South-central Florida Research Articles

Growth and Survival Outcomes for Immature Gopher Tortoises in Contrasting Habitats: A Test of Drone-Based Habitat Assessment.

Juvenile growth rate is a critical demographic parameter, as it shortens the time to maturity and often dictates how long individuals remain vulnerable to predation. However, developing a mechanistic understanding of the factors determining growth rates can be difficult for wild populations. The gopher tortoise (Gopherus polyphemus) is an ecosystem engineer threatened by habitat loss and deficient management of pinelands in the southeastern United States. We investigated the factors governing immature gopher tortoise growth and explored the use of drone-based imagery for habitat assessment by comparing predictive models based on ground-based plant surveys versus drone-derived data. From 2021 to 2022, we tracked and measured immature tortoises in native sandhill and human-modified, ruderal habitat in south-central Florida. Using quarterly, high-resolution drone imagery, we quantified plant cover types and vegetation indices at each occupied burrow and measured the frequency of occurrence of forage species by hand. Annual growth rates of immature tortoises in ruderal habitat were higher than those in sandhill and were the highest published for this species. Models based on drone-derived data were able to explain similar proportions of variation in growth as ground-collected measures of forage, especially during the late dry season when both types of models were most predictive. Habitat differences in forage nitrogen content were also more pronounced during this season, when dominant ground cover in ruderal habitat (bahiagrass) had much higher nitrogen content than dominant ground cover in sandhill (wiregrass). Despite concerns about potential growth-survival trade-offs, tortoises in ruderal habitat did not exhibit lower apparent survival. Our findings indicate that habitat dominated by nutritious non-native grass can provide a valuable supplement to native sandhill through the mechanism of increased growth rates due to higher forage quality. Finally, our study demonstrates that drone technology may facilitate management by providing less labor-intensive ways to assess habitat quality for this and other imperiled herbivores.

Regional variation in the landscape ecology of West Nile virus sentinel chicken seroconversion in Florida.

How landscape composition and configuration impact the distribution of multi-vector and multi-host mosquito vector-borne disease systems, such as West Nile virus (WNV), remains challenging because of complex habitat and resource requirements by hosts and vectors that affect transmission opportunities. We examined correlations between landscape composition and configuration and 2018 WNV sentinel chicken seroconversion in Florida, USA across the state and within five National Oceanic Atmospheric Administration (NOAA) bioclimatic regions to understand strength and variation of landscape effects during an elevated transmission year. Although few landscape studies have examined WNV in Florida, we expected higher percentages of residential or medium-developed landscapes and more fragmented landscapes would be positively correlated with WNV seroconversion owing to the main mosquito vector habitats and avian host distributions. However, we expected to find variation in the importance of forest, wetland, and agriculture landscapes across bioclimatic regions in the state. WNV seroconversion rates were calculated using Florida 2018 Department of Health WNV sentinel chicken seroconversion data from 187 flocks maintained by mosquito control programs. Percent land cover and edge density metrics were calculated for multiple land cover classes and within multiple buffer distances from chicken coops using 2019 National Land Cover Data. We used binomial generalized linear mixed effects models to calculate the importance of landscape metrics to WNV seroconversion. We found no statewide predictors of seroconversion, but as expected, the importance of landscape varied across regions. In the north-central part of the state, we found higher seroconversion in less populated suburban areas while higher seroconversion in south-central Florida was correlated with fragmented forested areas within 0.5 km of coops and intact woody wetland areas within 2 km of coops. This work corroborates previous findings that consistent landscape predictors of WNV are difficult to identify across broader geographic areas and sets the stage for additional work that incorporates climate and landscapes interactions for a greater understanding of WNV ecology in this geographic region.

The LTAR Grazing Land Common Experiment at Archbold Biological Station-University of Florida.

