View All Items

Title: VARIABILITY OF CARBON STOCK IN FLORIDA FLATWOODS ECOSYSTEMS UNDERGOING RESTORATION AND MANAGEMENT.
Creator: Becker, Kathryn, Hinkle, C. Ross, University of Central Florida
Abstract / Description: The global community is struggling with mitigating the effects of widespread habitat loss and degradation; the effects of which are being further magnified in the face of global climate change. Quality natural habitat is becoming increasingly limited and atmospheric carbon levels continue to rise. Therefore, land managers responsible for multiuse management are often faced with the dilemma of managing ecosystems for biodiversity, as well as optimizing ecosystem services such as carbon storage...
Show moreThe global community is struggling with mitigating the effects of widespread habitat loss and degradation; the effects of which are being further magnified in the face of global climate change. Quality natural habitat is becoming increasingly limited and atmospheric carbon levels continue to rise. Therefore, land managers responsible for multiuse management are often faced with the dilemma of managing ecosystems for biodiversity, as well as optimizing ecosystem services such as carbon storage and sequestration. However, some management techniques used to meet these objectives may yield conflicting results, specifically, the management tool of prescribed fire. Fire is crucial in maintaining species composition and structure in many ecosystems, but also results in high carbon emissions. Thus, it is important for land mangers to achieve the most efficient prescribed fire management regime to both preserve plant and animal communities, and optimize carbon storage. A former ranchland at the Disney Wilderness Preserve, Central Florida, USA is being restored to native ecosystems and managed to preserve biodiversity and increase carbon storage. This study quantified the carbon stocks within the aboveground biomass, litter, and top 90 cm of soil in five ecosystems at the Disney Wilderness Preserve, all of which are managed with prescribed fire every two to three years. These carbon stocks were compared in ecosystems in different stages of restoration: bahia grass pasture, pasture in restoration for longleaf pine flatwoods, and restored longleaf pine flatwoods. The carbon stocks were also compared among three restored flatwoods communities: longleaf pine flatwoods, slash pine flatwoods, and scrubby flatwoods. To determine the effects of the current prescribed fire management, carbon stocks were quantified and compared in recently burned areas (burned 4 months prior) and areas burned two to three years prior, in all ecosystems. Soil carbon properties were assessed using 13C isotope analysis. Aboveground biomass and litter carbon stocks were found to increase with higher stage of restoration, and were significantly less in areas with recent fire management. The results of this study did not provide evidence that soil carbon stock was significantly different in different stages of restoration or at different times since fire, but soil carbon stock was found to be significantly different among the flatwoods communities. In un-restored pasture and pasture in restoration sites, the soil was found to be increasingly depleted in 13C with increasing soil depth. This pattern indicated that carbon in the upper, more labile soil carbon pool had been derived from current C4 pasture or native grasses, while carbon in the deeper, more stable carbon pool is a legacy of the historical C3 forest vegetation that existed prior to conversion to pasture. Additionally, a pattern of less depletion in 13C with increasing time since deforestation was noted, indicating an increasing loss of historic forest carbon with increasing pasture age. As the pastures in restoration for longleaf pine flatwoods mature, the isotopic composition of the soil profile in the restored longleaf pine flatwoods may serve as a reference value for the soil profiles of these sites. Overall, the mean carbon stock in the aboveground biomass, litter and top 90 cm of soil in the un-restored pasture was ~13.3 kg C/m2, the carbon stock in the pasture in restoration was ~12.7 kg C/m2, the longleaf pine flatwoods had the highest carbon stock at ~17.7 kg C/m2, the scrubby flatwoods had the smallest carbon stock at ~7.7 kg C/m2, and the slash pine flatwoods had a carbon stock of ~15.8 kg C/m2.
Show less
Date Issued: 2011
Identifier: CFE0003603, ucf:48870
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003603

