of land use type were calculated within these buffers for 1990 and 1995. An ordination of lakes was done using Canonical Correspondence Analysis (CCA) to determine if the surrounding land use patterns were adequate to describe the trophic status of the lakes. Correlations between land use and water quality were found to be significant for the 1990 100 and 500 m buffers. Inter-set correlations showed that among land use types: residential, urban, agriculture, hardwoods, and wetlands were the most influential in determining water quality in that they had the most positive or negative correlation with the WA scores depending on the year and buffer zone. Excessively drained and very poorly drained soils were the most influential of the soil types. A Discriminant Function Analysis (DFA) was also performed to determine which land use and soil variables were effective in discriminating between oligotrophic, mesotrophic, and eutrophic lakes. Wetlands and very poorly drained soil were the most effective in discriminating between the groups of lakes. A multiple regression analysis was performed that determined correlations for 1990 and change in land use 100 m buffers contributed to our understanding of the relationship between land use and water quality. Effects of land use on water quality need to be considered when attempting to restore a lake or subjecting it to future land development.
Show less - Date Issued
- 2004
- Identifier
- CFE0000138, ucf:46174
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000138
- Title
- NATIVE FIRE REGIME AS A REFERENCE FOR ESTABLISHING MANAGEMENT PRACTICES.
- Creator
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Duncan, Brean, Weishampel, John, University of Central Florida
- Abstract / Description
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Our understanding of natural fire regimes in human-dominated landscapes is limited. Fire regimes operating in the pyrogenic ecosystems of Florida have been altered by fire suppression and fuel fragmentation. This is especially true of North Merritt Island, Florida, where human impacts have led to an incomplete knowledge of current fire regimes. We know that growing season fires frequently occurred within general return intervals and that many native terrestrial species require fire to remain...
Show moreOur understanding of natural fire regimes in human-dominated landscapes is limited. Fire regimes operating in the pyrogenic ecosystems of Florida have been altered by fire suppression and fuel fragmentation. This is especially true of North Merritt Island, Florida, where human impacts have led to an incomplete knowledge of current fire regimes. We know that growing season fires frequently occurred within general return intervals and that many native terrestrial species require fire to remain viable. A 20-year plus period of fire suppression caused structural and compositional changes to vegetation/fuels that led to catastrophic fires and the decline of native species populations such as the Florida Scrub-Jay. Fire has been reintroduced as a means to reduce fuels and maintain habitat requirements for native species. Scientific studies have documented the effects and benefits of prescribed burning on KSC/MINWR habitat/fuels structure. The necessity for fire to maintain vegetation/fuels structure and composition on the landscape is clear so fire is being applied to the landscape despite our imperfect knowledge of the native fire regime. It is imperative for the survival of many native species that fire managers be able to mimic the results of the native fire regime. Fire regime research is difficult in shrublands, and using dendrochronologic techniques are often not possible in flatwoods communities. I therefore used a process of remote sensing, GIS mapping, and spatial modeling to quantify lightning fire ignition properties, the current managed fire regime, and the natural fire regime. Chapter one develops a new remote sensing technique to accurately map burned areas in Florida scrub and pine flatwoods dominated communities on Kennedy Space Center, Merritt Island National Wildlife Refuge, Canaveral National Seashore, and Cape Canaveral Air Force Station, Florida. At the center of this technique is a newly developed separation index (SI) that was used to evaluate each individual satellite image band for its power to discriminate unburned and burned areas. Burned areas were classified and found to be highly accurate in relation to empirical fire records. This chapter addressed a number of issues relevant to the classification of burned areas including: the effect of geographic extent of remote sensing data on classification, determining the best bands for classification, and cleaning classification results by using GIS masking. It also serves as the first published effort to map fire scars in the Florida scrub and flatwoods vegetative communities of the southeastern U.S. using image processing techniques. Chapter two quantified a managed fire regime on John F. Kennedy Space Center, Florida and surrounding federal properties by mapping all fires between 1983 to 2005 using the image processing technique developed in chapter one, time series satellite imagery, and GIS techniques. The goals were to: (1) determine if an image processing technique designed for individual fire scar mapping could be applied to an image time series for mapping a managed fire regime in a rapid re-growth pyrogenic system; (2) develop a method for labeling mapped fire scar confidence knowing that a formal accuracy analysis was not possible; and (3) compare results of the managed fire regime with regional information on natural fire regimes to look for similarities/differences that might help optimize management for persistence of native fire-dependent species. The area burned by managed fire peaked when the drought index was low and was reduced when the drought index was high. This contrasts with the expectations regarding the natural fire regime of this region. Chapter three quantified the natural lightning ignition regime on Kennedy Space Center, Merritt Island National Wildlife Refuge, Canaveral National Seashore, and Cape Canaveral Air Force Station, Florida. Lightning is the natural ignition source in Florida, substantiating the need for understanding lightning fire incidence. Sixteen years of lightning data (1986-2003, excluding 1987 and 2002 due to missing data) from the NASA Cloud to Ground Lightning Surveillance System and fire ignition records were used to quantify the relationship between lightning incidence and fire ignition. Precipitation influenced the efficiency of lightning ignitions, particularly July precipitation. Negative polarity strikes caused the majority of ignitions. Pine flatwoods was ignited more frequently than expected given equal chance of ignition among landcover types. About half (51%) of detected fires were instantaneous ignitions and the other 49% were delayed an average of two days. Summer lightning ignitions were dominant, especially during July, with only one winter lightning ignition. Chapter four used an existing fire regime model (HFire) to simulate the natural fire regime (prior to European settlement) on Kennedy Space Center, Merritt Island National Wildlife Refuge, Canaveral National Seashore, and Cape Canaveral Air Force Station, Florida. A sensitivity analysis was performed to establish which parameters were most important and the range of variation surrounding empirically derived model information from the same model. A mosaic pattern of small fires dominated this fire regime with extremely large fires occurring during dry La Nina periods. Dead fuel moisture and wind speed had the largest influence on model outcome. The majority of variability was found to be in the largest fires. The research presenter here provides a comprehensive perspective on current and historic fire regimes that may be useful for optimizing land management on Kennedy Space Center, Merritt Island National Wildlife Refuge, Canaveral National Seashore, and Cape Canaveral Air Force Station, Florida and throughout the southeastern United States. Native fire dependent species are suffering from many changes imposed from human alteration. The success of conservation efforts protecting native fire dependent species hinge on my factors. Two of the largest factors are first protecting native habitat and then secondly managing that protected habitat to mimic natural maintenance processes for suitable structure and composition which may favor their demography. This study focuses on developing techniques necessary for producing information that can aid the optimization of fire management on these properties and within the southeastern United States, but may be useful in other fire maintained ecosystems globally.