The Archbold Biological Station-University of Florida (ABS-UF) Long-term Agroecosystem Research (LTAR) site lies in the heart of south-central Florida, representing subtropical humid grazing lands in North America and globally. Beef producers in this region face challenges due to climate variability, limited nutritive value of forages, poor soils, public concerns about water quality and greenhouse gas emissions, management trade-offs, economic uncertainty, and increasing urban encroachment. The ABS-UF Common Experiment, co-designed with stakeholders, will assess innovative management systems in comparison to prevailing management systems on key indicators of sustainability. Innovative management systems being tested are alternative fire (frequency and spatial extent) and grazing practices (stocking rate and system). The common experiment framework was implemented across a management intensity gradient spanning from native rangeland to cultivated pastures, including embedded wetlands. Issues that have arisen to date include difficulties in implementing prescribed fire and reduced productivity in cultivated pastures associated with innovative management, which led to an adjustment of the experimental treatment. A stakeholder advisory council will codesign future alternative treatments and guide experimental changes in this long-term experiment. Stakeholder engagement efforts revealed research priorities centered on financial strength, carbon (C) and greenhouse gas emissions, and water quality. Stakeholders are also interested in testing emerging technology such as the utility of virtual fencing. Results from ABS-UF provide a unique perspective from subtropical humid grazing lands for continental-scale cross-site synthesis on sustainable agroecosystems across LTAR.

Post-Fledging Movements and Factors that Influence Permanent Departure of Juvenile Crested Caracaras in Florida

ABSTRACT We tracked 48 young Crested Caracaras (Caracara plancus) in south-central Florida from fledging through their first year and sought to define the post-fledging pre-dispersal period and the timing and drivers of permanent departure (PD) from the natal area. By examining Euclidean distances between telemetry locations and the nest for each tagged caracara, we defined the post-fledging dependency period as the first 2 mo after fledging, when fledglings remained mostly within 2.5 km of the nest and were dependent on their parents for food. Before PD, young caracaras explored areas as much as 11 km from their nest but returned to the natal area, resulting in areas used by fledglings up to 6 times the average home range size of an adult breeding pair. Some caracaras remained within their parents’ home range for several months after fledging, even after becoming independent of their parents for food. A fledgling permanently departed its natal area when telemetry indicated it made an abrupt long-distance movement away from its natal area and did not return. We used generalized linear mixed models and a hierarchical modeling approach to test environmental and biological factors that may affect the timing of PD. The most supported model indicated that PD depended on parental reproductive strategy and on the timing of fledging relative to the length of the breeding season. Birds with parents that raised only one brood remained in the natal area for 11.6–21.0 wk longer than birds with parents that raised multiple broods in the same breeding season; fledglings from the first of two broods departed at a younger age, suggesting that the PD decision is partially triggered by the level of parental investment in the first and subsequent brood. Additionally, birds that fledged early in the breeding season departed the natal area 2.8–12.2 wk earlier than those that fledged later in the breeding season, and birds that were exposed to high heat during the nestling stage departed the natal area earlier than those exposed to less heat. The period between fledging and permanent departure from the natal area is important for the conservation of species with delayed dispersal. When developing a conservation strategy for Florida’s caracara population, attention should be paid to protecting areas used by fledglings until PD rather than just focusing on a limited protection zone around the nest.

Spatial patterns and sociodemographic predictors of chronic obstructive pulmonary disease in Florida.

