29 resultados para RESTORATION GENETICS
em Digital Commons at Florida International University
Resumo:
This dissertation examines the sociological process of conflict resolution and consensus building in South Florida Everglades Ecosystem Restoration through what I define as a Network Management Coordinative Interstitial Group (NetMIG). The process of conflict resolution can be summarized as the participation of interested and affected parties (stakeholders) in a forum of negotiation. I study the case of the Governor's Commission for a Sustainable South Florida (GCSSF) that was established to reduce social conflict. Such conflict originated from environmental disputes about the Everglades and was manifested in the form of gridlock among regulatory (government) agencies, Indian tribes, as well as agricultural, environmental conservationist and urban development interests. The purpose of the participatory forum is to reduce conflicts of interest and to achieve consensus, with the ultimate goal of restoration of the original Everglades ecosystem, while cultivating the economic and cultural bases of the communities in the area. Further, the forum aim to formulate consensus through envisioning a common sustainable community by providing means to achieve a balance between human and natural systems. ^ Data were gathered using participant observation and document analysis techniques to conduct a theoretically based analysis of the role of the Network Management Coordinative Interstitial Group (NetMIG). I use conflict resolution theory, environmental conflict theory, stakeholder analysis, systems theory, differentiation and social change theory, and strategic management and planning theory. ^ The purpose of this study is to substantiate the role of the Governor's Commission for a Sustainable South Florida (GCSSF) as a consortium of organizations in an effort to resolve conflict rather than an ethnographic study of this organization. Environmental restoration of the Everglades is a vehicle for recognizing the significance of a Network Management Coordinative Interstitial Group (NetMIG), namely the Governor's Commission for a Sustainable South Florida (GCSSF), as a structural mechanism for stakeholder participation in the process of social conflict resolution through the creation of new cultural paradigms for a sustainable community. ^
Resumo:
Melaleuca quinquenervia (Cav.) Blake (Myrtaceae) was imported into Florida from Australia over a century ago as a landscape plant. A favorable climate and periodic wildfires helped M. quinquenervia thrive; it now occupies about 200,000 hectares in southern Florida. A biological control (i.e., biocontrol) program against M. quinquenervia has been initiated, but not all biocontrol releases are successful. Some scientists have argued that poor biocontrol agent success may relate to genetic differences among populations of invasive weeds. I tested this premise by determining (1) the number and origins of M. quinquenervia introductions into Florida, (2) whether multiple introduction events resulted in the partitioning of Florida's M. quinquenervia populations into discrete biotypes, and (3) whether Oxyops vitiosa, an Australia snout beetle imported to control this weed, might discriminate among putative M. quinquenervia biotypes. Careful scrutiny of early horticultural catalogs and USDA plant introduction records suggested at least six distinct introduction events. Allozyme analyses indicated that the pattern of these introductions, and the subsequent redistribution of progeny, has resulted in geographic structuring of the populations in southern Florida. For example, trees on Florida's Gulf Coast had a greater effective number of alleles and exhibited greater heterozygosity than trees on the Atlantic Coast. Essential oil yields from M. quinquenervia leaves followed a similar trend; Gulf Coast trees yielded nearly twice as much oil as Atlantic Coast trees when both were grown in a common garden. These differences were partially explained by the predominance of a chemical phenotype (chemotype) very rich in the sesquiterpene (E)-nerolidol in M. quinquenervia trees from the Gulf Coast, but rich in a mixture of the monoterpene 1,8-cineole and the sesquiterpene viridiflorol in trees from the Atlantic Coast. Performance of O. vitiosa differed dramatically in laboratory studies depending on the chemotype of the foliage they were fed. Larval survivorship was four-fold greater on the (E)-nerolidol chemotype. Growth was also greater, with adult O. vitiosa gaining nearly 50% more biomass on the (E)-nerolidol plants than on the second chemotype. The results of this study thus confirmed the premise that plant genotype can affect the population dynamics of insects released as weed biocontrols. ^
Resumo:
The investigations of human mitochondrial DNA (mtDNA) have considerably contributed to human evolution and migration. The Middle East is considered to be an essential geographic area for human migrations out of Africa since it is located at the crossroads of Africa, and the rest of the world. United Arab Emirates (UAE) population inhabits the eastern part of Arabian Peninsula and was investigated in this study. Published data of 18 populations were included in the statistical analysis. The diversity indices showed (1) high genetic distance among African populations and (2) high genetic distance between African populations and non-African populations. Asian populations clustered together in the NJ tree between the African and European populations. MtDNA haplotypes database of the UAE population was generated. By incorporating UAE mtDNA dataset into the existing worldwide mtDNA database, UAE Forensic Laboratories will be able to analyze future mtDNA evidence in a more significant and consistent manner. ^
