Physical Sciences and Mathematics Commons^™

Space-For-Time Substitution Works In Everglades Ecological Forecasting Models, Amanda I. Banet, Joel C. Trexler

Department of Biological Sciences

Space-for-time substitution is often used in predictive models because long-term time-series data are not available. Critics of this method suggest factors other than the target driver may affect ecosystem response and could vary spatially, producing misleading results. Monitoring data from the Florida Everglades were used to test whether spatial data can be substituted for temporal data in forecasting models. Spatial models that predicted bluefin killifish (Lucania goodei) population response to a drying event performed comparably and sometimes better than temporal models. Models worked best when results were not extrapolated beyond the range of variation encompassed by the original …

Recreational Angler Perspectives Of Nonnative Fish Species And Mercury Advisories, Christopher J. Edwards

FIU Electronic Theses and Dissertations

The central Everglades serve as a Wildlife Management Area and as a Water Conservation Area for the Miami-Fort Lauderdale metropolitan area. It is also home to over 22 nonnative freshwater fish species and carries restrictive fish consumption guidelines for Mercury. In my study, boat anglers and canal bank anglers were personally interviewed in the field, to research their awareness and perspectives of these potential environmental and health threats. The study found 78% of anglers were aware of the presence of nonnative fish species, but favored native fish species, and that 69% were aware of mercury advisories, but did not eat …

Soil Building Processes In Reconstructed Tree Islands In The Everglades, Florida, Andres F. Rodriguez

FIU Electronic Theses and Dissertations

Soil building processes were studied in reconstructed tree islands in the Loxahatchee Impoundment Landscape Assessment, Florida. Soil building was evaluated by measuring litter production, litter decomposition, soil accretion, and changes in soil elevation under different hydrologic conditions, and by determining physicochemical characteristics of newly accreted soils. Tree islands showed higher litter production and soil accretion but a larger loss of soil elevation caused by subsidence at higher elevations and shorter inundation periods. Newly accreted soils exhibited higher nutrient concentrations, and organic matter (OM) than older soils. Most of the soil phosphorus was stored in the organic fraction. A positive correlation …

Online Solid Phase Extraction Liquid Chromatography Tandem Mass Spectrometry (Spe-Lc-Ms/Ms) Method For The Determination Of Sucralose In Reclaimed And Drinking Waters And Its Photo Degradation In Natural Waters From South Florida, Sudha Rani Butchu, Natalia Quinete, Venkata R. Panditi, Piero R. Gardinali

Department of Chemistry and Biochemistry

Background

Sucralose has gained popularity as a low calorie artificial sweetener worldwide. Due to its high stability and persistence, sucralose has shown widespread occurrence in environmental waters, at concentrations that could reach up to several μg/L. Previous studies have used time consuming sample preparation methods (offline solid phase extraction/derivatization) or methods with rather high detection limits (direct injection) for sucralose analysis. This study described a faster and sensitive analytical method for the determination of sucralose in environmental samples.

Results

An online SPE-LC–MS/MS method was developed, being capable to quantify sucralose in 12 minutes using only 10 mL of sample, with …

Barrier Island Response To Sea Level Rise In North Carolina, Evan D. Cook

FIU Electronic Theses and Dissertations

The state of North Carolina is home to some of the most spectacular barrier islands in the world. These features are constantly shifting, impacted by waves, tides, and wind. Studies of the Outer Banks, North Carolina have resulted in varied results, but a detailed analysis of the barrier system as a whole is lacking. Using historic topographic surveys (T-sheets) from the 19^th, the positions of various barrier segments were analyzed in relation to modern imagery.

Changes in area, width, and center line locations were evaluated over the past 150 years. In total, 74 percent of modern transects have …

Assessment Of The Occurrence And Potential Risks Of Antibiotics And Their Metabolites In South Florida Waters Using Liquid Chromatography Tandem Mass Spectrometry, Venkata Reddy Panditi

FIU Electronic Theses and Dissertations

An automated on-line SPE-LC-MS/MS method was developed for the quantitation of multiple classes of antibiotics in environmental waters. High sensitivity in the low ng/L range was accomplished by using large volume injections with 10-mL of sample. Positive confirmation of analytes was achieved using two selected reaction monitoring (SRM) transitions per antibiotic and quantitation was performed using an internal standard approach. Samples were extracted using online solid phase extraction, then using column switching technique; extracted samples were immediately passed through liquid chromatography and analyzed by tandem mass spectrometry. The total run time per each sample was 20 min. The statistically calculated …

Wildfire Assessment Using Farsite Fire Modeling: A Case Study In The Chihuahua Desert Of Mexico, John Brakeall

FIU Electronic Theses and Dissertations

The Chihuahua desert is one of the most biologically diverse ecosystems in the world, but suffers serious degradation because of changes in fire regimes resulting in large catastrophic fires. My study was conducted in the Sierra La Mojonera (SLM) natural protected area in Mexico. The purpose of this study was to implement the use of FARSITE fire modeling as a fire management tool to develop an integrated fire management plan at SLM.