Chronic obstructive pulmonary disease (COPD) is a chronic, inflammatory respiratory disease that obstructs airflow and decreases lung function and is a leading cause death globally. In the United States (US), the prevalence among adults is 6.2%, but increases with age to 12.8% among those 65 years or older. Florida has one of the largest populations of older adults in the US, accounting for 4.5 million adults 65 years or older. This makes Florida an ideal geographic location for investigating COPD as disease prevalence increases with age. Understanding the geographic disparities in COPD and potential associations between its disparities and environmental factors as well as population characteristics is useful in guiding intervention strategies. Thus, the objectives of this study are to investigate county-level geographic disparities of COPD prevalence in Florida and identify county-level socio-demographic predictors of COPD prevalence. This ecological study was performed in Florida using data obtained from the US Census Bureau, Florida Health CHARTS, and County Health Rankings and Roadmaps. County-level COPD prevalence for 2019 was age-standardized using the direct method and 2020 US population as the standard population. High-prevalence spatial clusters of COPD were identified using Tango's flexible spatial scan statistics. Predictors of county-level COPD prevalence were investigated using multivariable ordinary least squares model built using backwards elimination approach. Multicollinearity of regression coefficients was assessed using variance inflation factor. Shapiro-Wilks, Breusch Pagan, and robust Lagrange Multiplier tests were used to assess for normality, homoskedasticity, and spatial autocorrelation of model residuals, respectively. County-level age-adjusted COPD prevalence ranged from 4.7% (Miami-Dade) to 16.9% (Baker and Bradford) with a median prevalence of 9.6%. A total of 6 high-prevalence clusters with prevalence ratios >1.2 were identified. The primary cluster, which was also the largest geographic cluster that included 13 counties, stretched from Nassau County in north-central Florida to Charlotte County in south-central Florida. However, cluster 2 had the highest prevalence ratio (1.68) and included 10 counties in north-central Florida. Together, the primary cluster and cluster 2 covered most of the counties in north-central Florida. Significant predictors of county-level COPD prevalence were county-level percentage of residents with asthma and the percentage of current smokers. There is evidence of spatial clusters of COPD prevalence in Florida. These patterns are explained, in part, by differences in distribution of some health behaviors (smoking) and co-morbidities (asthma). This information is important for guiding intervention efforts to address the condition, reduce health disparities, and improve population health.

Modeling temporal and spatial variations of biogeochemical processes in a large subtropical lake: Assessing alternative solutions to algal blooms in Lake Okeechobee, Florida

Study region:Algal blooms (ABs), often exacerbated by excess nutrients from anthropogenic activities, can pose serious risks to public health, fisheries, and ecosystem structure and functions. Lake Okeechobee is located in southcentral Florida (USA), and with a surface area of 1730 km2, it is the largest subtropical lake in the United States. This lake is shallow, nutrient-rich, and subject to frequent and intense blooms of cyanobacteria, some of which are toxic. Study focus:In this study, a three-dimensional (3D) model was developed, coupling long-term monitoring data with complex physical, chemical, and ecological processes at fine spatial (15–1000 m horizontal mesh size) and temporal (1 h) resolution. We used this model to understand the influence of environmental factors and nutrient management on ABs dynamics in Lake Okeechobee. New Hydrological Insights for the Region:The model showed that ABs mostly developed in shallow nearshore regions near canal outlets, and then spread over the lake as a result of prevailing winds and currents. Hypothetical scenario modeling showed that reducing both nitrogen and phosphorus inputs by 50%–75% would be more effective at reducing ABs in the lake than targeting a single nutrient. The model could be used as a tool to assess the effectiveness of different nutrient management strategies in Lake Okeechobee and its watershed, while the framework could be adopted to other large water bodies facing similar issues.

Alzheimer’s Disease and Related Dementias Referral Outcomes among Diverse Rural Residents

AbstractBackgroundThis study to increase dementia detection in rural settings was conducted in a medically underserved area of southcentral Florida referred to as “the Glades.” Residents face multiple disparities related to Alzheimer’s disease and related dementias, including less than a 60% high school graduation rate, diabetes and hypertension as the primary health diagnosis, and increased exposure to ambient air particles from sugar cane burning.MethodLocations for testing included eight churches and a virtual “location,” for a total of ten sites. Individuals (N = 217) were cluster sampled within these sites. Participants were administered a brief educational intervention and brain health was screened using Nasreddine’s telephone “Mini‐MoCA” (2019), in which a score < 12 indicates cognitive risk. Referrals were determined for 133 participants.ResultsThe sample consisted of 59 virtual and 74 in‐person participants, with a range of 1 to 14 participants per church. Seventy percent were female, 57% lived alone, 13% had a previous memory test, and less than 1% had been previously diagnosed with dementia. The sample consisted primarily of four ethnicities, n = 44 (33%) African Americans, n = 21 (16%) Afro‐Caribbeans, n = 19 (14%) Hispanics, and n = 45 (34%) Whites.There was substantial variance in outcomes across sites, with an ICC = .179 (n = 133), indicating that 17.9% of the variance in referrals was between sites. Therefore, a mixed linear model approach was used for analysis with participants nested within sites (Feaster et al., 2011) The covariate of whether they had a previous memory test was not statistically significant and only reduced the ICC by .002. Neither gender, nor whether the person lived alone were statistically significant predictors of referrals, (p > .05), however adding ethnic group reduced the ICC to .102, a 47% reduction in intercept variance (N = 131). In particular, African American participants were significantly more likely to have referrals than White participants, g20 = 1.29, p<.001, OR = 3.66. Hispanic and Afro‐Caribbean participants were not significantly more likely to have referrals than White participants, p = .52 and p = .06 respectively.ConclusionFurther investigation is needed to determine place‐based factors that uniquely increase risk for African Americans in an 89% racially/ethnically diverse community.

