Board of Governors- State University System of South Florida, Academic and Student Affairs Committee

Board of Governors Meeting of the State University System of Florida, Academic and Student Affairs Committe Meeting held at Graham Center Ballroom, Modesto Maidique Campus, Florida International University on September 15, 2011

Are mangroves in the tropical Atlantic ripe for invasion? Exotic mangrove trees in the forests of South Florida

Abstract Two species of mangrove trees of Indo- Pacific origin have naturalized in tropical Atlantic mangrove forests in South Florida after they were planted and nurtured in botanic gardens. Two Bruguiera gymnorrhiza trees that were planted in the intertidal zone in 1940 have given rise to a population of at least 86 trees growing interspersed with native mangrove species Rhizophora mangle, Avicennia germinans and Laguncularia racemosa along 100 m of shoreline; the population is expanding at a rate of 5.6% year-1. Molecular genetic analyses confirm very low genetic diversity, as expected from a population founded by two individuals. The maximumnumber of alleles at any locus was three, and we measured reduced heterozygosity compared to native-range populations. Lumnitzera racemosa was introduced multiple times during the 1960s and 1970s, it has spread rapidly into a forest composed of native R. mangle, A. germinans, Laguncularia racemosa and Conocarpus erectus and now occupies 60,500 m2 of mangrove forest with stem densities of 24,735 ha-1. We estimate the population growth rate of Lumnitzera racemosa to be between 17 and 23% year-1. Populations of both species of naturalized mangroves are dominated by young individuals. Given the long life and water-dispersed nature of propagules of the two exotic species, it is likely that they have spread beyond our survey area. We argue that the species-depauperate nature of tropical Atlantic mangrove forests and close taxonomic relatives in the more species-rich Indo-Pacific region result in the susceptibility of tropical Atlantic mangrove forests to invasion by Indo-Pacific mangrove species.

Are mangroves in the tropical Atlantic ripe for invasion? Exotic mangrove trees in the forests of South Florida

Two species of mangrove trees of Indo- Pacific origin have naturalized in tropical Atlantic mangrove forests in South Florida after they were planted and nurtured in botanic gardens. Two Bruguiera gymnorrhiza trees that were planted in the intertidal zone in 1940 have given rise to a population of at least 86 trees growing interspersed with native mangrove species Rhizophora mangle, Avicennia germinans and Laguncularia racemosa along 100 m of shoreline; the population is expanding at a rate of 5.6% year-1. Molecular genetic analyses confirm very low genetic diversity, as expected from a population founded by two individuals. The maximumnumber of alleles at any locus was three, and we measured reduced heterozygosity compared to native-range populations. Lumnitzera racemosa was introduced multiple times during the 1960s and 1970s, it has spread rapidly into a forest composed of native R. mangle, A. germinans, Laguncularia racemosa and Conocarpus erectus and now occupies 60,500 m2 of mangrove forest with stem densities of 24,735 ha-1. We estimate the population growth rate of Lumnitzera racemosa to be between 17 and 23% year-1. Populations of both species of naturalized mangroves are dominated by young individuals. Given the long life and water-dispersed nature of propagules of the two exotic species, it is likely that they have spread beyond our survey area. We argue that the species-depauperate nature of tropical Atlantic mangrove forests and close taxonomic relatives in the more species-rich Indo-Pacific region result in the susceptibility of tropical Atlantic mangrove forests to invasion by Indo-Pacific mangrove species.

The drivers of perception: Identifying the driving factors of resident perceptions of municipal service quality in cities of South Florida

The idea of comparative performance assessment is crucial. Recent study findings show that in South Florida the use by most municipalities of external benchmarks for performance comparison is virtually non-existent. On one level this study sought to identify the factors impacting resident perceptions of municipal service quality. On a different and more practical level, this study sought to identify a core set of measures that could serve for multi jurisdictional comparisons of performance. ^ This study empirically tested three groups of hypotheses. Data were collected via custom designed survey instruments from multiple jurisdictions, representing diverse socioeconomic backgrounds, and across two counties. A second layer of analysis was conducted on municipal budget documents for the presence of performance measures. A third layer of analysis was conducted via face-to-face interviews with residents at the point of service delivery. Research questions were analyzed using descriptive and inferential statistic methodologies. ^ Results of survey data yielded inconsistent findings. In absolute aggregated terms, the use of sociological determinants to guide inquiry failed to yield conclusive answers regarding the factors impacting resident perceptions of municipal service quality. At disaggregated community levels, however, definite differences emerged but these had weak predictive ability. More useful were the findings of performance measures reporting via municipal budget documents and analyses of interviews with residents at the point of service delivery. Regardless of socio-economic profile, neighborhood characteristics, level of civic engagement or type of community, the same aspects were important to citizens when making assessments of service quality. For parks and recreation, respondents most frequently cited maintenance, facility amenities, and program offerings as important while for garbage collection services timely and consistent service delivery mattered most. Surprisingly municipalities participating in the study track performance data on items indicated as important by citizen assessments but regular feed back from residents or reporting to the same is rarely done. ^ The implications of these findings suggest that endeavors, such as the one undertaken in this study, can assist in determining a core set of measures for cross jurisdictional comparisons of municipal service quality, improving municipal delivery of services, and to communicate with the public. ^