Show less - Date Issued
- 2009
- Identifier
- CFE0002862, ucf:48051
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002862
- Title
- ASSESSING AND MODELING MANGROVE FOREST DYNAMICS ALONG THE TEMPERATE-SUBTROPICAL ECOTONE IN EASTERN FLORIDA.
- Creator
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Leitholf, Susan, Weishampel, John, University of Central Florida
- Abstract / Description
-
Mangrove ecosystems are among the world's most endangered biomes; nearly one-half of the overall coverage is threatened by human activity, invasive species, and global climate change. Mangroves play an important ecosystem role through detrital production and by providing: fisheries and wildlife nursery habitat, shoreline protection, a sink for nutrients, carbon, and sediment. In addition to human activity, the Florida mangroves (Avicennia germinans, Laguncularia racemosa, and Rhizophora...
Show moreMangrove ecosystems are among the world's most endangered biomes; nearly one-half of the overall coverage is threatened by human activity, invasive species, and global climate change. Mangroves play an important ecosystem role through detrital production and by providing: fisheries and wildlife nursery habitat, shoreline protection, a sink for nutrients, carbon, and sediment. In addition to human activity, the Florida mangroves (Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle) are being threatened by the invasive Brazilian pepper (Schinus terebinthifolius). This study was performed along a 261 km stretch of the east coast of Florida from Sebastian Inlet to the northern extent of mangroves, near St. Augustine. It entailed two parts. The first examined the phenology and leafing rates of the four species and attempted to find if there was a relationship between growth and latitude or temperature. Although a correlation between peaks in temperature and phenology was observed for all species, no leafing pattern could be discerned. In terms of mangrove growth for branch diameter, a logarithmic model (y=a + b•log [Initial diameter]) best fitted the data for R. mangle and L. racemosa but neither latitude nor temperature appeared to be important. However, S. terebinthifolius' and A. germinans's branch diameter growth were best represented by a logarithmic model (y=a + b•log [Initial diameter] + c•log x2) that incorporated temperature and latitudinal respectively. In the second part, a simulation model was developed to focus on understanding the relationships between establishment and competition among the three mangrove species and the invading S. terebinthifolius. This model was run under various invasion and/or climate change scenarios to determine possible outcomes under global climate change with or without the presence of S. terebinthifolius. Conclusions were drawn that under all scenarios of invasion, other than sea level rise as part of global climate change, S. terebinthifolius would dominate the landscape if allowed to invade and establish in areas in which it is not currently present although the amount of this response is dependent on the S. terebinthifolius response curves.
Show less - Date Issued
- 2008
- Identifier
- CFE0002187, ucf:47912
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002187
- Title
- MODELING CANOPY PHOTOSYNTHESIS OF A SCRUB-OAK ECOSYSTEM UNDER ELEVATED CO2.
- Creator
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Jones, Lori, Weishampel, John, University of Central Florida
- Abstract / Description
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Rising atmospheric CO2 and the need to understand potential impacts on terrestrial ecosystems has become increasingly recognized. Models can play a beneficial part in this research to enhance understanding of ecosystem responses to changing conditions like elevated CO2. In this study, data from a long term elevated CO2 experiment in a native forested ecosystem in east central Florida were employed to assess the utility of a multi-layer canopy photosynthesis model as a tool to better...