Direct and indirect pathways of land management effects on wetland plant litter decomposition

Litter decomposition is a fundamental process underpinning multiple ecosystem services. Despite a long history of research on decomposition, direct and indirect effects of multiple interactive land management on wetland decomposition yet remain less well understood. Here, we used a long-term whole-ecosystem wetland experiment in south-central Florida to investigate interactive effects of land-use intensification, cattle grazing and prescribed fire on in situ wetland plant litter decomposition. We further examined the direct and indirect pathways of land management effects on litter decomposition through changes in associated litter traits, soil properties, and soil microbial attributes using structural equation models. We used the litterbag technique that quantifies decomposition rates (k-values) and recalcitrant fractions (A-values). Our results showed that land-use intensification increased k-values in ungrazed wetlands and decreased k-values in grazed wetlands, but consistently reduced A-values regardless of other treatments. Prescribed fire individually suppressed litter decomposition by reducing k and increasing A. Further, these effects occurred through altering litter, soil, and microbial properties. Our results revealed that litter traits and soil properties were the first two strongest factors in determining wetland decomposition processes. Particularly, litter P and Mg contents and soil P and K contents were the best predictors for k, while litter Ca and lignin contents and soil pH, N and water content best predicted A. Moreover, microbial traits exhibited interactive effects with litter and soil properties to affect wetland litter decomposition. Our research suggests that cattle grazing could buffer against stimulating effect of land-use intensification on decomposition rates and thus avoid nutrient releases pulses. Our study further indicates that land-use intensification and fire suppression in subtropical wetlands could promote organic matter depletion and thus nutrient loss, highlighting the need to reduce anthropogenic disturbances to natural wetlands to maintain their capacity for providing associated regulating and supporting services.

Spatial distribution of per- and polyfluoroalkyl substances (PFAS) in waters from Central and South Florida.

Per- and polyfluoroalkyl substances (PFAS) are notoriously persistent pollutants that are found ubiquitously present in aquatic environments. They pose a big threat to aquatic life and human health given the bioaccumulation feature and significant adverse health effects associated. In our previous study, PFAS were found in surface waters from Biscayne Bay and tap waters from the East coast of South Florida, at levels that arouse human health and ecological concerns. Considering that Florida supports millions population as well as treasured, sensitive coastal and wetland ecosystems, we have expanded the PFAS monitoring study on the occurrence, composition, spatial distribution, and potential sources encompassing tap waters from counties on the West coast of South Florida and Central Florida, and surface waters from Tampa Bay, Everglades National Park adjacent canals, Key West, including Biscayne Bay area. A total of 30 PFAS were analyzed based on solid-phase extraction (SPE) followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). PFAS were detected in all tap water (N = 10) and surface water samples (N = 38) with total concentrations up to 169ng L-1. Higher PFAS concentrations (> 60ng L-1) are mostly observed from polluted rivers or coastal estuaries in Biscayne Bay, and sites nearby potential points sources (military airbases, wastewater facilities, airports, etc.). Our findings on current PFAS contamination levels from diverse aquatic environments provide additional information for the development of more stringent screening levels that are protective of human health and the environmental resources of Florida, which is ultimately anticipated as scientific understanding of PFAS israpidly growing.

Fire history and weather interact to determine extent and synchrony of mast-seeding in rhizomatous scrub oaks of Florida.

