120 resultados para annual research reports


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In the fall of 2005, U.S. Fish and Wildlife Services (USFWS) contracted with Florida International University (FIU) to study the physical and biological drivers underlying the distribution of woody plant species in the marl prairie habitat of the Cape Sable Seaside Sparrow (CSSS). This report presents what we have learned about woody plant encroachment based on studies carried out during the period 2006-2008. The freshwater marl prairie habitat currently occupied by the Cape Sable seaside sparrow (CSSS; Ammodramus maritimus mirabilis) is a dynamic mosaic comprised of species-rich grassland communities and tree islands of various sizes, densities and compositions. Landscape heterogeneity and the scale of vegetative components across the marl prairie is primarily determined by hydrologic conditions, biological factors (e.g. dispersal and growth morphology), and disturbances such as fire. The woody component of the marl prairie landscape is subject to expansion through multiple positive feedback mechanisms, which may be initiated by recent land use change (e.g. drainage). Because sparrows are known to avoid areas where the woody component is too extensive, a better understanding of invasion dynamics is needed to ensure proper management.

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Hydrologic modifications have negatively impacted the Florida Everglades in numerous significant ways. The compartmentalization of the once continuously flowing system into the Water Conservation Areas (WCAs) caused disruption of the slow natural flow of water south from Lake Okeechobee through the Everglades to Florida Bay. The ponding of water in the WCAs, the linking of water flow to controlled water levels, and the management of water levels for anthropogenic vs. ecological well-being has caused a reduction in the spatial heterogeneity of the Everglades leading to greater uniformity in topography and vegetation. These effects are noticeable as the degradation in structure of the Everglades Ridge and Slough environment and associated Tree Islands. In aquatic systems water flow is of fundamental importance in shaping the structure and function of the ecosystem. The organized patterns of parallel orientation of ridges, sloughs, and tear-drop shaped tree islands along historic flow paths attest to the importance of water movement in structuring this system. Our main objective was to operate and manage the LILA facility to provide a broad potential as a research platform for an integrated group of multidisciplinary, multi-agency scientists collaborating on multifunctional studies aimed primarily at determining the effects of CERP water management scenarios on the ecology of tree islands and ridge and slough habitats. We support Everglades water management, CERP, and the Long-Term Plan by defining hydrologic regimes that sustain healthy tree islands and ridge and slough ecosystems. Information gained through this project will help to reduce the uncertainty of predicting the tree island and ridge and slough ecosystem response to changes in hydrologic conditions. Additionally, we have developed the LILA site as a visual example of Everglades restoration programs in action.

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This document summarizes the activities that were accomplished in FY 2009 on the research project “Cape Sable seaside sparrow habitat – Vegetation Monitoring”, a collaborative effort among the US Army Corps of Engineers, Florida International University, and the US Geological Survey. The major activities in 2009 included field work, data analysis and presentations. The results of 2009 field work were presented at the 4th International Congress of Fire Ecology and Management, Savannah, GA from November 30 to Dec 5, 2009 and at the Cape Sable seaside sparrow (CSSS) Fire Meeting, held at the Krome Center, Homestead, FL on December 8, 2009. Field sampling was conducted between March 23 and June 3, 2009, during which we resurveyed 234 sites: 191 Census sites, 3 sites on Transect B, 7 sites on Transect D, and 33 sites on Transect F. The number of sites sampled in 2009 was higher than in any previous year, primarily because a large number of sites burned in Mustang Corner fire and three other wild fires in 2008 were included in 2009 sampling. At all sites surveyed in 2009, we recorded structural and compositional vegetation parameters following the methods used in previous years (2003-2008) and tagged shrubs and trees (woody plants > 1 m) present in the 5 x 60 m plots. In addition, for the first time, we measured height of sawgrass (Cladium jamaicense) stubble in the compositional plots at the sites that were burned in 2008. Field data were entered by field crews, and were thoroughly checked by Jay Sah (Co-PI) to ensure that the data were complete, correct, and compliant with sampling methodologies. The data are stored under a project folder on a shared network drive maintained by the Southeast Environmental Research Center (SERC) at FIU. The shared network drive is backed up daily.

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The pine rocklands of South Florida are characterized by an herbaceous flora with many narrowly endemic taxa, a diverse shrub layer containing several palms and numerous tropical hardwoods, and an overstory of south Florida slash pine (Pinus elliottii var. densa). Fire has been considered as an important environmental factor for these ecosystems, since in the absence of fire these pine forests are replaced by dense hardwood communities, resulting in loss of the characteristic pineland herb flora. Hence, in the Florida Keys pine forests, prescribed fire has been used since the creation of the National Key Deer Refuge. However, such prescribed burns were conducted in the Refuge mainly for fuel reduction, without much consideration of ecological factors. The USGS and Florida International University conducted a research study for four years, from 1998 to 2001, the objective of which was to document the response of pine rockland vegetation to a range of fire management options and to provide Fish and Wildlife Service and other land managers with information useful in deciding when and where to burn to perpetuate these unique pine forests. This study is described in detail in Snyder et al. (2005).