Show moreRising atmospheric CO2 and the need to understand potential impacts on terrestrial ecosystems has become increasingly recognized. Models can play a beneficial part in this research to enhance understanding of ecosystem responses to changing conditions like elevated CO2. In this study, data from a long term elevated CO2 experiment in a native forested ecosystem in east central Florida were employed to assess the utility of a multi-layer canopy photosynthesis model as a tool to better understand the responses to elevated CO2 in this ecosystem. Model results compared satisfactorily with the canopy gas exchange measurements in this ecosystem for the period modeled. Sensitivity analyses were used to evaluate the robustness of the model and understand the effects that changing model parameters had on model results, i.e. carbon assimilation in the system. The parameters evaluated included canopy height, leaf area density profile, number of canopy layers, maximum rate of carboxylation (Vcmax), and canopy species composition. Results of the sensitivity analyses point to structure and species as being important to carbon assimilation in this ecosystem. Although only an initial examination, this model could be a valuable tool to further understanding of the response of this important ecosystem to increasing CO2 and indicates that further work is certainly warranted.
Show less - Date Issued
- 2008
- Identifier
- CFE0002244, ucf:47908
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002244
- Title
- AN ASSESSMENT OF SEA TURTLE NESTING BEHAVIOR IN RELATION TO HURRICANE- AND RESTORATION-INDUCED BEACH MORPHODYNAMICS.
- Creator
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Long, Tonya, Weishampel, John, University of Central Florida
- Abstract / Description
-
Coastal habitats are highly dynamic and vulnerable to landscape-level disturbances such as storms and restoration projects. Along the east coast of Florida these areas are particularly valuable as they provide significant nesting habitat for two sea turtle species, the threatened loggerhead (Caretta caretta) and the endangered green turtle (Chelonia mydas). This coast was heavily impacted by three major hurricanes in 2004 and in some areas by large restoration projects in 2005. Recent remote...
Show moreCoastal habitats are highly dynamic and vulnerable to landscape-level disturbances such as storms and restoration projects. Along the east coast of Florida these areas are particularly valuable as they provide significant nesting habitat for two sea turtle species, the threatened loggerhead (Caretta caretta) and the endangered green turtle (Chelonia mydas). This coast was heavily impacted by three major hurricanes in 2004 and in some areas by large restoration projects in 2005. Recent remote sensing methods allow for broad evaluation of the shoreline and thus the ability to assess sea turtle nesting habitat at a landscape scale. I collected nesting data for southern Brevard County, Florida from 1989 – 2005 and for Canaveral National Seashore, Florida from 1995 – 2005. I used LiDAR (Light Detection and Ranging) and IfSAR (Interferometric Synthetic Aperture Radar) remote sensing to map sea turtle nesting habitat in both areas following the 2004 hurricanes and any subsequent restoration. Canaveral National Seashore underwent no restoration while southern Brevard County received extensive restoration. Topographic variables (e.g., total sand volume, width, and slope) derived from the remote sensing data were compared across three time periods (pre-hurricane, post-hurricane, and recovery period) and I compared nesting success data from 2004 to 2005. I built regression models for 2004 and 2005 to determine which topographic features influenced loggerhead and green turtle nesting the most. Green turtle nesting success declined from 2004 to 2005 only in highly restored areas while loggerhead nesting sucess declined throughout. Hurricanes caused a reduction in most of the topographic variables and restoration predominantly impacted aspects of the beach profile (e.g. slope and width). Loggerheads responded to profile characteristics (e.g. upper and lower beach slopes) though green turtles showed no consistent response to topography. The results indicate that both loggerheads and green turtles are sensitive to beach restoration, although loggerhead nesting is more influenced by beach morphology and green turtle nesting may be influenced more by other dune features such as vegetation cover.
Show less - Date Issued
- 2010
- Identifier
- CFE0003051, ucf:48344
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003051
- Title
- CHARACTERIZING THE VERTICAL STRUCTURE AND STRUCTURAL DIVERSITY OF FLORIDA OAK SCRUB VEGETATION USING DISCRETE-RETURN LIDAR.
- Creator
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Angelo, James, Weishampel, John, University of Central Florida
- Abstract / Description
-
Vertical structure, the top-to-bottom arrangement of aboveground vegetation, is an important component of forest and shrubland ecosystems. For many decades, ecologists have used foliage height profiles and other measures of vertical structure to identify discrete stages in post-disturbance succession and to quantify the heterogeneity of vegetation. Such studies have, however, required resource-intensive field surveys and have been limited to relatively small spatial extents (e.g.,
Show moreVertical structure, the top-to-bottom arrangement of aboveground vegetation, is an important component of forest and shrubland ecosystems. For many decades, ecologists have used foliage height profiles and other measures of vertical structure to identify discrete stages in post-disturbance succession and to quantify the heterogeneity of vegetation. Such studies have, however, required resource-intensive field surveys and have been limited to relatively small spatial extents (e.g., <15 ha). Light detection and ranging (lidar) is an active remote sensing technology with enormous potential to characterize the three-dimensional structure of vegetation over broad spatial scales. In this study, discrete-return lidar data were used to create vertical profiles for over 500 vegetation patches on approximately 1000 ha of an oak scrub landscape in the Kennedy Space Center/Merritt Island National Wildlife Refuge area on the east-central coast of Florida. Nonparametric multivariate analysis of variance (NPMANOVA) tests detected significant differences among the profiles belonging to the four predominant land use/land cover (LULC) types in the study area. For the dominant LULC category (Herbaceous upland non-forested), pairwise NPMANOVA comparisons indicated that there were significant differences between vertical profiles for some of the distinct time since fire (TSF) values. Measures of vertical structural diversity (VSD) were calculated from the vertical profiles and then null, linear, and quadratic models relating VSD to TSF were compared via an Akaike information criterion (AIC) model selection procedure. As predicted by the Intermediate Disturbance Hypothesis, the quadratic model was the best model for the Herbaceous upland non-forested LULC category, but it explained less than 3% of the total variation in VSD. When fire frequency was considered in conjunction with TSF for this LULC category, however, the model that was quadratic in both predictor variables was the best model among the candidates and explained over 6% of the total variation in VSD. These results support the Extended Keystone Hypothesis, which predicts that disturbance generates discrete structural patterns across landscapes, and the Intermediate Disturbance Hypothesis, since the VSD of the predominant LULC category was maximized at intermediate levels of fire disturbance (i.e., intermediate values of TSF and/or fire frequency). In addition to demonstrating the ability of discrete-return lidar to characterize the vertical structure of vegetation at the landscape scale, this research has potential management implications. Using the techniques developed in this study, practitioners can compare the vertical structure of managed ecosystems to reference natural systems to evaluate the efficacy of managed disturbance regimes.