In disturbance-prone ecosystems, fitness consequences of plant reproductive strategies are often determined by the relative timing of seed production and disturbance events, but the role of disturbances as proximate drivers of seed production has been overlooked. We use long-term data on seed production in Quercus chapmanii, Q. geminata and Q. inopina, rhizomatous oaks found in south central Florida's oak scrub, to investigate the role of fire history and its interaction with weather in shaping acorn production and its synchrony. Acorn production increased with the time since last fire, combined with additive or interactive effects of spring precipitation (+) or drought (-). Furthermore, multiple matrix regression models revealed that ramet pairs with shared fire history were more synchronous in seed production than ones that burned in different years. Long-term trends suggest that increasingly drier spring weather, in interaction with fire frequency, may drive a decline of seed production. Such declines could affect the community of acorn-reliant vertebrates in the Florida scrub, including endangered Florida scrub-jays (Aphelocoma coerulescens). These results illustrate that fire can function as a proximate driver of seed production in mast-seeding species, highlighting the increasingly recognized importance of interactions among reproductive strategies and disturbance regimes in structuring plant populations and communities. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'.

Watershed Response to Legacy Phosphorus and Best Management Practices in an Impacted Agricultural Watershed in Florida, U.S.A.

Soil phosphorus (P) built up due to past management practices, legacy P, in the Lake Okeechobee Watershed (LOW) in south-central Florida, U.S.A., is often discussed as the root cause of lake eutrophication. Improvement of the lake’s water quality requires the identification of critical P sources and quantifying their contributions. We performed a global sensitivity analysis of the Watershed Assessment Model (WAM), a common evaluation tool in LOW environmental planning, using the Morris method. A pre-calibrated WAM setup (Baseline) of the LOW sub-watershed, Taylor Creek Nubbin Slough (TCNS), was used as a test case. Eight scenarios were formulated to estimate the contributions of various P sources. The Morris analysis indicated that total phosphorus (TP) loads were highly sensitive to legacy P in improved pastures, the major land use covering 46.2% of TCNS. The scenario modeling revealed that legacy P, inorganic fertilizers, and other sources contribute 63%, 10%, and 32%, respectively, to the Baseline TP load of 111.3 metric tons/y to the lake. Improved pastures, dairies, citrus, and field crops are the top TP load contributors. Our results have important implications for water quality improvement plans in the LOW and highlighted the need for accurate spatial mapping of legacy P and incorporation of such information in modeling efforts for watersheds demonstrating legacy P problems.

First Documentation of Two Types of Aboveground Den Structures in the Eastern Spotted Skunk (Spilogale putorius)

Spilogale putorius (Eastern Spotted Skunk) is a small, nocturnal carnivore that typically spends daylight hours resting in underground den sites. During a study on the den-site selection of S. p. ambarvalis (Florida Spotted Skunk) in the dry prairie of south-central Florida in 2016 and 2017, we tracked individuals to discernible aboveground structures composed of vegetation on 25 occasions. These structures were 1 of 2 easily distinguishable types: large mounds of vegetation primarily composed of shredded Serenoa repens (Saw Palmetto), or smaller cup-like structures with a horizontal entrance that resembled a ground-nesting bird's nest. These sites were occasionally reused by individual skunks, and on 1 occasion we observed 2 female spotted skunks occupying a site at the same time. Due to the absence of other wildlife species in the study area capable of making such structures, we believe that these structures were created by the skunks themselves. While Eastern Spotted Skunks are known to pull vegetation into their underground burrows, and have been documented occupying man-made structures (e.g., haystacks) as den sites, our observations represent the first documentation of aboveground, self-constructed structures being repeatedly used by this species. Use of these structures might be unique to Florida Spotted Skunk due to reduced predation risk or occasional flooding in the region that temporarily reduces availability of underground den sites.

