Over the last few decades coral reefs have faced unprecedented declines in health due to natural and anthropogenic sources. Until recently few studies have examined genotypic variation of growth and thermal stress resistance in Acropora cervicornis. This study aims to assess the potential for energy trade-offs between growth and thermal stress resistance by following 120 coral fragments from 12 genotypes of Acropora cervicornis over the course of 15 months to determine average growth rates for each genotype. Following the completion of the growth observation a bleaching event occurred in the lower Florida Keys providing the opportunity for examining thermal stress resistance. We found that the coral genotype had a significant effect on growth and survival; however no significant correlation was observed between growth under normal conditions and thermal stress resistance. This result shows that there is not a trade-off between growth and thermal stress resistance and that a genotype’s ability to resist thermal stress cannot be predicted from growth under normal conditions. The lack of a trade-off facilitates intraspecific competition. For genotypes with similar thermal stress tolerances but different growth characteristics, the increase in frequency of disturbances could result in the increased abundance of faster growing genotypes relative to the slow growing genotypes. These results emphasize the importance of maintaining coral nurseries as gene banks to protect the genetic diversity of the reef area in which it is located. Through protecting a wide variety of genotypes, the likelihood of preserving those that have a high thermal tolerance, disease resistance, or faster growth rates is increased.

Disturbance events affect forest composition and structure across a range of spatial and temporal scales, and forest development may differ after natural, anthropogenic, or compound disturbances. Following large, natural disturbances, salvage logging is a common yet controversial management practice around the globe. While the short-term impacts of salvage logging have been studied in many systems, the long-term effects remain unclear. Further, while natural disturbances create many persistent and unique microsite conditions, little is known about the long-term influence of microsites on forest development. We capitalized on over eighty years of data on stand development following the 1938 hurricane in New England to provide the longest known evaluation of salvage logging impacts, as well as to highlight developmental trajectories for eastern hemlock (Tsuga canadensis)-white pine (Pinus strobus) forests under a variety of disturbance histories. Eight decades following disturbance, there were no differences in current overstory composition between areas that were logged, hurricane disturbed, or hurricane disturbed and salvage logged, but white pine declined across most sites. In contrast, structural characteristics remain distinct between the three management histories. In the unsalvaged area, the diversity of microsites and the coverage of uprootings and pits influenced overstory tree composition, diversity, and structural characteristics. These findings underscore the long-term influence of salvage logging on forest development and the importance of natural disturbance-mediated microsite conditions on tree species growth and survival. Future salvage logging efforts should consider these impacts and provide a greater range of unsalvaged areas across the landscape to maintain these important structural legacies over the long term.

The Veracruz Reef System (VRS) is located in the southwestern Gulf of Mexico. It is comprised of 28 coral reefs in various stages of development and conservation. They are protected under the Parque Nacional Sistema Arrecifal Veracruzano National Park created in 1992. There are many threats to the reefs of the VRS, including the Port and city of Veracruz, which hosts half a million inhabitants and Mexico’s oldest active port. The inhabitants of Veracruz have used reef resources for thousands of years, as evidenced in archaeological sites on Sacrificios island, and constructions throughout the city, most notably in the San Juan de Ulúa Fort which was built entirely of coral skeletons. Despite the usage and protection given under the National Park, there is relatively little known about the health and condition of the stony corals in the System. There has only been one large scale study of 21 reefs conducted in the VRS in the late 1980’s. Since then, the National Park was created and 28 reefs are now recognized. This study performed point-intercept transects on 24 of these reefs including five reefs added to the official list in 2012. Point-intercept transects were surveyed at 63 sites between 2007 and 2014. Percent cover was calculated for seven functional groups. Additionally, demographic data of a subset of individual stony coral colonies were assessed on each transect. The functional group with the greatest cover in the VRS was crustose coralline algae (mean ± S.E.: 28.9% ± 1.97), stony corals had the second highest cover (21.5% ± 1.24). The Jamapa river divides the VRS into two groups the Veracruz group to the North and the Anton Lizardo group to the south of the river mouth. The Veracruz group had lower crustose coralline algae cover (28.1% ± 2.71) and coral cover (17.8% ± 1.55) than the Anton Lizardo group (29.6% ± 2.87 CCA and 25.3% ± 1.86 coral cover). The highest average coral cover on a reef was recorded at Ahogado Chico (45.5% ± 5.58), and the highest cover recorded on a single transect was 70% at Santiaguillo reef. The lowest coral cover was recorded at the fringing reefs on the north of the VRS, Punta Gorda and Punta Brava which had less than 1% coral cover. Coral colonies averaged 69.1 cm ± 3.10 in length at the VRS, 56.8 cm ± 2.98 in the Veracruz group and 81.7 cm ± 5.11 in the Antón Lizardo group. Old partial mortality was 25% ± 1.05 overall and similar between groups, recent partial mortality was 1.2% ± 0.21 and 1% at both groups. Disease prevalence was 3.9% for the VRS, 2.9% ± 0.88 in the Veracruz group and 4.9% ± 1.11 in the Antón Lizardo group. Overall, these reefs are faring slightly better than other reefs in the Caribbean having higher coral cover and larger colonies. However, the great variability in the health and condition of these reefs demands added attention and clear management goals to ensure their persistence in the face of ever growing threats. It is important to decrease the sources of stress, such as construction and poor waste water management in the area, better regulate fishing and approach a watershed wide management plan which takes into account upstream effects from the rivers that discharge into the Veracruz Reef System.

