The Influence of Phosphorus on Periphyton Mats from the Everglades and Three Tropical Karstic Wetlands

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 Role of the Everglades Mangrove Ecotone Region (EMER) in Regulating Nutrient Cycling and Wetland Productivity in South Florida

The authors summarize the main findings of the Florida Coastal Everglades Long-Term Ecological Research (FCE-LTER) program in the EMER, within the context of the Comprehensive Everglades Restoration Plan (CERP), to understand how regional processes, mediated by water flow, control population and ecosystem dynamics across the EMER landscape. Tree canopies with maximum height <3 m cover 49% of the EMER, particularly in the SE region. These scrub/dwarf mangroves are the result of a combination of low soil phosphorus (P < 59 μg P g dw−1) in the calcareous marl substrate and long hydroperiod. Phosphorus limits the EMER and its freshwater watersheds due to the lack of terrigenous sediment input and the phosphorus-limited nature of the freshwater Everglades. Reduced freshwater delivery over the past 50 years, combined with Everglades compartmentalization and a 10 cm rise in coastal sea level, has led to the landward transgression (1.5 km in 54 years) of the mangrove ecotone. Seasonal variation in freshwater input strongly controls the temporal variation of nitrogen and P exports (99%) from the Everglades to Florida Bay. Rapid changes in nutrient availability and vegetation distribution during the last 50 years show that future ecosystem restoration actions and land use decisions can exert a major influence, similar to sea level rise over the short term, on nutrient cycling and wetland productivity in the EMER.

A Conceptual Framework to Develop Long-Term Ecological Research and Management Objectives in the Wider Caribbean Region

The Caribbean Sea and its watersheds show signs of environmental degradation. These fragile coastal ecosystems are susceptible to environmental impacts, in part because of their oligotrophic conditions and their critical support of economic development. Tourism is one of the major sources of income in the Caribbean, making the region one of the most ecotourism dependent in the world. Yet there are few explicit, long-term, comprehensive studies describing the structure and function of Caribbean ecosystems. We propose a conceptual framework using the environmental signature hypothesis of tropical coastal settings to develop a series of research questions for the reef–sea-grass–wetland seascape. We applied this approach across 13 sites throughout the region, including ecosystems in a variety of coastal settings with different vulnerabilities to environmental impacts. This approach follows the strategy developed by the Long Term Ecological Research program of the National Science Foundation to establish ecological research questions best studied over decades and large spatial areas.

Influence of teleost abundance on the distribution and abundance of sharks in Florida Bay, USA

Understanding the factors that influence the distribution and abundance of predators, including sharks, is important for predicting the impacts of human changes to the environment. Such studies are particularly important in Florida Bay, USA where there are planned large-scale changes to patterns of freshwater input from the Everglades ecosystem. Studies of many marine predators suggest that links between predator and prey habitat use may vary with spatial scale, but there have been few studies of the role of prey distribution in shaping habitat use and abundance of sharks. We used longline catches of sharks and trawls for potential teleost prey to determine the influence of teleost abundance on shark abundance at the scale of regions and habitats in Florida Bay. We found that shark catch per unit effort (CPUE) was not linked to CPUE ofteleosts at the scale of sampling sites, but shark CPUE was positively correlated with the mean CPUE for teleosts within a region. Although there does not appear to be a strong match between the abundance of teleosts and sharks at small spatial scales, regional shark abundance is likely driven, at least partially, by the availability of prey. Management strategies that influence teleost abundance will have cascading effects to higher trophic levels in Florida Bay.

An analysis of the factors that influence regional economic development cooperation

This dissertation is a comparative case study of regional cooperation in the field of economic development. In the 21st century global economy, proponents of regionalism have put forth fresh arguments for collective action. A regional approach to economic development activity presents a classic social dilemma: How can local officials collectively improve the economic prospects of a region, and remain autonomous to act in the best interest of the local community? This research examines the role of social capital in overcoming this social dilemma. ^ Three (3) comparable Metropolitan Statistical Areas (MSAs) form the empirical basis of this research. The Houston MSA, the Atlanta MSA and the Miami MSA present distinct variations of regionalized economic development activity. This dissertation seeks to explain this disparity in the dependent variable. The hypothesis is that accrued social capital is crucial to obtaining economic development cooperative agreements.^ This qualitative research utilized secondary demographic and economic databases, survey instruments, interviews, field observations, and a review of legislative and administrative decisions to formulate a clear understanding of the factors influencing the current state of regional economic development cooperation within each region. The study concludes that the legislative and executive decisions of state government exert inordinate influence on the capacity of local officials to cooperate regionally for economic development purposes.^

Racialized sexualities within the romance tour industry: The influence of affect and emotion upon transnational hierarchies of desire