Show less - Date Issued
- 2010
- Identifier
- CFE0003254, ucf:48520
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003254
- Title
- MODELING CARBON ALLOCATION, GROWTH AND RECOVERY IN SCRUB OAKS EXPERIENCING ABOVEGROUND DISTURBANCE.
- Creator
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Seiler, Troy, Weishampel, John, University of Central Florida
- Abstract / Description
-
Allocation of assimilated carbon amongst plant metabolic processes and tissues is important to understanding ecosystem carbon cycles. Due to the range of spatio-temporal scales and complex process interactions involved, direct measurements of allocation in natural environments are logistically difficult. Modeling approaches provide tools to examine these patterns by integrating finer scale process measurements. One such method is root:shoot balance, where plant growth is limited by either...
Show moreAllocation of assimilated carbon amongst plant metabolic processes and tissues is important to understanding ecosystem carbon cycles. Due to the range of spatio-temporal scales and complex process interactions involved, direct measurements of allocation in natural environments are logistically difficult. Modeling approaches provide tools to examine these patterns by integrating finer scale process measurements. One such method is root:shoot balance, where plant growth is limited by either shoot activity (i.e. photosynthesis) or root activity (i.e. water and nutrient uptake). This method shows promise for application on frequently disturbed systems which perturb aboveground biomass and thus create imbalances in root and shoot activities. In this study, root:shoot balance, allometric relationships and phenological patterns were used to model carbon allocation and growth in Florida scrub oaks. The model was tested using ecosystem gas exchange (i.e. eddy covariance) and meteorological data from two independent sites at Merritt Island National Wildlife Refuge, FL which experienced two different types of disturbance events: a prescribed burn in 2006 and wind damage from Hurricane Frances in 2004. The effects of the two disturbance events, which differed greatly in magnitude and impact, were compared to identify similarities and differences in plant allocation response. Model results and process-based sensitivity analysis demonstrated the strong influence of autotrophic respiration on plant growth and allocation processes. Also, fine root dynamics were found to dominate partitioning trends of carbon allocated to growth. Overall, model results aligned well with observed biomass trends, with some discrepancies that suggest fine root turnover to be more dynamic than currently parameterized in the model. This modeling approach can be extended through the integration with more robust process models, for example, mechanistic photosynthesis, nitrogen uptake and/or dynamic root turnover models.
Show less - Date Issued
- 2011
- Identifier
- CFE0003664, ucf:48819
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003664
- Title
- APPLICATIONS OF AIRBORNE AND PORTABLE LIDAR IN THE STRUCTURAL DETERMINATION, MANAGEMENT, AND CONSERVATION OF SOUTHEASTERN U.S. PINE FORESTS.
- Creator
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Listopad, Claudia, Weishampel, John, University of Central Florida
- Abstract / Description
-
Active remote sensing techniques, such as Light Detection and Ranging (LiDAR), have transformed the field of forestry and natural resource management in the last decade. Intensive assessments of forest resources and detailed structural assessments can now be accomplished faster and at multiple landscape scales. The ecological applications of having this valuable information at-hand are still only being developed. This work explores the use of two active remote sensing techniques, airborne and...
