Ramona Oviedo-Prieto

Bio: Ramona Oviedo-Prieto is an academic researcher. The author has contributed to research in topics: Chloridoideae & Endemism. The author has an hindex of 1, co-authored 2 publications receiving 2 citations.

Populations of a tropical epiphytic orchid are destabilized in its peripheral range by hurricane and an exotic herbivore

Abstract: In a time of global change, having an understanding of the nature of biotic and abiotic factors that drive a species' range may be the sharpest tool in the toolbox of conservation and management of threatened species. However, such information are lacking for most tropical and epiphytic species due to the complexity of life history, the roles of stochastic events, and the diversity of habitat across the span of a distribution. In this study, we conducted repeated census across the core and peripheral range of Trichocentrum undulatum, a threatened orchid that is found throughout the island of Cuba (species core range) and southern Florida (the northern peripheral range). We used demographic matrix modeling and stochastic simulations to investigate the impacts of herbivory, hurricanes, and logging (in Cuba) on projected population growth rates (λ and λs) among sites. Our study indicates that the Florida population is under high extinction risk and most populations in the core range show less interannual variability, but, with the exception of one population, are also in decline. The peripheral population experienced higher herbivory damage than did the core populations, by a native inflorescence-crippling fly, Melanagromyza miamensis, and an invasive, mortality-triggered scale, Diaspis boisduvalii. The latter was found in the Florida population only. Hurricanes increased levels of mortality and had a negative effect on λ. However, λ increased following hurricane events due to increased recruitment and decreased herbivory. Life table response experiments suggest that higher adult survival was the largest contributor to the higher λ observed in the growing Cuba populations, as compared with the population in Florida. Logging simulations in Cuba indicate that populations can maintain stability only if selective logging of host trees occurs at low frequency. Reintroduction of the species in its northern peripheral habitat is needed to ameliorate the threats from sea-level rise and invasive herbivorous insects to secure the current species' northern, continental range margin. Our study exhibits how vital rates and ecological interactions vary across a species distribution and respond under differing stochastic events.

Rediscovery of Bouteloua vaneedenii (Gramineae: Chloridoideae): endemic species from the West Indies Redescubrimiento de Bouteloua vaneedenii (Gramineae: Chloridoideae): especie endémica de las Indias Occidentales

Abstract: Bouteloua vaneedenii is an endemic and extremely rare grass of the West Indies. Very few collections are known, and the most recent collection is from 1922. With the aim of finding the species, a team of Mexican and Cuban agrostologists conducted a field trip and found B. vaneedenii in the same locality where it was collected in 1922 on dry limestone rocks. Although it was stated that B. vaneedenii probably was extinct from Cuba, vigorous populations remain in at least 2 localities in Pastelillo. Further exploration may lead to the discovery of additional populations and the reevaluation of its current conservation status.

Rediscovery of Bouteloua vaneedenii (Gramineae: Chloridoideae): endemic species from the West Indies

Abstract: Bouteloua vaneedenii is an endemic and extremely rare grass of the West Indies. Very few collections are known, and the most recent collection is from 1922. With the aim of finding the species, a team of Mexican and Cuban agrostologists conducted a field trip and found B. vaneedenii in the same locality where it was collected in 1922 on dry limestone rocks. Although it was stated that B. vaneedenii probably was extinct from Cuba, vigorous populations remain in at least 2 localities in Pastelillo. Further exploration may lead to the discovery of additional populations and the reevaluation of its current conservation status.

Phylogeny of the Bouteloua curtipendula Complex (Poaceae: Chloridoideae) Based on Nuclear Ribosomal and Plastid DNA Sequences from Diploid Taxa

Abstract: The Bouteloua curtipendula complex (Poaceae: Chloridoideae) has been treated as a group of 12 species distributed from Canada to Argentina. Due to considerable morphological variation, putative hybridization, polyploidy (including aneuploidy), and apomixis, circumscription of and relationships among taxa have been uncertain. To infer the phylogeny of this complex, two non-coding regions, the internal transcribed spacer (nrDNA) and trnT-L-F (cpDNA), were sequenced and analyzed by maximum parsimony and maximum likelihood methods. Character-state reconstruction was carried out to test the utility of morphological characters used for species circumscription. Nuclear and plastid data revealed similar phylogenetic patterns, albeit with a lower level of resolution from the trnT-L-F sequences. Results support monophyly of the Bouteloua curtipendula complex, but not the species monophyly, except for B. triaena, which forms a strongly supported clade in both phylogenies. The origin of the Bouteloua curtipendula complex seems to be recent with low divergence between taxa. All of the morphological characters used to circumscribe species were found to be homoplasious.

Initial Population Analysis and Mycorrhizal Fungi of the Leafless Epiphytic Orchid, Campylocentrum pachyrrhizum, in Florida

Abstract: Campylocentrum pachyrrhizum Rchb.f. Rolfe, also known as the ribbon orchid, is native to southern Florida, the West Indies, and northern South America. In Florida, it is restricted to the Fakahatchee Strand and is currently state-listed as endangered, but virtually nothing is known about the orchid’s biology, ecology, and current status. The purpose of this study was to document ribbon orchid populations within the northern portion of the Fakahatchee Strand (Florida Panther NWR) and to identify some of the biotic and abiotic factors critical to its survival. During 2016–2022, a total of 118 ribbon orchids were recorded at five sites on 21 host trees comprising two species (Annona glabra, Fraxinus caroliniana). The majority (80%) were rooted on pop ash, and over half (54%) were rooted at the base of trees 100–150 cm above the high water mark. The number of orchids decreased from year to year, with the largest drop (2017–2018) coinciding with damage from Hurricane Irma. At the end of the 2022 survey, only 44 orchids remained. Mycorrhizal fungi isolated from two plants were identified as a Ceratobasidium species. We urge land managers to take immediate action to safeguard this species throughout southern Florida.