Non-native species introductions are in large part unintended consequences of economic openness. Cuba has experienced one of the world’s most distinctive geopolitical histories, including dramatically less trade and tourism compared to other islands in the Caribbean, which may dampen the dominant vectors of invasive-species dispersal. Our research questions were threefold: (1) Does Cuba support fewer non-native plants than expected given its size, location, and habitat complexity? (2) Is Cuba’s non-native plant assemblage distinct from other Caribbean islands? (3) Accounting for biogeographic context, is Cuba’s non-native plant diversity consistent with its modern economic isolation? To address these questions, we generated an approximation of the invasive flora of the West Indies (>700 invasive or potentially invasive species) and determined the among-island distribution of these plants on 44 islands. We used regression and nonmetric multidimensional scaling analysis to investigate how plant diversity in the West Indies related to biogeographic and environmental characteristics, commercial shipping patterns, historical trade, and tourism pressure.
Results/Conclusions
Cuba has hundreds fewer non-native plants than expected for its area; other biogeographic variables and measures of habitat diversity were not predictive of non-native plant richness in the West Indies. Cuba’s species assemblage overlapped with other islands in the Greater Antilles but diverged enough to suppose that range expansion is incomplete and that invasions manifest differently among locations. Tourism in combination with island area were the best predictors of non-native plant diversity, explaining 90% of species richness across a broad range of Caribbean islands. Container shipping – the standard method of transporting international cargo –and historical trade were surprisingly inconsequential in our results. Compared to trade, tourism is less commonly associated with species redistribution but several studies support the causality of tourists transporting seeds in their belongings and indirectly contributing to introductions through association with horticultural imports, habitat disturbance, and the flow of commerce that can be, or be contaminated with, invasive plants. Tourism’s central role in biological invasions is parsimonious given it is the region’s economic engine and offers a pivotal perspective for the research and management of biological invasion, particularly for Cuba. Cuba has been among the least visited and most regionally isolated Caribbean locations over the last 60 years but that is rapidly changing and presents both a vulnerability to increased biological invasions and an opportunity for policies that minimize non-native plant dispersal to (and from) Cuba.