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A comprehensive, broadly accepted vegetation classification is important for ecosystem management, particularly for planning and monitoring. South Florida vegetation classification systems that are currently in use were largely arrived at subjectively and intuitively with the involvement of experienced botanical observers and ecologists, but with little support in terms of quantitative field data. The need to develop a field data-driven classification of South Florida vegetation that builds on the ecological organization has been recognized by the National Park Service and vegetation practitioners in the region. The present work, funded by the National Park Service Inventory and Monitoring Program - South Florida/Caribbean Network (SFCN), covers the first stage of a larger project whose goal is to apply extant vegetation data to test, and revise as necessary, an existing, widely used classification (Rutchey et al. 2006). The objectives of the first phase of the project were (1) to identify useful existing datasets, (2) to collect these data and compile them into a geodatabase, (3) to conduct an initial classification analysis of marsh sites, and (4) to design a strategy for augmenting existing information from poorly represented landscapes in order to develop a more comprehensive south Florida classification.

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Fire, which affects community structure and composition at all trophic levels, is an integral component of the Everglades ecosystem (Wade et al. 1980; Lockwood et al. 2003). Without fire, the Everglades as we know it today would be a much different place. This is particularly true for the short-hydroperiod marl prairies that predominate on the eastern and western flanks of Shark River Slough, Everglades National Park (Figure 1). In general, fire in a tropical or sub-tropical grassland community favors the dominance of C4 grasses over C3 species (Roscoe et al. 2000; Briggs et al. 2005). Within this pyrogenic graminoid community also, periodic natural fires, together with suitable hydrologic regime, maintain and advance the dominance of C4 vs C3 graminoids (Sah et al. 2008), and suppress the encroachment of woody stems (Hanan et al. 2009; Hanan et al. unpublished manuscript) originating from the tree islands that, in places, dominate the landscape within this community. However, fires, under drought conditions and elevated fuel loads, can spread quickly throughout the landscape, oxidizing organic soils, both in the prairie and in the tree islands, and, in the process, lead to shifts in vegetation composition. This is particularly true when a fire immediately precedes a flood event (Herndon et al. 1991; Lodge 2005; Sah et al. 2010), or if so much soil is consumed during the fire that the hydrologic regime is permanently altered as a result of a decrease in elevation (Zaffke 1983).

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For the last two decades, the Cape Sable seaside sparrow (CSSS), a federally endangered species, has been a pivot point for water management operations in the Everglades, primarily because a decline in sparrow population in the early 1990s was attributed in part to managementinduced alterations in hydrologic regimes. With a goal of understanding the response of landscape-level processes to hydrological restoration and its interaction with fire, a study intended to monitor vegetation structure and composition throughout the marl prairie landscape has been conducted since 2003 with funding from U.S. Army Corps of Engineers (USACE). In the first three years (2003-2005), vegetation structure and composition was characterized in relation to the existing hydrologic regime and fire history. During 2006-2010, vegetation was resampled to assess vegetation change within the sparrow habitat. This document summarizes the vegetation change pattern observed between the two sampling periods in sub-population A, C, E and F, emphasizing the work accomplished in FY 2010.

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Within Big Cypress National Preserve (BICY), oak-dominated forests and woodlands as well as tropical and temperate hardwood hammocks are integral components of the landscape and are biodiversity hotpots for both flora and fauna. These broadleaved forest communities serve as refugia for many of the Preserve’s wildlife species during prolonged flooding and fires. However, both prolonged flooding and severe fires, which are important and necessary disturbance vectors within this landscape, can have deleterious effects on these forested communities. This is particularly true in the case of fires, which under extreme conditions associated with drought and elevated fuel loads, can burn through these forested communities consuming litter and understory vegetation and top killing most, if not all, of the trees present.

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Florida citrus represents approximately 70 percent of the industry production in the United States; therefore, any associated agricultural and industrial contamination is of concern and a focus of attention. The use of synthetic organic chemicals has become a farmer's necessity in order to supply consumers with high quality products, free of pest damage. However, industrial citrus wastes and chemical residual levels worry not only government agencies but also consumers since they indicate a serious habitat risk. This study assesses citrus industrial processes and the paths that chemical substances follow from the time the citrus seed is planted until consumers get a final product as either fresh fruit or processed product. The study is built on information from United States Environmental Protection Agency (US EPA) manuals, Dade County Environmental Resources Management (DERM) inspection records, United States Food and Drug Administration (US FDA) regulations, Florida standards, journal publications, and research reports. Pollution prevention (P2 or prevention-of-pollution) alternatives are identified; alternatives are proposed, evaluated, and included. Strategies are described and pollution prevention opportunities proposed to minimize citrus wastes generation, chemical residuals in products, their environmental impact and health risk aspects while maximizing product quality.

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Customer survey results for 2012-2013.

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Division of Research's annual report for fiscal year 2011.

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This conference was designed to offer a view to novice scholars of what scholarship is and provide insights on how to share knowledge with others.