Resumo:
Speciation can be understood as a continuum occurring at different levels, from population to species. The recent molecular revolution in population genetics has opened a pathway towards understanding species evolution. At the same time, speciation patterns can be better explained by incorporating a geographic context, through the use of geographic information systems (GIS). Phaedranassa (Amaryllidaceae) is a genus restricted to one of the world’s most biodiverse hotspots, the Northern Andes. I studied seven Phaedranassa species from Ecuador. Six of these species are endemic to the country. The topographic complexity of the Andes, which creates local microhabitats ranging from moist slopes to dry valleys, might explain the patterns of Phaedranassa species differentiation. With a Bayesian individual assignment approach, I assessed the genetic structure of the genus throughout Ecuador using twelve microsatellite loci. I also used bioclimatic variables and species geographic coordinates under a Maximum Entropy algorithm to generate distribution models of the species. My results show that Phaedranassa species are genetically well-differentiated. Furthermore, with the exception of two species, all Phaedranassa showed non-overlapping distributions. Phaedranassa viridiflora and P. glauciflora were the only species in which the model predicted a broad species distribution, but genetic evidence indicates that these findings are likely an artifact of species delimitation issues. Both genetic differentiation and nonoverlapping geographic distribution suggest that allopatric divergence could be the general model of genetic differentiation. Evidence of sympatric speciation was found in two geographically and genetically distinct groups of P. viridiflora. Additionally, I report the first register of natural hybridization for the genus. The findings of this research show that the genetic differentiation of species in an intricate landscape as the Andes does not necessarily show a unique trend. Although allopatric speciation is the most common form of speciation, I found evidence of sympatric speciation and hybridization. These results show that the processes of speciation in the Andes have followed several pathways. The mixture of these processes contributes to the high biodiversity of the region.
Resumo:
Periphyton communities dominate primary production in much of the Florida Everglades wetland and therefore contribute to soil production, ecosystem metabolism and secondary production as well as the composition of dependent communities. Decades of research in the Everglades have supported research findings from other wetland types that cumulatively show that periphyton communities respond very rapidly to alterations in the two dominant drivers of wetland structure and function—hydrology and water quality. Hydrology controls periphyton productivity and composition by regulating moisture availability, substrate types available for colonization and supply of nutrients. Nutrients, particularly the limiting nutrient in this system, phosphorus (P), control levels of production and community composition. Because periphyton communities are well-established to be related to hydrology and water quality, an indicator was developed based on three periphyton attributes: abundance, quality (i.e., nutrient content) and community composition. This assessment tool offers a qualitative assessment of ecosystem response to potential changes in management activities at a time scale appropriate for active management. An example is provided of how the indicator can be used to assess the current water quality and hydrological conditions from high-density spatial surveys. Detected patterns of deterioration align with expectations derived from model predictions and known sources of nutrients and unnatural hydrologic regimes. If employed adaptively in ecosystem management, this tool can be used to both detect and react to change before the system has been irreparably altered.
Resumo:
The pink shrimp, Farfantepenaeus duorarum, familiar to most Floridians as either food or bait shrimp, is ubiquitous in South Florida coastal and offshore waters and is proposed as an indicator for assessing restoration of South Florida's southern estuaries: Florida Bay, Biscayne Bay, and the mangrove estuaries of the lower southwest coast. Relationships between pink shrimp and salinity have been determined in both field and laboratory studies. Salinity is directly relevant to restoration because the salinity regimes of South Florida estuaries, critical nursery habitat for the pink shrimp, will be altered by changes in the quantity, timing, and distribution of freshwater inflow planned as part of the Comprehensive Everglades Restoration Project (CERP). Here we suggest performance measures based on pink shrimp density (number per square meter) in the estuaries and propose a restoration assessment and scoring scheme using these performance measures that can readily be communicated to managers, policy makers, and the interested public. The pink shrimp is an appropriate restoration indicator because of its ecological as well as its economic importance and also because scientific interest in pink shrimp in South Florida has produced a wealth of information about the species and relatively long time series of data on both juveniles in estuarine nursery habitats and adults on the fishing grounds. We suggest research needs for improving the pink shrimp performance measure.