Title: Miami-Dade Task Force: A Content Analysis of How Coastal Communities View Sea Level Rise as a Threat.
Creator: Alvaro, Francisco, Jacques, Peter, Knox, Claire, Hinkle, Ross, University of Central Florida
Abstract / Description: Sea level rise (SLR) has become a serious threat for coastal communities in recent years. Many communities, including South Florida, are already having the security of their daily lives impacted as climate change causes SLR and other environmental impacts to worsen. This study reviews the Miami-Dade Sea Level Rise Task Force Report to determine how this coastal county government views SLR as a threat. Using mixed content analysis to analyze the report qualitatively and quantitatively, the...
Show moreSea level rise (SLR) has become a serious threat for coastal communities in recent years. Many communities, including South Florida, are already having the security of their daily lives impacted as climate change causes SLR and other environmental impacts to worsen. This study reviews the Miami-Dade Sea Level Rise Task Force Report to determine how this coastal county government views SLR as a threat. Using mixed content analysis to analyze the report qualitatively and quantitatively, the Task Force's recommendations are categorized based on their focus on security, infrastructure, economics, and the environment. One finds the concerns of the people to maintain their property and infrastructure, as well as their access to water and other basic needs, as insurance costs spike and funding becomes more difficult to obtain. Policies will have to be revised using updated scientific studies, modeling, and mapping to mitigate against the worse-case scenarios.
Show less
Date Issued: 2019
Identifier: CFE0007427, ucf:52705
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007427

Title: Characterizing biogeochemical shifts in two Salix Caroliniana Michx. encroached freshwater subtropical marshes.
Creator: Ho, Janet, Chambers, Lisa, Hinkle, Ross, Savage, Anna, University of Central Florida
Abstract / Description: Shrub encroachment is a common disturbance in wetlands, but little is known about how shrub encroachment impacts functions such as carbon (C) storage and nitrogen (N) cycling. The objective of this thesis was to identify differences in physiochemical properties (within soil, water and leaf tissue) and biogeochemical processes (soil respiration, enzyme activity, litter decomposition, and N cycling) in two subtropical freshwater marshes encroached by coastal plain willow (Salix caroliniana...
Show moreShrub encroachment is a common disturbance in wetlands, but little is known about how shrub encroachment impacts functions such as carbon (C) storage and nitrogen (N) cycling. The objective of this thesis was to identify differences in physiochemical properties (within soil, water and leaf tissue) and biogeochemical processes (soil respiration, enzyme activity, litter decomposition, and N cycling) in two subtropical freshwater marshes encroached by coastal plain willow (Salix caroliniana Michx.). Two study regions (Moccasin Island and Lake Apopka) were selected because of their location in the St. John's River watershed and their unique histories and hydroperiod, allowing for an investigation of how synonymous the effects of willow-encroachment are across sites. A stratified random sampling design was employed in each region, identifying three plot types: willow ((>)80 % willow aboveground coverage), adjacent marsh ((>)80% herbaceous aboveground coverage and (<)1 m from willows), and control marsh ((>)80% herbaceous aboveground coverage and (>)10 m from willows) plots. Triplicate soil samples were collected in each plot in the wet and dry seasons of 2017 and analyzed for physiochemical properties (bulk density, moisture, nutrient content) and used in laboratory assays to measure soil respiration, enzyme activity, and potential N mineralization and denitrification rates. Leaf tissue was collected from the dominant vegetation in each plot and analyzed for nutrient content (total C, lignin-C, and total N). Short-term litter decay rate was determined using a litter-bag field experiment. Bioavailable N and dissolved organic C (DOC) concentrations were determined from surface and porewater collected from the center of each plot. In Moccasin Island, lower decomposition rates and greater denitrification, potential N mineralization, and soil C and N content were detected in willow and adjacent marsh plots, suggesting greater C storage and N cycling in willow-encroached marshes compared to non-encroached control marshes in Moccasin Island. Conversely, soil C and N content was lowest in willow plots in Lake Apopka. Decomposition and microbial activity (enzyme activity and respiration) were lowest in willow dominated areas and correlated to soil nutrient concentrations. In both regions, microbial compositional changes (gene copy number) were detected between plot types, mainly in bacteria (?-proteobacteria and Bacteroidetes) for Moccasin Island and archaea and fungi abundance in Lake Apopka. Ultimately, willow plots in both regions had greater lignin-C content and short-term litter C storage. Greater bioavailable N was also observed in adjacent and/or willow plots in both regions. However, soil C storage and N cycling differences were not synonymous between the two regions. Future studies of willow effects will need to look at multiple sites or risk making inaccurate generalizations. From the findings from this study, wetland processes can be altered in willow-encroached marshes and this data can help land managers decide where to allocate resources based on valued ecosystem services.
Show less
Date Issued: 2018
Identifier: CFE0007015, ucf:52043
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007015