High density and survival of a native small carnivore, the Florida spotted skunk (Spilogale putorius ambarvalis), in south-central Florida

Abstract The eastern spotted skunk (Spilogale putorius) is a species of conservation concern across much of its range and has experienced a population decline since the 1940s. Little is known about the Florida spotted skunk (S. p. ambarvalis), a subspecies endemic to peninsular Florida, but previous studies and the frequency of incidental observations suggest that populations of this subspecies might be more abundant than the two eastern spotted skunk subspecies that occur elsewhere. To better understand the status and demography of the Florida spotted skunk, we assessed the density and survival of a population occurring predominantly in dry prairie habitat in south-central Florida. To obtain density estimates, we trapped spotted skunks on a mark–recapture grid over 11 independent 4-day trapping sessions from 2016 to 2018. To obtain survival estimates, we monitored weekly survival of 38 radiocollared spotted skunks (20 collared initially in 2016 and 18 collared initially in 2017) from February 2016 to August 2017. We captured a minimum of 91 unique spotted skunks on 404 occasions on the mark–recapture grid and our density estimates ranged from 6.52 ± 2.93 skunks/km2 to 23.29 ± 7.65 skunks/km2, depending on trapping session, but seasonal differences in density were not significant. The sex ratio of spotted skunks at our site was 1.0M:3.8F. Mean annual survival for all spotted skunks was 0.714 (0.503–0.925, 95% CI), and sex, season, and year did not have significant effects on survival. This survival estimate is the highest reported thus far for any skunk species. Collectively, the density and survival estimates from our study are higher than those of many other mephitids and mustelids of similar size, and these findings reinforce the value of studying locally abundant populations of small carnivores to better inform the conservation, management, and potential restoration of these species in the future.

Evaluation of the cytotoxic and genotoxic effects of Sida planicaulis Cav extract using human neuroblastoma cell line SH-SY5Y

ABSTRACT Sida planicaulis is a weed thought to have originated in Brazil, where it is present in abundant quantities, but also this plant is also found in south-central Florida, Indian Ocean Islands, and the Pacific Islands. Sida planicaulis produces neurotoxicity that adversely affects livestock breeding with heavy animal losses and consequent negative impact on Brazil’s economy. The aim of this study was to determine the chemical profile, cytotoxic and genotoxic effects of ethanolic extracts of S. planicaulis collected in winter (leaf extract) and summer (leaf extract and leaf + flower extract) using an in vitro model of human neuroblastoma cell line SH-SY5Y. Phytochemical screening demonstrated the presence of alkaloids, flavonoids, and apolar compounds. Rutin, quercetin, and swainsonine were detected by HPLC and GC/MS, respectively. Phosphorus, potassium, iron, and zinc were the inorganic elements found. Extracts produced cytotoxicity at all concentrations tested (7–4,000 μg/ml) as evidenced by the colorimetric assay [3-(4,5-dimethyl-thiazol-2-yl) −2,5-diphenyl-tetrazolium bromide (MTT)]. Based upon the alkaline comet assay extracts were found to induce genotoxicity at concentrations ranging from 0.437 to 7 μg/ml. DNA damage produced by extracts was affirmed using a modified comet assay with the enzymes Endo III and FPG in a concentration dependent manner. Further, enzyme-modified comet assay showed both oxidized purines and pyrimidines, and consequently oxidative stress was related to genomic instability and cell death. Data suggest that low concentrations of ethanolic extracts of S. planicaulis (different seasons) induced increased DNA damage related to oxidative stress and chemical composition.

Paleolimnological assessment of six lakes on the Kissimmee Chain, with implications for restoration of the Kissimmee–Okeechobee–Everglades system, Florida, USA

Whitmore TJ, Riedinger-Whitmore MA, Reed ZE, Curtis JH, Yang H, Evans DE, Cropper NR, Alvarado KS, Lauterman FM, Scott A, Leonard CR, Franklin DL. 2020. Paleolimnological assessment of six lakes on the Kissimmee Chain, with implications for restoration of the Kissimmee–Okeechobee–Everglades system, Florida, USA. Lake Reserv Manage. 36:218–242. The Kissimmee Basin in south central Florida contains a large, freshwater network that includes the Kissimmee River and nearly 2 dozen lakes that are headwaters of the Florida Everglades. Management of these lakes is an important part of Everglades restoration. We report a paleolimnological investigation of 6 lakes in the Upper Kissimmee Basin. Engineering activities connected the lakes and permanently altered hydrology in the 19th and 20th centuries. The lakes were naturally meso-eutrophic, but changes in lake levels and nutrient loading contributed to different degrees of eutrophication. Cyanobacteria were present historically at low levels in Lakes East Tohopekaliga, Cypress, and Tohopekaliga, but increased during the 20th century. Lake Jackson lacked cyanobacteria until recently, but Lakes Kissimmee and Marian have had high levels of cyanobacteria since predisturbance times. Profound changes in the lakes occurred after engineering activities eliminated natural large fluctuations in water levels that periodically dried large portions of the basins. Salt-tolerant biological indicators previously alternated with freshwater organisms. Large water-level fluctuations moderated aquatic-plant standing crops and reduced organic matter accumulation. Lakes Kissimmee and Marian showed greatest evidence of former associated wetlands, but lacked large variations in water levels. We recommend disconnecting these lakes from each other and from the Kissimmee River to reestablish large, natural fluctuations in water levels that were part of healthy ecosystem function. Former wetlands should be restored to slow the downstream cascade of nutrients to Lake Okeechobee and the Everglades. This study demonstrates that paleolimnology is useful for assessing hydrological changes that potentially affect lake restoration efforts.

