Characterisation and modelling of the native and invaded niche of castor bean (Ricinus communis): the Iberian Peninsula as a case study

Ricinus communis (Euphorbiaceae), commonly known as castor bean, is a species of great economic and cultural importance. Native to the northeast region of Africa, its earliest uses by humans date back to the Late Pleistocene. Castor bean is currently distributed in temperate and tropical zones in both hemispheres and has become an invasive species in several areas of the world. However, there are still no detailed studies to confirm whether it exclusively occupies environments similar to its native range or whether it has expanded its climatic niche. The main objective of this study is to characterize and model the climatic ecological niche of castor bean in its native region (northeast Africa) and in an invaded area (Iberian Peninsula). We will determine the differences between the two niches to assess whether this species is expanding its niche and identify the potentially habitable regions for castor bean. To characterize and model the castor bean niche, we use occurrence data in both areas and 19 bioclimatic variables. Our results show that castor bean occupies areas with climates absent in its native range, indicating a wide ecological plasticity that could have facilitated its naturalization in the Iberian Peninsula and other areas worldwide.