No abstract

Aim  We searched for evidence of floristic homogenization in widespread oceanic archipelagos.Location  Twelve oceanic archipelagos in the Atlantic and Pacific oceans: Ascension, Azores, Canary, Cape Verde, Desventuradas, Easter, Galápagos, Hawaii, Juan Fernández, Madeira, Puerto Rico and Savage.Methods  By using Jaccard’s index, we established the floristic similarity between pairs of archipelagos at two stages: original (pre‐European; Jo) and current flora (Jc). Then, we calculated ΔJ = Jc–Jo, where positive differences imply that similarity has increased floristic homogenization.Results  We found that floristic similarity increased fourfold on average, from 1.6% to 6.3% for original and current floras, respectively. In fact, we recorded 64 cases in which floristic similarity increased and only two in which it decreased. The importance of invasions exceeds that of extirpations as a driver of biotic change by more than an order of magnitude (2679 versus 142 species, respectively).Main conclusions  The vascular floras of these 12 insular oceanic systems have increased in compositional similarity, a phenomenon consistent with the trend towards biotic homogenization. It can be characterized as a teleconnected process that operates across vast geographical distances, driven by the unprecedented capacity of humans for translocation. Trends in biotic homogenization differ depending on the geographical location (i.e. Pacific < Atlantic archipelagos) and phylogenetic groups (island vascular plants > island birds reported in a previous study), emphasizing the complexity of biotic change.

No abstract

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Eugenia fragrans var.? fajardensis was described in 1895 and raised to species status in 1923 as E. fajardensis. In 1925, it was relegated to the synonymy of Anamomis fragrans (Myrcianthes fragrans). Since 2001, we have re-discovered wild plants and herbarium specimens, including a previously unidentified isotype of E. fajardensis, supporting the validity of this species. Here we designate a lectotype and an epitype for E. fajardensis. In addition, we provide: 1) an extended description for the species including the previously unknown flowers and fruits, an illustration, and photographs of live plants, 2) a key for the 24 taxa of Eugenia reported for Puerto Rico and the Virgin Islands, and 3) descriptions of the three known populations. These populations collectively hold 182 plants in the islands of Puerto Rico, Culebra, and Vieques. Based on the IUCN Red List Criteria, E. fajardensis meets the requirements to be considered a Critically Endangered species. ResumenEugenia fragrans var.? fajardensis fue descrita en 1895 y elevada al estatus de especie en 1923 como E. fajardensis. En 1925, esta especie fue relegada como un sinónimo de Anamomis fragrans (Myrcianthes fragrans). Desde el 2001, hemos redescubierto poblaciones silvestres y especímenes de herbario, incluyendo un isotipo previamente desconocido de E. fajardensis, los cuales apoyan la validez de la especie. En este artículo designamos un lectotipo y un epitipo para E. fajardensis. Además, proveemos: 1) una descripción extendida de la especie incluyendo flores y frutos, anteriormente desconocidos, una ilustración, y fotografías de plantas vivas, 2) una clave para distinguir los 24 taxones del género Eugenia reportadas para Puerto Rico e Islas Vírgenes, y 3) descripciones de las tres poblaciones conocidas. Estas poblaciones en conjunto contienen 182 plantas en las islas de Puerto Rico, Culebra y Vieques. De acuerdo con los Criterios de la Lista Roja del UICN, E. fajardensis cumple con los requisitos para ser considerada una especie en Peligro Crítico de Extinción.