In the Florida Everglades, remodeling of natural wetlands to promote agriculture and human settlement, have profoundly altered its hydrologic regime. As a result of anthropogenic changes, many restoration programs have been initiated to restore hydrologically controlled wetland ecosystems. One such restoration project that has been ongoing for the past 27 years is the Hole-in-the-Donut restoration program in Everglades National Park. The restoration program is unique in that it utilized an unorthodox technique to restore the landscape. The viability of the restoration technique was assessed by coupling long-term hydrologic and evapotranspiration data with water chemistry analyses. Key results indicated that the restoration method did not change groundwater levels within and down gradient of the restored sites. Evapotranspiration rates were significantly reduced as a function of restoration. Concentrations of ions and nutrients were significantly different in groundwater and surface water within the restored areas compared to outside the restored areas.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Jessica Canfield / Nature based tourism is a growing trend across the world today. Ecotourism is a specific nature based tourism type, defined by the International Ecotourism Society (TIES) as “Responsible travel to natural areas that conserves the environment and improves the well-being of local people.” The ‘ecolodge,’ is a term that refers to the site and structure where ecotourists stay and where ecotourism activities occur. The intention of an ecolodge is to find a balance between three factors: conservation, local communities, and interpretation for travelers and workers. Every ecolodge is unique in form and function to uphold sustainability best practices and to meet specific environmental and climatic needs of a region. As more and more tourists choose to travel to environmentally sensitive areas of the world, ecolodge use must increase in order to preserve environmental and cultural assets (Honey, 2008). In other countries, like Costa Rica and Kenya, many ecolodges have successfully balanced these three components creating an overall trend towards ecolodges and ecotourism operations, shifting away from traditional accommodation types. However, as the U.S. tourism market continues to grow, there is yet to be a notable ecolodge presence. Some ecotourism experts would argue that true ecotourism--equally finding balance between conservation, guest interpretation, and community support--will never be possible to create in the U.S. Many believe it is the ‘supporting local communities’ aspect of ecotourism which cannot be met. The treatment of indigenous people, as well as the structure of the nation’s economy in the U.S. is different compared to developing countries where ecolodge design has found success. Interestingly, certified sustainable site development is becoming prevalent in the U.S. Frameworks such as LEED and SITES are used to improve the rigor of sustainability design. Design guidelines for ecolodges share similar goals with LEED and SITES. But ecolodge design is not prevalent in the U.S. This may be due to the lack of an international ecolodge certification system. If the ecotourism industry can progress from ecolodge guidelines (which are largely unknown) to an international ecolodge certification, truly authentic ecolodges will become the standard (Mehta, 2007). To explore how ecolodges can be used in a U.S. National Park, this project focuses on the Flamingo District in the Everglades National Park, Florida. A projective design methodology is used. The data collection methods include precedent studies, interviews, on-site observation, and site analysis. Flamingo, located in the southernmost point of the Everglades was destroyed by hurricane Katrina in 2005. The National Park Service is seeking a business concessioner to 1) oversee the construction of new lodging area, and 2) operate all business activities—recreation rentals, marina operations, general store, and dining—in the district. The goal of this research project is to create an ecolodge design that can serve Flamingo’s needs and serve as a model for future ecolodge design in U.S. National Parks.

