315 resultados para the Everglades


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More than half of the original Everglades extent formed a patterned peat mosaic of elevated ridges, lower and more open sloughs, and tree islands aligned parallel to the dominant flow direction. This ecologically important landscape structure remained in a dynamic equilibrium for millennia prior to rapid degradation over the past century in response to human manipulation of the hydrologic system. Restoration of the patterned landscape structure is one of the primary objectives of the Everglades restoration effort. Recent research has revealed that three main drivers regulated feedbacks that initiated and maintained landscape structure: the spatial and temporal distribution of surface water depths, surface and subsurface flow, and phosphorus supply. Causes of recent degradation include but are not limited to perturbations to these historically important controls; shifts in mineral and sulfate supply may have also contributed to degradation. Restoring predrainage hydrologic conditions will likely preserve remaining landscape pattern structure, provided a sufficient supply of surface water with low nutrient and low total dissolved solids content exists to maintain a rainfall-driven water chemistry. However, because of hysteresis in landscape evolution trajectories, restoration of areas with a fully degraded landscape could require additional human intervention.

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Limestone-based (karstic) freshwater wetlands of the Everglades, Belize, Mexico, and Jamaica are distinctive in having a high biomass of CaCO3-rich periphyton mats. Diatoms are common components of these mats and show predictable responses to environmental variation, making them good candidates for assessing nutrient enrichment in these naturally ultraoligotrophic wetlands. However, aside from in the Everglades of southern Florida, very little research has been done to document the diatoms and their environmental preferences in karstic Caribbean wetlands, which are increasingly threatened by eutrophication. We identified diatoms in periphyton mats collected during wet and dry periods from the Everglades and similar freshwater karstic wetlands in Belize, Mexico, and Jamaica. We compared diatom assemblage composition and diversity among locations and periods, and the effect of the limiting nutrient, P, on species composition among locations. We used periphyton-mat total P (TP) as a metric of availability. A total of 176 diatom species in 45 genera were recorded from the 4 locations. Twenty-three of these species, including 9 that are considered indicative of Everglades diatom flora, were found in all 4 locations. In Everglades and Caribbean sites, we identified assemblages and indicator species associated with low and high periphyton-mat TP and calculated TP optima and tolerances for each indicator species. TP optima and tolerances of indicator species differed between the Everglades and the Caribbean, but weighted averaging models predicted periphyton-mat TP concentrations from diatom assemblages at Everglades (R2  =  0.56) and Caribbean (R2  =  0.85) locations. These results show that diatoms can be effective indicators of water quality in karstic wetlands of the Caribbean, but application of regionally generated transfer functions to distant sites provides less reliable estimates than locally developed functions.

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In this article, I offer an institutional history of the ecosystem concept, tracing shifts in its meaning and application as it has become the key organizing principle for the Everglades restoration program in Florida. Two institutional forms are analyzed here: (1) quasigovernmental organizations, a term I use to describe interagency science collaboratives and community stakeholder organizations, and (2) government bureaucracies, which are the administrative agencies tasked with Everglades restoration planning and implementation. In analyzing these knowledge trajectories, I both document the complex networks of relations that facilitate the ecosystem’s emergence as an object of knowledge and examine the bureaucratic claims to authority that circumscribe the ecosystem’s transformation into policy.

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The Florida Everglades is extremely oligotrophic and sensitive to small increases in phosphorus (P) concentrations. P enrichment is one of the dominant anthropogenic impacts on the ecosystem and is therefore a main focus of restoration efforts. In this review, we synthesize research on P biogeochemistry and the impact of P enrichment on ecosystem structure and function in the Florida Everglades. There are clear patterns of increased P concentrations and altered structure and processes along nutrient-enrichment gradients in the water, periphyton, soils, macrophytes, and consumers. Periphyton, an assemblage of algae, bacteria, and associated microfauna, is abundant and has a large influence on phosphorus cycling in the Everglades. The oligotrophic Everglades is P-starved, has lower P concentrations and higher nitrogen–phosphorus (N:P) ratios, and has oxidized to only slightly reduced soil profiles compared to other freshwater wetland ecosystems. Possible general causes and indications of P limitation in the Everglades and other wetlands include geology, hydrology, and dominance of oxidative microbial nutrient cycling. The Everglades may be unique with respect to P biogeochemistry because of the multiple causes of P limitation and the resulting high degree of limitation.