Title: Mucking About: Hydrologic Regime and Soil Carbon Storage in Restored Subtropical Wetlands.
Creator: Huber, Alicia, Bohlen, Patrick, Hinkle, Ross, Chambers, Lisa, University of Central Florida
Abstract / Description: Wetlands are extremely important ecosystems that have declined drastically worldwide, continue to be lost, and are threatened globally. They perform a number of important ecosystem services such as flood control, provide habitat for many species, and have aesthetic and recreational value. Wetlands are also important to the global carbon (C) cycle. Wetland soils are especially effective C sinks because they have high primary productivity and low decomposition rates due to flooded, anoxic...
Show moreWetlands are extremely important ecosystems that have declined drastically worldwide, continue to be lost, and are threatened globally. They perform a number of important ecosystem services such as flood control, provide habitat for many species, and have aesthetic and recreational value. Wetlands are also important to the global carbon (C) cycle. Wetland soils are especially effective C sinks because they have high primary productivity and low decomposition rates due to flooded, anoxic conditions. Increased recognition of wetlands' value has led to more ecological and hydrological restoration of degraded wetlands to mitigate the effects of wetland destruction. Hydrological restoration, which attempts to recreate natural hydroperiod and water levels in wetlands, is expected to increase soil C storage. Many studies have estimated the C stock in different wetland ecosystems across biomes, but few have examined hydrological drivers of soil C variation across wetland types. This study investigated the relationship between hydrologic variables (hydroperiod and average water depth) and soil C storage in three types of hydrologically restored wetlands (marsh, bay swamp, and cypress swamp) at the Disney Wilderness Preserve (DWP) in central Florida, USA. I collected 150 50-cm soil cores along existing monitoring transects in sampled wetlands where water elevation data had been collected since 1995 to examine the relationship between hydrologic variable and soil C storage. I analyzed a combination of generalized linear mixed models (glmm), evaluated using AICc. Mean water depth was a better predictor than hydroperiod of soil C concentration and stock. Mean water depth had a significant positive relationship with soil C concentration in bay swamps and marshes and soil C stock in marshes. However, this effect was small and often outweighed by other factors such as differences in vegetative community, soil depth, or local site conditions. Water depth had no significant relationship with soil C concentration in cypress swamps or upland communities or on soil C stock in bay swamps, cypress swamps, or uplands. Wetland community type had a strong influence on soil C variation, with bay swamp soils having the highest mean soil C concentration followed by cypress swamp, marsh, and upland soils, respectively. Soil C concentration generally decreased with soil depth. Bay swamps also had the highest soil C stock, followed by cypress swamp, marsh, and upland soils, respectively. Together, the sampled wetland communities cover approximately 22% of the sampled communities at DWP, yet store an estimated 47% of the total soil C to a 90 cm depth. The results of this study affirm the importance of inundation for soil C storage in wetlands, but also highlight that there are a number of other complex variables affecting soil C in different types of wetlands such as differences in litter quality and decomposition rates.
Show less
Date Issued: 2017
Identifier: CFE0007122, ucf:51930
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007122

