Harnessing large-scale biodiversity data to infer the current distribution of Vanilla planifolia (Orchidaceae)

Abstract

Although vanilla is one of the most popular flavours in the world, there is still uncertainty concerning the native distribution of the species that produces it, Vanilla planifolia. To circumscribe the native geographical extent of this economically important species more precisely, we propose a new landscape-based approach to incorporate information from open-source databases and validate occurrences. In this approach, we include metrics to account for habitat suitability and population sustainability in terms of the biotic (co-occurrence of pollinators and dispersers) and abiotic (habitat quality) factors limiting plant distributions. To further validate occurrences within the resulting distribution, we compare the presence of morphologically similar wild relatives, assess the heterogeneity of ecological niches and verify the correct identification of herbarium specimens. Results from this approach suggest that V. planifolia has a larger geographical distribution than previously recognized; we hypothesize that populations naturally dispersed from Mesoamerica and became established in South America (with a south-eastern limit in Brazil). The recognition of an improved estimate of the distribution of this species will increase the accuracy of predictive models, promote further species circumscription, improve the efficacy of conservation strategies, and help to ensure the sustainability of a valuable, sought-after spice.