DISSERTATION RESEARCH: Comparative phylogeography of three co-distributed Neotropical mangrove species

University Of Florida, Gainesville FL

Investigators

Abstract

Mangroves provide valuable ecosystem services and habitats for many economically important animals, such as fish, birds, and marine invertebrates. Red (Rhizophora mangle), black (Avicennia germinans), and white (Laguncularia racemosa) mangroves are coastal trees found in estuarine habitats throughout the Neotropics. This project will use genetic tools, evolutionary analyses and niche modeling to analyze current distributions, and then use these data to model past and future geographical distributions for the three species. The project will also investigate the correlation between dispersal ability and observed patterns of genetic diversity, and infer how seed dispersal potential can affect the genetic structure of populations on broad geographic scales. One graduate student will be trained in diverse molecular methods, niche modeling and phylogenetic analyses, and undergraduates will be introduced to a diversity of field and laboratory techniques. A series of talks and presentations will broadly disseminate results of the study in Florida, Aruba, Cayman Islands, and Jamaica where the three mangrove species will be collected. The comparative phylogeography of coastal and marine animals in the southeastern U. S. has been well studied, with many taxa exhibiting a phylogeographic discontinuity at the southern tip of Florida. In contrast, only two studies have examined the phylogeography of coastal or marine plant species in this region. In the Caribbean, studies of historical biogeography have similarly been heavily biased towards vertebrates. Further study of coastal plants is needed in Florida and the Caribbean to facilitate phylogeographic synthesis for the region. The researchers will investigate the phylogeographic histories of three mangrove species (Rhizophora mangle, Avicennia germinans, and Laguncularia racemosa) in Florida. They will test the hypothesis that phylogeographic structure is less pronounced in these highly dispersed organisms than in other coastal organisms, and that propagule size, longevity and proximity to water will be negatively correlated with phylogeographic structure. To help place these patterns in a broader context, the researchers will also investigate the phylogeography of R. mangle in the Caribbean. This project will use multiple molecular markers, including complete plastid genomes, RAD-Seq data, and microsatellites, each with different modes of inheritance and mutation rates, to thoroughly investigate the phylogeography of these three species. Data obtained will facilitate a synthesis of animal and plant phylogeographic and biogeographic studies in Florida and the Caribbean, and also help identify future conservation priorities in the different areas.