• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 46
  • Tagged with
  • 48
  • 48
  • 15
  • 14
  • 12
  • 12
  • 11
  • 10
  • 10
  • 9
  • 9
  • 9
  • 8
  • 8
  • 7
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Tenoroc State Recreation Area: a conceptual master plan study

Walker, Michelle 25 April 2009 (has links)
Reclamation has been required since the mid-1970s in Florida and many other states that mine land for phosphate. While often controversial, land reclamation has involved a variety of technologies and regulations which often reflect the complexity of economical ecological and political forces involved in the decision-making process. Most often reclamation procedures are dictated by economic constraints and less often by environmental concerns. In 1982, Borden, inc. donated a 6.040 7 acre abandoned phosphate mine, located within Polk County In Central Florida, to the State of Florida. In 1989, the site was designated by the State of Florida as a state recreation area known today as Tenoroc State Recreation Area. The Area currently provides facilities for hiking, picnicking, and horseback riding with a particular emphasis on quality fishing within its manmade lakes. lt is the intent of the state to integrate land reclamation functions with the recreational potentials of the site thus providing a public use area that will generate support revenue (Scruggs 1992). The primary difference between the reclamation activities at Tenoroc and those reclamation activities of today is the lack of a conceptual plan. For the most part reclamation at Tenoroc has been planned as stand-alone projects with minimal foresight of the needs for future recreational uses, drainage patterns, or continuing reclamation activities. At this point a conceptual master plan is needed to integrate hydrological and land reclamation functions with the recreational potentials of the site into a framework for future management and development of Tenoroc. The goals and objectives of this study are as follows 1 To produce a plan for the restoration of Tenoroc State Recreation Area which will address the reclamation of natural systems with an emphasis on wildlife habitat and landscape diversity. 2 To provide for safety and recreation of visitors and staff, and 3. To develop a plan for a unique, educational and recreational experience that will fulfill the objectives of the Florida Department of Natural Resources. The process of reclamation starts the moment man begins to explore the earth for its minerals. Since mining is here to stay reclamation should be looked upon as a continuation of succession of the landscape, rather than repair of a damaged landscape. By approaching reclamation holistically, as just another step in the mining process; through proper planning, management and program, the strife for achieving a balance between our quality of life and our sustainability become that much more of a reality. / Master of Landscape Architecture
42

Effects of freshwater discharges and habitat architecture on oyster reef community development and diversity

Unknown Date (has links)
Oyster reefs support diverse estuarine communities and food webs. Factors controlling oyster reef community development were studied on restored reefs in the St. Lucie Estuary. Freshwater discharges create stresses that cause oyster mortality, habitat loss and reduction in reef community diversity. Using structural equation modeling, it was demonstrated that salinity, turbidity, and chlorophyll-a gradients influence oysters and some reef invertebrate species, but did not support the predictions of the Intermediate Disturbance Hypothesis. In contrast, diversity and species richness were greatest at low stress sites. A field experiment showed that topographic relief and architectural complexity enhanced colonization and growth of reef-building species (e.g.oysters and mussels). The relief by complexity interaction had a higher order, synergistic effect on oyster abundance. When considered separately, increasing relief further enhanced dominant sessile taxa (cirripeds and ascideans) ; while, increasing complexity supported greater species richness and the abundance of cirripeds. / by Elizabeth A. Salewski. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
43

Development, evaluation, and application of spatio-temporal wading bird foraging models to guide everglades restoration

Unknown Date (has links)
In south Florida, the Greater Everglades ecosystem supports sixteen species of wading birds. Wading birds serve as important indicator species because they are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality. Models that establish habitat relationships from distribution patterns of wading birds can be used to predict changes in habitat quality that may result from restoration and climate change. I developed spatio-temporal species distribution models for the Great Egret, White Ibis, and Wood Stork over a decadal gradient of environmental conditions to identify factors that link habitat availability to habitat use (i.e., habitat selection), habitat use to species abundance, and species abundance (over multiple scales) to nesting effort and success. Hydrological variables (depth, recession rate, days since drydown, reversal, and hydroperiod) over multiple temporal scales and with existing links to wading bird responses were used as proxies for landscape processes that influence prey availability (i.e., resources). In temporal foraging conditions (TFC) models, species demonstrated conditional preferences for resources based on resource levels at differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of wetland inundation was concentrated in shallow depths. Similar responses were observed in spatial foraging conditions (SFC) models predicting spatial occurrence over time, accounting for spatial autocorrelation. The TFC index represents conditions within suitable depths that change daily and reflects patch quality, whereas the SFC index spatially represents suitability of all cells and reflects daily landscape patch abundance. I linked these indices to responses at the nest initiation and nest provisioning breeding phases from 1993-2013. The timing of increases and overall magnitude of resource pulses predicted by the TFC in March and April were strongly linked to breeding responses by all species. Great Egret nesting effort and success were higher with increases in conspecific attraction (i.e., clustering). Wood Stork nesting effort was closely related to timing of concurrently high levels of patch quality (regional scale) and abundance (400-m scale), indicating the importance of a multi-scaled approach. The models helped identify positive and negative changes to multi-annual resource pulses from hydrological restoration and climate change scenarios, respectively. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
44