Title: Habitat distribution and abundance of crayfishes in two Florida spring-fed rivers.
Creator: Manteuffel, Tiffani, Hinkle, Ross, King, Joshua, Stout, I, Stolen, Eric, University of Central Florida
Abstract / Description: Crayfish are an economically and ecologically important invertebrate, however, research on crayfish in native habitats is patchy at best, including in Florida, even though the Southeastern U.S. is one of the most speciose areas globally. This study investigated patterns of abundance and habitat distribution of two crayfishes (Procambarus paeninsulanus and P. fallax) in two Florida spring-fed rivers (Wakulla River and Silver River, respectively). Study sites were surveyed once each season from...
Show moreCrayfish are an economically and ecologically important invertebrate, however, research on crayfish in native habitats is patchy at best, including in Florida, even though the Southeastern U.S. is one of the most speciose areas globally. This study investigated patterns of abundance and habitat distribution of two crayfishes (Procambarus paeninsulanus and P. fallax) in two Florida spring-fed rivers (Wakulla River and Silver River, respectively). Study sites were surveyed once each season from April 2015 to March 2016 with baited minnow traps checked every other day, four times each survey. Habitat and environmental parameters evaluated included dominant vegetation or bottom type, percent cover, organic matter content, water depth, moon illumination and dissolved oxygen. Abundance was estimated with N-mixture models. Model selection judged the relative evidence between hypotheses relating habitat and environmental covariates to crayfish abundance. P. paeninsulanus distribution and abundance in Wakulla River was explained by time of year, dissolved oxygen and dominant bottom and vegetation type. P. fallax distribution and abundance in Silver River was explained by time of year and percent coverage of vegetation. Detection of P. paeninsulanus was higher than P. fallax and abundance of P. paeninsulanus was more heterogenous than P. fallax (6-18 versus 12-14 per site in summer survey). Distribution of P. paeninsulanus as described by vegetation and bottom type also seems to follow heterogeneity in management areas in Wakulla River. Results will assist managers in understanding potential impact of herbicidal control of Hydrilla verticillata on crayfish. This study also fills knowledge gaps on Florida crayfish natural history and ecology.
Show less
Date Issued: 2016
Identifier: CFE0006474, ucf:51442
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006474

Title: Effects of weaning age on body composition and growth of ex situ California sea lion (Zalophus californianus) pups.
Creator: Davis, Brandon, Worthy, Graham, Hinkle, Ross, Nolan, Elizabeth, University of Central Florida
Abstract / Description: Pinnipeds exhibit a wide range of lactation strategies that vary from just a few days to nearly three years in duration. Phocids have a relatively short, intense nursing period culminating with weaning after just a few days or weeks, while dependent otariids generally take several months of consuming a combined milk and solid food diet before being completely independent. The transition to nutritional independence can be particularly challenging for newly weaned pups, which must adjust to...
Show morePinnipeds exhibit a wide range of lactation strategies that vary from just a few days to nearly three years in duration. Phocids have a relatively short, intense nursing period culminating with weaning after just a few days or weeks, while dependent otariids generally take several months of consuming a combined milk and solid food diet before being completely independent. The transition to nutritional independence can be particularly challenging for newly weaned pups, which must adjust to behavioral, physiological and nutritional changes as a milk diet is replaced with solid food. An interruption in energy resources during this formative stage could result in a prioritization away from growth, maintenance, or activity resulting in suboptimal development.Three groups of ex situ California sea lion (Zalophus californianus) pups were examined during the initial period of independence after they were weaned at approximately five, seven, and nine months of age. Absolute growth rates of pups were calculated and changes in body composition were estimated using blubber depth measurements and deuterium oxide dilution to determine if weaning age had an effect on subsequent pup development and growth. Blood urea nitrogen and blood glucose levels were observed for their response to changes in body condition, while thyroid hormone levels in the blood were examined as a possible nutritional stress indicator during the pup's transition to solid food.When compared to in situ pups, the 5 month old pups in the present study had significantly greater body mass (39.6 (&)#177; 1.6 kg, p(<) 0.01), axillary girth (85.3 (&)#177; 2.9 cm, p(<) 0.01), and axillary blubber depth (2.3 (&)#177; 0.1 cm, p(<) 0.01) compared to 5 month old in situ pups (26.6 (&)#177; 5.2 kg / 70.6 (&)#177; 5.34 cm / 1.5 (&)#177; 0.2 cm). Nine month old ex situ pups had significantly greater axillary blubber depth (3.7 (&)#177; 0.9 cm, p(<) 0.01) and total body lipid percentage (24.9 (&)#177; 4.7%, p= 0.01) than in situ pups (1.5 (&)#177; 0.2 cm / 17.1 (&)#177; 4.9%). Although all pups in the present study survived the transition to solid food, there were apparent differences in how the different age groups responded physiologically. The five month old pups began the switch to solid food with the lowest overall blubber depth (2.6 (&)#177; 0.9 cm) and experienced the greatest change in body mass (-8.5 (&)#177; 1.6 kg) and composition while taking the longest to begin physiological recovery (31.7 (&)#177; 1.2 d). In contrast, the 9 month old pups entered the transition with more energy reserves (24.9 (&)#177; 4.7% TBL), began consuming solid food sooner (16.3 (&)#177; 0.6 d), and were able to utilize reserves more efficiently to minimize loss and promote faster growth.
Show less
Date Issued: 2014
Identifier: CFE0005598, ucf:50259
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005598

