Systematics, Biogeography and Leaf Anatomy and Architecture of Bursera subgen. Bursera (Burseraceae) in the Greater Antilles and the Bahamas

This dissertation presents a comprehensive study on the origin and evolutionary relationships of the species of Bursera in Cuba, Hispaniola, Jamaica and the Bahamas. The goals of the first chapter were to test monophyly of the group, revisit a recent transfer of two species of Bursera to Commiphora, and place recently discovered mainland species using the reconstructed phylogenies. Additionally, divergence estimations using fossils were used as independent tests of several hypotheses regarding the arrival of the modern biota to the Greater Antilles and Bahamas (GAB). I conclude that all endemic taxonomic entities of the genus in this region belong to Bursera subgen. Bursera but that two separate lineages colonized the GAB via dispersal. The genus diversified during the Middle Miocene to Pliocene, and the data corroborate several paleogeographic events during that interval. The second chapter presents informative characters from leaf anatomy and leaf architecture for the 14 endemic species of Bursera distributed in the GAB. There is evidence for some evolutionary tendencies in the group, among them a trend toward small, simple, amphistomatic and unifacial leaves, character states for which ecological correlates can now be studied. Morphological and anatomical evidence corroborates phylogenetic results in suggesting that a population of B. glauca in Cuba is a new species. Finally, the third chapter constitutes the first taxonomic account and description of all known endemic species of Bursera in the region and reflects the results of the previous chapters. The primary results are as follows: (1) a new species from eastern Cuba, B. yaterensis, is described; (2) five species of Commiphora are returned to Bursera; (3) B. nashii is treated as conspecific with B. glauca; and (4) B. ovata is treated as conspecific with B. trinitensis. A dichotomous key is provided using mostly vegetative characters due to the frequent lack of adequate reproductive material and the relative uniformity of most floral and fruit characters. Each species description includes leaf architecture (morphology and venation pattern) and anatomy, introducing characters that could and should be used for describing and distinguishing other Bursera in Meso- and South America as well as for African Commiphora

Biodiversity in a university campus in the sabana de Bogotá: plants and tethrapods inventory

Los ecosistemas urbanos incluyen áreas suburbanas y asentamientos conectados por corredores de conmutación y tierras afectadas por la energía y materiales del núcleo urbano. Estos ecosistemas presentan enormes retos para la conservación de la biodiversidad por la alta concentración de humanos, las marcadas perturbaciones, y en Colombia la información sobre la biodiversidad allí es limitada. Se hizo un inventario de las plantas vasculares, anfibios, reptiles sin plumas y con ellas (aves), y mamíferos en el campus de la Universidad Militar Nueva Granada, Sabana de Bogotá, cordillera Oriental colombiana, ~2550 m snm. El campus se ubica entre dos centros urbanos, Cajicá y Zipaquirá, y es un mosaico de ambientes urbanizados, de uso agropecuario, y con remanentes de ecosistemas naturales asociados al río Bogotá. Se registraron 205 especies de plantas, una especie de rana, una de serpiente, 80 especies de aves y 10 de mamíferos. La mayoría de los árboles del campus son plantados; una considerable proporción de plantas son exóticas y algunas son invasoras. Aves residentes y migratorias usan el campus, y representan casi el 40% de las especies conocidas para la Sabana. Entre los mamíferos hay seis especies no voladoras y posiblemente tres murciélagos, y también hay una especie exótica e invasiva, el ratón casero Mus musculus. El campus es refugio para especies amenazadas (e.g., Porphyriops melanops) y especies poco conocidas (e.g., Akodon sp.). Deben hacerse esfuerzos en el manejo adecuado del campus, e idealmente alrededor de él, manteniendo suficientes espacios verdes y humedales para conservar las especies silvestres.Urban ecosystems include suburban and settlements connected by commuting corridors and lands affected by the energy and materials from the urban core. These ecosystems present enormous challenges for the conservation of biodiversity given their high concentration of human beings and the marked disturbances and, in Colombia, the little information about biodiversity in these environments. An inventory of vascular plants, amphibians, feathered and non-feathered reptiles, and mammals was carried out at Universidad Militar Nueva Granada, in the Sabana de Bogotá, Andes Eastern Cordillera of Colombia, 2,550 m.a.s.l. The campus is located between two urban cores, Cajicá and Zipaquirá, and it is a mosaic of urbanized environments, lands for agriculture and livestock, and remnants of natural ecosystems associated to the Bogotá River. Two hundred-five (205) plant species, one frog species, one snake species, 80 birds species and 10 mammal species were recorded. Most trees on campus have been planted; a considerable proportion of plants are exotic and some of them are recognized as invasive species. Resident and migratory birds use the campus and represent almost 40% of the known species for the Sabana de Bogotá. Among the mammals there are six non-flying mammals and possibly three bat species, and also an exotic and invasive species, the house mouse Mus musculus, was found on campus. The campus serves as refuge for threatened (e.g., Porphyriops melanops) and poorly known species (e.g., Akodon sp.). Efforts must be done to properly manage the campus, and ideally its surroundings, preserving enough green spaces and wetlands to allow the conservation of the wildlife that still survives there

Burseraceae: a model for studying the Amazon flora

A well-studied group of plants can serve as a model for addressing issues in conservation, evolution, and biogeography, making it possible to assign conservation status with confidence and detecting not only those taxa that are most threatened but also those that represent basal, unique, and/or relictual members of entire lineages. Clarified higher-level phylogenetic relationships open the door to more refined systematics of clades without having to worry if they are para- or polyphyletic. A well-studied group can also be an excellent testing ground for new or under-utilized tools and independent data sets. Research on the Burseraceae, with over 100 taxa in the Amazon, is rapidly arriving at the point where the family can be used effectively both as a tool for conservation and as a model for studying the processes influencing the origin and maintenance of high diversity in the Amazonian flora. First, we are resolving higher-level phylogenies as well as species-level taxonomy in various clades, allowing comparative approaches. Second, the family occurs throughout Amazonia and is well-represented in most habitats overall, but most of the taxa are restricted in their distributions and/or habitats; this makes it possible to test the relative importance of geographic barriers vs. habitat diversity in the speciation process. The family is sufficiently large to provide adequate statistical power for hypothesis testing and yet small enough to achieve the necessary sampling intensity, allowing us to assess the relative impacts of morphological innovation, ecological opportunity, and biogeographic events on the diversification of Burseraceae and related groups