Climatic niche shifts along the worldwide expansion of jimsonweed (Datura stramonium L.)

Abstract Biological invasions are one of the main drivers of global change. The European arrival to America in the late fifteenth century, and subsequent new trade routes, were critical events in the introduction of alien species, which have been increasing rapidly since the seventeenth century. In this study, we examine the global distribution and model the climatic niche of Datura stramonium , a cosmopolitan noxious weed. D. stramonium is of Mesoamerican origin and was introduced to Europe 450 years ago, thus is an illustrative case of the invasion associated with this colonization process. Analyzing D. stramonium occurrences and climatic data from global databases, we fit models in geographical and climatic space to determine if the species has undergone climatic niche shifts during its worldwide colonization process. We address the relationship between niche dynamics and residence time in D. stramonium , and we identify climatically suitable areas that show high risk of being colonized in the near future, which could help prevent invasion. In its non-native area, D. stramonium occupies climates similar to the native range (43% niche stability) but has also expanded remarkably into cooler climates (57% niche expansion). Niche unfilling is negligible (1%) when considering the non-native area globally. Low levels of niche unfilling in D. stramonium do not appear to be related to longer residence time but may instead be linked to a closer climate match between the native and non-native ranges. The large niche expansion towards cooler climates in three non-native ranges (Europe, North America and Asia) is associated with a remarkable increase in the frequency of low temperatures in the available climate compared to the native range. Despite a very long residence time, the species may still expand its distribution, notably in the warm zones in the non-native area.