Coastal wetlands are globally important environments for biogeochemical cycling and are the object of intensive research related to the sequestration and exchange of carbon with oceans, continents, and the atmosphere. Wetland soil core records of organic carbon (OC) provide insights about future ecosystem responses to global change by identifying temporal variability in the context of environmental changes including sea level rise (SLR), anthropogenic reductions in freshwater flow, and landscape-scale disturbance events. My studies of Gulf of Mexico mangroves involved the use of radiometrically-dated soil cores to identify spatial and temporal accumulation trends of various constituents including organic and carbonate carbon, and macro-nutrients. My dissertation includes a literature review to assess the timescales of these processes and refine global perspectives on coastal wetland vulnerability. The contributions of organic and mineral matter to soil accretion (mm yr-1) was measured to (a) quantify how the supply of each may allow regional mangroves to keep pace with various SLR scenarios and, (b) assess wetland carbon sink capacity and stability in southwest Florida and the Yucatan Peninsula of Mexico. Mangroves in this region are largely devoid of terrigenous mineral sediments, and it has been hypothesized that storm surge-driven accretion of marine sediments could improve the capability of these locations to keep pace with SLR. Rates of accretion and organic matter accumulation were statistically similar across all four study regions, whereas mineral deposition rates ranged over two orders of magnitude. The volumetric contribution of mineral sediment to accretion is minimized by its high density. Organic matter, whose porous structures allow for highly variable densities, can contribute to a wide range of accretion rates and is a strong predictor of accretion. Future sustainability of these wetlands is more strongly dependent on the balance between soil organic matter production and preservation than the provision of storm-derived mineral sediments. To understand how OC sequestration will respond to SLR, the spatial and temporal variability of OC burial rates (g m-2 yr-1) were examined across ecosystem gradients in salinity, nutrient availability and mangrove productivity in the coastal Everglades. Results showed relatively little spatial variability and indicated that OC burial in the region is slow compared to rates in mangroves globally. However, significant regional differences in OC burial were observed in the context of primary productivity. Over a centennial timescale, mid-stream sites sequestered roughly 22% of annual net primary production and upstream sites preserved less than 10%. Least efficient sequestration occurs in the oligohaline ecotone, where increases in groundwater salinities and the potential for sulfate reduction have been recorded in the past decade. These findings indicate a significant slowdown in OC burial, and suggest that accelerating SLR will cause a substantial loss of historically sequestered carbon. The loss and potential out-welling of this carbon (including particulate and dissolved organic matter, dissolved CO2, and carbonate alkalinity) has important and complex implications for neighboring marine ecosystems including coral reefs and seagrass meadows. Several recent high-profile publications have used 5–15 years of soil accumulation rates to model wetland SLR-vulnerability outcomes over the next 50–100 years. To provide perspectives on these models, data that were generated from observations on multiple timescales (sub-annual to millennial) around the globe were used in a meta-analysis to determine the role of observational timescale on assessment outcomes. This analysis focused on rates of accretion and elevation change because of the wide availability of these data. Results demonstrate that rates of soil-body change exhibit a dependence on the length of time over which observations are made. Timescale hierarchies are driven by post-depositional diagenesis, ecosystem state changes, and regional effects primarily related to hydrology and sediment supply. Longer periods of observation utilizing multiple geochronological methods are needed to differentiate trend-changes from apparent changes that, in fact, may be due to regular periodicity. A conceptual model is presented that categorizes and explains timescale hierarchies in a soil’s geochemical history.

The distinctive karstic, freshwater wetlands of the northern Caribbean and Central American region support the prolific growth of calcite-rich periphyton mats. Aside from the Everglades, very little research has been conducted in these karstic wetlands, which are increasingly threatened by eutrophication. This study sought to (i) test the hypothesis that water depth and periphyton total phosphorus (TP) content are both drivers of periphyton biomass in karstic wetland habitats in Belize, Mexico and Jamaica, (ii) provide a taxonomic inventory of the periphytic diatom species in these wetlands and (iii) examine the relationship between periphyton mat TP concentration and diatom assemblage at Everglades and Caribbean locations. Periphyton biomass, nutrient and diatom assemblage data were generated from periphyton mat samples collected from shallow, marl-based wetlands in Belize, Mexico and Jamaica. These data were compared to a larger dataset collected from comparable sites within Everglades National Park. A diatom taxonomic inventory was conducted on the Caribbean samples and a combination of ordination and weighted-averaging modeling techniques were used to compare relationships between periphyton TP concentration, periphyton biomass and diatom assemblage composition among the locations. Within the Everglades, periphyton biomass showed a negative correlation with water depth and mat TP, while periphyton mat percent organic content was positively correlated with these two variables. These patterns were also exhibited within the Belize, Mexico and Jamaica locations, suggesting that water depth and periphyton TP content are both drivers of periphyton biomass in karstic wetland systems within the northern Caribbean region. A total of 146 diatom species representing 39 genera were recorded from the three Caribbean locations, including a distinct core group of species that may be endemic to this habitat type. Weighted averaging models were produced that effectively predicted mat TP concentration from diatom assemblages for both Everglades (R2=0.56) and Caribbean (R2=0.85) locations. There were, however, significant differences among Everglades and Caribbean locations with respect to species TP optima and indicator species. This suggests that although diatoms are effective indicators of water quality in these wetlands, differences in species response to water quality changes can reduce the predictive power of these indices when applied across systems.

The current study describes the composition and activity of the snake community of the Pa-hay-okee wetlands of Everglades National Park. The study was conducted from January 1987 to January 1989. Sixteen species were observed, with Thamnophis sauritus, Thamnophis sirtalis, Nerodia fasciata pictiventris, and Agkistrodon piscivorus representing 90.2% of the total sample. The seasonal distribution and activity of the snakes were closely related to fluctuations in the water table. Most activity occurred in the winter months as snakes migrated west following the drying water edge of Shark River Slough. Seventy percent of all snakes observed during this study were either injured or dead on the road. Over 50% of annual mortality occurred during migration. The impact that road mortality is having on the local snake community cannot be ignored. Management options are provided to minimize loss. A comparison is made to the snake community of the Long Pine Key Region of Everglades National Park.