Show moreActive remote sensing techniques, such as Light Detection and Ranging (LiDAR), have transformed the field of forestry and natural resource management in the last decade. Intensive assessments of forest resources and detailed structural assessments can now be accomplished faster and at multiple landscape scales. The ecological applications of having this valuable information at-hand are still only being developed. This work explores the use of two active remote sensing techniques, airborne and portable LiDAR for forestry applications in a rapidly changing landscape, Southeastern Coastal Pine woodlands. Understanding the strengths and weaknesses of airborne and portable LiDAR, the tools used to extract structural information, and how to apply these to managing fire regimes are key to conserving unique upland pine ecosystems. Measuring habitat structure remotely and predicting habitat suitability through modeling will allow for the management of specific species of interest, such as threatened and endangered species. Chapter one focuses on the estimation of canopy cover and height measures across a variety of conditions of secondary upland pine and hardwood forests at Tall Timbers Research Station, FL. This study is unique since it uses two independent high resolution small-footprint LiDAR datasets (years 2002 and 2008) and extensive field plot and transect sampling for validation. Chapter One explores different tools available for metric derivation and tree extraction from discrete return airborne LiDAR data, highlighting strengths and weaknesses of each. Field and LiDAR datasets yielded better correlations for stand level comparisons, especially in canopy cover and mean height data extracted. Individual tree crown extraction from airborne LiDAR data significantly under-reported the total number of trees reported in the field datasets using either Fusion/LVD and LiDAR Analyst (Overwatch). Chapter two evaluates stand structure at the site of one of the longest running fire ecology studies in the US, located at Tall Timbers Research Station (TTRS) in the southeastern U.S. Small footprint high resolution discrete return LiDAR was used to provide an understanding of the impact of multiple disturbance regimes on forest structure, especially on the 3-dimensional spatial arrangement of multiple structural elements and structural diversity indices. LiDAR data provided sensitive detection of structural metrics, diversity, and fine-scale vertical changes in the understory and mid-canopy structure. Canopy cover and diversity indices were shown to be statistically higher in fire suppressed and less frequently burned plots than in 1- and 2-year fire interval treated plots, which is in general agreement with the increase from 2- to 3-year fire return interval being considered an "ecological threshold" for these systems (Masters et al. 2005). The results from this study highlight the value of the use of LiDAR in evaluating disturbance impacts on the three-dimensional structure of pine forest systems, particularly over large landscapes. Chapter three uses an affordable portable LiDAR system, first presented by Parker et al. (2004) and further modified for extra portability, to provide an understanding of structural differences between old-growth and secondary-growth forests in the Red Hills area of southwestern Georgia and North Florida. It also provides insight into the strengths and weaknesses in structural determination of ground-based portable systems in contrast to airborne LiDAR systems. Structural plot metrics obtained from airborne and portable LiDAR systems presented some similarities (i.e. canopy cover), but distinct differences appeared when measuring canopy heights (maximum and mean heights) using these different methods. Both the airborne and portable systems were able to provide gap detection and canopy cover estimation at the plot level. The portable system, when compared to the airborne LiDAR sensor, provides an underestimation of canopy cover in open forest systems (<50% canopy cover), but is more sensitive in detection of cover in hardwood woodland plots (>60% canopy cover). The strength of the portable LiDAR system lies in the detection of 3-dimensional fine structural changes (i.e. recruitment, encroachment) and with higher sensitivity in detecting lower canopy levels, often missed by airborne systems. Chapter four addresses a very promising application for fine-scale airborne LiDAR data, the creation of habitat suitability models for species of management and conservation concerns. This Chapter uses fine scale LiDAR metrics, such as canopy cover at various height strata, canopy height information, and a measure of horizontal vegetation distribution (clumped versus dispersed) to model the preferences of 10 songbirds of interest in southeast US woodlands. The results from this study highlight the rapidly changing nature of habitat conditions and how these impact songbird occurrence. Furthermore, Chapter four provides insight into the use of airborne LiDAR to provide specific management guidance to enhance the suitable habitat for 10 songbird species. The collection of studies presented here provides applied tools for the use of airborne and portable LiDAR for rapid assessment and responsive management in southeastern pine woodlands. The advantages of detecting small changes in three-dimensional vegetation structure and how these can impact habitat functionality and suitability for species of interest are explored throughout the next four chapters. The research presented here provides an original and important contribution in the application of airborne and portable LiDAR datasets in forest management and ecological studies.
Show less - Date Issued
- 2011
- Identifier
- CFE0003697, ucf:48831
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003697
- Title
- The Feminine Margin: The Re-Imagining of One Professor's Rhetorical Pedagogy--A Curriculum Project.
- Creator
-
Alvarez, Camila, Brenckle, Martha, Bowdon, Melody, Mauer, Barry, Weishampel, John, University of Central Florida
- Abstract / Description
-
Writing pedagogy uses techniques that institutionalize dichotomous thinking rather than work against it. Cartesian duality has helped to create the marginalization of people, environments, and animals inherent in Western thought. Writing pedagogy based in current-traditional rhetoric uses a writing process that reinforces the hierarchical structure of Self/Other, Author/Reader, and Teacher/Student. This structure, in conjunction with capitalism, prioritizes the self and financial gain while...
Show moreWriting pedagogy uses techniques that institutionalize dichotomous thinking rather than work against it. Cartesian duality has helped to create the marginalization of people, environments, and animals inherent in Western thought. Writing pedagogy based in current-traditional rhetoric uses a writing process that reinforces the hierarchical structure of Self/Other, Author/Reader, and Teacher/Student. This structure, in conjunction with capitalism, prioritizes the self and financial gain while diminishing and objectifying the other. The thought process behind the objectification and monetization of the other created the unsustainable business and life practices behind global warming, racism, sexism, and environmental destruction. A reframing of pedagogical writing practices can fight dichotomous thinking by re-imagining student writers as counter-capitalism content creators. Changing student perceptions from isolation to a transmodern, humanitarian, and feminist ethics of care model uses a self-reflexive ethnography to form a pedagogy of writing that challenges dichotomous thought(-)by focusing on transparency in my teaching practice, the utilization of liminality through images, the use of technology to publish student work, and both instructor and student self-reflection as a part of the writing and communication process. This practice has led me to a theory of resistance and influence that I have titled The Resistance Hurricane, a definition of digital rhetoric that includes humanitarian and feminist objectives that I have titled Electric Rhetoric, and a definition for the digitally mediated product of that rhetoric that I call Electric Blooms or electracy after Gregory Ulmer's term for digital media.