P118 Campus Food Insecurity and Pantry Awareness at a Public University in South Central Florida

<h3>Background</h3> Higher education institutions have reported from 21 to 59% of their students experiencing food insecurity, meaning they lack the resources to be able to obtain enough food. Food insecurity can negatively impact students' academic performance, physical health, and mental health. Thus, many campuses have established on-site food pantries to address this issue. <h3>Objective</h3> To establish the prevalence of food insecurity among students and their awareness and use of the campus food pantry. <h3>Study Design, Setting, Participants</h3> An online survey was administered to students at the University of South Florida in Fall 2019. A convenience sample of 497 students with representation from all academic colleges completed the survey via Qualtrics. <h3>Measurable Outcome/Analysis</h3> Descriptive analysis was conducted using SPSS 26. To determine food security status, only completed responses (n = 434) from the U.S. Department of Agriculture's 6-item short form Food Security Survey Module were included. <h3>Results</h3> Of the 434 students, 309 were categorized as food secure (71.2%); 90 were low food secure (20.7%), and 35 were very low food secure (8.1%) in the previous 30 days of taking the survey. Of the food insecure students (n = 125), 5 visited the pantry because they needed assistance (4.0%), 3 visited but not for assistance (2.4%), 76 heard of the pantry but never visited (60.8%), and 41 had never heard of the pantry (32.8%). When asked if students would use the pantry if they needed, 38 said they would not use it for various reasons including: embarrassment, perception of foods provided (eg, canned foods high in sodium), lack of awareness (eg, did not know the physical location of the pantry), and perception of the purpose of the pantry (eg, for undergraduates only). <h3>Conclusions</h3> Findings from this survey can help higher education institutions identify student food insecurity needs and barriers to campus food pantry access.

Evergreen Production System for Southern Highbush Blueberries in Florida

In central and south-central Florida, many southern highbush blueberries (SHB) are grown in an evergreen system, in which the plants do not go dormant, and are managed to retain their leaves from the previous year through harvest the following spring to support early flowering and fruit set. The evergreen system has also been used under tunnels in north-central Florida. This new 3-page publication of the UF/IFAS Horticultural Sciences Department, written by Douglas A. Phillips, Jeffrey G. Williamson, and Patricio R. Munoz, provides an overview of the evergreen production system for SHB in Florida.

Differential Effects of Elevation and Microtopography on Gopher Tortoise Burrow Distributions in Southern Florida

In southern Florida, Gopher Tortoises (Gopherus polyphemus) occupy mesic flatwoods and Florida scrub communities where habitat and climatic conditions differ from other portions of the species' range. Both of these habitats appear suboptimal for tortoises due to saturated soils in mesic flatwoods and low forage abundance in scrub. Nonetheless, these habitats support large numbers of tortoises in southern Florida, albeit at low intensities. We assessed influences of elevation and microtopography on the spatial distributions of tortoise burrows and examined burrow use patterns within six sites at Avon Park Air Force Range in south-central Florida. The six sites differed in dominant soil types and vegetation communities, allowing comparisons of burrow distributions among mesic flatwoods, Florida scrub, and mixed flatwoods-scrub habitats (two replicate sites each). Point-process modeling identified significant influences of microtopography on burrow intensities that superseded the effects of site-wide elevation trends in five of the six sites. The effects of microtopography were most pronounced in flatwoods, suggesting greater reliance on areas of slightly higher elevation in mesic habitat, presumably in response to saturated soils and frequent flooding. Burrow use patterns during an exceedingly wet year also suggested that tortoises respond behaviorally to unsuitable hydrology by moving frequently among burrows that were flooded with groundwater. Microtopographic variation may be an important predictor of small-scale habitat use for fossorial reptiles, especially in mesic soils, which could be readily explored using increasingly available LiDAR-derived elevation data combined with the modeling approach demonstrated here.