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Ecological monitoring is key to successful ecosystem restoration. Because all components within an ecosystem cannot be monitored, it is important to select indicators that are representative of the system, integrate system responses, clearly respond to system change, can be effectively and efficiently monitored, and are easily communicated. The roseate spoonbill is one ecological indicator species that meets these criteria within the Everglades ecosystem. Monitoring of roseate spoonbills in Florida Bay over the past 70 years has shown that aspects of this species’ reproduction respond to changes in hydrology and corresponding changes in prey abundance and availability. This indicator uses nesting location, nest numbers and nesting success in response to food abundance and availability. In turn, prey abundance is a function of hydrological conditions (especially water depth) and salinity. Metrics and targets for these performance measures were established based on previous findings. Values of each metric were translated into indices and identified as stoplight colors with green indicating that a given target has been met, yellow indicating that conditions are below the target, but within an acceptable range of it, and red indicating the measure is performing poorly in relation to the target.

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The hydrodynamics of tree islands during the growth of newly planted trees has been found to be influenced by both vegetation biomass and geologic conditions. From July 2007 through June 2009, groundwater and surface-water levels were monitored on eight recently planted tree islands at the Loxahatchee Impoundment Landscape Assessment (LILA) facility in Boynton Beach, Florida, USA. Over the 2-year study, stand development coincided with the development of a water-table depression in the center of each of the islands that was bounded by a hydraulic divide along the edges. The water-table depression was greater in islands composed of limestone as compared to those composed of peat. The findings of this study suggest that groundwater evapotranspiration by trees on tree islands creates complex hydrologic interactions between the shallow groundwater in tree islands and the surrounding surface water and groundwater bodies.

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Efforts to rehydrate and restore surface water flow in karst wetlands can have unintended consequences, as these highly conductive and heterogeneous aquifers create a close connection between groundwater and surface water. Recently, hydrologic restoration efforts in the karstic Taylor Slough portion of the Everglades has changed from point source delivery of canal water (direct restoration), to the use of a series of surface water recharge retention basins (diffuse restoration). To determine the influence of restoration on groundwater-surface water interactions in the Taylor Slough headwaters, a water budget was constructed for 1997–2011 using 70 hydro-meteorological stations. With diffuse restoration, groundwater seepage from the Everglades toward the urban boundary increased, while the downstream delivery of surface water to the main portion of the slough declined. The combined influence of diffuse restoration and climate led to increased intra-annual variability in the volume of groundwater and surface water in storage but supported a more seasonally hydrated wetland compared to the earlier direct tactics. The data further indicated that hydrologic engineering in karst wetland landscapes enhances groundwater-surface water interactions, even those designed for restoration purposes.

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Recent studies suggest that coastal ecosystems can bury significantly more C than tropical forests, indicating that continued coastal development and exposure to sea level rise and storms will have global biogeochemical consequences. The Florida Coastal Everglades Long Term Ecological Research (FCE LTER) site provides an excellent subtropical system for examining carbon (C) balance because of its exposure to historical changes in freshwater distribution and sea level rise and its history of significant long-term carbon-cycling studies. FCE LTER scientists used net ecosystem C balance and net ecosystem exchange data to estimate C budgets for riverine mangrove, freshwater marsh, and seagrass meadows, providing insights into the magnitude of C accumulation and lateral aquatic C transport. Rates of net C production in the riverine mangrove forest exceeded those reported for many tropical systems, including terrestrial forests, but there are considerable uncertainties around those estimates due to the high potential for gain and loss of C through aquatic fluxes. C production was approximately balanced between gain and loss in Everglades marshes; however, the contribution of periphyton increases uncertainty in these estimates. Moreover, while the approaches used for these initial estimates were informative, a resolved approach for addressing areas of uncertainty is critically needed for coastal wetland ecosystems. Once resolved, these C balance estimates, in conjunction with an understanding of drivers and key ecosystem feedbacks, can inform cross-system studies of ecosystem response to long-term changes in climate, hydrologic management, and other land use along coastlines.