Fisheries managers have the potential to significantly improve reef fish management in the Gulf of Mexico through the use of ecosystem-based approaches to fisheries management. Ecosystem-based approaches are needed to address the effects of fishing on trophodynamic interactions, to better account for ecosystem-scale processes in model projections, and to recognize the short and long-term biomass tradeoffs associated with making regulatory choices. My research was concentrated around three objectives: (1) characterizing the trophodynamic interactions between Gulf of Mexico fishes, in order to construct an invaluable tool (a Gulf of Mexico Atlantis model) to be used in ecological hypothesis testing and policy performance evaluation for years to come; (2) predicting ecological indicators for the Gulf of Mexico that both respond to fishing pressure and are robust to observational error, and; (3) evaluating the performance of an ecosystem-based policy options for managing reef fish species in the Gulf of Mexico. To accomplish these objectives, a spatial, trophodynamic ecosystem model- Atlantis, was employed to represent the Gulf of Mexico marine ecosystem. To characterize trophic interactions between modeled species, I applied a maximum likelihood estimation procedure to produce Dirichlet probability distributions representing the likely contribution of prey species to predators’ diets. This provided mode values (the peak of the distribution) and associated error ranges, which describe the likely contribution of a prey item in a predator’s diet. The mode values were used to parameterize the availabilities (diet) matrix of the Gulf of Mexico Atlantis model. Investigating trophic interactions was useful for determining which species within the Atlantis model were data rich, and justified the emphasis on reef fish species and their prey items in subsequent analyses. Once parameterized and calibrated, I used the Atlantis model to project ecological indicators over a 50 year time horizon (2010-2060) under varying levels of fishing mortality. Principal component analysis was used to evaluate ecological indicator trajectories in multivariate space, to rank indicators according to how well they describe variability in ecosystem structure (termed ‘importance’), to reveal redundancies in the information conveyed, to quantify interannual noise and to determine how robust indicators are to observational error. Reef fish catch, Red snapper biomass, King mackerel biomass and Species richness indicators ranked the highest in terms of importance and robustness to error and in having low levels of interannual noise (i.e., requiring less frequent monitoring). I then used a management strategy evaluation (MSE) framework in Atlantis to evaluate some of these same indicators under an ecosystem-based approach to fisheries management – using robust harvest control rules to manage reef fishes. I found that this ecosystem-based policy option was able to maintain higher reef fish biomass, catch and ecosystem-wide biodiversity under any given level of fishing mortality when compared to a status quo management approach. These results suggest that harvesting under the HCRs encourages an alternative ecosystem state with a more Pareto-efficient tradeoff frontier than the status-quo policy. A potentially reduced extinction risk for reef fish is plausible under this ecosystem-based policy option. This research provides a quantitative look at the fishery performance and ecological tradeoffs associated with various policy options. MSE methodology using ecosystem-based policy performance metrics is also demonstrated. Tool development and findings from this research should aid in the development of ecosystem-based policies for this region.

The South Florida Everglades is a unique ecosystem. Intensive water management in the system has facilitated agricultural, urban, and economic development. The Everglades offers a variety of ecosystem services (ES) to the people living in this region. Nevertheless, the ecosystem is under imminent threat of climate change, which would alter the way water is managed today and ultimately affect the ES offered by the system. On the other hand, substantial restoration is underway that aims to restore the Everglades closer to its historic condition. This research tried to map the public’s preference for Everglades restoration. Using a geocoded discrete-choice survey dataset, the study showed variation in the public’s preference by changing the levels of ES. Additionally, the general public’s attitude toward climate change risk to the Everglades and preference for mitigation were also assessed using the survey data.