Title: Effects of mechanical habitat disturbance on the diversity and network structure of plant-bee interaction networks in Central Florida.
Creator: Carman, Karlie, Hinkle, Ross, Jenkins, David, King, Joshua, University of Central Florida
Abstract / Description: Ecological interactions within a community shape the structure of ecosystems and influence ecosystem function. Plant-pollinator interactions exist as mutualistic exchange networks that may collapse as habitat loss occurs, thereby threatening the overall health of an ecosystem. Understanding the impacts of human-mediated habitat disturbance on ecological interactions is therefore crucial for conservation efforts. Archbold Biological Station (ABS) in Venus, Florida contains over 2000 hectares...
Show moreEcological interactions within a community shape the structure of ecosystems and influence ecosystem function. Plant-pollinator interactions exist as mutualistic exchange networks that may collapse as habitat loss occurs, thereby threatening the overall health of an ecosystem. Understanding the impacts of human-mediated habitat disturbance on ecological interactions is therefore crucial for conservation efforts. Archbold Biological Station (ABS) in Venus, Florida contains over 2000 hectares of protected Florida scrub habitat nested within a human-dominated environment that is threatened by anthropogenic habitat disturbance. In past studies, over 113 bee species and 157 associated host plants, many endemic to the Lake Wales Ridge, have been found on ABS property, providing an understanding of this system's plant-bee network. Using those data as a baseline, this study investigated the effects of varying levels of mechanical habitat disturbance intensity on the diversity and network structure of plant-bee interaction networks. Flowering plant abundance, richness, diversity, and composition as well as bee abundance and composition were significantly different across mechanical habitat disturbance levels. Interactions between bees and flowering plants also differed with varying disturbance intensity. From these results, it is clear that plants, bees and interactions between them are impacted by mechanical habitat disturbance in this system. This project informs management efforts not only for natural systems with the threat of alteration, but also for agricultural systems, many of which heavily rely on flower visitation by bee pollinators. This research also contributes to the growing field of interaction ecology by increasing understanding of habitat alteration effects on a valuable ecological interaction and ultimately ecosystem function.
Show less
Date Issued: 2014
Identifier: CFE0005311, ucf:50505
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005311

Title: 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

Title: Biogeochemical effects of sea level rise-induced transitions within coastal wetlands.
Creator: Steinmuller, Havalend, Chambers, Lisa, Hinkle, Ross, Bohlen, Patrick, Beazley, Melanie, University of Central Florida
Abstract / Description: As sea level rise (SLR) affects coastal wetlands, ecosystem responses can include vertical accretion, landward transgression, or submergence. Sea level rise-induced transitions can alter key biogeochemical transformations within wetland soils, impacting the ability of these systems to provide ecosystem services, specifically carbon (C) storage and water quality regulation. Through a series of complementary laboratory and field-based studies, biogeochemical responses to salinity, vegetation...
Show moreAs sea level rise (SLR) affects coastal wetlands, ecosystem responses can include vertical accretion, landward transgression, or submergence. Sea level rise-induced transitions can alter key biogeochemical transformations within wetland soils, impacting the ability of these systems to provide ecosystem services, specifically carbon (C) storage and water quality regulation. Through a series of complementary laboratory and field-based studies, biogeochemical responses to salinity, vegetation shifts, and submergence were investigated. Changes in nutrient dynamics associated with saltwater intrusion were evaluated by artificially adding saline water to different freshwater wetland soil types, indicating that potential exports of critical nutrients (forms of nitrogen, phosphorus, and C) out of freshwater wetland soils is mediated by soil type. A controlled laboratory experiment was conducted to determine the potential degradability of C stored within submerging coastal wetland soils under both aerobic and anaerobic conditions. Under aerobic conditions, 66% more carbon dioxide was produced than under anaerobic conditions and 4x greater carbon dioxide was produced at 90-100cm depths than at the surface. At the same site, the degradability of carbon stores was examined through organic matter fractionation, stable isotopic examination, and determining the abundance of key microbial genes. Both total soil C and stores of bioavailable nutrients increased with depth, while organic matter quality decreased. Finally, the biogeochemical impacts of two separate vegetation transitions occurring co-incidentally with sea level rise were investigated: mangrove encroachment into salt marsh, and more salt- and inundation-tolerant herbaceous encroachment into herbaceous marsh. Conclusions from these studies demonstrate that vegetation transitions alter both soil nutrient storage and fast-cycling nutrient pools, indicating that biogeochemical transitions occur in advance of changes in vegetative species dominance. Results from these chapters holistically address how biogeochemical functioning, specifically nutrient cycling, regulation of water quality, and C sequestration, within coastal wetlands responds to stressors associated with SLR.
Show less
Date Issued: 2019
Identifier: CFE0007536, ucf:52584
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007536

