A numerical model has been developed to study the temporal and spatial variations of Phosphorus mass and fluxes around the tree islands of Shark River Slough in the Everglades. The developed model is based on a conceptualization of physical, chemical and biological processes that consider advective and diffusive transport of dissolved Phosphorus, adsorption on to soil, input from rainfall and external sources, and Phosphorus cycling in biomass. The biomass related processes are Phosphorus uptake, release as litter, transport as suspended litter and release from the decomposition of the deposited litter. The water flow and transport of dissolved Phosphorus in the numerical model are implemented originally in the simulator MODHMS. However, the transport equations for dissolved Phosphorus were also coded separately, as well as the balance equation for suspended litter particles and deposited litter. The parameterization of the model was conducted by using the data collected by Ross et al. [2004] in three tree islands of Shark River Slough, as well as other parameters reported among the literature. The model was calibrated in three phases. Initially, Manning coefficients were adjusted from surface water velocity data collected by Bazante et al. [2004]. Then the calibration of several groundwater flow parameters was performed from water table data collected at wells by Ross et al. [2004]. In the third phase, the Phosphorus input rate from external sources and the initial concentration of Phosphorus were calibrated by assuming that the average surveyed Phosphorus concentration in soil pore water remains approximately constant over a 10 year period. The quantitative assessment of the spatial distribution and temporal variations of Phosphorus mass and fluxes around tree islands obtained from the developed model corroborate the negative effect of the rainfall events on Phosphorus accumulation in the head of the tree island. However, the possible positive effect of the ET driven water flows on Phosphorous accumulation was found not as relevant as hypothesed by other authors in the literature. According to the model results, most of the Phosphorus transport in the tree islands occurs as suspended particles in surface water, even though the transport of dissolved Phosphorus in pore water cannot be neglected around the head of the island. The model results also suggest that an input of Phosphorus from external sources (e.g., animal activity such as bird guano and other sources) is needed to preserve the average Phosphorus levels in the head and in the whole tree island. Finally, Phosphorus accumulation and losses in certain areas of the tree island suggest changes in vegetation that need to be investigated in future work. The developed model can be used as a predicting tool to gain insight into the potential effects of restoration scenarios in tree islands environments. The model could be run for hypothetical future conditions and contribute to provide quantitative information for conservation and restoration efforts in the Everglades and similar wetlands.

Thesis--University of Chicago. / Bibliography: p. 123-127.

Concentrations of 18 metals, including toxic metals (As, Cd, Cr, Ni and Pb) and essential metals (Al, Ba, Be, Co, Cu, Fe, Li, Mg, Mn, K, Sr, V and Zn) in various compartments (sediment, floc, and periphyton) were measured in the Florida Everglades to (i) establish the spatial distribution pattern of the metals in the Everglades and (ii) quantify the major sources of the 18 metals present in the Everglades. The highest mean concentrations of all metals analyzed in the Everglades were detected in soil, followed by floc and periphyton. Most metals exhibited random spatial distribution patterns. Risk assessment using Sediment Quality Guidelines (SQGs) concluded that all toxic metals (Cd, Cr, Pb, Ni, Cu, Zn and As) exhibited average concentrations that were well below FL guidelines as well as other domestic and international guidelines. On the basis of the current study, the Everglades can be considered a pristine environment.

Fire plays a key role in the ecology of the Everglades and is a ubiquitous tool for managing the structure, function, and ecosystem services of the Greater Everglades watershed. Decades of hydrologic modifications have led to the alteration of plant community composition and fire regime in much of the Everglades. To create a better understanding of post-fire recovery in sawgrass (Cladium jamaicense) communities, sawgrass marshes in the northern Everglades were studied along a chronosequence of time since fire and along a nutrient gradient. Areas closer to a water nutrient source and with fewer mean days dry contained greater total and dead aboveground graminoid biomass whereas live graminoid biomass was greater in areas with less time since fire and with fewer days dry. Post-fire characteristics of sawgrass marshes can provide insight on the effectiveness of fire management practices in the maintenance and restoration of quality habitat in the northern Everglades. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Thesis (Ph.D)--City Planning, Georgia Institute of Technology, 2010. / Committee Chair: Elliott, Michael; Committee Member: Carroll, C. Ronald; Committee Member: Contant, Cheryl; Committee Member: Norton, Bryan; Committee Member: Stiftel, Bruce. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Little Blue Herons, Snowy Egrets, and Tricolored Herons that nest in the Everglades have declined sharply over the past decade, due in part to food resource limitations. Here, I examined the diet of small herons to determine how prey characteristics affected the fitness of small herons in the highly modified Florida Everglades. Analysis of these diet differences showed birds nesting in 2017, a hydrologically dryer-than average year, and a more taxonomically varied diet were associated with nest success and improved body condition of nestlings. Over half (51%) of the fish biomass Little Blue Herons consumed were non-native species, compared to 14% and 19% non-native fish biomass consumed by Snowy Egrets and Tricolored Herons, respectively. Surprisingly, <7% of fish biomass available in the Everglades were comprised of non-native fish species, suggesting that small herons, and Little Blue Herons in particular, may be using alternative foraging habitats, to supplement their dietary needs. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Landscape characteristics, disturbances, and temporal variability influence predator-prey relationships, but are often overlooked in experimental studies. In the Everglades, seasonal disturbances force the spatial overlap of predators and prey, potentially increasing predation risk for prey. This study examined seasonal and diel patterns of fish use of canals and assessed predation risk for small fishes using an encounter rate model. I deployed an imaging sonar in Everglades canals to quantify density and swimming speeds of fishes, and detect anti-predator behaviors by small fishes. Generally, seasonal declines of marsh water-levels increased the density of large fishes in canals. Densities of small and large fishes were positively correlated and, as small-fish density increased, schooling frequency also increased. At night, schools disbanded and small fishes were observed congregating along the canal edge. The encounter rate model predicted highest predator-prey encounters during the day, but access to cover may reduce predation risk for small fishes.