Show less - Date Issued
- 2019
- Identifier
- CFE0007777, ucf:52371
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007777
- Title
- Seascape genetics and rehabilitation efficiency in the Florida manatee.
- Creator
-
Hall, Madison, Worthy, Graham, Weishampel, John, Hoffman, Eric, Dyer, Rodney, University of Central Florida
- Abstract / Description
-
The Florida manatee (Trichechus manatus latirostris) was recently downlisted federally from (")endangered(") to (")threatened(") despite acknowledgments of remaining threats to long term population persistence. Challenges to future manatee conservation include, but are not limited to, increases in frequency of harmful algal blooms, intensifying anthropogenic disturbance, and loss of warm-water habitat. The goals of this dissertation were 1) to assess threats to the manatee via a comprehensive...
Show moreThe Florida manatee (Trichechus manatus latirostris) was recently downlisted federally from (")endangered(") to (")threatened(") despite acknowledgments of remaining threats to long term population persistence. Challenges to future manatee conservation include, but are not limited to, increases in frequency of harmful algal blooms, intensifying anthropogenic disturbance, and loss of warm-water habitat. The goals of this dissertation were 1) to assess threats to the manatee via a comprehensive, long-term (1973-2016), retrospective analysis of the manatee rescue and rehabilitation partnership (MRRP) and 2) to use seascape genetics analysis to examine whether abiotic, biotic, or anthropogenic seascape variables could significantly describe genetic distance patterns in space for this genetically depauperate population. Results from the MRRP analysis revealed that anthropogenic threats were the most significant reason for manatees to be rescued and rehabilitated. Manatees rescued due to watercraft injuries spent long periods in recovery before succumbing or being released resulting in significant expense to the rehabilitation system. Additionally, the seascape genetics analysis indicated that watercraft activity best explained spatial genetic patterns in the manatee population. It is established that anthropogenic use of watercraft negative affects manatees through the mechanisms of sub-lethal injury and mortality, and these results suggest there may be further negative impacts via the disruption of population genetic connectivity. Future management practices should seriously consider manatee/vessel interactions as watercraft strikes are costly for management, place pressure on the manatee population, and could disrupt population gene flow with potentially dire consequences. Mitigating anthropogenic impacts on the Florida manatee population is critical for future conservation and should be a primary focus.
Show less - Date Issued
- 2019
- Identifier
- CFE0007647, ucf:52465
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007647
- Title
- Quantifying the impacts of oyster reef restoration on oyster coverage, wave attenuation and seagrass fragment retention in Mosquito Lagoon, Florida.
- Creator
-
Garvis, Stephanie, Walters, Linda, Weishampel, John, Virnstein, Robert, University of Central Florida
- Abstract / Description
-
The goal of this project was to determine the effects of oyster reef restoration on oyster coverage, wave height dissipation and seagrass recruitment. First, to assess the current versus historical coverage of natural, dead and restored oyster reefs within Mosquito Lagoon, aerial photographs from 2009, provided by Saint Johns River Water Management District, were digitized using ArcGIS software. Live reefs, restored reefs and dead reefs were screen digitized using a reef 'signature' in order...
Show moreThe goal of this project was to determine the effects of oyster reef restoration on oyster coverage, wave height dissipation and seagrass recruitment. First, to assess the current versus historical coverage of natural, dead and restored oyster reefs within Mosquito Lagoon, aerial photographs from 2009, provided by Saint Johns River Water Management District, were digitized using ArcGIS software. Live reefs, restored reefs and dead reefs were screen digitized using a reef 'signature' in order to estimate the area of each type of reef. The 2009 maps were used as a guide to digitizing the historical aerial photographs (1943, 1951, 1967, 1971, 1984, 1995, 2006). Dead reefs increased both in number and aerial extent during the study period (1943 (-) 2009), with 2009 having over 10 acres of dead reef coverage. Dead reefs were more likely to be found along major boating channels. Several dead reefs exhibited migration into the mangrove islands located landward of the 1943 footprint, with some dead reefs completely washing up into the shoreline. Restoration of dead reefs added 0.5 acres of live oysters to the Mosquito Lagoon area as of January 2009. Second, I examined how different oyster reef types (natural reef, restored reef, dead reef) reduced wave height. To determine wave height attenuation on each reef type, experiments were conducted in a 9 meter long wave tank using sensors that measured changes in wave height. For each reef type, replicate reefs were created in the wave tank. Shoreline sediment without oysters was used as a control. Using the wave generator, wave heights similar to Mosquito Lagoon boat wakes were created. Restored reefs reduced the incoming wave height by 25% compared to sediment without oysters. Lastly, I examined the potential link between oyster reef restoration and recruitment of seagrass fragments. Monthly surveys were performed to quantify the number of seagrass fragments encountering the three oyster reef types: dead reefs, natural reefs and restored reefs. The quantity of seagrass fragments was found to be similar on the three different reef types, but did show a significant trend of seasonality, which corresponds with the growing season of Halodule wrightii. Next, I tested retention of experimentally manipulated seagrass fragments on five natural and five restored reefs. Restored reefs retained seagrass fragments for significantly longer than natural reefs. I also measured seagrass fragment entanglement on each reef type inside the wave tank. I found that seagrass fragments were significantly more likely to become entangled and retained on restored reefs compared to dead and natural reefs. Overall, these metrics are important for determining the success of long-term oyster restoration project in Mosquito Lagoon, Florida. This project has found that oyster restoration is increasing the area of oyster habitat as well as providing important ecosystem services.