Title: Physiological Constraints on Warm-Water Habitat Site Selection and Utilization by the Florida Manatee (Trichechus manatus latirostris) in East Central Florida.
Creator: Spellman, Ann, Worthy, Graham, Noss, Reed, Hinkle, Ross, DeFreese, Duane, University of Central Florida
Abstract / Description: Living at the northern limits of its geographic range, the Florida manatee is particularly susceptible to cold stress-related mortality during the winter months, with most deaths occurring in the lower two-thirds of the state. Contributing to this cold stress susceptibility is the manatee's limited physiological and behavioral responses available when thermally stressed. While capable of migrating south in response to falling water temperatures, manatees must still find warm water when...
Show moreLiving at the northern limits of its geographic range, the Florida manatee is particularly susceptible to cold stress-related mortality during the winter months, with most deaths occurring in the lower two-thirds of the state. Contributing to this cold stress susceptibility is the manatee's limited physiological and behavioral responses available when thermally stressed. While capable of migrating south in response to falling water temperatures, manatees must still find warm water when ambient river temperature drops below 20(&)deg;C for more than a few days. This is in part due to the species low metabolic rate, limited capacity for thermogenesis, and limited ability to raise its metabolic rate. Prolonged exposure to cold temperatures may result in cold stress syndrome, which involves a number of potentially life-threatening, if not fatal physiological changes. Survival during the winter months is therefore, dependent upon the manatee's ability to balance basic physiological needs, primarily the need to forage and to obtain fresh water with the need to stay warm.When identifying which animals are most susceptible and where, analyses of statewide manatee mortality records from 1996 through 2011 (n = 823) indicated that, size and location matter. Medium to large-sized calves accounted for the majority of documented death from cold stress (46.6%), while subadults and small calves were the least represented size classes (14.3 % and 9.5%, respectively). Adults slightly outnumbered subadults (15.8%). Males outnumbered females in all size classes but gender differences were not statistically significant. With regards to location, two areas of the state, the southwest and central east coasts showed the highest incidents of cold stress-related mortality. Both are regions with no primary, natural warm-water springs and whose principal warm-water refugia are power plant effluents. Brevard County on the central east coast is the area most at risk during cold weather events accounting for more than 25% of all cold stress deaths statewide. Warm-water sites within this region are few and relatively underrepresented in the literature in an area well-studied in terms of manatee abundance and distribution relative to the operational power plant. Results from cold stress data analyses emphasize the importance of identifying and characterizing the physical attributes of both known and suspected secondary warm-sites used by manatees in this region for both long and short term protection of the species, and its critical habitat.Three locations within Brevard County identified as passive thermal basins (PTBs), and classified as secondary warm-water sites, have been documented supporting in excess of 100 manatees on numerous occasions, and during winters of varying severity. Unique in physical appearance, distance to forage, hydrology including thermal profiles, and when it was used by manatees, each site challenged the accepted definitions and criteria of what constitutes an acceptable and appropriate warm-water site.Through analyses of photo-identification records, site fidelity at two of these warm-water sites, the Berkeley Canal and the Desoto Canal, was established for a minimum of 20 highly identifiable animals, 15 of which used adjacent sites within the same year, and 6 that used both sites but during different years. Observations of daily use patterns within the sites supported optimization of thermoregulation through adjustments in both vertical and horizontal movement, the latter of which seemed to follow the path of the sun. Manatees using the sites also made use of bottom sediment presumably to stay warm at all three locations. Temperature data indicated that water temperatures monitored in the sediment at secondary sites were some of the highest in the county. The predictable movements during all but the coldest weather fronts indicated that manatees utilized these sites during the early morning and afternoon hours when ambient river temperatures were coldest, gradually returning to the river to feed as ambient temperatures began to rise later in the afternoon.The availability of PTBs in proximity to primary warm-water sites within the region may provide an important component needed for manatees to successfully balance the need to forage with the need to stay warm by providing a network that allows for more efficient foraging while reducing exposure to sub-critical ambient river temperatures. The challenge of balancing the need to forage and to maintain homeostasis in the face of thermal stress is complex. This complexity was best approached and better understood through use of a manatee energetics model. The model was designed to facilitate simulation of an unlimited number of different case scenarios involving the exposure of virtually created manatees to a variety of winter conditions as might be experienced by real manatees in a natural system. Sixty-four different simulations were run using six virtual manatees of differing ages, gender, physical parameters, and knowledge of warm-water sites. Simulations were conducted using actual winter water temperature data from Brevard secondary sites and the ambient river from both a mild and a severe winter season. Outcomes, measured as changes in physical parameters indicative of body condition (i.e. mass, percent body fat, blubber depth, girths, etc.), showed that all else being equal, calves in the 2 year-old range fared poorly in all scenarios when compared to individuals of larger size. Subadults fared better than larger adults. This outcome illustrates the complex relationship between size, energy requirements and the synergistic effects of body mass, body fat and blubber thickness on SA:V ratio. Model outcomes agree closely with manatee cold stress mortality analyses predicting that medium to large-sized calves are most susceptible to CS, followed by adults, then subadults.Because all models are simplifications of complex systems, the manatee energetics model is not without its flaws and limitations. The current version of the model could not predict the point at which cold stress mortality would occur. However, a cold stress warning system incorporated into the design alerts the user if potential CSS is likely based on changing physical parameters. Another limitation was the inability of the model to account for the behavioral plasticity of individual subjects since virtual manatees respond to water temperatures based on the user defined rules. A number of additional limitations related to gaps in existing manatee data the gaps were identified and defined. Despite these gaps, the model is designed to allow for incorporation of additional interactions, feedback loops and relevant data as it becomes available and as additional physiological interactions and energy requirements are more clearly defined. Sensitivity analyses, a feature of the model that allowed for modifications in a number of physical as well as environmental parameters, provided an otherwise unlikely opportunity to see how incremental changes in input values, specifically the starting values for mass, percent body fat and blubber depth affected the model's outcome. Ultimately the goal of the model was to facilitate a better understanding of complex relationships by challenging our preconceived understanding of the manatee and its environment
Show less
Date Issued: 2014
Identifier: CFE0005419, ucf:50428
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005419

