The distribution of the invasive Acacia longifolia shows an expansion towards southern latitudes in South America

Abstract

Contemporary climate change, in particular higher temperatures, may greatly enhance the expansion of invasive species. Acacia longifolia (Fabaceae, subgenus Phyllodineae) is a native species of Southeast Australia and Tasmania, invasive in South Africa, Mediterranean Europe and South America. According to several records, this species has been introduced in Southern Brazil and Uruguay for fixation of dunes and for ornamental purposes in the mid-20th century and has since then caused several environmental and socio-economic problems. However, its current distribution in these south American countries is undocumented, as well as the types of habitats it has invaded since its introduction. In this context, during May 2019 we performed a study through a latitudinal and climatic gradient along the coast, from southern Brazil (Santa Catarina and Rio Grande do Sul states) to Uruguay, to evaluate the presence of A. longifolia taking into consideration previous records of this species. Our observations showed an increase in tree density along the coast, from Brazil to Uruguay, with a clear distribution southward. It was not possible to confirm earlier observations of this species in southern Brazil (with the exception of Florianópolis), which may be associated with changes in temperature and precipitation in this region.