Using aerial census techniques, I collected data on the population, reproduction and nesting habits of Bald Eagles in Florida Bay, Florida, for three consecutive breeding seasons (Oct - Mar, 1987 - 1990). For analysis I consolidated my data with those collected by Robertson et al. between 1959 and 1986 for a total of 26 seasons. The breeding population of Bald Eagles in Florida Bay has been stable since censuses began in 1959. However, numbers of subadult eagles in Florida Bay have declined sharply since the early 1960’s. Breeding density was apparently limited by territoriality. Nesting success was positively correlated with early commencement of nesting, number of active breeding territories and the history of individual breeding territories. Success was negatively correlated with the amount of rainfall during the breeding season. Most (87%) nesting failures occurred during the incubation stage. Nearly all nests were built in mangrove [Laguricularia racemosa, Avicenia germinans and Rhizophora mangle) trees and of these more than half were dead. The success of a nesting attempt was independent of changes in nests or nest sites.

Freshwater use is a major concern in the mass production of algae for biofuels. This project examined the use of canal water obtained from the Everglades Agricultural Area as a base medium for the mass production of algae. This water is not suitable for human consumption, and it is currently used for crop irrigation. A variety of canals were found to be suitable for water collection. Comparison of two methods for algal production showed no significant difference in biomass accumulation. It was discovered that synthetic reticulated foam can be used for algal biomass collection and harvest, and there is potential for its application in large-scale operations. Finally, it was determined that high alkaline conditions may help limit contaminants and competing organisms in growing algae cultures.

This project empirically determined the controls of groundwater discharge potential and surface water chemistry in southern Taylor Slough, Everglades National Park, Florida. Potential for groundwater discharge was calculated as the difference in equivalent freshwater stage between groundwater and surface water on a daily basis for two sites (upland and coastal) along southern Taylor Slough. Upstream water stages were shown to vary most similarly to the timing of groundwater discharge potential in coastal Taylor Slough. Surface water major ion chemistry did not apparently change as a result of groundwater discharge potential. Surface water major ion chemistry at the coastal site was controlled by surface water flow direction, while at the more inland site surface water major ion chemistry was controlled by upstream water levels and evapotranspiration. Surface water phosphorus concentrations at the coastal site were controlled by groundwater discharge and flows of local surface water.

Methanogenesis was studied in soils from two sawgrass wetlands of the Florida Everglades. Marl soils exhibited a significantly higher potential rate of methanogenesis than peat soils. In these wetlands, methanogenesis: (1) decreased rapidly with increasing soil depth, (2) increased at higher temperatures and lower Eh, (3) was stimulated by organic compounds (cellulose, glucose and acetate), and (4) remained unaffected by added ammonium. Lowering the Eh in the peat and marl soils with sulfide or sulfate stimulated methanogenesis. In January 1990, phosphate caused a significant increase in methanogenesis. The potential rates of methanogenesis decreased to undetectable levels when water levels dropped below the surface, and peaked one month after the start of the wet season. Methanogenesis appeared to be a relatively important process in carbon cycling in marl soils and these soils do not accumulate peat. Therefore, one possible explanation for peat accumulation in sawgrass wetlands may be their low rates of methanogenesis.

Freshwater ecosystems have been recognized as important components of the global carbon cycle, and the flux of organic matter (OM) from freshwater to marine environments can significantly affect estuarine and coastal productivity. The focus of this study was the assessment of carbon dynamics in two aquatic environments, namely the Florida Everglades and small prairie streams in Kansas, with the aim of characterizing the biogeochemistry of OM. In the Everglades, particulate OM (POM) is mostly found as a layer of flocculent material (“floc”). While floc is believed to be the main energy source driving trophic dynamics in this oligotrophic wetland, not much is known about its biogeochemistry. The objective of this study was to determine the origin/sources of OM in floc using biomarkers and pigment-based chemotaxonomy to assess specific biomass contributions to this material, on a spatial (freshwater marshes vs. mangrove fringe) and seasonal (wet vs. dry) scales. It was found that floc OM is derived from the local vegetation (mainly algal components and macrophyte litter) and its composition is controlled by seasonal drivers of hydrology and local biomass productivity. Photo-reactivity experiments showed that light exposure on floc resulted in photo-dissolution of POC with the generation of significant amounts of both dissolved OM (DOM) and nutrients (N & P), potentially influencing nutrient dynamics in this ecosystem. The bio-reactivity experiments determined as the amount and rate of CO2 evolution during incubation were found to vary on seasonal and spatial scales and were highly influenced by phosphorus limitation. Not much is known on OM dynamics in small headwater streams. The objective of this study was to determine carbon dynamics in sediments from intermittent prairie streams, characterized by different vegetation cover for their watershed (C4 grasses) vs. riparian zone (C3 plants). In this study sedimentary OM was characterized using a biomarker and compound specific carbon stable isotope approach. It was found that the biomarker composition of these sediments is dominated by higher plant inputs from the riparian zone, although inputs from adjacent prairie grasses were also apparent. Conflicting to some extent with the River Continuum Concept, sediments of the upper reaches contained more degraded OM, while the lower reaches were enriched in fresh material deriving from higher plants and plankton sources as a result of hydrological regimes and particle sorting.