Title: Estimated diets, diet overlap, and winter habitat associations of four grassland sparrows in Florida dry prairie.
Creator: Korosy, Marianne, Noss, Reed, Quintana-Ascencio, Pedro, Roth, James, Hinkle, Ross, Bowman, Reed, University of Central Florida
Abstract / Description: North American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of diet and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. This dissertation investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two...
Show moreNorth American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of diet and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. This dissertation investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two consecutive winters. Grasshopper and Henslow's sparrows showed higher relative abundance in wet-mesic prairie and Bachman's Sparrows were more abundant in dry-mesic prairie across all fire treatments. Abundances of Grasshopper and Bachman's sparrows were best predicted by plant community association and secondly by time since fire; whereas for Henslow's Sparrows, habitat and time since fire were equally important. Fall molt-period diets and diet overlap were modeled for resident Florida Grasshopper and Bachman's sparrows using stable carbon and nitrogen isotope ratios of bird feathers and potential food sources, e.g., arthropods and seeds. Grasshoppers (Orthoptera, including a variety of species foraging on both C3 and C4 herbs), spiders, dragonflies, flies, beetles and weevils comprised the majority of the diets of adult and juvenile Florida Grasshopper Sparrows and Bachman's Sparrows, but in differing proportions. Despite the similarity in reconstructed diets for the two sparrow species, analysis of diet overlap suggested that approximately half of the Florida Grasshopper Sparrows had diets consisting of higher trophic level prey than Bachman's Sparrows. Winter diets and diet overlap among Grasshopper, Henslow's, and Bachman's sparrows were reconstructed using stable carbon and nitrogen isotope ratios of feathers and potential arthropod and seed food sources. Sparrows were captured and recaptured in winter 2007-2008 using systematic flush-netting, removing a tail feather at first capture and then removing the regrown feather when birds were recaptured. Winter diets of all three sparrows included a variety of arthropods, grass seeds, and sedge seeds, but Bachman's Sparrow winter diets spanned greater trophic diversity than either of the migratory sparrows. Estimated diets of Henslow's and Grasshopper sparrows differed from that of Bachman's Sparrow but Henslow's Sparrow diets did not differ from Grasshopper Sparrow diets. This is the first study of fall and winter sparrow diets in Florida based on stable isotopes and the first study in peninsular Florida on habitat associations of ground-dwelling sparrows.
Show less
Date Issued: 2013
Identifier: CFE0005363, ucf:50475
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005363