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Marjory Stoneman Douglass delivering presentation, April 3, 1973. Marjory Stoneman Douglas was born on April 7, 1890. In South Florida she is best known for her environmental advocacy passionately fighting for the protection and preservation of the Florida Everglades. As a writer, her most influential book was the book The Everglades: River of Grass (1947), which redefined the popular conception of the Everglades as a treasured river instead of a worthless swamp. Moving to South Florida to pursuit a career in journalism, she began writing for the Miami Herald newspaper and then worked as freelance writer, producing over one hundred short stories that were published in popular magazines. Throughout her long life (lived until age 108), she received numerous awards, including the Presidential Medal of Freedom and was inducted into several halls of fame. She died on May 14, 1998. A statue of her invites visitors at Fairchild Tropical Botanic Garden in Miami, Florida to sit with her statue and contemplate the garden. Two South Florida public schools are named in her honor: Broward County Public Schools' Marjory Stoneman Douglas High School and Miami-Dade County Public Schools' Marjory Stoneman Douglas Elementary School.

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Charles Perry shaking hands with Marjory Stoneman Douglas in front of easel with map of Florida. Charles Edward Perry (Chuck), 1937-1999, was the founding president of Florida International University in Miami, Florida. He grew up in Logan County, West Virginia and received his bachelor's and masters's degrees from Bowling Green State University. He married Betty Laird in 1960. In 1969, at the age of 32, Perry was the youngest president of any university in the nation. The name of the university reflects Perry’s desire for a title that would not limit the scope of the institution and would support his vision of having close ties to Latin America. Perry and a founding corps opened FIU to 5,667 students in 1972 with only one large building housing six different schools. Perry left the office of President of FIU in 1976 when the student body had grown to 10,000 students and the university had six buildings, offered 134 different degrees and was fully accredited. Charles Perry died on August 30, 1999 at his home in Rockwall, Texas. He is buried on the FIU campus in front of the Graham Center entrance. Marjory Stoneman Douglas was born on April 7, 1890. In South Florida she is best known for her environmental advocacy passionately fighting for the protection and preservation of the Florida Everglades. As a writer, her most influential book was the book The Everglades: River of Grass (1947), which redefined the popular conception of the Everglades as a treasured river instead of a worthless swamp. Moving to South Florida to pursuit a career in journalism, she began writing for the Miami Herald newspaper and then worked as freelance writer, producing over one hundred short stories that were published in popular magazines. Throughout her long life (lived until age 108), she received numerous awards, including the Presidential Medal of Freedom and was inducted into several halls of fame. She died on May 14, 1998. A statue of her invites visitors at Fairchild Tropical Botanic Garden in Miami, Florida to sit with her statue and contemplate the garden. Two South Florida public schools are named in her honor: Broward County Public Schools' Marjory Stoneman Douglas High School and Miami-Dade County Public Schools' Marjory Stoneman Douglas Elementary School.

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Charles Perry and Marjory Stoneman Douglas in front of easel with map of Florida. Charles Edward Perry (Chuck), 1937-1999, was the founding president of Florida International University in Miami, Florida. He grew up in Logan County, West Virginia and received his bachelor's and masters's degrees from Bowling Green State University. He married Betty Laird in 1960. In 1969, at the age of 32, Perry was the youngest president of any university in the nation. The name of the university reflects Perry’s desire for a title that would not limit the scope of the institution and would support his vision of having close ties to Latin America. Perry and a founding corps opened FIU to 5,667 students in 1972 with only one large building housing six different schools. Perry left the office of President of FIU in 1976 when the student body had grown to 10,000 students and the university had six buildings, offered 134 different degrees and was fully accredited. Charles Perry died on August 30, 1999 at his home in Rockwall, Texas. He is buried on the FIU campus in front of the Graham Center entrance. Marjory Stoneman Douglas was born on April 7, 1890. In South Florida she is best known for her environmental advocacy passionately fighting for the protection and preservation of the Florida Everglades. As a writer, her most influential book was the book The Everglades: River of Grass (1947), which redefined the popular conception of the Everglades as a treasured river instead of a worthless swamp. Moving to South Florida to pursuit a career in journalism, she began writing for the Miami Herald newspaper and then worked as freelance writer, producing over one hundred short stories that were published in popular magazines. Throughout her long life (lived until age 108), she received numerous awards, including the Presidential Medal of Freedom and was inducted into several halls of fame. She died on May 14, 1998. A statue of her invites visitors at Fairchild Tropical Botanic Garden in Miami, Florida to sit with her statue and contemplate the garden. Two South Florida public schools are named in her honor: Broward County Public Schools' Marjory Stoneman Douglas High School and Miami-Dade County Public Schools' Marjory Stoneman Douglas Elementary School.