Resumo:
We have developed a comprehensive ecological indicator for invasive exotic plants, a human-influenced component of the Everglades that could threaten the success of the restoration initiative. Following development of a conceptual ecological model for invasive exotic species, presented as a companion paper in this special issue, we developed criteria to evaluate existing invasive exotic monitoring programs for use in developing invasive exotic performance measures. We then used data from the selected monitoring programs to define specific performance measures, using species presence and abundance as the basis of the indicator for invasive exotic plants. We then developed a series of questions used to evaluate region and/or individual species status with respect to invasion. Finally, we used an expert panel who had answered the questions for invasive exotic plants in the Everglades Lake Okeechobee model to develop a stoplight restoration report card to communicate invasive exotic plant status. The report card system provides a way to effectively evaluate and present indicator data to managers, policy makers, and the public using a uniform format among indicators. Collectively, the model, monitoring assessment, performance measures, and report card enable us to evaluate how invasive plants are impacting the restoration program and how effectively that impact is being managed. Applied through time, our approach also allows us to follow the progress of management actions to control the spread and reduce the impacts of invasive species and can be easily applied and adapted to other large-scale ecosystem projects.
Resumo:
We developed a conceptual ecological model (CEM) for invasive species to help understand the role invasive exotics have in ecosystem ecology and their impacts on restoration activities. Our model, which can be applied to any invasive species, grew from the eco-regional conceptual models developed for Everglades restoration. These models identify ecological drivers, stressors, effects and attributes; we integrated the unique aspects of exotic species invasions and effects into this conceptual hierarchy. We used the model to help identify important aspects of invasion in the development of an invasive exotic plant ecological indicator, which is described a companion paper in this special issue journal. A key aspect of the CEM is that it is a general ecological model that can be tailored to specific cases and species, as the details of any invasion are unique to that invasive species. Our model encompasses the temporal and spatial changes that characterize invasion, identifying the general conditions that allow a species to become invasive in a de novo environment; it then enumerates the possible effects exotic species may have collectively and individually at varying scales and for different ecosystem properties, once a species becomes invasive. The model provides suites of characteristics and processes, as well as hypothesized causal relationships to consider when thinking about the effects or potential effects of an invasive exotic and how restoration efforts will affect these characteristics and processes. In order to illustrate how to use the model as a blueprint for applying a similar approach to other invasive species and ecosystems, we give two examples of using this conceptual model to evaluate the status of two south Florida invasive exotic plant species (melaleuca and Old World climbing fern) and consider potential impacts of these invasive species on restoration.
Resumo:
Developing scientifically credible tools for measuring the success of ecological restoration projects is a difficult and a non-trivial task. Yet, reliable measures of the general health and ecological integrity of ecosystems are critical for assessing the success of restoration programs. The South Florida Ecosystem Restoration Task Force (Task Force), which helps coordinate a multi-billion dollar multi-organizational effort between federal, state, local and tribal governments to restore the Florida Everglades, is using a small set of system-wide ecological indicators to assess the restoration efforts. A team of scientists and managers identified eleven ecological indicators from a field of several hundred through a selection process using 12 criteria to determine their applicability as part of a system-wide suite. The 12 criteria are: (1) is the indicator relevant to the ecosystem? (2) Does it respond to variability at a scale that makes it applicable to the entire system? (3) Is the indicator feasible to implement and is it measureable? (4) Is the indicator sensitive to system drivers and is it predictable? (5) Is the indicator interpretable in a common language? (6) Are there situations where an optimistic trend with regard to an indicator might suggest a pessimistic restoration trend? (7) Are there situations where a pessimistic trend with regard to an indicator may be unrelated to restoration activities? (8) Is the indicator scientifically defensible? (9) Can clear, measureable targets be established for the indicator to allow for assessments of success? (10) Does the indicator have specificity to be able to result in corrective action? (11) What level of ecosystem process or structure does the indicator address? (12) Does the indicator provide early warning signs of ecological change? In addition, a two page stoplight report card was developed to assist in communicating the complex science inherent in ecological indicators in a common language for resource managers, policy makers and the public. The report card employs a universally understood stoplight symbol that uses green to indicate that targets are being met, yellow to indicate that targets have not been met and corrective action may be needed and red to represent that targets are far from being met and corrective action is required. This paper presents the scientific process and the results of the development and selection of the criteria, the indicators and the stoplight report card format and content. The detailed process and results for the individual indicators are presented in companion papers in this special issue of Ecological Indicators.