Comparing salinity models in Whitewater Bay using remote sensing

Unknown Date (has links)
This study compared models that used remote sensing to assess salinity in Whitewater Bay. The quantitative techniques in this research allow for a less costly and quicker assessment of salinity values. Field observations and Landsat 5 TM imagery from 2003-2006 were separated into wet and dry seasons and temporally matched. Interpolation models of Inverse Distance Weighting and Kriging were compared to empirical regression models (Ordinary Least Squares and Geographically Weighted Regression - GWR) via their Root Mean Square Error. The results showed that salinity analysis is more accurate in the dry season compared with the wet season. Univariate and multivariate analysis of the Landsat bands revealed the best band combination for salinity analysis in this local area. GWR is the most conducive model for estimating salinity because field observations are not required for future predictions once the local formula is established with available satellite imagery. / by Donna Selch. / Thesis (M.A.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
45

Perceived risk versus actual risk to sea-level rise: a case study in Broward County, Florida

Unknown Date (has links)
Global climate change stressors downscale to specific local vulnerabilities, requiring customized adaptation strategies. Southeast Florida has a high likelihood of sealevel rise impact to due to the low-lying porous limestone geology. High risk is coupled with high exposure due to high-valued coastal properties, productive ecosystems, and dense populations. Coastal populations are particularly at risk due to erosion, inundation and storm surge, but interior populations are also susceptible to rising water tables and extended periods of inundation. All of these impacts are amplified by sea-level rise. Robust sea-level rise adaptation options require significant economic costs. If perceived risk does not adequately line up with actual risk, lack of funds and preparation will prevent implementation of the most effective strategies. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
46

Interpretation of seafloor topologies based on IKONOS satellite imagery of a shallow-marine carbonate platform: Florida Bay to the Florida Reef Tract

Unknown Date (has links)
A benthic environments classification system is devised from digital interpretations of multi-spectral IKONOS satellite imagery for 1,360 km2 of the carbonate platform and presented in a comprehensive digitized map. The classification scheme is designed as a 7th order hierarchical structure that integrates 5 Physiographic Realms, 24 Morphodynamic Zones, 11 Geoforms, 39 Landforms, 6 dominant surface sediment types, 9 dominant biological covers and 3 densities of biological covers for the description of benthic environments. Digital analysis of the high-resolution (4 m) IKONOS imagery employed ESRI's ArcMap to manually digitize 412 mapping units at a scale of 1:6,000 differentiated by spectral reflectance, color tones, and textures of seafloor topologies. The context of each morphodynamic zone is characterized by the content and areal distribution (in km2) of geomorphic forms and biological covers. Over 58% of the mapping area is occupied by sediment flats, and seagrasses are colonized in almost 80% of the topologies. / by Jacob Thomas Steinle. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
47

Abundance, Distribution, and Habitat Use of Sharks in Two Northeast Florida Estuaries

McCallister, Michael Philip 01 January 2012 (has links)
Sharks are considered top predators in many marine ecosystems, and can play an important role in structuring those communities. As a result, it is necessary to understand the factors that influence their abundance and distribution. This is particularly important as fishery managers develop fishery management plans for sharks that identify areas that serve as essential fish habitat (EFH). This includes nursery habitat where sharks are born and juveniles spend the early part of their life. However, our understanding of shark habitat use in the northeast Florida waters is limited. The goal of this thesis was to characterize the abundance and distribution of sharks in northeast Florida estuaries, and to examine the effect of abiotic and biotic factors affecting shark habitat use. A bottom longline survey conducted from 2009 – 2011 indicated that 11 shark species use the estuarine waters of northeast Florida during summer months. Atlantic sharpnose (Rhizoprionodon terraenovae), blacktip (Carcharhinus limbatus), bonnethead (Sphyrna tiburo), and sandbar sharks (Carcharhinus plumbeus) were the most abundant species and made up 87.1% of the total catch. Month, bottom water temperature, and depth were the most important factors determining the presence and abundance of these species. This study also examined the role of prey abundance in determining the abundance of Atlantic sharpnose sharks. The probability of catching an Atlantic sharpnose shark, and the abundance of Atlantic sharpnose sharks, were most influenced by site. Neither potential prey abundance nor preferred prey abundance were not significant factors effecting Atlantic sharpnose abundance. This may be a result of prey sampling not providing an accurate measure of the true availability of prey resources. Other factors, such as predation risk, may better explain habitat use patterns of Atlantic sharpnose sharks. Continued sampling will give a better understanding of the factors influencing shark habitat use in this area.
48

Factors Limiting Native Species Establishment On Former Agricultural Lands

Weiler-Lazarz, Annalisa M 01 January 2012 (has links)
Restoration of abandoned, nonnative species-dominated agricultural lands provides opportunities for conserving declining shrubland and grassland ecosystems. Land-use legacies, such as elevated soil fertility and pH from agricultural amendments, often persist for years and can favor nonnative species at the expense of native species. Understanding the factors that limit native species establishment on abandoned agricultural lands can provide important insights for restoration and conservation of native species on human-modified lands. I conducted two field experiments on abandoned agricultural lands: a former pasture on Martha’s Vineyard, MA and a former citrus grove at Merritt Island National Wildlife Refuge (MINWR) in Titusville, FL. In these experiments I tested how soil chemical properties affect native and nonnative species abundance and how different methods of removing nonnative, invasive species affect native and nonnative species abundance. In the first experiment, specifically I tested how restoration treatments affect competition between existing nonnative agricultural plant species and native plant species that are targets for sandplain grassland restoration on Martha’s Vineyard, MA. At MINWR, I examined how lowering soil fertility with carbon additions and lowering soil pH by applying sulfur affects nonnative species richness and cover (in two former citrus groves that were historically scrub/ scrubby flatwoods. Overall, I found that biotic factors, such as competition with nonnative species, play a stronger role in limiting native species establishment than soil chemical properties. Likewise, control of nonnative, invasive species is most effective with mechanical treatments to physically reduce cover, rather than altering soil chemical properties

Page generated in 0.0635 seconds