Show less - Date Issued
- 2012
- Identifier
- CFE0004538, ucf:49250
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004538
- Title
- Flying under the LiDAR: relating forest structure to bat community diversity.
- Creator
-
Butterfield, Anna, Weishampel, John, Noss, Reed, King, Joshua, University of Central Florida
- Abstract / Description
-
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
- The behavior of humans and wildlife with respect to roads: insights for mitigation and management.
- Creator
-
Grace, Molly, Noss, Reed, Weishampel, John, Hoffman, Eric, Johnson, Steve, University of Central Florida
- Abstract / Description
-
Road ecology is the study of how roads and wildlife interact. Traditionally, road ecologists have primarily focused on one effect of roads: roadkill. Though roadkill can have devastating effects on wildlife populations, roads have sub-lethal impacts that are gaining more and more attention from the scientific community. These sub-lethal impacts include noise, light, and chemical pollution as well as altered habitat structure, which can all influence animal behavior. In this dissertation, I...
Show moreRoad ecology is the study of how roads and wildlife interact. Traditionally, road ecologists have primarily focused on one effect of roads: roadkill. Though roadkill can have devastating effects on wildlife populations, roads have sub-lethal impacts that are gaining more and more attention from the scientific community. These sub-lethal impacts include noise, light, and chemical pollution as well as altered habitat structure, which can all influence animal behavior. In this dissertation, I applied a behavioral ecology framework to study specific lethal and sub-lethal road effects with the goal of improving mitigation efforts. In Chapters 1 and 2, I evaluated how human behavior may be modified to reduce wildlife-vehicle collisions; traditionally efforts have been made to modify wildlife road crossing behavior. I found that Roadside Animal Detection Systems, which warn drivers when animals are near the road, are successful in reducing crash risk; however, care must be taken to ensure that drivers do not become acclimated to the warning system. In Chapters 3 and 4, I evaluated how traffic noise affects subadult growth and adult abundance and communication of anuran amphibians (frogs and toads), a taxon widely recognized as one of the most negatively impacted by roads. I found that through traffic noise alters tadpole behavior, it does not appear to have a negative effect on their growth. Traffic noise does, however, negatively affect adult anuran abundance. My results indicate that this reduction in abundance is caused by the interference of traffic noise with anuran communication.
Show less - Date Issued
- 2017
- Identifier
- CFE0006595, ucf:51275
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006595
- Title
- Tidal hydrodynamic response to sea level rise and coastal geomorphology in the Northern Gulf of Mexico.
- Creator
-
Passeri, Davina, Hagen, Scott, Medeiros, Stephen, Wang, Dingbao, Weishampel, John, University of Central Florida
- Abstract / Description
-
Sea level rise (SLR) has the potential to affect coastal environments in a multitude of ways, including submergence, increased flooding, and increased shoreline erosion. Low-lying coastal environments such as the Northern Gulf of Mexico (NGOM) are particularly vulnerable to the effects of SLR, which may have serious consequences for coastal communities as well as ecologically and economically significant estuaries. Evaluating potential changes in tidal hydrodynamics under SLR is essential for...
Show moreSea level rise (SLR) has the potential to affect coastal environments in a multitude of ways, including submergence, increased flooding, and increased shoreline erosion. Low-lying coastal environments such as the Northern Gulf of Mexico (NGOM) are particularly vulnerable to the effects of SLR, which may have serious consequences for coastal communities as well as ecologically and economically significant estuaries. Evaluating potential changes in tidal hydrodynamics under SLR is essential for understanding impacts to navigation, ecological habitats, infrastructure and the morphologic evolution of the coastline. The intent of this research is to evaluate the dynamic effects of SLR and coastal geomorphology on tidal hydrodynamics along the NGOM and within three National Estuarine Research Reserves (NERRs), namely Grand Bay, MS, Weeks Bay, AL, and Apalachicola, FL. An extensive literature review examined the integrated dynamic effects of SLR on low gradient coastal landscapes, primarily in the context of hydrodynamics, coastal morphology, and marsh ecology. Despite knowledge of the dynamic nature of coastal systems, many studies have neglected to consider the nonlinear effects of SLR and employed a simplistic (")bathtub(") approach in SLR assessments. More recent efforts have begun to consider the dynamic effects of SLR (e.g., the nonlinear response of hydrodynamics under SLR); however, little research has considered the integrated feedback mechanisms and co-evolution of multiple interdependent systems (e.g., the nonlinear responses and interactions of hydrodynamics and coastal morphology under SLR). Synergetic approaches that integrate the dynamic interactions between physical and ecological environments will allow for more comprehensive evaluations of the impacts of SLR on coastal systems.Projecting future morphology is a challenging task; various conceptual models and statistical methods have been employed to project future shoreline positions. Projected shoreline change rates from a conceptual model were compared with historic shoreline change rates from two databases along sandy shorelines of the. South Atlantic Bight and NGOM coasts. The intent was not to regard one method as superior to another, but rather to explore similarities and differences between the methods and offer suggestions for projecting shoreline