Community forestry is an evolving approach to forest management, shown to maintain forest cover, while generating income for local communities. In Sierra Norte (SN), a region with no public protected areas, indigenous communities have been actively conserving their forests for decades, through conservation zoning and careful management of their logging areas. This study found that across 22 communities in SN, an estimated 2,949,116.50 m3 of timber were produced from 1993 to 2013, while the region maintains 78% forest cover. About 75% of the forest is under some form of community conservation. Community governance plays a major role, as rules and regulations regarding use, access, and conservation of communal lands are established and enforced by community members. The findings of this study support arguments that advocate for community forest management, as forest communities prove to maintain forest cover and decrease degradation, thus reducing greenhouse gas emissions and enhancing forest carbon stocks.

This thesis research employs a multi-pronged analysis approach to contribute to the existing knowledge regarding land use and water quality in southern Miami Dade County. Nutrient concentrations for TP, NOx-N, and NH3-N were evaluated for water quality monitoring stations across seven canals for two time periods: 1990-2003 and 2009-2014. Overall, the sites did not surpass the mandated TP threshold but a number of sites exceeded the NOx-N and NH3-N criteria set by multiple government agencies. Statistical tests demonstrated that the sites had differing distributions, not sharing similar median concentrations. Land use classifications were derived for the area interest for the years 1994 and 2013. Regression models relating land use classifications to nutrient concentrations at various spatial scales provided mixed results. Lastly, a trend analysis for nutrient concentrations at the stations for 1990-2003 and 2009-2014 demonstrated that there were either no trends or a decreasing trend at most sites.

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 fewer fish because of them. Demographic characteristics were found to predict awareness, which differed significantly between angler types. Public awareness campaigns of nonnative fish impacts should target high school educated, canal bank anglers while mercury advisories should be directed at canal bank anglers, who typically keep and consume their catch more than boat anglers, to those who live more than 30 miles from the area, and all anglers under the age of 48.

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 fire spread. March experienced the fastest rate of fire spread, while September experienced the slowest rate of fire spread. The results of my study provide a tool for wildfire management through the use geospatial technologies and, in particular, FARSITE fire modeling in SLM and Mexico.

Madagascar, a country whose extraordinary levels of endemism and biodiversity are celebrated globally by scientists and laymen alike, yet historically has received surprisingly little research attention, is the setting of the present dissertation. Here, I contribute to the need for applied research by: 1) focusing on the most intensely fished section of the Toliara Barrier Reef, the Bay of Ranobe; 2) characterizing the marine environment, the human population, and the fisheries; and 3) collecting the longest known time-series of data on fisheries of Madagascar, thereby providing a useful baseline for future analyses. In Chapter 1, the bathymetry of the Bay was characterized following a unique application of the boosted regression tree classifier to the RGB bands of IKONOS imagery. Derivation of water depths, based on DOS-corrected images, following a generic, log-transformed multiple linear regression approach produced a predictive accuracy of 1.28 m, whereas model fitting performed using the boosted regression tree classifier, allowing for interaction effects (tree complexity= 2), provided increased accuracy (RMSE= 1.01 m). Estimates of human population abundance, distribution, and dynamics were obtained following a dwelling-unit enumeration approach, using IKONOS Panchromatic and Google Earth images. Results indicated, in 2016, 31,850 people lived within 1 km of the shore, and 28,046 people lived within the 12 coastal villages of the Bay. Localized population growth rates within the villages, where birth rates and migration are combined, ranged from 2.96% - 6.83%, greatly exceeding official estimates of 2.78%. Annual pirogue counts demonstrated a shift in fishing effort from south to the north. Gear and boat (pirogue) profiles were developed, and the theoretical maximum number of fishermen predicted (n= 4,820), in 2013, from a regression model based on pirogue lengths (R2= 0.49). Spatial fishing effort distribution was mapped following a satellite-based enumeration of fishers-at-sea, resulting in a bay-wide estimate of intensity equaling 33.3 pirogue-meters km-2. Landings and CPUE were characterized, with respect to finfish, by family, species, gear, and village. Expansion of landings to bay-wide fisheries yields indicated 1,885.8 mt year-1 of mixed fisheries productivity, with an estimated wholesale value of 1.64 million USD per annum.