Resumo:
In south Florida, tropical hardwood forests (hammocks) occur in Everglades tree islands and as more extensive forests in coastal settings in the nearby Florida Keys. Keys hammocks have been less disturbed by humans, and many qualify as “old-growth,” while Everglades hammocks have received much heavier use. With improvement of tree island condition an important element in Everglades restoration efforts, we examined stand structure in 23 Keys hammocks and 69 Everglades tree islands. Based on Stand Density Index and tree diameter distributions, many Everglades hammocks were characterized by low stocking and under-representation in the smaller size classes. In contrast, most Keys forests had the dense canopies and open understories usually associated with old-growth hardwood hammocks. Subject to the same caveats that apply to off-site references elsewhere, structural information from mature Keys hammocks can be helpful in planning and implementing forest restoration in Everglades tree islands. In many of these islands, such restoration might involve supplementing tree stocking by planting native trees to produce more complete site utilization and a more open understory.
Resumo:
Historic changes in water-use management in the Florida Everglades have caused the quantity of freshwater inflow to Florida Bay to decline by approximately 60% while altering its timing and spatial distribution. Two consequences have been (1) increased salinity throughout the bay, including occurrences of hypersalinity, coupled with a decrease in salinity variability, and (2) change in benthic habitat structure. Restoration goals have been proposed to return the salinity climates (salinity and its variability) of Florida Bay to more estuarine conditions through changes in upstream water management, thereby returning seagrass species cover to a more historic state. To assess the potential for meeting those goals, we used two modeling approaches and long-term monitoring data. First, we applied the hydrological mass balance model FATHOM to predict salinity climate changes in sub-basins throughout the bay in response to a broad range of freshwater inflow from the Everglades. Second, because seagrass species exhibit different sensitivities to salinity climates, we used the FATHOM-modeled salinity climates as input to a statistical discriminant function model that associates eight seagrass community types with water quality variables including salinity, salinity variability, total organic carbon, total phosphorus, nitrate, and ammonium, as well as sediment depth and light reaching the benthos. Salinity climates in the western sub-basins bordering the Gulf of Mexico were insensitive to even the largest (5-fold) modeled increases in freshwater inflow. However, the north, northeastern, and eastern sub-basins were highly sensitive to freshwater inflow and responded to comparatively small increases with decreased salinity and increased salinity variability. The discriminant function model predicted increased occurrences ofHalodule wrightii communities and decreased occurrences of Thalassia testudinum communities in response to the more estuarine salinity climates. The shift in community composition represents a return to the historically observed state and suggests that restoration goals for Florida Bay can be achieved through restoration of freshwater inflow from the Everglades.
Resumo:
Large numbers of colonially nesting herons, egrets, ibises, storks and spoonbills were one of the defining natural phenomena of the historical Everglades. Reproduction of these species has been tracked over at least a century, and some clear responses to dramatic anthropogenic hydrological alterations have been established. These include a marked decline in nesting populations of several species, and a movement of colonies away from the over-drained estuarine region. Ponding in a large portion of the freshwater marsh has favored species that hunt by sight in deep water (egrets, cf. 25–45 cm), while tactile feeders (ibises and storks) that depend on concentrated prey in shallow water (5–25 cm) have become proportionately much less common. There has been a marked increase in the interval between exceptionally large breeding aggregations of White Ibises (Eudocimus albus). Loss of short hydroperiod wetlands on the margins of the Everglades have delayed nest initiations 1–2 months by Wood Storks (Mycteria americana) resulting in poor nesting success. These responses are consistent with mechanisms that involve foraging, and the availability and production of prey animals, and each of the relationships is highly dependent on hydrology. Here, we define a group of characteristics about wading bird dynamics (= indicators) that collectively track the specific ecological relationships that supported ibises and storks in the past. We suggest four metrics as indicators of restoration success: timing of nesting by storks, the ratio of nesting ibises + storks to Great Egrets, the proportion of all nests located in the estuarine/freshwater ecotone, and the interval between years with exceptionally large ibis nestings. Each of these metrics has historical (e.g., predrainage) data upon which to base expectations for restoration, and the metrics have little measurement error relative to the large annual variation in numbers of nests. In addition to the strong scientific basis for the use of these indicators, wading birds are also a powerful tool for public communication because they have strong aesthetic appeal, and their ecological relationships with water are intuitively understandable. In the interests of communicating with the public and decision-makers, we integrate these metrics into a single-page annual “traffic-light” report card for wading bird responses. Collectively, we believe these metrics offer an excellent chance of detecting restoration of the ecosystem functions that supported historical wading bird nesting patterns.