changes in SLR assessments.The influence of incorporating future shoreline changes into hydrodynamic modeling assessments of SLR was evaluated for the NGOM coast. Astronomic tides and hurricane storm surge were simulated under present conditions, the projected 2050 sea level with present-day shorelines, and the projected 2050 sea level with projected 2050 shorelines. Results demonstrated that incorporating shoreline changes had variable impacts on the hydrodynamics; storm surge was more sensitive to the shoreline changes than astronomic tides. It was concluded that estimates of shoreline change should be included in hydrodynamic assessments of SLR along the NGOM. Evaluating how hydrodynamics have been altered historically under a changing landscape in conjunction with SLR can provide insight to future changes. The Grand Bay estuary has undergone significant landscape changes historically. Tidal hydrodynamics were simulated for present and historic conditions (dating back to 1848) using a hydrodynamic model modified with unique sea levels, bathymetry, topography, and shorelines representative of each time period. Changes in tidal amplitudes varied across the domain. Harmonic constituent phases sped up from historic conditions. Tidal velocities in the estuary were stronger historically, and reversed from being flood dominant in 1848 to ebb dominant in 2005. To project how tidal hydrodynamics may be altered under future scenarios along the NGOM and within the three NERRs, a hydrodynamic model was used to simulate present (circa 2005) and future (circa 2050 and 2100) astronomic tides. The model was modified with projections of future sea levels as well as shoreline positions and dune elevations obtained from a Bayesian network (BN) model. Tidal amplitudes within some of the embayments increased under the higher SLR scenarios; there was a high correlation between the change in the inlet cross-sectional area under SLR and the change in the tidal amplitude within each bay. Changes in harmonic constituent phases indicated faster tidal propagation in the future scenarios within most of the bays. Tidal velocities increased in all of the NERRs which altered flood and ebb current strengths.The work presented herein improves the understanding of the response of tidal hydrodynamics to morphology and SLR. This is beneficial not only to the scientific community, but also to the management and policy community. These findings will have synergistic effects with a variety of coastal studies including storm surge and biological assessments of SLR. In addition, findings can benefit monitoring and restoration activities in the NERRs. Ultimately, outcomes will allow coastal managers and policy makers to make more informed decisions that address specific needs and vulnerabilities of each particular estuary, the NGOM coastal system, and estuaries elsewhere with similar conditions.
Show less - Date Issued
- 2015
- Identifier
- CFE0006049, ucf:50962
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006049
- Title
- Movements, fishery interactions, and unusual mortalities of bottlenose dolphins.
- Creator
-
Shippee, Steven, Worthy, Graham, Walters, Linda, Weishampel, John, Wells, Randall, University of Central Florida
- Abstract / Description
-
Bottlenose dolphins inhabiting coastlines and estuaries in Florida have been impacted in the past decade by development, algal blooms, catastrophic pollution, and fishery interactions (FI). Dolphins react to disturbance and environmental stressors by modifying their movements and habitat use, which may put them in jeopardy of conflict with humans. FI plays an increasing role in contributing to dolphin mortalities. I investigated dolphin movements, habitat use, residency patterns, and...
Show moreBottlenose dolphins inhabiting coastlines and estuaries in Florida have been impacted in the past decade by development, algal blooms, catastrophic pollution, and fishery interactions (FI). Dolphins react to disturbance and environmental stressors by modifying their movements and habitat use, which may put them in jeopardy of conflict with humans. FI plays an increasing role in contributing to dolphin mortalities. I investigated dolphin movements, habitat use, residency patterns, and frequency of FI with sport fishing. Tagging studies with short-term data tags and bolt on radio-transmitters were done in several locations in Florida and the east coast providing fine-scale measurements of swimming, daily travels, and foraging activity. Transit speeds agreed with the predicted mean cost of transport as dolphins spent much of their day and night travelling and resting while swimming. Increased foraging was detected by stomach temperature changes revealing dolphins fed at night with a peak starting just after sunset. Dolphin abundance, site fidelity, ranging, stranding mortality, and community structure was characterized at Choctawhatchee and Pensacola Bays in the Florida Panhandle via surveying and photo-identification. Results showed they made frequent inshore movements, maintained site fidelity to specific areas, and comprised several distinct communities. FI was assessed at offshore reefs and coastal fishing piers near Destin, FL and Orange Beach, AL, showing that some dolphins demonstrate affinity to this activity. Harmful interactions with dolphins on reefs and at fishing piers negatively affect their resident communities. Mitigation of FI is suggested by use of avoidance strategies, gear modifications, and improved fish release practices.
Show less - Date Issued
- 2014
- Identifier
- CFE0005550, ucf:50273
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005550
- Title
- Using Land Cover Mapping and Landscape Metrics to Evaluate Effects of Urban Development on Ecological Integrity in Florida.
- Creator
-
Gilbrook, Michael, Weishampel, John, Hinkle, Ross, Jenkins, David, Brody, Samuel, University of Central Florida
- Abstract / Description
-
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