The purpose of this research was to investigate the effects of wetland restoration on the water balance, flushing time, and water chemistry of southern Taylor Slough, a major water way in Everglades National Park. Water balance and flushing time equations were calculated on a monthly time step from 2001 – 2011. Water chemistry of major ions and nutrients were analyzed and correlated with water flushing times. Results showed that evapotranspiration followed by water volume had the greatest influence on flushing time. The flushing times varied between 3 and 78 days, with longer times observed between October and December, and the shorter times between March and May. Ion concentrations at the coastal areas decreased with increased flushing times. Increased surface water inflow that resulted from restoration projects and water management changes were productive in the rainy season and should result in increased flushing times and decreased ion concentrations in Taylor Slough.

This dissertation examined the impacts of multiple collaborative planning and implementation processes on ecosystem management of the Everglades wetlands of South Florida. In particular, the research focused on collaboration's role in (1) reducing phosphorus pollution in runoff from the Everglades Agricultural Area in the historic northern Everglades and (2) improving the water flow regime in Shark Slough of the southern Everglades. Restoration of the greater Everglades watershed is the largest such initiative in the world, and it may also be the most collaborative, with scores of these processes used at various scales since the mid-1960s. Ecosystem management is the most advanced approach to environmental governance, and its three tenets of integrative, adaptive, and ecologically protective governance provide a framework for evaluating environmental planning processes. Proponents of collaborative processes believe they are exceptionally suited to promoting the tenets of ecosystem management. Critics of collaboration, however, are concerned with the potential for cooptation of environmental interests, among other issues. Using qualitative case study methodology, the research found that collaborative processes improved ecosystem management, but not to the degree expected by collaboration proponents. Collaborative processes were integrative of values, information, activities, and political support across the ecosystem, yet integration had biases and limits as a result of groups' strategic behaviors and processes' emphasis on reaching agreement rather than fully exploring the issues. Cooptation of environmental interests was not a significant problem. Collaborative processes promoted adaptation and social learning in specific cases, but at a macro level helped to maintain the status quo of the dominant water management agencies and technocratic paradigms. Process outcomes were protective of ecological health in that they made steady, incremental progress towards ecological restoration. Progress had significant setbacks however, because collaboratively developed policies were subject to capture by economic interests. Despite the collaborative improvements in ecosystem management, ecological health remains a distant and uncertain prospect for the Everglades.

Draining the Everglades has been the central issue of southern Florida ever since the state was apnexed by the U.S. in .1845. Not until the twentieth century did water resource managers realize the detrimental repercussions of draining the Everglades. Now, south Florida finds itself in a state of crisis. In the aquifers and Lake Okeechobee water levels have dropped. Nutrient pollution has caused cattails to overrun the saw grass, from which the Everglades get there name. Continued development has placed more strain on the Everglades, and human water uses have often.been put under restraints due to lack of water. In order to understand the political and social priorities that guided the various water management agencies in the Everglades to this state of crisis, this research will review key events throughout the history of the Everglades, specifically analyzing what led to these events and how management reacted to them. This research will then analyze the priorities demonstrated through the various stages of water management in order to determine the presence of underlying social attitudes. Finally, this research will analyze the social attitudes as they pertain to water management in order to determine the presence of governing attitudes and paradigms, as well as implications of current attitudes on the future of the Everglades.