Plant Invasions in South America

Although South America is the fourth largest continent, it houses about 60% of the global terrestrial life and the highest number of plant species. Besides its great native biodiversity, there are an unknown number of introduced non-native plants and at least 2, 677 known naturalized non-native plants in South America. Despite the growing knowledge on the richness and general status of non-native species, the real extent of distribution, abundance, and effects of invasive plants in South America are largely unknown. Here, we used country-level data on the number and identity of naturalized plant species to test which factors were related to non-native plant naturalization in the continent. To do so, we (i) compiled a list of the most prominent invasive plants in the continent and (ii) reviewed the existing legislation in place to prevent and manage plant invasions. We found that mean latitude and number of bioclimates were good predictors of naturalized plant richness. We also found that plant invasions have pervasive impacts in South American ecosystems, but that the real magnitude of the impacts was vastly unknown because very few invasive species and invaded ecosystems have been studied. We also found that South American countries have legislations in place to manage plant invasions, but there were no integrated efforts across the countries to collaboratively address biological invasions. In conclusion, we show that there is information about the identity and distribution of most invasive plants, but there is a lack of comprehensive understanding of the impacts and future consequences on biodiversity and human wellbeing. We also highlight the importance of a more collaborative approach to prevent and manage invasions in the continent.