Abstract P154: Disparities in Geographic and Temporal Trends of Myocardial Infarction Hospitalizations in Florida, 2005-2014

Background: Knowledge of the extent of geographic disparities in the burden of myocardial infarction (MI) is useful for allocation of scarce public health resources to reduce health disparities and improve population health, regardless of whether MI is the primary or secondary cause for hospitalization. The objectives of this study were to identify: (a) geographic disparities in hospitalization risks for MI in Florida; and (b) the temporal changes in these disparities from 2005 to 2014. Methodology: We aggregated county-level data for principal and secondary inpatient MI-related hospital discharges in Florida between 2005 and 2014 by 2-year intervals and calculated age- and sex- adjusted MI hospitalization risks for each time interval. We identified spatial clusters of low- and high-risk MI hospitalization risks using circular spatial scan statistics and tracked MI risks in clusters that persisted throughout the 10-year study period. We also assessed health disparities between persistent high- and low-risk clusters at the end of the study (2013-2014) compared to the beginning of the study (2005-2006) periods. Results: MI hospitalization risks decreased by 15% in Florida overall during the 10-year study period. However, we found persistent disparities in MI risks by geographic location, with high-risk clusters occurring in north-, west-, south-central and southeast Florida, and low-risk clusters occurring in southeast and southwest Florida. A low-risk cluster that transitioned to high-risk status in the last four years of study was identified in northwest Florida. We also found substantial differences in the magnitude of decline in MI risks amongst clusters, with risks decreasing by 5%, 16% and 31% in high-risk clusters in west central, south central and north central Florida, respectively, and by 6.5% and 26% in low-risk clusters in southwest and southeast Florida, respectively. Furthermore, the risks only decreased during the first 6-8 years of study, after which they leveled off or ticked upwards. Consequently, health disparities between high- and low-risk clusters at the end of the study compared to the beginning of the study period decreased by 57% and 31.5% in north- and south-central Florida, respectively, but they remained relatively unchanged in west central Florida. Moreover, MI hospitalization risks in high-risk clusters lag behind those in low-risk clusters by at least a decade. Conclusion: Myocardial infarction hospitalization risks declined modestly during 10-year study period. However, persistent disparities continue to exist across space and time. Addressing these disparities will require targeting intervention efforts to counties with persistently high risks.

Disparities in Temporal and Geographic Patterns of Myocardial Infarction Hospitalization Risks in Florida.

Knowledge of geographical disparities in myocardial infarction (MI) is critical for guiding health planning and resource allocation. The objectives of this study were to identify geographic disparities in MI hospitalization risks in Florida and assess temporal changes in these disparities between 2005 and 2014. This study used retrospective data on MI hospitalizations that occurred among Florida residents between 2005 and 2014. We identified spatial clusters of hospitalization risks using Kulldorff’s circular and Tango’s flexible spatial scan statistics. Counties with persistently high or low MI hospitalization risks were identified. There was a 20% decline in hospitalization risks during the study period. However, we found persistent clustering of high risks in the Big Bend region, South Central and southeast Florida, and persistent clustering of low risks primarily in the South. Risks decreased by 7%–21% in high-risk clusters and by 9%–28% in low-risk clusters. The risk decreased in the high-risk cluster in the southeast but increased in the Big Bend area during the last four years of the study. Overall, risks in low-risk clusters were ahead those for high-risk clusters by at least 10 years. Despite MI risk declining over the study period, disparities in MI risks persist. Eliminating/reducing those disparities will require prioritizing high-risk clusters for interventions.