Firebreaks proved to detain 100% of wildfire outbreaks. The rosetophilous scrub experienced the fastest rate of fire spread and lowland creosote bush scrub experienced the slowest rate of …

Hydrogeophysical Characterization Of Anisotropy In The Biscayne Aquifer Using Geophysical Methods, Albert Yeboah-Forson

FIU Electronic Theses and Dissertations

The anisotropy of the Biscayne Aquifer which serves as the source of potable water for Miami-Dade County was investigated by applying geophysical methods. Electrical resistivity imaging, self potential and ground penetration radar techniques were employed in both regional and site specific studies. In the regional study, electrical anisotropy and resistivity variation with depth were investigated with azimuthal square array measurements at 13 sites. The observed coefficient of electrical anisotropy ranged from 1.01 to 1.36. The general direction of measured anisotropy is uniform for most sites and trends W-E or SE-NW irrespective of depth. Measured electrical properties were used to estimate …

Landscape Pattern – Marl Prairie/Slough Gradient: Vegetation Composition Along The Gradient And Decadal Vegetation Change Pattern In Shark Slough: Annual Report 2012, Jay P. Sah, Michael S. Ross, Pablo L. Ruiz

SERC Research Reports

In the southern Everglades, vegetation in both the marl prairie and ridge and slough landscapes is sensitive to large-scale restoration activities associated with the Comprehensive Everglades Restoration Plan (CERP) authorized by the Water Resources Development Act (WRDA) 2000 to restore the south Florida ecosystem. More specifically, changes in hydrologic regimes at both local and landscape scales are likely to affect vegetation composition along marl prairie-slough gradient resulting in a shift in boundary between plant communities in these landscapes. To strengthen our ability to assess how vegetation would respond to changes in underlying ecosystem drivers along the gradient, an improved understanding …

Trends In Water Quality Within The Broward County Portion Of The Biscayne Aquifer, Leigh Auwers Ammon

FIU Electronic Theses and Dissertations

Continuous and reliable monitoring of contaminants in drinking water, which adversely affect human health, is the main goal of the Broward County Well Field Protection Program. In this study the individual monitoring station locations were used in a yearly and quarterly spatiotemporal Ordinary Kriging interpolation to create a raster network of contaminant detections. In the final analysis, the raster spatiotemporal nitrate concentration trends were overlaid with a pollution vulnerability index to determine if the concentrations are influenced by a set of independent variables. The pollution vulnerability factors are depth to water, recharge, aquifer media, soil, impact to vadose zone, and …

Water Demand And Allocation In The Mara River Basin, Kenya/Tanzania In The Face Of Land Use Dynamics And Climate Variability, Shimelis B. Dessu

FIU Electronic Theses and Dissertations

The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and …

Monitoring Of Tree Island Condition In The Southern Everglades: Hydrologic Driven Decadal Changes In Tree Island Woody Vegetation Structure And Composition: 2012 Annual Report, Pablo L. Ruiz, Michael S. Ross, Jay P. Sah

SERC Research Reports

This report examines the interaction between hydrology and vegetation over a 10-year period, between 2001/02 and 2012 within six permanent tree island plots located on three tree islands, two plots each per tree island, established in 2001/02, along a hydrologic and productivity gradient. We hypothesize that: (H1) hydrologic differences within plots between census dates will result in marked differences in a) tree and sapling densities, b) tree basal area, and c) forest structure, i.e., canopy volume and height, and (H2) tree island growth, development, and succession is dependent on hydrologic fluxes, particularly during periods of prolonged droughts or below average …

Modeling Light Use Efficiency In A Subtropical Mangrove Forest Equipped With Co2 Eddy Covariance °C, Jordan G. Barr

FCE LTER Journal Articles

Despite the importance of mangrove ecosystems in the global carbon budget, the relationships between environmental drivers and carbon dynamics in these forests remain poorly understood. This limited understanding is partly a result of the challenges associated with in situ flux studies. Tower-based CO₂ eddy covariance (EC) systems are installed in only a few mangrove forests worldwide, and the longest EC record from the Florida Everglades contains less than 9 years of observations. A primary goal of the present study was to develop a methodology to estimate canopy-scale photosynthetic light use efficiency in this forest. These tower-based observations represent a …

Water Quality Monitoring Program For Bermuda's Coastal Resources Final Report, Henry O. Briceño, Joseph N. Boyer

SERC Research Reports

No abstract provided.

Summertime Influences Of Tidal Energy Advection On The Surface Energy Balance In A Mangrove Forest, Jordan G. Barr, J. D. Fuentes, M. S. Delonge, T. L. O'Halloran, J. C. Zeiman

FCE LTER Journal Articles

Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive 10-day study was conducted in …

Mechanisms Of Bicarbonate Use Influence The Photosynthetic Carbon Dioxide Sensitivity Of Tropical Seagrasses, Justin E. Campbell, James W. Fourqurean

FCE LTER Journal Articles

The photosynthetic bicarbonate () use properties of three widely distributed tropical seagrasses were compared using a series of laboratory experiments. Photosynthetic rates of Thalassia testudinum, Halodule wrightii, and Syringodium filiforme were monitored in an enclosed chamber while being subjected to shifts in pH and dissolved inorganic carbon. Specific mechanisms of seagrass use were compared by examining the photosynthetic effects of the carbonic anhydrase inhibitor acetazolamide (AZ). All seagrasses increased photosynthetic rates with reduced pH, suggesting a large effect of dissolved aqueous carbon dioxide (CO_2(aq)). However, there was considerable interspecific variation in pH response. T. testudinum was …