Online international introduction sites that offer romance tours to American men in search of a foreign bride are an important and rapidly growing component of the internet dating industry; the number of these agencies in the U.S. tripled from two hundred to six hundred in the past 10 years. Previous scholars have examined the so-called `mail order bride' industry in order to demonstrate that the women involved are agents and not victims. Many scholars have also highlighted the importance of race in shaping American men's desires in one particular region or country. My dissertation provides an important addition to the literature surrounding romance tourism by including participants from all three major regions associated with romance tourism: Eastern Europe, South America, and Southeast Asia. I collected the data for the dissertation by becoming a participant observer of a romance tour in Ukraine, Colombia, and the Philippines. I argue that romance tourism is an important example of the global intimate, and the ways in which globalized processes are created and sustained through everyday intimate emotions and interactions. By examining the ways in which the emotions of desire, disgust, and anxiety influence individual romance tour participant's constructions of racialized hierarchies, the links between individual emotions and global systems are revealed. The concept of the global intimate challenges the hierarchy of scale that places the body, the home, and the intimate on a much lower level than the scale of the global or the national, and at the same time challenges the binary that divides the individual from the global. Through highlighting the different emotional negotiations that are constantly occurring in the romance tour industry, I highlight the important ways in which individual emotions and affects influence global processes on a large scale and vice versa.^

The Influence of Psychological Predictors and Cognitive Behavioral Stress Management Intervention on Antiretroviral Therapy (ART) Adherence Among HIV-Positive Female Haitian Alcohol Users

Purpose: Over half the HIV-infected persons in the Caribbean, the second most HIV-impacted region in the world, live in Haiti. Using secondary data from a parent study, this research assessed the effects of psychological and social factors on antiretroviral therapy (ART) adherence among Haitian, HIV-positive, female alcohol users. Theoretical Foundation and Research Questions: Using the Theory of Planned Behavior/Reasoned Action and the Information, Motivation, Behavior skills model as guiding theoretical frameworks, the study examined the effectiveness of an adapted cognitive behavioral stress management (CBSM-A) intervention in improving ART adherence. The effect of psychological factors (depression, anxiety, beliefs about medicine, and social support), social factors (stigma, relationship status, and educational attainment), and alcohol on adherence to ART was assessed. Methods: The sample consisted of 116 female ART patients who were randomly assigned to the CBSM-A intervention or the wait-list control group. Participants completed intervention sessions as well as pre- and post-test assessments. Analyses of variance, t-tests, and point biserial correlations were used to test hypotheses. Results: Surprisingly, ART adherence rates significantly decreased for both groups combined [F (1, 108) = 8.79, p = .004]; there was no significant difference between the intervention and control groups with regard to the magnitude of change between baseline and post assessment. On average, depression decreased significantly among participants in the CBSM-A group only [(t (62) = 5.54, p < .001)]. For both groups combined, alcohol use significantly decreased between baseline and post-assessment [(F (1, 78) = 34.70, p < .001)]; there was no significant difference between the intervention and control groups with regard to the magnitude of change between baseline and post-assessment. None of the variables were significantly correlated with ART adherence. Discussion: Adherence to ART did not improve in this sample, nor were any of the variables significantly associated with adherence. The findings suggest that additional supportive and psychological services may be needed in order to promote higher adherence to ART among HIV-positive females. More research may be needed on this sample; a focus on mental health issues, partner conflict, family and sexual history may allow for better targeting and more successful interventions.

An Analysis of the Factors that Influence Regional Economic Development Cooperation

This dissertation is a comparative case study of regional cooperation in the field of economic development. In the 21st century global economy, proponents of regionalism have put forth fresh arguments for collective action. A regional approach to economic development activity presents a classic social dilemma: How can local officials collectively improve the economic prospects of a region, and remain autonomous to act in the best interest of the local community? This research examines the role of social capital in overcoming this social dilemma. Three (3) comparable Metropolitan Statistical Areas (MSAs) form the empirical basis of this research. The Houston MSA, the Atlanta MSA and the Miami MSA present distinct variations of regionalized economic development activity. This dissertation seeks to explain this disparity in the dependent variable. The hypothesis is that accrued social capital is crucial to obtaining economic development cooperative agreements. This qualitative research utilized secondary demographic and economic databases, survey instruments, interviews, field observations, and a review of legislative and administrative decisions to formulate a clear understanding of the factors influencing the current state of regional economic development cooperation within each region. The study concludes that the legislative and executive decisions of state government exert inordinate influence on the capacity of local officials to cooperate regionally for economic development purposes.

Racialized Sexualities within the Romance Tour Industry: the Influence of Affect and Emotion Upon Transnational Hierarchies of Desire

Online international introduction sites that offer romance tours to American men in search of a foreign bride are an important and rapidly growing component of the internet dating industry; the number of these agencies in the U.S. tripled from two hundred to six hundred in the past 10 years. Previous scholars have examined the so-called ‘mail order bride’ industry in order to demonstrate that the women involved are agents and not victims. Many scholars have also highlighted the importance of race in shaping American men’s desires in one particular region or country. My dissertation provides an important addition to the literature surrounding romance tourism by including participants from all three major regions associated with romance tourism: Eastern Europe, South America, and Southeast Asia. I collected the data for the dissertation by becoming a participant observer of a romance tour in Ukraine, Colombia, and the Philippines. I argue that romance tourism is an important example of the global intimate, and the ways in which globalized processes are created and sustained through everyday intimate emotions and interactions. By examining the ways in which the emotions of desire, disgust, and anxiety influence individual romance tour participant’s constructions of racialized hierarchies, the links between individual emotions and global systems are revealed. The concept of the global intimate challenges the hierarchy of scale that places the body, the home, and the intimate on a much lower level than the scale of the global or the national, and at the same time challenges the binary that divides the individual from the global. Through highlighting the different emotional negotiations that are constantly occurring in the romance tour industry, I highlight the important ways in which individual emotions and affects influence global processes on a large scale and vice versa.