Background/Question/Methods: Previous studies on invasive floras for the Caribbean have shown that invasive species in this region are quite diverse in terms of their taxonomy, life-forms, and ecological attributes. These studies have also shown that about 44% of all invasive plant species on Caribbean islands are woody species (including invasive alien trees, shrubs, and woody vines) that are currently spreading across a variety of habitat types ranging from open, highly disturbed sites to relatively intact forests. Using a regional dataset of >600 invasive plant species, I review the history of introduction (e.g., continent of origin, reason for introduction, and date of introduction) and what is known about the biology and ecology of woody invaders on Caribbean islands to assess how human activity has influenced the invasion of woody species on these islands over time. I also identify and summarize the impacts of some of the most problematic woody invaders that are able to colonize shaded and relatively undisturbed habitats across the region. Results/Conclusions: I identified a total of 275 woody species (comprising 63 families and 194 genera) that are regarded as invasive on Caribbean islands. The plant families with the largest number of invasive species are Fabaceae, Malvaceae, and Myrtaceae and these accounted for 37% of all woody invaders. Most woody invaders in the Caribbean are native to Asia and America and the cumulative number of invasive species in this region has been steadily increasing during the last 200 years, but since 1875, this trend has been led by species introduced as ornamentals. Currently, woody invaders are successfully invading all major habitats across the Caribbean, exacerbating conservation issues and threatening native biodiversity. The most widespread woody invader across the region is Leucaena leucocephala, which occurs on all the islands analyzed mostly in ruderal sites (e.g., roadsides and abandoned fields), while species such are Castilla elastica, Melia azedarach, Psidium guajava, Schefflera actinophylla, Schinus terebinthifolia, Spathodea campanulata, and Syzygium jambos are colonizing shaded and relatively undisturbed forests. Our combined results indicate that historical factors related to the type, intensity, and frequency of human-mediated introductions of alien species have been influencing the composition of woody invaders in the Caribbean during the last 200 years. These factors are important for understanding current patterns of invasions, but they are also crucial for planning adequate management actions for the control and prevention of current and future invasions.