Resumo:
Lake Okeechobee, Florida, located in the middle of the larger Kissimmee River-Lake Okeechobee-Everglades ecosystem in South Florida, serves a variety of ecosystem and water management functions including fish and wildlife habitat, flood control, water supply, and source water for environmental restoration. As a result, the ecological status of Lake Okeechobee plays a significant role in defining the overall success of the greater Everglades ecosystem restoration initiative. One of the major ecological indicators of Lake Okeechobee condition focuses on the near-shore and littoral zone regions as characterized by the distribution and abundance of submerged aquatic vegetation (SAV) and giant bulrush (Scirpus californicus(C.A. Mey.) Steud.). The objective of this study is to present a stoplight restoration report card communication system, common to all 11 indicators noted in this special journal issue, as a means to convey the status of SAV and bulrush in Lake Okeechobee. The report card could be used by managers, policy makers, scientists and the public to effectively evaluate and distill information about the ecological status in South Florida. Our assessment of the areal distribution of SAV in Lake Okeechobee is based on a combination of empirical SAV monitoring and output from a SAV habitat suitability model. Bulrush status in the lake is related to a suitability index linked to adult survival and seedling establishment metrics. Overall, presentation of these performance metrics in a stoplight format enables an evaluation of how the status of two major components of Lake Okeechobee relates to the South Florida restoration program, and how the status of the lake influences restoration efforts in South Florida.
Resumo:
Recent research makes clear that much of the Everglade’s flora and fauna have evolved to tolerate or require frequent fires. Nevertheless, restoration of the Everglades has thus far been conceptualized as primarily a water reallocation project. These two forces are directly linked by the influence of water flows on fire fuel moisture content, and are indirectly linked through a series of complex feedback loops. This interaction is made more complex by the alteration and compartmentalization of current water flows and fire regimes, the lack of communication between water and fire management agencies, and the already imperiled state of many local species. It is unlikely, therefore, that restoring water flows will automatically restore the appropriate fire regimes, leaving the prospect of successful restoration in some doubt. The decline of the Cape Sable seaside sparrow, and its potential for recovery, illustrates the complexity of the situation.
Resumo:
During the 1960s, water management practices resulted in the conversion of the wetlands that fringe northeastern Florida Bay (USA) from freshwater/oligohaline herbaceous marshes to dwarf red mangrove forests. Coincident with this conversion were several ecological changes to Florida Bay’s fauna, including reductions in the abundances of top trophic-level consumers: piscivorous fishes, alligators, crocodiles, and wading birds. Because these taxa rely on a common forage base of small demersal fishes, food stress has been implicated as playing a role in their respective declines. In the present study, we monitored the demersal fishes seasonally at six sites over an 8-year time period. During monitoring, extremely high rainfall conditions occurred over a 3.5-year period leading to salinity regimes that can be viewed as “windows” to the area’s natural past and future restored states. In this paper, we: (1) examine the changes in fish communities over the 8-year study period and relate them to measured changes in salinity; (2) make comparisons among marine, brackish and freshwater demersal fish communities in terms of species composition, density, and biomass; and (3) discuss several implications of our findings in light of the intended and unintended water management changes that are planned or underway as part of Everglades restoration. Results suggest the reduction in freshwater flow to Florida Bay over the last several decades has reduced demersal fish populations, and thus prey availability for apex consumers in the coastal wetlands compared to the pre-drainage inferred standard. Furthermore, greater discharge of freshwater toward Florida Bay may result in the re-establishment of pre-1960s fauna, including a more robust demersal-fish community that should prompt increases in populations of several important predatory species.