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The Everglades is a sub-tropical coastal wetland characterized among others by its hydrological features and deposits of peat. Formation and preservation of organic matter in soils and sediments in this wetland ecosystem is critical for its sustainability and hydrological processes are important divers in the origin, transport and fate of organic matter. With this in mind, organic matter dynamics in the greater Florida Everglades was studied though various organic geochemistry techniques, especially biomarkers, bulk and compound specific δ13C and δD isotope analysis. The main objectives were focused on how different hydrological regimes in this ecosystem control organic matter dynamics, such as the mobilization of particulate organic matter (POM) in freshwater marshes and estuaries, and how organic geochemistry techniques can be applied to reconstruct Everglades paleo-hydrology. For this purpose organic matter in typical vegetation, floc, surface soils, soil cores, and estuarine suspended particulates were characterized in samples selected along hydrological gradients in the Water Conservation Area 3, Shark River Slough and Taylor Slough. ^ This research focused on three general themes: (1) Assessment of the environmental dynamics and source-specific particulate organic carbon export in a mangrove-dominated estuary. (2) Assessment of the origin, transport and fate of organic matter in freshwater marsh. (3) Assessment of historical changes in hydrological conditions in the Everglades (paleo-hydrology) though biomarkes and compound specific isotope analyses. This study reports the first estimate of particulate organic carbon loss from mangrove ecosystems in the Everglades, provides evidence for particulate organic matter transport with regards to the formation of ridge and slough landscapes in the Everglades, and demonstrates the applicability of the combined biomarker and compound-specific stable isotope approach as a means to generate paleohydrological data in wetlands. The data suggests that: (1) Carbon loss from mangrove estuaries is roughly split 50/50 between dissolved and particulate carbon; (2) hydrological remobilization of particulate organic matter from slough to ridge environments may play an important role in the maintenance of the Everglades freshwater landscape; and (3) Historical changes in hydrology have resulted in significant vegetation shifts from historical slough type vegetation to present ridge type vegetation. ^

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This poster presentation from the May 2015 Florida Library Association Conference, along with the Everglades Explorer discovery portal at http://ee.fiu.edu, demonstrates how traditional bibliographic and curatorial principles can be applied to: 1) selection, cross-walking and aggregation of metadata linking end-users to wide-spread digital resources from multiple silos; 2) harvesting of select PDFs, HTML and media for web archiving and access; 3) selection of CMS domains, sub-domains and folders for targeted searching using an API. Choosing content for this discovery portal is comparable to past scholarly practice of creating and publishing subject bibliographies, except metadata and data are housed in relational databases. This new and yet traditional capacity coincides with: Growth of bibliographic utilities (MarcEdit); Evolution of open-source discovery systems (eXtensible Catalog); Development of target-capable web crawling and archiving systems (Archive-it); and specialized search APIs (Google). At the same time, historical and technical changes – specifically the increasing fluidity and re-purposing of syndicated metadata – make this possible. It equally stems from the expansion of freely accessible digitized legacy and born-digital resources. Innovation principles helped frame the process by which the thematic Everglades discovery portal was created at Florida International University. The path -- to providing for more effective searching and co-location of digital scientific, educational and historical material related to the Everglades -- is contextualized through five concepts found within Dyer and Christensen’s “The Innovator’s DNA: Mastering the five skills of disruptive innovators (2011). The project also aligns with Ranganathan’s Laws of Library Science, especially the 4th Law -- to "save the time of the user.”