Woody Debris in the Mangrove Forests of South Florida

Woody debris is abundant in hurricane-impacted forests. With a major hurricane affecting South Florida mangroves approximately every 20 yr, carbon storage and nutrient retention may be influenced greatly by woody debris dynamics. In addition, woody debris can influence seedling regeneration in mangrove swamps by trapping propagules and enhancing seedling growth potential. Here, we report on line-intercept woody debris surveys conducted in mangrove wetlands of South Florida 9–10 yr after the passage of Hurricane Andrew. The total volume of woody debris for all sites combined was estimated at 67 m3/ha and varied from 13 to 181 m3/ha depending upon differences in forest height, proximity to the storm, and maximum estimated wind velocities. Large volumes of woody debris were found in the eyewall region of the hurricane, with a volume of 132 m3/ha and a projected woody debris biomass of approximately 36 t/ha. Approximately half of the woody debris biomass averaged across all sites was associated as small twigs and branches (fine woody debris), since coarse woody debris >7.5 cm felled during Hurricane Andrew was fairly well decomposed. Much of the small debris is likely to be associated with post-hurricane forest dynamics. Hurricanes are responsible for large amounts of damage to mangrove ecosystems, and components of associated downed wood may provide a relative index of disturbance for mangrove forests. Here, we suggest that a fine:coarse woody debris ratio ≤0.5 is suggestive of a recent disturbance in mangrove wetlands, although additional research is needed to corroborate such findings.

Evaluating the relative contributions of hydroperiod and soil fertility on growth of south Florida mangroves

Low and high water periods create contrasting challenges for trees inhabiting periodically flooded wetlands. Low to moderate flood durations and frequencies may bring nutrient subsidies, while greater hydroperiods can be energetically stressful because of oxygen deficiency. We tested the hypothesis that hydroperiod affects the growth of mangrove seedlings and saplings in a greenhouse experiment by varying flood duration while keeping salinity and soil fertility constant. We measured the growth of mangrove trees along a hydroperiod gradient over a two-year period by tracking fine-scale diameter increment. Greenhouse growth studies indicated that under a full range of annual flood durations (0–8760 h/year), hydroperiod alone exerted a significant influence on growth for one species, Laguncularia racemosa, when flooding was imposed for two growing seasons. Field evaluations, on the other hand, indicated that increased flood duration may provide nutrient subsidies for tree growth. Diameter growth was related curvilinearly to site hydroperiod, including flood duration and frequency, as well as to salinity and soil fertility. An analysis of soil physico-chemical parameters suggests that phosphorus fertility, which was also linked directly to hydroperiod, is likely to influence growth on south Florida mangrove sites. The physical removal of phosphorus by greater flood frequencies from upland sources and/or addition of phosphorus from tidal flooding balanced against increased soil aeration and reduced water deficits may be an extremely important growth determinant for south Florida mangroves.

Regional climate gradients in precipitation and temperature in response to climate teleconnections in the Greater Everglades ecosystem of South Florida

Precipitation and temperature in Florida responds to climate teleconnections from both the Pacific and Atlantic regions. In this region south of Lake Okeechobee, encompassing NWS Climate Divisions 5, 6, and 7, modern movement of surface waters are managed by the South Florida Water Management District and the US Army Corps of Engineers for flood control, water supply, and Everglades restoration within the constraints of the climatic variability of precipitation and evaporation. Despite relatively narrow, low-relief, but multi-purposed land separating the Atlantic Ocean from the Gulf of Mexico, South Florida has patterns of precipitation and temperature that vary substantially on spatial scales of 101–102 km. Here we explore statistically significant linkages to precipitation and temperature that vary seasonally and over small spatial scales with El Niño-Southern Oscillation (ENSO), the Atlantic Multidecadal Oscillation (AMO), and the Pacific Decadal Oscillation (PDO). Over the period from 1952 to 2005, ENSO teleconnections exhibited the strongest influence on seasonal precipitation. The Multivariate ENSO Index was positively correlated with winter (dry season) precipitation and explained up to 34 % of dry season precipitation variability along the southwest Florida coast. The AMO was the most influential of these teleconnections during the summer (wet season), with significant positive correlations to South Florida precipitation. These relationships with modern climate parameters have implications for paleoclimatological and paleoecological reconstructions, and future climate predictions from the Greater Everglades system.