Florida (3)	+ -
carbon (2)	+ -
ecology (2)	+ -
sea level rise (2)	+ -
BUN (1)	+ -

Bachman's Sparrow (1)	+ -
Bay Swamp (1)	+ -
Cypress Swamp (1)	+ -
Everglades (1)	+ -
FRAGSTATS (1)	+ -
Florida Grasshopper Sparrow (1)	+ -
Florida manatee (1)	+ -
Florida scrub (1)	+ -
Freshwater Marsh (1)	+ -
GIS (1)	+ -
Grasshopper Sparrow (1)	+ -
Habitat Fragmentation (1)	+ -
Henslow's Sparrow (1)	+ -
Interaction (1)	+ -
Land Cover (1)	+ -
Landsat (1)	+ -
Miami-Dade (1)	+ -
SIAR (1)	+ -
SIBER (1)	+ -
Subtropical Wetlands (1)	+ -
Urban Sprawl (1)	+ -
Wetland Restoration (1)	+ -
bee (1)	+ -
biogeochemical cycles (1)	+ -
body composition (1)	+ -

University of Central Florida (11)	+ -
Hinkle, Ross (10)	+ -
Chambers, Lisa (3)	+ -
Bohlen, Patrick (2)	+ -
Jenkins, David (2)	+ -

King, Joshua (2)	+ -
Noss, Reed (2)	+ -
Worthy, Graham (2)	+ -
Alvaro, Francisco (1)	+ -
Beazley, Melanie (1)	+ -
Becker, Kathryn (1)	+ -
Bowman, Reed (1)	+ -
Brody, Samuel (1)	+ -
Carman, Karlie (1)	+ -
Davis, Brandon (1)	+ -
DeFreese, Duane (1)	+ -
Gilbrook, Michael (1)	+ -
Hinkle, C. Ross (1)	+ -
Ho, Janet (1)	+ -
Huber, Alicia (1)	+ -
Jacques, Peter (1)	+ -
Knox, Claire (1)	+ -
Korosy, Marianne (1)	+ -
Manteuffel, Tiffani (1)	+ -
Nolan, Elizabeth (1)	+ -
Quintana-Ascencio, Pedro (1)	+ -
Roth, James (1)	+ -
Savage, Anna (1)	+ -
Spellman, Ann (1)	+ -
Steinmuller, Havalend (1)	+ -

Search In

Sort Results By:

Narrow results by:

Topical Subject

Collection

Type of Resource

Language

Creator

Format

Owner